Carbon nanosheets as the electrode material in supercapacitors的翻译
电化学英文文献总结解析
❖ [2]Yan Lin,Li Ruiyi.Three-dimensional activated reduced graphene oxide nanocup/nickel aluminum layered double hydroxides composite with super high electrochemical and capacitance performances.Electrochimica Acta 95 (2013) 146– 154.
❖ Layered double hydroxides (LDHs) described by the general formula[(M2+)1−x(M3+)x(OH−)2]x+(An−)x/n·mH2O, in which M2+ and M3+ represent divalent and trivalent cations being incorporated in layers and An− interlayer anion, have been used for the preparation of various electrode materials, e.g. electrocatalysts.
❖ The present work provides a convenient single-step procedure for the preparation of the electrode materials showing the electrocatalytic activity and makes an important contribution to the formation of N-doped carbon nanotubes with the use of as-prepared Ni-based LDHs.
文献-MAX相刻蚀 MXene-LDH (1)
Three-dimensional porous MXene/layered double hydroxide composite for high performance supercapacitorsYa Wang 1,Hui Dou *,1,Jie Wang,Bing Ding,Yunling Xu,Zhi Chang,Xiaodong HaoJiangsu Key Laboratory of Material and Technology for Energy Conversion,College of Materials Science and Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing,210016,PR Chinah i g h l i g h t sg r a p h i c a l a b s t r a c tMXene/LDH was prepared by liquid phase deposition method.LDH platelets homogeneously grown on e-MXene substrate forms a 3D porous structure.3D porous structure facilitates active sites exposure and electrolyte penetration.MXene/LDH shows excellent electro-chemical properties forsupercapacitors.a r t i c l e i n f oArticle history:Received 21April 2016Received in revised form 1July 2016Accepted 16July 2016Keywords:Layered double hydroxide MXene3D porous structure Supercapacitorsa b s t r a c tIn this work,an exfoliated MXene (e-MXene)nanosheets/nickel-aluminum layered double hydroxide (MXene/LDH)composite as supercapacitor electrode material is fabricated by in situ growth of LDH on e-MXene substrate.The LDH platelets homogeneously grown on the surface of the e-MXene sheets construct a three-dimensional (3D)porous structure,which not only leads to high active sites exposure of LDH and facile liquid electrolyte penetration,but also alleviates the volume change of LDH during the charge/discharge process.Meanwhile,the e -MXene substrate forms a conductive network to facilitate the electron transport of active material.The optimized MXene/LDH composite exhibits a high speci fic capacitance of 1061F g À1at a current density of 1A g À1,excellent capacitance retention of 70%after 4000cycle tests at a current density of 4A g À1and a good rate capability with 556F g À1retention at 10A g À1.©2016Elsevier B.V.All rights reserved.1.IntroductionThe impending global energy crisis has prompted intense research into the development of various types of sustainable en-ergy conversion and storage systems [1,2].Recently,electrochemical capacitors,also called supercapacitors (SCs),have attracted considerable attention owing to their high power density and excellent cyclic stability compared with rechargeable batteries [3,4].According to energy storage mechanisms,SCs can be divided into electrochemical double-layer capacitors (EDLCs)which store the charge through rapid ion adsorption/desorption process at the electrode/electrolyte interface,and pseudocapacitors that store energy by reversible faradic reactions proceeded on the electrode surface [5e 9].Due to the purely physical process,EDLCs exhibit rapid charging/discharging rate but relative low energy density*Corresponding author.E-mail address:dh_msc@ (H.Dou).1These authors contributed equally to thiswork.Contents lists available at ScienceDirectJournal of Power Sourcesjournal h omepage:www.elsevier.co m/lo cate/jp owsour/10.1016/j.jpowsour.2016.07.0620378-7753/©2016Elsevier B.V.All rights reserved.Journal of Power Sources 327(2016)221e 228[10e12].In contrast,the pseudocapacitors with much higher ca-pacity emerge as alternative devices[13,14].The mostly used pseudocapacitive electrode materials are transition metal oxides/ hydroxides/sulfides,such as NiO[15],MnO2[16],Co3O4[17], NiCo2O4[18,19],Ni(OH)2[20]and NiCo2S4[21],and conductive polymers[22,23],such as polyaniline and polypyrrole.Among them,layered metallic double hydroxides(LDHs),are considered as potential SCs electrode materials because of their high redox ac-tivity,low cost and environmentally friendly nature[24e26].To further improve the electrochemical performance of LDHs, considerable efforts were devoted to engineer the morphology and structure of LDHs[27e29].For example,NiAl-LDH microspheres with tunable interior architecture were fabricated by in situ growth method.The hollow NiAl-LDH microspheres exhibited a high spe-cific pseudocapacitance of735F gÀ1[30].However,the electro-chemical performance of LDHs is still limited by the poor conductivity and cyclic stability.To address these issues,substantial research efforts have been focused on making composite materials of LDHs and conductive additives[31,32].For example,delaminated NiAl-LDHs were incorporated between graphene nanosheets to form a layered hybrid structure which showed excellent electro-chemical performance with high specific capacitance and good cyclic stability as electrode material[33].But it is indispensable to delaminate both NiAl-LDH and graphene nanosheets prior to pre-paring the composite.And then,our group fabricated a composite of NiAl-LDH/graphene(NiAl-LDH/GNS)by liquid phase deposition method,the NiAl-LDH homogeneously grew on the surface of GNS and exhibited a significant enhancement of electrochemical per-formance.However,GNS has to be reduced from GO in a further step and GNS was easily aggregated due to its intrinsic property [34].MXenes,a novel group of two-dimensional transition metal carbides or carbonitrides,including Ti3C2,Ti2C,Nb2C,V2C and Ti3CN,have attracted wide attention owing to ultrahigh elec-trical conductivity,high specific capacitance and chemical sta-bility[35e38].Yury et al.reported that the conductivity of the rolled MXenefilm can reach150,000S mÀ1.When used as electrode material for supercapacitors,the MXene achieved a high specific capacitance with245F gÀ1at2mV sÀ1.In addition, after10,000charge/discharge cycles at a current density of 10A gÀ1,the capacitance retention of MXene electrode still maintained almost100%[39].Therefore,MXene can act as a favorable conductive substrate to combine with pseudocapaci-tance electrode materials for the enhancing performance concern.Recently,Ling et al.prepared theflexible freestanding PVA/MXenefilm,and the conductivity of thefilm was signifi-cantly improved from0.04S mÀ1to22,433S mÀ1with the MXene content increasing from40%to90%.Benefiting from the enhanced conductivity,the PVA/MXenefilm exhibited ultrahigh volumetric capacitance[40].Herein,we propose a liquid phase deposition(LPD)method to fabricate three-dimensional(3D)porous nanocomposite of nickel-aluminum layered double hydroxide platelets(LDH)on the exfoliated MXene(e-MXene)sheets(MXene/LDH)as elec-trode material for supercapacitors.Optimum ratio of the com-posite can be achieved through tuning the mass ratio of LDH and e-MXene.The LDH platelets homogeneously grown on the surface of the e-MXene construct a porous3D network which provides fast pathway for ion transport and large active area for redox reaction of LDH.Meanwhile,e-MXene substrate forms a conductive network,which accelerates electron transport and improves the electrical conductivity of MXene/LDH composite. Benefiting from these advantages,the MXene/LDH composite exhibits a high specific capacitance,excellent rate capability and stability.2.Experimental2.1.Materials synthesis2.1.1.Preparation of multilayered MXene(Ti3C2)1g of MAX(Ti3AlC2)was added into10mL HF solution(40wt%) and magnetically stirred for18h at room temperature.Multilay-ered MXene(m-MXene)was obtained after centrifuging,washing with deionized water and absolute alcohol repeatedly,and dried ina vacuum oven at room temperature.2.1.2.Exfoliation of m-MXeneTypically,0.9g of m-MXene powder was magnetically stirred in 15mL dimethyl sulfoxide(DMSO)for18h at room temperature. After diluting with deionized water,DMSO-intercalated MXene was separated by centrifugation at3500rpm for5min.The obtained powder was dispersed in deionized water with ultrasonication for 6h.After centrifuged at3500rpm for1h and dried in a vacuum oven at room temperature,e-MXene sheets were obtained.2.1.3.Preparation of the Ni-containing parent solution11mmol of Ni(NO3)2$6H2O was dissolved in22mL of deionized water with powerful stirring,and the solution was slowly regulated to pH7.5with ammonia water.The obtained precipitate was dried at room temperature after repeatedly washing with water and absolute alcohol.Then the dried powder was poured into40mL of NH4F(0.66mol LÀ1),and the solution was vigorously stirred for 48h at room temperature.The Ni-containing parent solution was achieved byfiltration.2.1.4.Synthesis of the MXene/LDH composites30mg of e-MXene was dispersed in Ni-containing parent so-lution with ultrasonication for1h in a plastic beaker.Then10mmol of H3BO3and0.25mmol of Al(NO3)3$9H2O were dissolved in20 and40mL deionized water,respectively.The H3BO3solution and Al(NO3)3solution were poured successively into the above e-MXene suspension and the mixture was shaken ultrasonically un-der N2atmosphere to form a homogeneous solution,which was then set at50 C for48h.Subsequently,the product was centri-fuged and washed several times with deionized water and dried in a vacuum oven at30 C for24h,which was designated as M30/LDH. With the same procedure,20mg or50mg of MXene was added into the system to get M20/LDH and M50/LDH,respectively.The content of e-MXene in the composite is calculated by weighing the mass of MXene/LDH.The weight percentage of MXene in M20/LDH,M30/ LDH and M50/LDH composites are approximately35%,38%and 51%,respectively.2.1.5.Synthesis of LDHFor comparison,pure LDH was prepared via a coprecipitation process[34].3mmol Ni(NO3)2$6H2O and1mmol Al(NO3)3$9H2O were dissolved in100mL water.The obtained solution was mixed with50mL of0.08mol LÀ1NaOH solution under stirring and kept at60 C for5h.The precipitate was washed several times with deionized water and absolute alcohol,then dried in a vacuum oven at60 C to get the LDH.2.2.Material characterizationThe crystal structures were measured through X-ray diffraction (XRD)by a Bruker D8Advanced X-ray diffractometer with Cu K a radiation(0.15406nm).The Fourier transform infrared spectros-copy(FT-IR)spectra were tested on a Nicolet750Fourier transform infrared spectrometer.The N2adsorptionÀdesorption isotherms were conducted by a Micromeritics BK122T-B analyzer.The specificY.Wang et al./Journal of Power Sources327(2016)221e228 222surface area was calculated according the BrunauerÀEmmettÀ-Teller(BET)method.The pore size distribution were obtained from BarretÀJoynerÀHalenda(BJH)desorption branch of the isotherm. X-ray photoelectron spectroscopy(XPS)was conducted on a Perkin-Elmer PHI550spectrometer using Al K a as the X-ray source. The morphologies were characterized by scanning electron mi-croscope(SEM,Hitachi S4800),transmission electron microscopy and high-resolution transmission electron microscopy(TEM, HRTEM,JEOL JEM-2010).The electrical conductivity test was car-ried out on a ST-2722semiconductor powder resistivity apparatus (Suzhou Jingle Electronic technology Co.Ltd.,China).2.3.Electrochemical measurementsAll the electrochemical performances were carried out in6M KOH electrolyte using three-electrode system at room temperature. The working electrodes were prepared by pressing the as-prepared composites,carbon black and a polytetrafluoroethylene(PTFE) binder in the weight ratio of85:10:5onto foamed Ni grids(1cmÀ2) and then dried at50 C in the vacuum oven for several hours.The electrode material mass loading is5mg cmÀ2.A platinum foil was used as counter electrode and a saturated calomel electrode(SCE) as reference electrode,respectively.The cyclic voltammetry(CV), galvanostatic charge/discharge(GCD)and electrochemical imped-ance spectroscopy(EIS)measurements were carried out with a CHI660C electrochemical working station.CV tests were performed in the potential range from0to0.6V(vs.SCE)at different scan rates.GCD curves were measured between0and0.55V(vs.SCE)at different current densities.3.Results and discussionThe synthetic process of the MXene/LDH composite is illustrated in Scheme1.Firstly,MAX(Ti3AlC2)powders were added into HF solution to obtain the m-MXene plates.Then,the m-MXene plates were delaminated by DMSO to produce e-MXene sheets.After the e-MXene sheets were dispersed in the mixed solution containing Ni parent solution([NiF x](xÀ2)À),Al3þand H3BO3,the[NiF x](xÀ2)Àwere gradually hydrolyzed to[Ni(OH)x](xÀ2)À,which proceeded dehy-dration condensation reactions with the hydroxyl groups on the surface of e-MXene and linked to e-MXene.Meanwhile,Al3þinserted into the crystal lattices and then LDHflakes were formed and anchored on the e-MXene sheets to yield the3D porous MXene/LDH nanocomposite.The tight connection between LDH and e-MXene in MXene/LDH constructs a highly efficient conduc-tive network and retains the structure stability during electro-chemical process.And the porous structure improves the electrolyte penetration and provides more active sites for making full use of LDH pseudocapacitance.X-ray diffraction(XRD)and Fourier transform infrared spec-troscopy(FT-IR)were carried out to characterize the composition of the composites.The XRD patterns of e-MXene,LDH and M30/LDH are exhibited in Fig.1a.The diffraction peak of(002)at2q¼7.7 for e-MXene sheets is lower than that for m-MXene plates at2q¼8.8 , which illustrates the increase of interlayer spacing and successful exfoliation of m-MXene(Fig.S1a)[41].The XRD peaks of LDH at 2q¼11.3 ,21.5 ,35.8 and61.8 correspond to the(003),(006), (012)and(110)crystal planes(JCPDS15-0087)of brucite-like crystal.M30/LDH shows almost all characteristic peaks both of e-MXene and LDH.More interestingly,(002)diffraction peak for M30/ LDH shifts to lower angle than that for e-MXene,suggesting deposition of LDH on e-MXene sheets inhibits the aggregation of e-MXene.Additionally,the composites M20/LDH and M50/LDH with different e-MXene content present identical XRD pattern to M30/ LDH(Fig.S1b).As shown in Fig.1b,the FT-IR spectrum of LDH exhibits absorption bands at3448,1637and1384cmÀ1,which correspond to the O e H stretching vibration of water molecules in the interlayer,hydrogen-bonded OH groups and N e O stretching vibration from NO3À,respectively.Some other absorption peaks below800cmÀ1are attributed to the metalÀoxygen stretching or bending modes in the brucite-like crystal lattice of LDH[42].These characteristic IR absorptions of LDH can be clearly identified in the FT-IR spectrum of M30/LDH,also accounting for the existence of LDH in the composite.M20/LDH and M50/LDH show almost similar FT-IR spectra to M30/LDH(Fig.S2).The surface characteristic of M30/LDH was studied using X-ray photoelectron spectroscopy(XPS)as shown in Fig.2.Fig.2a shows Ni2p,Al2p,O1s,C1s and Ti2p core levels from survey of M30/LDH composite.In the Ni2p XPS spectrum(Fig.2b),the peaks at857and 875eV are assigned to the2p3/2and2p1/2levels of Ni2þ, respectively,suggesting the existence of LDH in the composite[43]. The O1s spectrum shows a peak at531.2eV,which is attributed to C e TiÀO x(Fig.2c).The high resolution Ti2p spectrum can be deconvoluted into six peaks(Fig.2d),corresponding to C e TiÀF x (460.2eV),Ti e O(458.6eV),TiO2-x F x(459.3eV)and Ti atoms (455.0eV,455.8eV and457.2eV)[44].The XPS results further demonstrate the existence of the negatively-charged groups and the formation of LDH on the e-MXene.The morphology of as-obtained samples was investigated by scanning electron microscope(SEM)and transmission electron microscope(TEM).The SEM images of the m-MXene and M30/LDH composite are shown in Fig.3.It is demonstrated in Fig.3a that the Al layers were selectively etched in HF solution forming m-MXene plates.The m-MXene plates were efficiently exfoliated with DMSO to form e-MXene sheets(Fig.S3a).After reacted with Ni parent solution and Al3þ,the surface of e-MXene is covered with frizzy LDH platelets.However,the abundant LDH platelets on the e-MXene aggregate together for M20/LDH because the amount of e-MXene substrate is not enough for LDH platelets to deposit (Fig.S3b).With increasing amount of e-MXene,LDH platelets distribute homogeneously on e-MXene surface,forming a3D porous and open structure for M30/LDH(Fig.3b).Fig.3c reveals that LDH platelets are grown on two sides of e-MXene sheets, efficiently preventing the aggregation of individual e-MXene sheets.Nevertheless,with the continued increase of e-MXene content,the surface of e-MXene cannot be covered completelywith Scheme1.Illustration of the fabrication route of the MXene/LDH composite.Y.Wang et al./Journal of Power Sources327(2016)221e228223LDH platelets for M50/LDH (Fig.S3c ),which leads to restacking of e-MXene sheets.For comparison,the morphology of LDH demon-strates large particles with aggregated flakes (Fig.S3d ).The struc-ture of M30/LDH is further evidenced by TEM image.The LDH platelets grown on the e-MXene exhibit gauze-like morphology and connected with each other (Fig.3d),which could provide ef ficient ion transport pathway and large active surface area for the electrode.To track the growth process of MXene/LDH composite,the SEM images of M30/LDH after different reaction time (4,8,12,24,36and 48h)are shown in Fig.S4.It can be clearly seen few LDH plates grow on the surface of e-MXene after 4h.With the increase of reaction time,LDH plates gradually deposit on the substrate.Finally,LDH platelets distributed homogeneously on e-MXene surface forms a 3D porous and open structure after 48h.The for-mation of such unique structure could be mainly attributed to interaction between [Ni(OH)x ](x À2)Àand hydroxyl groups existing on the surface of e-MXene.The textural properties of the M30/LDH and LDH were revealed by N 2-sorption measurements.The N 2adsorption/desorption iso-therms of M30/LDH,LDH (Fig.4)and e-MXene (Fig.S5)are of type IV with a clear hysteresis loop,indicating mesoporous character-istics.Their textural parameters are listed in Table S1.The speci fic surface area and pore volume of M30/LDH are 72.34m 2g À1and 0.34cm 3g À1,respectively,which are much higher than those of LDH (18.10m 2g À1and 0.027cm 3g À1)and e-MXene (6.3m 2g À1and 0.021cm 3g À1).As seen in the inset of Fig.4,the BJH (Barrett-Joy-ner-Halenda)pore size distribution (PSD)of LDH distributes at 2e 9nm.The PSD curve of M30/LDH shows similar shape but a particularly high volume at ~3nm.The speci fic 3D porous structure of M30/LDH could enhance the exposure of active sites and accel-erate the ion transport.In order to investigate the electrochemical properties of the obtained composite as an active supercapacitor electrode material,the MXene/LDH electrodes were investigated with athree-Fig.1.(a)XRD patterns of e-MXene,LDH and M30/LDH composite.(b)FT-IR spectra of LDH and M30/LDHcomposite.Fig.2.(a)XPS spectra survey (b e d)the core-level Ni 2p,O 1s and Ti 2p of M30/LDH.Y.Wang et al./Journal of Power Sources 327(2016)221e 228224electrode system in 6M KOH aqueous electrolyte.Fig.5a shows the cyclic voltammetry (CV)curves of e-MXene,LDH and M30/LDH at a scan rate of 5mV s À1.The CV curves of LDH and M30/LDH exhibit a pair of redox peaks,which corresponds to the typical pseudoca-pacitive behavior of Ni 2þ/Ni 3þin alkaline electrolyte.The possible Faradic redox reaction is based on the following equation:Ni ðOH Þ2þOH À/NiOOH þH 2O þe À(1)Compared with LDH and e-MXene,the M30/LDH displays enhanced redox peak currents,indicating a much highercapacitance.With increasing scan rate from 2mV s À1to 50mV s À1,the weakly deviated redox current peaks suggest good pseudoca-pacitive behavior (Fig.5b).In addition,M30/LDH exhibits higher redox peak currents and larger integral domain of the CV curves compared with e-MXene,M20/LDH and M50/LDH (Fig.S6a and 6b ),suggesting more effective utilization of the electroactive species.The electrochemical performance of M30/LDH is further studied with galvanostatic charge-discharge (GCD)measurement.The speci fic capacitance (C s ,F g À1)of the electrode is calculated ac-cording to the following equation:C s ¼I $D t =m $D v(2)where I ,D t ,m ,D v are the constant current (A),discharge time (s),the active material mass (g),the total potential window (V),respectively.The nonlinear discharge curves (Fig.5c)of M30/LDH electrode show typical pseudocapacitive behavior,which agrees well with CV results.From the discharge curves,M30/LDH composite shows a high speci fic capacitance of 655F g À1based on whole composite mass at 1A g À1.The speci fic capacitance of e-MXene is only 46F g À1at a current density of 0.5A g À1and 27F g À1at 10A g À1(Fig.S6c ).Compared with e-MXene,LDH and other two MXene/LDH composites,M30/LDH electrode presents much longer discharge time at the identical current density,indicating the best charge storage performance (Fig.S6c e e ).Fig.5d compares the calculated speci fic capacitances of LDH,M20/LDH,M30/LDH and M50/LDH electrodes at different current densities based on the whole composite mass.M30/LDH electrode presents the highest speci fic capacitance at all current densities.Due to the low mass of LDH,the speci fic capacitances of M50/LDH electrode are even lower than those of LDH electrode at lower current densities.The LDH electrode shows the poorest rate capa-bility with only 19.2%retention at a high current density of 10A g À1.Fig.3.SEM images of (a)m-MXene plates,(b)M30/LDH,(c)cross-section SEM image of M30/LDH,(d)TEM image ofM30/LDH.Fig.4.N 2adsorption-desorption isotherms and pore size distributions (inset)of M30/LDH and LDH.Y.Wang et al./Journal of Power Sources 327(2016)221e 228225The M30/LDH electrode indicates 51%of the capacitance (333F g À1)retention at 10A g À1,superior to M20/LDH (46%)and M50/LDH (43%)electrodes.The speci fic capacitances of all samples based on LDH at different current densities are also shown in Fig.5e.At a current density of 1A g À1,the initial speci fic capacitance of M30/LDH is as high as 1061F g À1.With increasing current density to 10A g À1,the capacitance retention of M20/LDH,M30/LDH,M50/LDH and LDH are 46.8%,52.4%,43.2%and 19.2%,respectively.The M30/LDH shows much better electrochemical performance than LDH and other two composites.Furthermore,the speci fic capaci-tance and capacitance retention of M30/LDH composite are much higher than those of LDH-based composites containing other conductive substrates,such as carbon nanotubes and graphene (Table S2)[45e 48].The high speci fic capacitance and the good rate capability of the M30/LDH,on one hand,could be attributed to the exposure of more LDH surface active sites during the electrode reaction process.On the other hand,the e-MXene substrate pro-vides an effectively conductive network for electron transport.For e-MXene,LDH,M20/LDH,M30/LDH and M50/LDH composites,the electrical conductivities are 2.65Â105,0.32,1.73Â104,2.15Â104and 2.58Â104S m À1,respectively.The results indicate that MXene could dramatically improve the electrical conductivity of MXene/LDH composites.To further understand the effect of the MXene on the electro-chemical behavior of the MXene/LDH,electrochemical impedance spectroscopy (EIS)tests were investigated.Fig.5f shows the Nyquist plots of LDH and M30/LDH electrodes,which consist of an arc in the high frequency region followed by linear shape in the low frequency region.The curve on the juncture of axis at high fre-quency acts as an internal resistance of active species,ionic resis-tance of electrolyte and the contact resistance within the electrode.The internal resistance of M30/LDH composite is lower than those of LDH and other composites (Fig.S6f ).The vertical line in the low frequency region represents ideal capacitive behavior.From the expended view in the inset of Fig.5f,M30/LDH has more vertical line than other samples in low frequency region,which probably results from that the anchored LDH on the e-MXene can inhibits the aggregation of e-MXene sheets.Meanwhile,the e-MXene sheets bridging the LDH nanoplates form a conductive network,which facilitates rapid electron transfer between the electrolyte and active material.The cycle stability is vital to the electrochemical capacitors.The cycle life test of M30/LDH composite is investigated by GCD tech-nique at a current density of 4A g À1as shown in Fig.6.Interest-ingly,the gradually increasing of the speci fic capacitance of M30/LDH at first 50cycles is attributed to the activation of theelectrodeFig.5.(a)CV curves of e-MXene,LDH and the M30/LDH at a scan rate of 5mV s À1in 6M KOH.(b)CV curves of M30/LDH at different scan rates.(c)The discharge curves of M30/LDH at different current densities based on the whole composite mass.Speci fic capacitance of LDH,M20/LDH,M30/LDH and M50/LDH at different current densities (d)based on the composite mass (e)based on LDH.(f)Nyquist plots of M30/LDH and LDH.Y.Wang et al./Journal of Power Sources 327(2016)221e 228226[49].After 4000cycle tests,the capacitance retention is 70%comparing with maximum capacitance.The excellent cycle stabil-ity of the M30/LDH is due to the stability of the structure.It can be certi fied from the SEM image of M30/LDH electrode after 4000cycle tests at 4A g À1in the inset of Fig.6.The original 3D porous structure of M30/LDH can be maintained,which alleviates the volume change of LDH during the charge/discharge process.The high capacitance of the M30/LDH up to 1061F g À1with excellent electrochemical stability and rate performance due to the synergic effect between e-MXene and LDH can be explained as follows.Firstly,the as-prepared composite through the dehydration condensation between the hydroxyl groups on the surface of e-MXene and [Ni(OH)x ](x À2)Àkeeps the tight connection between e-MXene and LDH sheets,at the same time decreases the overlapping of LDH and e-MXene sheets to form a 3D porous structure.Such 3D unique structure of MXene/LDH can offer highly ef ficient pathways towards electrons and ions.The e-MXene sheets offer a conductive network by bridging the LDH nanoplates,and the channels formed between the e-MXene substrates and LDH nanoplates facilitate the ionic transportation [50,51].Then,it can also provide more active sites for making full use of LDH pseudocapacitance and allow better contact of the electrode material with the electrolyte,which offers larger zone for ion diffusion and electron transport during the charge/discharge process [52].Finally,this hydrid structure with good electronic and ionic conduction could also improve the charge Àdischarge ef ficiency and relax the tension from the volume change induced by phase transformation of Ni e OH,thus making sure the good reversibility upon cycling [53].4.ConclusionsIn summary,by using e-MXene sheets as a conductive substrate,the 3D porous MXene/LDH nanocomposite as supercapacitor electrode material has been successfully prepared by a liquid phase deposition method.The LDH platelets homogeneously anchored on the surface of the e-MXene sheets allow to excellent Faradaic uti-lization of the electro-active surface and facile electrolyte pene-tration,also alleviate the volume change during the charge/discharge process.Meanwhile,e-MXene substrate forms a conductive network accelerating electron transport.Therefore,the optimized M30/LDH exhibits excellent electrochemical perfor-mance with high speci fic capacitances of 1061F g À1and 556F g À1at current densities of 1A g À1and 10A g À1respectively,and a capacitance retention of 70%after 4000cycle tests at a cur-rent density of 4A g À1.These results suggest its high promising prospective for supercapacitors.AcknowledgementsThis work was supported by the National Basic Research Pro-gram of China (973Program)(No.2014CB239701),National Natural Science Foundation of China (No.51372116),Natural Science Foundation of Jiangsu Province (BK20151468,BK2011030),the Fundamental Research Funds for the Central Universities of NUAA (NJ20160104),Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD).Appendix A.Supplementary dataSupplementary data related to this article can be found at /10.1016/j.jpowsour.2016.07.062.References[1]S.Chu,A.Majumdar,Nature 488(2012)294e 303.[2] A.S.Arico,P.Bruce,B.Scrosati,J.M.Tarascon,W.Van Schalkwijk,Nat.Mater.4(2005)366e 377.[3]P.Simon,Y.Gogotsi,Nat.Mater.7(2008)845e 854.[4] D.Dubal,O.Ayyad,V.Ruiz,P.G omez-Romero,Chem.Soc.Rev.44(2015)1777e 1790.[5]R.K €otz,M.Carlen,Electrochim.Acta 45(2000)2483e 2498.[6]Z.Yu,L.Tetard,L.Zhai,J.Thomas,Energy Environ.Sci.8(2015)702e 730.[7] C.Yuan,B.Gao,L.Shen,S.Yang,L.Hao,X.Lu,F.Zhang,L.Zhang,X.Zhang,Nanoscale 3(2011)529e 545.[8]J.Yan,Q.Wang,T.Wei,Z.Fan,Adv.Energy Mater.4(2014)1300816.[9]N.L.Torad,R.R.Salunkhe,Y.Li,H.Hamoudi,M.Imura,Y.Sakka,C.C.Hu,Y.Yamauchi,Chem.Eur.J.20(2014)7895e 7900.[10]O.Barbieri,M.Hahn,A.Herzog,R.K €otz,Carbon 43(2005)1303e 1310.[11]L.L.Zhang,X.Zhao,Chem.Soc.Rev.38(2009)2520e 2531.[12] D.A.Dinh,K.N.Hui,K.S.Hui,Energy Environ.Focus 3(2014)98e 120.[13]Q.Lu,J.G.Chen,J.Q.Xiao,Angew.Chem.Int.Ed.52(2013)1882e 1889.[14]G.A.Muller,J.B.Cook,H.S.Kim,S.H.Tolbert,B.Dunn,Nano Lett.15(2015)1911e 1917.[15] C.Yuan,X.Zhang,L.Su,B.Gao,L.Shen,J.Mater.Chem.19(2009)5772e 5777.[16]S.Liu,K.S.Hui,K.N.Hui,ChemNanoMat 1(2015)593e 602.[17]X.Xia,J.Tu,Y.Mai,X.Wang,C.Gu,X.Zhao,J.Mater.Chem.21(2011)9319e 9325.[18]L.Shen,L.Yu,X.Y.Yu,X.Zhang,X.W.D.Lou,Angew.Chem.Int.Ed.54(2015)1868e 1872.[19]L.Li,J.Xu,J.Lei,J.Zhang,F.McLarnon,Z.Wei,N.Li,F.Pan,J.Mater.Chem.A 3(2015)1953e 1960.[20]R.R.Salunkhe,J.Lin,V.Malgras,S.X.Dou,J.H.Kim,Y.Yamauchi,Nano Energy11(2015)211e 218.[21]Y.Zhu,Z.Wu,M.Jing,X.Yang,W.Song,X.Ji,J.Power Sources 273(2015)584e 590.[22]K.Zhang,L.L.Zhang,X.Zhao,J.Wu,Chem.Mater.22(2010)1392e 1401.[23] D.Zhang,X.Zhang,Y.Chen,P.Yu,C.Wang,Y.Ma,J.Power Sources 196(2011)5990e 5996.[24]M.Shao,R.Zhang,Z.Li,M.Wei,D.G.Evans,X.Duan,mun.51(2015)15880e 15893.[25]J.Cheng,J.Zhang,F.Liu,RSC Adv.4(2014)38893e 38917.[26]R.Ma,J.Liang,X.Liu,T.Sasaki,J.Am.Chem.Soc.134(2012)19915e 19921.[27] A.Forticaux,L.Dang,H.Liang,S.Jin,Nano Lett.15(2015)3403e 3409.[28] C.Wang,X.Zhang,Z.Xu,X.Sun,Y.Ma,ACS Appl.Mat.Interfaces 7(2015)19601e 19610.[29]R.Ma,T.Sasaki,Acc.Chem.Res.48(2014)136e 143.[30]M.Shao,F.Ning,Y.Zhao,J.Zhao,M.Wei,D.G.Evans,X.Duan,Chem.Mater.24(2012)1192e 1197.[31]M.Li,F.Liu,J.Cheng,J.Ying,X.Zhang,J.Alloys Compd.635(2015)225e 232.[32]H.Maki,M.Takigawa,M.Mizuhata,ACS Appl.Mat.Interfaces 7(2015)17188e 17198.[33]Y.Wimalasiri,R.Fan,X.Zhao,L.Zou,Electrochim.Acta 134(2014)127e 135.[34]L.Zhang,J.Wang,J.Zhu,X.Zhang,K.San Hui,K.N.Hui,J.Mater.Chem.A 1(2013)9046e 9053.[35]M.R.Lukatskaya,O.Mashtalir,C.E.Ren,Y.Dall ’Agnese,P.Rozier,P.L.Taberna,M.Naguib,P.Simon,M.W.Barsoum,Y.Gogotsi,Science 341(2013)1502e 1505.[36]M.Naguib,O.Mashtalir,J.Carle,V.Presser,J.Lu,L.Hultman,Y.Gogotsi,M.W.Barsoum,ACS Nano 6(2012)1322e 1331.[37]M.Naguib,V.N.Mochalin,M.W.Barsoum,Y.Gogotsi,Adv.Mater.26(2014)992e 1005.Fig.6.Cyclic performance of the M30/LDH at a current density 4A g À1(the inset shows the SEM image of M30/LDH electrode after a 4000-cycle test at 4A g À1).Y.Wang et al./Journal of Power Sources 327(2016)221e 228227。
电池英语及翻译 专业术语
Alkaline batteries ：碱性电池Capacitor batteries：电容电池Carbon zinc batteries ：碳锌电池Lead acid batteries：铅酸电池Lead calcium batteries：铅钙电池Lithium batteries ：锂电池Lithium ion batteries ：锂离子电池Lithium polymer batteries：锂聚合物电池Nickel cadmium batteries ：镍镉电池Nickel iron batteries ：镍铁电池Nickel metal hydride batteries ：金属氧化物镍氢电池/镍氢电池Nickel zinc batteries：镍锌电池Primary batteries ：原电池Rechargeable batteries ：充电电池Sealed lead acid batteries：密封铅酸电池Silver cadmium batteries ：银钙电池Silver oxide batteries ：银氧化物电池Silver zinc batteries：银锌电池Zinc chloride batteries：银氯化物电池Zinc air batteries：锌空电池Environmental Protection batteries:环保电池Lithium batteries ：锂电池Lithium ion batteries ：锂离子电池Lithium polymer batteries：锂聚合物电池铅酸蓄电池 Lead-acid battery起动铅酸电池 Lead-acid starter batteries摩托车用铅酸电池 Lead-acid batteries for motorcycles内燃机车用铅酸电池 Lead-acid batteries for disel locomotive电动道路车辆用铅酸电池 Lead-acid batteries for electric road vehicles小型阀控密封式铅酸电池 small-sized valve-regulated lead-acid batteries航空用铅酸电池 Aircraft lead-acid batteries固定型阀控密封式铅酸蓄电池 Lead-acid batteries for stationary valve-regulated铅酸电池用极板 plate for lead-acid battery铅锭 lead ingots牵引用铅酸电池 Lead-acid traction batteies电解液激活蓄电池electrolyte activated battery更多电池资讯：/电池产品认证指导网站：/ekeyword.php?ekeyid=6vent valve 排气阀filling device for pleral cells 电池组填充装置negative electrode 负电极negative plate 负极板addition reagent for negative plate 负极板添加剂indicator 指示器top cover 上盖vent plug 液孔塞expanded grid 扩展式板栅specific gravity indicator 比重指示器electrolyte level control pipe 电解液液面控制管electrolyte level indicator 电解液液面指示器electrolyte level sensor 电解液液面传感器hard rubber container 硬橡胶槽envelope separator 包状隔板woven cloth tube 纺布管spongy lead 海绵状铅partition 隔壁over the partition type 越过隔壁型through the partition type 贯通隔壁贯通型separator 隔板(1)battery rack(2)battery stand(3)battery stillage 蓄电池架/蓄电池底垫active material 活性物质glass fiber separator 玻璃纤维隔板glass mat 玻璃纤维绵glass mat tube 玻璃纤维绵管spacing washer 间隔垫圈reinforced fiber separator 强化纤维隔板polarity mark plate 极性标记板pole 极柱pole insulator 极柱绝缘子pole nut 极柱螺母plate 极板plate foot 极板足plate supporter 极板支撑件element 极板群/极群组pole bolt 极柱螺栓plate lug 极板耳dilute sulfuric acid 稀硫酸steel can 金属罐steel container 金属蓄电池槽(1)madribs(2)element rest 鞍子/极群组座tubular plate 管状极板gelled electrolyte 胶体电解液更多电池资讯：/电池产品认证指导网站：/ekeyword.php?ekeyid=6grid板栅caution label 警告标签synthetic resin separator 合成树脂隔板plastics container 塑料蓄电池槽synthetic fiber separator 合成纤维隔板connector sunken type 沉没型连接器connetor exposed type 露出型连接器safety valve test 安全阀测试ampere-hour efficency 安时效率one charge distance range 一次充电行程gas recombination on negative electrode typecut-off discharge 终止放电/截止放电阴极气体再化合型/阴极气体复合型(1）specific characteristic (2)energy density (1)比特性（2）能量密度recovering charge 恢复充电(1)open circuit voltage(2)off-load voltage 开路电压/空载电压overcharge 过充电gassing 析气overcharge life test 过充电寿命试验accelerated life test 加速寿命试验active material utilization 活性物质利用率theoretical capacity of active material 活性物质的理论容量over discharge 过放电intermittent discharge 间歇放电full charge 完全充电full discharge 完全放电reverse charge 反充电/反向充电quick charge 快速放电allowable minimum voltage 允许最小电压equalizing charge 均衡充电creeping 蠕变group voltage 组电压shallow cycle endurance 轻负荷寿命/轻负荷循环寿命characteristic of electrolyte decrease 电解液减少特性nominal voltage 标称电压high rate discharge 高率放电high rate discharge characteristic 高率放电特性5 second voltage at discharge 放电 5 秒电压（1）cold cranking ampere（2）cold cranking performance（1）冷启动电流（2）冷启动性能cycle life test 循环寿命测试maximum voltage at discharge 最大放电电压30 second voltage at discharge 放电 30 秒电压residual capacity 残存容量(1)hour rate(2) discharge rate （1）小时率（2）放电率更多电池资讯：/电池产品认证指导网站：/ekeyword.php?ekeyid=6(1) self discharge (2) local action （1）自放电（2）局部自放电(1) self discharge rate(2) local action rate （1）自放电率（2）局部自放电率actual capacity 实际容量(1)starting capability(2)cranking ability 启动能力cranking current 启动电流battery clamp test 电池夹钳测试power density 功率密度momentary discharge 瞬间放电modified constant voltage charge 修正恒定电压充电initial capacity 初始容量gas recombination by catalyser type 触媒气体复合式initialcharge 初始充电viberation test 振动试验predetermined voltage 预定电压total voltage 总电压activation test for dry charged battery 干式荷电蓄电池活化试验salting 盐析earthquake-proof characteristics 防震性能dielectric voltage withstand test 电介质耐压试验short time discharge 短时间放电escaped acid mist test 酸雾逸出测试terminal voltage 端子电压cell voltage 单电池电压step charge阶段充电short-circuit current 短路电流storage test 保存测试high rate discharge at low temperature 低温高率放电rated voltage 额定电压rated capacity 额定容量fixed resistance discharge 定阻抗放电constant voltage charge 恒压充电constant voltage life test 恒压寿命测试constant current charge 恒流充电constant voltage constant current charge 恒流恒压充电constant current discharge 恒流放电constant watt discharge 恒功率放电low rate discharge characteristics 低率放电特征trickle charge 涓流充电trickle charge current 涓流充电电流trickle charge life test 涓流充电寿命测试thermal runaway 热失控driving pattern test 运行测试capacity in driving pattern test 运行测试更多电池资讯：/电池产品认证指导网站：/ekeyword.php?ekeyid=6boost charge急充电floating charge浮充电floating charge voltage 浮充电电压floating charge current 浮充电电流(1)mean voltage (2)average voltage 平均电压on-load voltage 负载电压discharge duration time 放电持续时间(1)final voltage(2)cut-off voltage(3)end voltagedepth of discharge 放电深度discharge voltage 放电电压discharge current 放电电流discharge current density 放电电流密度discharge watt-hour 放电瓦时discharge characteristics 放电特性discharged ampere-hour 放电安时explosion proof test 防爆测试auxiliary charge 补充电maintenance factor 维护率storage characteristics 保存特性终止电压/截止电压gas recombinating efficiencycharge 充电气体复合效率/气体再化合效率charge acceptance test 充电可接受性试验start-of-charge current 充电开始电流charge efficiency 充电效率end-of-charge voltage 充电结束电压specific gravity of electrolyte at the end of charge充电结束时电解液比重charge voltage 充电电压charge current 充电电流charged watt-hour 充电瓦时charge characteristic 充电特性charge ampere-hour 充电安时deep cycle endurance 重负荷循环寿命/重复合寿命weight engergy density 重量能量密度rubber pad 橡胶垫lower level line 下液面线side terminal 侧端子collective exhaust unit 公共的排放单元sintered plaque 烧结极板sintered separator 烧结隔板sintered plate 烧结极板catalyst plug 催化塞spine 芯骨strap 带更多电池资讯：/电池产品认证指导网站：/ekeyword.php?ekeyid=6spacer 隔离物insulating tube绝缘管intercell connector连接线/连接条connector cover连接管盖float mounted plug 浮动安装的栓(1)pasted plate (2)grid type plate 涂膏式极板braidd tube 编织管(1)flame-arrester vent plug (2)flam-retardant vent plug 安全塞explosion and splash proof construction 防爆防溅结构baffle 保护板pocket type plate 袋式极板bottom hole-down 底孔向下（固定）bolt fastening terminal 螺栓连接端子male blade 阳片monoblock container 整体槽positive electrode 正极positive plate 正极板leading wire terminal 引线端子retainer mat 止动垫片ribbed separator 肋隔板(1)jumping wire (2)inter low wire 跳线end plate 端板filling plug 注液塞plante plate 形成式极板/普朗特极板tubular plate 管式极板low electric resistance separator 低电阻隔板tapered terminal post 锥形接线柱electrolyte 电解液container 蓄电池槽/蓄电池壳set of container 成套蓄电池槽level-scope mounted plug 透视塞/透视栓handle 手柄jug 取液管(1)connector;(2)plug concent (1)连接器；(2)插座式连接器connector wire 连接线connecting bar 连杆connecting bar cover 连杆帽lead 引线/连接线edge insulator 绝缘卡side frame 侧框架battery cubicle 蓄电池箱perforated separator 多孔隔板burning rod (铅)焊条terminal 端子更多电池资讯：/电池产品认证指导网站：/ekeyword.php?ekeyid=6terminal connector 端子连接条terminal cover 端子盖terminal base 端子座tab 接线片lead bushing 铅套corrugated separator 波形隔板(1)lead dioxide;(2)lead peroxide (1)二氧化铅；(2)过氧化铅(1)woven separator;(2)nonwoven separator (1)织物隔板；(2)非织物隔板vent hole 通气孔exhaust tube 排气管antipolar mass 反极性物质output cable 输出电缆microporous rubber separator 微孔像胶隔板specific gravity indicator 比重计leaf separator 叶片式隔板lid sealing compound 密封剂/封口剂sealing gasket 密封衬垫/垫圈lid 蓄电池盖set of lid 系列的盖方通盖板cover board底板solepiece钢珠steel ball压钢珠press steel ball防爆阀valve preventing explosion大电流(倍率)放电discharge in high rate current标称电压Normal voltage标称容量normal capacity放电容量discharge capacity充电上限电压limited voltage in charge放电下限电压更多电池资讯：/电池产品认证指导网站：/ekeyword.php?ekeyid=6terminating voltage in discharge 恒流充电constant current charge恒压充电constant voltage charge恒流放电constant current discharge放电曲线discharge curve充电曲线charge curve放电平台discharge voltage plateau容量衰减capacity attenuation起始容量initial discharge capacity流水线pipelining传送带carrying tape焊极耳welding the current collector卷绕wind叠片layer贴胶带stick tape点焊spot welding超声焊ultrasonic weldingThe terminating voltage in discharge of the battery is 3.0 volt. The limited voltage in charge of the battery is 4.2 volt.三元素Nickle-Cobalt-Manganese Lithium Oxidethree elements materials钴酸锂Cobalt Lithium Oxide锰酸锂Manganese Lithium Oxide石墨graphite更多电池资讯：/电池产品认证指导网站：/ekeyword.php?ekeyid=6烘箱oven真空烘箱vacuum oven搅拌机mixing devicevacuum mixing device涂布机coating equipment裁纸刀paper knife ,,,,,,cutting knife分条机equipment for cutting big piece to much pieces辊压机roll press equipment电阻点焊机spot welding machine超声点焊机ultrasonic spot welding machine卷绕机winder自动叠片机auto laminating machine激光焊机laser welding machine注液机infusing machine真空注液机vacuum infusion machine预充柜pre-charge equipment化成柜formation systems分容柜grading systems测试柜testing systems内阻仪battery inner resistance tester万用表multimeter转盘式真空封口机turntable type vacuum sealing machine更多电池资讯：/电池产品认证指导网站：/ekeyword.php?ekeyid=6自动冲膜机automatic aluminum membrane shaper序号首字母英文中文1 A aging 老化2 B battery charger3 black-fleck 黑斑4 C cap 盖板充电器5 capacity density 能量密度6 capacity grading 分容7 cathode tab welding 极耳超焊8 cell 电芯9 charge(capacity) retention 荷电（容量）保持10 checking code 检码11 concave spot 凹点12 constant current charge 恒流充电13 constant current discharge 恒流放电14 constant voltage charge 恒压充电15 corrective measures 纠正措施16 crack 裂纹17 cut-off voltage 终止电压18 cycle life 循环寿命19 D dark trace 暗痕20 degrade 降级21 dent 凹痕22 discharge depth 放电深度23 distortion 变形24 drape 打折25 E Electrical and MechanicalServices Department 机电部26 electrolyte 电解，电解液27 empaistic 压纹28 end-off voltage 放电截止电压29 environmentally friendly 对环境友好30 equipment first inspection 设备首检31 erode 腐蚀32 explosion-proof line 防爆线33 F first inspection 首检34 formation 化成35 fracture 断裂36 I inspection 检验37 insulate 绝缘38 internal resistance 内阻更多电池资讯：/电池产品认证指导网站：/ekeyword.php?ekeyid=639 J jellyroll 卷芯40 joint 接缝，结合点41 L laser deflecting 偏光42 laser reticle 激光刻线43 laser welding-flatwise weld 激光焊接-平焊laser welding-standing weld 激光焊接-立焊44 leakage 漏液45 leak-checking 测漏46 leaving out of welding 漏焊47 limited charge voltage 充电限制电压48 local action 自放电49 M margin turnly 翘边50 measuring the dimension of cells 电芯卡尺寸51 meet requirement 达到要求52 memory effects 记忆效应53 N nick 划痕54 nominal voltage 标称电压55 notice-board confirmation 看板确认56 nugget 硬块57 O obverse 正面58 open circuit voltage 开路电压59 over charge 过充60 over discharge 过放61 over the thickness 超厚62 P particle 颗粒63 PE membrane PE 膜64 pit 坑点65 placing cells into the box 电芯装盒66 point inspection 点检67 preventive measures 预防措施68 pricking the tapes 扎孔69 process inspection 制程检验70 put the battery piled up 将电芯叠放在一起71 Q qualified products 合格品72 quality assurance 质量保证73 quality control 质量控制74 quality improvement 质量改进75 quality match 品质配对76 quality planning 质量策划77 R rated capacity 额定容量78 recharge 再充电79 refitting the can of cell 电芯壳口整形80 requirment 要求81 reverse 背面，反面更多电池资讯：/电池产品认证指导网站：/ekeyword.php?ekeyid=682 rework 返工83 ringing cells into pyrocondensation films84 S safety vent 安全阀85 sand aperture 砂眼86 scar 疤痕87 secondary battery 二次电池88 select appearance 选外观sharp-set 批锋89 short circuit checking 测短路90 smudginess 污物91 spot welding by laser 激光点焊92 spot welding place 点焊位置93 spraying the code 喷码94 spur 毛刺95 sticking the PVC cover boards 贴面垫96 storing 陈化97 storing with high voltage 高压储存98 T tabs deflection 极耳歪斜99 tabs excursion 极耳错位100 technics requiment 工艺要求101 U ultrasonic welding 超声波焊接102 ultrasonic welding strength 超焊强度103 unqualified products 不合格品104 W wave 波浪105 working procedure 工序套热缩膜Voltage：Units of measuring electrical current, all batteries are rated in volts DC. (DirectCurrent). This determines how much energy is needed to power your equipment. Voltage plateau:（电压平台）A slow decrease in voltage over a long period of time. As a rule, the plateau extendsfrom the first voltage drop at the start of the discharge to the bend of the curveafter which the voltage drops rapidly at the end.Nominal Voltage（标称电压）The voltage of a battery, as specified by the manufacturer, discharging at aspecified rate and temperature.Working voltage（工作电压）The working voltage of a cell or battery begins at its electrical connections as soon as an electrical consumer is connected to it.Discharging voltage, average voltage (放电电压)更多电池资讯：/电池产品认证指导网站：/ekeyword.php?ekeyid=6The average discharging voltage is the average value of the dischargingvoltageduring the entire discharging process with a related discharging current.Open circuit voltage (OCV 开路电压)The voltage of a battery when there is no current flowing.Closed-Circuit Voltage (CCV 闭路电压)The potential or voltage of a battery when it is discharging or charging.State of charge:The rate of charge capacity vs. whole capacity.Initial voltage（起始电压）A battery＇s initial voltage is the working voltage when discharging begins. End-point voltage (End voltage, Cutoff voltage, Final voltage)截止电压Specified closed circuit voltage at which a service output test is terminated. End-of-discharge voltageThe battery voltage when discharge is terminated.End-of-charge voltageThe battery voltage when charge is terminated.Cutoff voltage (V)The battery voltage at which charge or discharge is terminated.Definition: Capacity(容量）The capacity of a cell is defined as how manymilli-amp-hours (mAh) of current the cell canstore and subsequently deliver.One milli-amp (mA) is 1/1000th of an Amp. Somelarger cell capacities are expressed in Amp-hours(Ah).“Rated capacity” is varies with discharge rate,temperature, and cutoff voltage.Rated capacity is different from power or energyExample:If a cell is rated at 1000 mAh, then it can deliverthe following:1000 mA of current for 1 hour500 mA of current for 2 hours200 mA of current for 5 hours2000 mA of current for 1/2 hourDefinition: Energy Density(能量密度，包括体积比能量和质量比能量）The energy density of a cell is a measure of howmuch energy can be stored in the cell per unitvolume or per unit weight.E (watt-hours) = cell voltage x capacity rating更多电池资讯：/电池产品认证指导网站：/ekeyword.php?ekeyid=6? Energy density per unit volume is called the“volumetric energy density” and is expressed interms of watt-hours/liter (wh/l).Energy density per unit weight is called the“gravimetric energy density” and is expressedin terms of watt-hours/kilogram (wh/kg).These measurements are useful when you aretrying to determine which cell has the mostcapacity per unit volume or weight.1.Self Discharge自放电2.Uniformity of the Li-ion Batteries3.steel strap 钢带4.Burst vent 防爆阀5.Filling port 注液孔锂离子电池的一致性6.spirally wound type cylindrical wound type7.foil 箔圆柱形8.parallel-plate prismatic design 方形叠片式设计Ageing （老化）-Permanent loss of capacity with frequent use orthe passage of time due to unwanted irreversible chemical reactions in the cell.Anode（阳极） - The electrode in an electrochemical cell where oxidation takes place,releasing electrons.During discharge the negative electrode of the cell is the anode.During charge the situation reverses and the positive electrode of the cell is the anode.Cathode（阴极） - The electrode in an electrochemical cell where reduction takesplace, gaining electrons.During discharge the positive electrode of the cell is the cathode. During chargethe situation reverses andthe negative electrode of the cell is the cathode.Cycle （循环）- A single charge and discharge of a battery.Depth of discharge DOD （放电深度）- The ratio of the quantity of electricity orcharge removed from a cell on discharge to its rated capacity.Internal impedance（交流内阻） - Resistance to the flow of AC current within a cell.It takes into account the capacitive effect of the plates forming the electrodes.Internal resistance（直流内阻）- Resistance to the flow of DC electric current withina cell,causing a voltage drop across the cell in closed circuit proportional to the currentdrain from the cell.A low internal impedance is usually required for a high rate cell.更多电池资讯：/电池产品认证指导网站：/ekeyword.php?ekeyid=6锂离子电池的内阻英语概念到底用哪个概念，是Internal resistance还是Internalimpedance，一些电池说明书内阻用 Internal resistance，也有的用 Internal impedance，我认为 Internal impedance 较好些，因为国内测的电池内阻基本都是交流内阻，而外文也有这样定义的（我在别的帖子也粘贴过）：Internal impedance（交流内阻） - Resistance to the flow of AC current within a cell.It takes into account the capacitive effect of the plates forming theelectrodes.Internal resistance（直流内阻）- Resistance to the flow of DC electric current withina cell,causing a voltage drop across the cell in closed circuit proportional to the currentdrain from the cell.A low internal impedance is usually required for a high rate cell.在 IEC6196002 中，只定义为 Internal resistance，而用交流的方法测得的内阻，叫Internala.c. resistance（交流内阻）用直流的方法测得的内阻，叫 Internal d.c. resistance（直流内阻），其实 Internal a.c.resistance 测得就是阻抗，这样看来不如用 Internal impedance（交流内阻）和 Internal resistance （直流内阻）这两个概念把它们进行分清，以免混淆。
电池英语及翻译术语专业英语词汇_英语词汇
Alkaline batteries ：碱性电池Capacitor batteries：电容电池Carbon zinc batteries ：碳锌电池Lead acid batteries：铅酸电池Lead calcium batteries：铅钙电池Lithium batteries ：锂电池Lithium ion batteries ：锂离子电池Lithium polymer batteries：锂聚合物电池Nickel cadmium batteries ：镍镉电池Nickel iron batteries ：镍铁电池Nickel metal hydride batteries ：金属氧化物镍氢电池/镍氢电池Nickel zinc batteries：镍锌电池Primary batteries ：原电池Rechargeable batteries ：充电电池Sealed lead acid batteries：密封铅酸电池Silver cadmium batteries ：银钙电池Silver oxide batteries ：银氧化物电池Silver zinc batteries：银锌电池Zinc chloride batteries：银氯化物电池Zinc air batteries：锌空电池Environmental Protection batteries:环保电池Lithium batteries ：锂电池Lithium ion batteries ：锂离子电池Lithium polymer batteries：锂聚合物电池铅酸蓄电池 Lead-acid battery起动铅酸电池 Lead-acid starter batteries摩托车用铅酸电池 Lead-acid batteries for motorcycles内燃机车用铅酸电池 Lead-acid batteries for disel locomotive电动道路车辆用铅酸电池 Lead-acid batteries for electric road vehicles小型阀控密封式铅酸电池 small-sized valve-regulated lead-acid batteries航空用铅酸电池 Aircraft lead-acid batteries固定型阀控密封式铅酸蓄电池 Lead-acid batteries for stationary valve-regulated铅酸电池用极板 plate for lead-acid battery铅锭 lead ingots牵引用铅酸电池 Lead-acid traction batteies电解液激活蓄电池 electrolyte activated battery更多电池资讯：电池产品认证指导网站：valve 排气阀filling device for pleral cells 电池组填充装置negative electrode 负电极negative plate 负极板addition reagent for negative plate 负极板添加剂indicator 指示器top cover 上盖vent plug 液孔塞expanded grid 扩展式板栅specific gravity indicator 比重指示器electrolyte level control pipe 电解液液面控制管electrolyte level indicator 电解液液面指示器electrolyte level sensor 电解液液面传感器hard rubber container 硬橡胶槽envelope separator 包状隔板woven cloth tube 纺布管spongy lead 海绵状铅partition 隔壁over the partition type 越过隔壁型through the partition type 贯通隔壁贯通型separator 隔板(1)battery rack(2)battery stand(3)battery stillage 蓄电池架/蓄电池底垫active material 活性物质glass fiber separator 玻璃纤维隔板glass mat 玻璃纤维绵glass mat tube 玻璃纤维绵管spacing washer 间隔垫圈reinforced fiber separator 强化纤维隔板polarity mark plate 极性标记板pole 极柱pole insulator 极柱绝缘子pole nut 极柱螺母plate 极板plate foot 极板足plate supporter 极板支撑件element 极板群/极群组pole bolt 极柱螺栓plate lug 极板耳dilute sulfuric acid 稀硫酸steel can 金属罐steel container 金属蓄电池槽(1)madribs(2)element rest 鞍子/极群组座tubular plate 管状极板gelled electrolyte 胶体电解液更多电池资讯：电池产品认证指导网站：板栅caution label 警告标签synthetic resin separator 合成树脂隔板plastics container 塑料蓄电池槽synthetic fiber separator 合成纤维隔板connector sunken type 沉没型连接器connetor exposed type 露出型连接器safety valve test 安全阀测试ampere-hour efficency 安时效率one charge distance range 一次充电行程gas recombination on negative electrode typecut-off discharge 终止放电/截止放电阴极气体再化合型/阴极气体复合型(1）specific characteristic (2)energy density (1)比特性（2）能量密度recovering charge 恢复充电(1)open circuit voltage(2)off-load voltage 开路电压/空载电压overcharge 过充电gassing 析气overcharge life test 过充电寿命试验accelerated life test 加速寿命试验active material utilization 活性物质利用率theoretical capacity of active material 活性物质的理论容量over discharge 过放电intermittent discharge 间歇放电full charge 完全充电full discharge 完全放电reverse charge 反充电/反向充电quick charge 快速放电allowable minimum voltage 允许最小电压equalizing charge 均衡充电creeping 蠕变group voltage 组电压shallow cycle endurance 轻负荷寿命/轻负荷循环寿命characteristic of electrolyte decrease 电解液减少特性nominal voltage 标称电压high rate discharge 高率放电high rate discharge characteristic 高率放电特性5 second voltage at discharge 放电 5 秒电压（1）cold cranking ampere（2）cold cranking performance（1）冷启动电流（2）冷启动性能cycle life test 循环寿命测试maximum voltage at discharge 最大放电电压30 second voltage at discharge 放电 30 秒电压residual capacity 残存容量(1)hour rate(2) discharge rate （1）小时率（2）放电率更多电池资讯：电池产品认证指导网站：self discharge (2) local action （1）自放电（2）局部自放电(1) self discharge rate(2) local action rate （1）自放电率（2）局部自放电率actual capacity 实际容量(1)starting capability(2)cranking ability 启动能力cranking current 启动电流battery clamp test 电池夹钳测试power density 功率密度momentary discharge 瞬间放电modified constant voltage charge 修正恒定电压充电initial capacity 初始容量gas recombination by catalyser type 触媒气体复合式initialcharge 初始充电viberation test 振动试验predetermined voltage 预定电压total voltage 总电压activation test for dry charged battery 干式荷电蓄电池活化试验salting 盐析earthquake-proof characteristics 防震性能dielectric voltage withstand test 电介质耐压试验short time discharge 短时间放电escaped acid mist test 酸雾逸出测试terminal voltage 端子电压cell voltage 单电池电压step charge阶段充电short-circuit current 短路电流storage test 保存测试high rate discharge at low temperature 低温高率放电rated voltage 额定电压rated capacity 额定容量fixed resistance discharge 定阻抗放电constant voltage charge 恒压充电constant voltage life test 恒压寿命测试constant current charge 恒流充电constant voltage constant current charge 恒流恒压充电constant current discharge 恒流放电constant watt discharge 恒功率放电low rate discharge characteristics 低率放电特征trickle charge 涓流充电trickle charge current 涓流充电电流trickle charge life test 涓流充电寿命测试thermal runaway 热失控driving pattern test 运行测试capacity in driving pattern test 运行测试更多电池资讯：电池产品认证指导网站：charge急充电floating charge浮充电floating charge voltage 浮充电电压floating charge current 浮充电电流(1)mean voltage (2)average voltage 平均电压on-load voltage 负载电压discharge duration time 放电持续时间(1)final voltage(2)cut-off voltage(3)end voltagedepth of discharge 放电深度discharge voltage 放电电压discharge current 放电电流discharge current density 放电电流密度discharge watt-hour 放电瓦时discharge characteristics 放电特性discharged ampere-hour 放电安时explosion proof test 防爆测试auxiliary charge 补充电maintenance factor 维护率storage characteristics 保存特性终止电压/截止电压gas recombinating efficiencycharge 充电气体复合效率/气体再化合效率charge acceptance test 充电可接受性试验start-of-charge current 充电开始电流charge efficiency 充电效率end-of-charge voltage 充电结束电压specific gravity of electrolyte at the end of charge充电结束时电解液比重charge voltage 充电电压charge current 充电电流charged watt-hour 充电瓦时charge characteristic 充电特性charge ampere-hour 充电安时deep cycle endurance 重负荷循环寿命/重复合寿命weight engergy density 重量能量密度rubber pad 橡胶垫lower level line 下液面线side terminal 侧端子collective exhaust unit 公共的排放单元sintered plaque 烧结极板sintered separator 烧结隔板sintered plate 烧结极板catalyst plug 催化塞spine 芯骨strap 带更多电池资讯：电池产品认证指导网站：隔离物insulating tube绝缘管intercell connector连接线/连接条connector cover连接管盖float mounted plug 浮动安装的栓(1)pasted plate (2)grid type plate 涂膏式极板braidd tube 编织管(1)flame-arrester vent plug (2)flam-retardant vent plug 安全塞explosion and splash proof construction 防爆防溅结构baffle 保护板pocket type plate 袋式极板bottom hole-down 底孔向下（固定）bolt fastening terminal 螺栓连接端子male blade 阳片monoblock container 整体槽positive electrode 正极positive plate 正极板leading wire terminal 引线端子retainer mat 止动垫片ribbed separator 肋隔板(1)jumping wire (2)inter low wire 跳线end plate 端板filling plug 注液塞plante plate 形成式极板/普朗特极板tubular plate 管式极板low electric resistance separator 低电阻隔板tapered terminal post 锥形接线柱electrolyte 电解液container 蓄电池槽/蓄电池壳set of container 成套蓄电池槽level-scope mounted plug 透视塞/透视栓handle 手柄jug 取液管(1)connector;(2)plug concent (1)连接器；(2)插座式连接器connector wire 连接线connecting bar 连杆connecting bar cover 连杆帽lead 引线/连接线edge insulator 绝缘卡side frame 侧框架battery cubicle 蓄电池箱perforated separator 多孔隔板burning rod (铅)焊条terminal 端子更多电池资讯：电池产品认证指导网站：connector 端子连接条terminal cover 端子盖terminal base 端子座tab 接线片lead bushing 铅套corrugated separator 波形隔板(1)lead dioxide;(2)lead peroxide (1)二氧化铅；(2)过氧化铅(1)woven separator;(2)nonwoven separator (1)织物隔板；(2)非织物隔板vent hole 通气孔exhaust tube 排气管antipolar mass 反极性物质output cable 输出电缆microporous rubber separator 微孔像胶隔板specific gravity indicator 比重计leaf separator 叶片式隔板lid sealing compound 密封剂/封口剂sealing gasket 密封衬垫/垫圈lid 蓄电池盖set of lid 系列的盖方通盖板cover board底板solepiece钢珠steel ball压钢珠press steel ball防爆阀valve preventing explosion大电流(倍率)放电discharge in high rate current 标称电压Normal voltage标称容量normal capacity放电容量discharge capacity充电上限电压limited voltage in charge 放电下限电压更多电池资讯：电池产品认证指导网站：voltage in discharge恒流充电constant current charge恒压充电constant voltage charge恒流放电constant current discharge 放电曲线discharge curve充电曲线charge curve放电平台discharge voltage plateau 容量衰减capacity attenuation起始容量initial discharge capacity 流水线pipelining传送带carrying tape焊极耳welding the current collector卷绕wind叠片layer贴胶带stick tape点焊spot welding超声焊ultrasonic weldingThe terminating voltage in discharge of the battery is volt. The limited voltage in charge of the battery is volt.三元素Nickle-Cobalt-Manganese Lithium Oxidethree elements materials钴酸锂Cobalt Lithium Oxide锰酸锂Manganese Lithium Oxide石墨graphite更多电池资讯：电池产品认证指导网站：烘箱oven真空烘箱vacuum oven搅拌机mixing devicevacuum mixing device涂布机coating equipment裁纸刀paper knife ,,,,,,cutting knife分条机equipment for cutting big piece to much pieces 辊压机roll press equipment电阻点焊机spot welding machine超声点焊机ultrasonic spot welding machine 卷绕机winder自动叠片机auto laminating machine激光焊机laser welding machine注液机infusing machine真空注液机vacuum infusion machine预充柜pre-charge equipment化成柜formation systems分容柜grading systems测试柜testing systems内阻仪battery inner resistance tester 万用表multimeter转盘式真空封口机turntable type vacuum sealing machine更多电池资讯：电池产品认证指导网站：自动冲膜机automatic aluminum membrane shaper序号首字母英文中文1 A aging 老化2 B battery charger3 black-fleck 黑斑4 C cap 盖板充电器5 capacity density 能量密度6 capacity grading 分容7 cathode tab welding 极耳超焊8 cell 电芯9 charge(capacity) retention 荷电（容量）保持10 checking code 检码11 concave spot 凹点12 constant current charge 恒流充电13 constant current discharge 恒流放电14 constant voltage charge 恒压充电15 corrective measures 纠正措施16 crack 裂纹17 cut-off voltage 终止电压18 cycle life 循环寿命19 D dark trace 暗痕20 degrade 降级21 dent 凹痕22 discharge depth 放电深度23 distortion 变形24 drape 打折25 E Electrical and MechanicalServices Department 机电部26 electrolyte 电解，电解液27 empaistic 压纹28 end-off voltage 放电截止电压29 environmentally friendly 对环境友好30 equipment first inspection 设备首检31 erode 腐蚀32 explosion-proof line 防爆线33 F first inspection 首检34 formation 化成35 fracture 断裂36 I inspection 检验37 insulate 绝缘38 internal resistance 内阻更多电池资讯：电池产品认证指导网站：J jellyroll 卷芯40 joint 接缝，结合点41 L laser deflecting 偏光42 laser reticle 激光刻线43 laser welding-flatwise weld 激光焊接-平焊laser welding-standing weld 激光焊接-立焊44 leakage 漏液45 leak-checking 测漏46 leaving out of welding 漏焊47 limited charge voltage 充电限制电压48 local action 自放电49 M margin turnly 翘边50 measuring the dimension of cells 电芯卡尺寸51 meet requirement 达到要求52 memory effects 记忆效应53 N nick 划痕54 nominal voltage 标称电压55 notice-board confirmation 看板确认56 nugget 硬块57 O obverse 正面58 open circuit voltage 开路电压59 over charge 过充60 over discharge 过放61 over the thickness 超厚62 P particle 颗粒63 PE membrane PE 膜64 pit 坑点65 placing cells into the box 电芯装盒66 point inspection 点检67 preventive measures 预防措施68 pricking the tapes 扎孔69 process inspection 制程检验70 put the battery piled up 将电芯叠放在一起71 Q qualified products 合格品72 quality assurance 质量保证73 quality control 质量控制74 quality improvement 质量改进75 quality match 品质配对76 quality planning 质量策划77 R rated capacity 额定容量78 recharge 再充电79 refitting the can of cell 电芯壳口整形80 requirment 要求81 reverse 背面，反面更多电池资讯：电池产品认证指导网站：rework 返工83 ringing cells into pyrocondensation films84 S safety vent 安全阀85 sand aperture 砂眼86 scar 疤痕87 secondary battery 二次电池88 select appearance 选外观sharp-set 批锋89 short circuit checking 测短路90 smudginess 污物91 spot welding by laser 激光点焊92 spot welding place 点焊位置93 spraying the code 喷码94 spur 毛刺95 sticking the PVC cover boards 贴面垫96 storing 陈化97 storing with high voltage 高压储存98 T tabs deflection 极耳歪斜99 tabs excursion 极耳错位100 technics requiment 工艺要求101 U ultrasonic welding 超声波焊接102 ultrasonic welding strength 超焊强度103 unqualified products 不合格品104 W wave 波浪105 working procedure 工序套热缩膜Voltage：Units of measuring electrical current, all batteries are rated in volts DC.(DirectCurrent). This determines how much energy is needed to power your equipment.Voltage plateau:（电压平台）A slow decrease in voltage over a long period of time. As a rule, the plateauextendsfrom the first voltage drop at the start of the discharge to the bend of thecurveafter which the voltage drops rapidly at the end.Nominal Voltage（标称电压）The voltage of a battery, as specified by the manufacturer, discharging at aspecified rate and temperature.Working voltage（工作电压）The working voltage of a cell or battery begins at its electrical connections assoon as an electrical consumer is connected to it.Discharging voltage, average voltage (放电电压)更多电池资讯：电池产品认证指导网站：average discharging voltage is the average value of the dischargingvoltageduring the entire discharging process with a related discharging current.Open circuit voltage (OCV 开路电压)The voltage of a battery when there is no current flowing.Closed-Circuit Voltage (CCV 闭路电压)The potential or voltage of a battery when it is discharging or charging. State of charge:The rate of charge capacity vs. whole capacity.Initial voltage（起始电压）A battery＇s initial voltage is the working voltage when discharging begins. End-point voltage (End voltage, Cutoff voltage, Final voltage)截止电压Specified closed circuit voltage at which a service output test is terminated. End-of-discharge voltageThe battery voltage when discharge is terminated.End-of-charge voltageThe battery voltage when charge is terminated.Cutoff voltage (V)The battery voltage at which charge or discharge is terminated.Definition: Capacity(容量）The capacity of a cell is defined as how manymilli-amp-hours (mAh) of current the cell canstore and subsequently deliver.One milli-amp (mA) is 1/1000th of an Amp. Somelarger cell capacities are expressed in Amp-hours(Ah).“Rated capacity” is varies with discharge rate,temperature, and cutoff voltage.Rated capacity is different from power or energyExample:If a cell is rated at 1000 mAh, then it can deliverthe following:1000 mA of current for 1 hour500 mA of current for 2 hours200 mA of current for 5 hours2000 mA of current for 1/2 hourDefinition: Energy Density(能量密度，包括体积比能量和质量比能量）The energy density of a cell is a measure of howmuch energy can be stored in the cell per unitvolume or per unit weight.E (watt-hours) = cell voltage x capacity rating更多电池资讯：电池产品认证指导网站：Energy density per unit volumeis called the“volumetric energy density” and is expressed interms of watt-hours/liter (wh/l).Energy density per unit weight is called the“gravimetric energy density” and is expressedin terms of watt-hours/kilogram (wh/kg).These measurements are useful when you aretrying to determine which cell has the mostcapacity per unit volume or weight.Discharge自放电of the Li-ion Batteriesstrap 钢带vent 防爆阀 port 注液孔锂离子电池的一致性wound type cylindrical wound type箔圆柱形prismatic design 方形叠片式设计Ageing （老化）-Permanent loss of capacity with frequent use orthe passage of time due to unwanted irreversible chemical reactions in the cell.Anode（阳极） - The electrode in an electrochemical cell where oxidation takes place,releasing electrons.During discharge the negative electrode of the cell is the anode.During charge the situation reverses and the positive electrode of the cell is the anode.Cathode（阴极） - The electrode in an electrochemical cell where reduction takesplace, gaining electrons.During discharge the positive electrode of the cell is the cathode. During chargethe situation reverses andthe negative electrode of the cell is the cathode.Cycle （循环）- A single charge and discharge of a battery.Depth of discharge DOD （放电深度）- The ratio of the quantity of electricity orcharge removed from a cell on discharge to its rated capacity.Internal impedance（交流内阻） - Resistance to the flow of AC current within a cell.It takes into account the capacitive effect of the plates forming the electrodes.Internal resistance（直流内阻）- Resistance to the flow of DC electric current withina cell,causing a voltage drop across the cell in closed circuit proportional to the currentdrain from the cell.A low internal impedance is usually required for a high rate cell.更多电池资讯：电池产品认证指导网站：锂离子电池的内阻英语概念到底用哪个概念，是Internal resistance还是Internalimpedance，一些电池说明书内阻用 Internal resistance，也有的用 Internal impedance，我认为 Internal impedance 较好些，因为国内测的电池内阻基本都是交流内阻，而外文也有这样定义的（我在别的帖子也粘贴过）：Internal impedance（交流内阻） - Resistance to the flow of AC current within a cell.It takes into account the capacitive effect of the plates forming the electrodes.Internal resistance（直流内阻）- Resistance to the flow of DC electric current withina cell,causing a voltage drop across the cell in closed circuit proportional to the currentdrain from the cell.A low internal impedance is usually required for a high rate cell.在 IEC6196002 中，只定义为 Internal resistance，而用交流的方法测得的内阻，叫Internal. resistance（交流内阻）用直流的方法测得的内阻，叫 Internal . resistance（直流内阻），其实 Internal.resistance 测得就是阻抗，这样看来不如用 Internal impedance（交流内阻）和 Internal resistance （直流内阻）这两个概念把它们进行分清，以免混淆。
(节选)新能源材料外文翻译----Ti3C2 MXene作为金属(Li、Na、K、Ca)离子电池的高容量电极
MXenes有希望成为锂离子电池和锂离子电容器的电极材料。尽管MXenes对于Li的容量与商业的石墨电极锂离子电池（372,mAh/g）相近，MXenes表现出杰出的处理高循环率的能力。例如，对于无添加剂终止的Ti3C2，在36℃的循环效率下，可获得110mAh/g的可逆容。注意，石墨不能处理这样的高循环速率。这是因为Ti3C2对锂原子C2（0.07eV）上的扩散势垒区比锐钛矿TiO2(0.35—0.65eV)和石墨的小。然而，电子性能的研究和MXenes的应用需要利用其它金属离子电池。目前还没有使用MXenes电极的钠离子电池或其它金属离子电池的数据被报道。在这篇文章中，我们选择Ti3C2作为例子和最佳研究MXene并且利用第一性原理密度泛函理论计算，就它作为不同金属（Li、Na、K和Ca）离子电池的电极材料表现的性能作报告。
毕业论文外文翻译-负载银的掺氮石墨烯概论
学号：10401604常州大学毕业设计（论文）外文翻译（2014届）外文题目Easy synthesis of nitrogen-doped graphene–silvernanoparticle hybrids by thermal treatment ofgraphiteoxide with glycine and silver nitrate 译文题目通过水热处理氧化石墨烯、甘氨酸和硝酸银简便地合成掺氮石墨烯-银纳米粒子复合物外文出处CARBON50(2012)5148–5155学生王冰学院石油化工学院专业班级化工106校内指导教师罗士平专业技术职务副教授校外指导老师专业技术职务二○一四年二月通过水热处理氧化石墨烯、甘氨酸和硝酸银简便地合成氮杂石墨烯-银纳米粒子杂合物Sundar Mayavan,Jun-Bo Sim,Sung-Min Choi摘要：氮杂石墨烯-银纳米粒子杂合物在500℃通过水热处理氧化石墨烯（GO）、甘氨酸和硝酸银制得。
甘氨酸用于还原硝酸根离子，甘氨酸和硝酸根混合物在大约200℃分解。
分解的产物可作为掺杂氮的来源。
水热处理GO、甘氨酸和硝酸银混合物在100℃可形成银纳米粒子，200℃时GO还原，300℃时产生吡咯型掺氮石墨烯，500℃时生成吡咯型掺氮石墨烯。
合成物质中氮原子所占百分比为13.5%.在合成各种纳米金属粒子修饰的氮杂石墨烯方面，该合成方法可能开辟了一个新的路径，其在能量储存和能量转换设备方面很有应用价值。
1.引言石墨烯是所有石墨材料的基本构件，其蜂窝状晶格由单层碳原子排列而成。
它表现出与结构有关的独特电子、机械和化学性质，具有较高的比表面积（2630-2965m2g-1）[1–3]。
化学掺杂杂原子石墨烯像掺杂氮原子，极大地引起了人们的兴趣，因其在传感器、燃料电池的催化剂和锂离子电池的电极等方面具有应用潜力[4–6]。
氮原子的掺杂改变了石墨烯的电子特性和结构特性，导致其电子移动性更强，产生更多的表面缺位。
钴酸镍
Engineeringfirecracker-like beta-manganese dioxides@spinel nickel cobaltates nanostructures for high-performance supercapacitorsMin Kuang a,Zhong Quan Wen b,Xiao Long Guo a,Sheng Mao Zhang c,Yu Xin Zhang a,b,*a College of Materials Science and Engineering,Chongqing University,Chongqing400044,PR Chinab National Key Laboratory of Fundamental Science of Micro/Nano-Devices and System Technology,Chongqing University,Chongqing400044,PR Chinac Laboratory for Special Functional Materials,Henan University,Kaifeng475004,PR Chinah i g h l i g h t s g r a p h i c a l a b s t r a c tNiCo2O4nanosheets were decorated on b-MnO2nanowires by a facile and large-scale method.Thefirecracker core e shell architec-ture exhibited a high capacitance of 343F gÀ1.Excellent cycling stability:95% capacitance retention after3000 cycles.The asymmetric supercapacitor yiel-ded a maximum power density of 2.5kW kgÀ1.a r t i c l e i n f oArticle history:Received1April2014 Received in revised form18June2014Accepted22July2014 Available online30July2014Keywords:Spinel nickel cobaltate SupercapacitorsManganese oxides Electrochemical performance a b s t r a c tAn effective and rational strategy is developed for large-scale growth offirecracker-like Ni-substituted Co3O4(NiCo2O4)nanosheets on b-MnO2nanowires(NWs)with robust adhesion as high-performance electrode for electrochemical capacitors.The NiCo2O4e MnO2nanostructures display much higher spe-cific capacitance(343F gÀ1at current density of0.5A gÀ1),better rate capability(75.3%capacitance retention from0.5A gÀ1to8A gÀ1)and excellent cycle stability(5%capacitance loss after3000cycles) than Co3O4e MnO2nanostructures.Moreover,an asymmetric supercapacitor based on NiCo2O4e MnO2 NWs as the positive electrode and activated graphenes(AG)as the negative electrode achieves an energy density of9.4Wh kgÀ1and a maximum power density of2.5kW kgÀ1.These attractivefindings suggest this novel core e shell nanostructure promising for electrochemical applications as an efficient super-capacitive electrode.©2014Elsevier B.V.All rights reserved.1.IntroductionSupercapacitors are one class of energy storage systems that have attracted tremendous attention due to their superior advan-tages including high power/energy density,excellent cycling stability and fast charge/discharge capability[1].Compared with secondary batteries,supercapacitors can provide high power in short-term pulses and be used as peak power sources in hybrid electric vehicles,memory backup devices,and back-up supplies to protect against power disruption[2].On the basis of energy storage mechanism,there are two types of supercapacitors,namely elec-trical double-layer capacitors(EDLCs)and pseudocapacitors[3]. Recent research efforts have been made by exploiting novel elec-trode materials for supercapacitors with both high energy density and power density.Transition metal oxides,such as RuO2[4],MnO2*Corresponding author.College of Materials Science and Engineering,Chongqing University,Chongqing400044,PR China.Tel./fax:þ862365104131.E-mail address:zhangyuxin@(Y.X.Zhang).Contents lists available at ScienceDirect Journal of Power Sourcesjournal ho mep age:www.elsevi /locate/jpowsour/10.1016/j.jpowsour.2014.07.1440378-7753/©2014Elsevier B.V.All rights reserved.Journal of Power Sources270(2014)426e433[5,6,7,8],NiO[9],Co3O4[5,10,11]and TiO2[8,12,13,14],contribute pseudocapacitance,although most of them suffer from low abun-dance,high cost for their raw materials,low electrical conductivity, and poor rate capability and reversibility during the char-ge e discharge process.Recently,a ternary metallic oxide,spinel nickel cobaltite (NiCo2O4),has drawn much research interest[15,16,17,18,19].The higher electrochemical capacitive performances may mainly derive from the superior electrochemical activity of NiCo2O4.More significantly,it is reported that NiCo2O4possesses a much better electronic conductivity,at least two orders of magnitude higher, and higher electrochemical activity than nickel oxides and cobalt oxides[20,21,22,23].For example,Wang and co-workers[23]ob-tained nickel cobaltite nanowires on carbon cloth with a specific capacitance of245F gÀ1at1A gÀ1.Liu et al.[16]reported that NiCo2O4@NiCo2O4core/shell nanoflake array showed a specific capacitance of1.55F cmÀ2at2mA cmÀ2.Jiang et al.[21]synthe-sized the hierarchical porous NiCo2O4nanowires which exhibited a specific capacitance of743F gÀ1at1A gÀ1.Very recently,rational design of multicomponent combination or mild methods has been applied to improve the specific capacitance of supercapacitors, which can provide the synergistic effect of all individual constitu-ents,as well as efficient and rapid pathways for ion and electron transport(at their surfaces and throughout the bulk of the chemical distributions)[8,9,16].In addition,manganese oxides(MnO2), characterized by a low-cost material with a large theoretical ca-pacity,abundant and environmentally friendly nature,have attracted significant interest as a promising alternative electrode material for supercapacitors[6,7,8].It has been reported that,one-dimensional nanomaterials can facilitate the electrical transport along the axial direction,while maintaining high external surface area and thus high capacitance at fast charging-discharging rates [4,6,9].To the best of our knowledge,there is little work on rational design offirecrackers-like NiCo2O4e MnO2NWs composite material for supercapacitors.In this work,we develop a cost-effective and simple strategy to design and fabricate novelfirecrackers-like NiCo2O4e MnO2NWs as an electrode for high-performance supercapacitors.The morphology,structure and electrochemical properties of the firecrackers-like NiCo2O4e MnO2NWs were investigated.Remark-ably,due to their1D nanoporous nanosheet microstructure and higher electrical conductivity compared with Co3O4e MnO2NWs, these NiCo2O4e MnO2NWs manifest a high specific capacity of 343F gÀ1,excellent cycling stability and high rate capability. Furthermore,an asymmetric supercapacitor device based on NiC-o2O4e MnO2//AG is assembled,which shows a maximum energy density of9.4Wh kgÀ1and a maximum power density of 2.5kW kgÀ1.2.Experimental2.1.Material synthesisAll reagents were of analytical purity and used without any further purification.MnOOH NWs were prepared by a hydrother-mal method.In a typical procedure,a37mL suspension containing the297mg manganese dioxide,together with2mL ethanol was made.Then the solution was transferred into a50mL stainless-steel autoclave and heated at120 C for24h,and then naturally cooled down to room temperature.The products were collected by filtration,washed with deionized water and ethanol,andfinally dried at60 C for12h.The obtained MnOOH NWs were re-dispersed into80mL of ethanol and sonicated for20min to reach good dispersion.Afterward, 1.0mmol nickel nitrate (Ni(NO3)2),2.0mmol cobalt nitrate(Co(NO3)2),2mmol ammonium fluoride(NH4F)and5mmol urea were dissolved in80mL DI water to form a transparent pink solution.The above two solutions were then mixed and heated to90 C in an oil bath for8h.After the solution was cooled down to room temperature naturally,the product was collected through centrifugation and washed with DI water and ethanol for several times.The products were then dried, followed by annealing at300 C for2h with a slow heating rate of 1 C minÀ1in order to get well-defined crystallized NiCo2O4e MnO2 NWs hybrid structure.For comparison,Co3O4e MnO2nano-structures were synthesized through a similar route and subse-quent annealing in air atmosphere.For the direct growth of Co3O4 nanosheets on MnO2NWs,single Co(NO3)2salt was added into the reaction solution instead of the Ni(NO3)2and Co(NO3)2.Except for the above parameters,the rest were the same as that of the syn-thesis of NiCo2O4e MnO2NWs.2.2.Materials characterizationThe crystallographic information of as-prepared products was established by powder X-ray diffraction(XRD,D/max1200,CuK a). The structure and morphology of the products were carried out with focused ion beam scanning electron microscopy(ZEISS AURIGA FIB/SEM)and transmission electron microscopy(TEM, ZEISS LIBRA200).Nitrogen adsorption e desorption isotherms were obtained using a micromeritics ASAP2020sorptometer.2.3.Electrochemical measurementsThe working electrode was prepared by mixing80%active ma-terials,10%carbon black,and10%polyvinylidenefluoride(PVDF)in N-methyl-2-pyrrolidone(NMP)and the slurry was spread onto a foam nickel current collector(1Â1cm2).The electrode was heated at120 C for10h to evaporate the solvent and then uniaxially pressed under10MPa.The electrochemical tests of various samples werefirst conducted using a three electrode system in2M KOH using the CHI660E electrochemical workstation.The reference electrode was an Ag/AgCl electrode and counter electrode was a Pt plate.Typically,the loading mass of active material was around 2.8mg.The positive electrodes were investigated by cyclic vol-tammetry(CV)technique with varying the scan rate of 5e100mV sÀ1at potential between0and0.5V.Galvanostatic charge e discharge(GCD)experiments were performed with cur-rent densities ranged from0.5to8A gÀ1at a potential of0e0.43V. The electrochemical impedance spectroscopy(EIS)was conducted in the frequency range between100kHz and0.01Hz with a perturbation amplitude of5mV versus the open-circuit potential.For the tests with a two-electrode configuration,two slices of electrode material with the same size were assembled together withfilter paper soaked in2M KOH solution before being con-nected to the potentiostat.In the two-electrode system,NiC-o2O4e MnO2NWs and activated graphenes(AG)were the positive electrode and negative electrode,respectively.CVs were recorded as scan rates of5,10,20,40,60and100mV sÀ1.GCD curves were obtained at constant current densities of0.25,0.5,1,2and4A gÀ1. All the operating current densities were calculated based on the total weight of NiCo2O4e MnO2NWs with AG.3.Results and discussion3.1.Structure and morphologyFig.1shows the composition and crystallite phase purity of the firecracker-like NiCo2O4e MnO2NWs.Almost all the identified peaks are indexed with the standard XRD pattern of spinel struc-ture NiCo2O4(JCPDS NO.20-0781,Space group:FÂ3(202),latticeM.Kuang et al./Journal of Power Sources270(2014)426e433427constants:a ¼b ¼c ¼0.811nm)and b -MnO 2(JCPDS NO.24-0735,tetragonal symmetry with P 42/nm space group and lattice con-stants of a ¼4.399nm and c ¼2.874nm).No characteristic im-purity peak is observed,indicating that the high-purity firecrackers-like NiCo 2O 4e MnO 2NWs are produced by the simple co-precipitation method.Furthermore,the composition and crys-tallite phase of the pure MnOOH NWs are examined by X-ray powder diffraction (See Supplementary information,SI-1).All of the re flections of the XRD pattern can be readily indexed to a monoclinic phase MnOOH (manganite,JCPDS No:41-1379).As illustrated in Fig.2a,the pure MnOOH NWs are prepared by a hydrothermal method.Subsequently,the pure MnOOH NWs are immersed into the reaction solution containing Ni(NO 3)2,Co(NO 3)2,NH 4F and urea.During the following hydrothermal crystallization process,the hydrolysis e precipitation process of NH 4F and urea takes place,which forms the rudiments of firecracker-like Ni,Co e hydroxide e carbonate (See Supplementary information,SI-2a ).Deriving from the continuously proceeding reaction the rudiments of firecracker-like Ni,Co e hydroxide e carbonate were formed,andFig.2.(a)Schematic illustration of the synthesis of NiCo 2O 4e MnO 2NWs,(b)SEM image of pure MnOOH nanowires,(c)SEM image of the precursor,(d,e)low-magni fication and enlarged SEM images of the NiCo 2O 4e MnO 2NWs.Fig.1.XRD pattern of the NiCo 2O 4e MnO 2NWs.M.Kuang et al./Journal of Power Sources 270(2014)426e 433428then fully developed when the reaction time was prolonged(See Supplementary information,SI-2b and c).Moreover,increasing the reaction time to18h,the Ni,Co e hydroxide e carbonate is grown larger and the structure of nanowire is destroyed(See Supplementary information,SI-2d).Afterward,these precursor nanowires are annealed at300 C for2h,and NiCo2O4e MnO2NWs are obtained accordingly.Fig.2b shows SEM image of the pure MnOOH NWs.As shown in Fig2b,it can be seen that the large-scale and uniform features of the pure MnOOH NWs.The average diameter of the MnOOH NWs is range of100e150nm,and the length can reach tens of micrometers.Fig.2c shows that the hy-droxide precursors are uniformly grown on MnOOH NWs.As shown in Fig.2c,the every(Ni,Co)hydroxide precursor nanowires has uniform diameter of approximately1m m,which is much larger than that of pure MnOOH NWs.Moreover,thefirecracker-like Ni e Co e hydroxide e carbonate have an average diameter of 200nm and length up to around400nm.After heat treatment,the basic morphology of the sample is perfectly conserved without calcination-induced significant alterations(Fig.2d and e).Inter-estingly,thefirecracker-like Co3O4e MnO2NWs are also obtained in the absence of Ni(NO3)2salt(See Supplementary information,SI-3 and SI-4).Moreover,we have done the experiment without MnO2 NWs while keeping all the other conditions the same.What we obtained was the pure NiCo2O4nanorods and Co3O4nanosheets, respectively(See Supplementary information,SI-5).The structural characteristics of the NiCo2O4e MnO2and Co3O4e MnO2NWs are further investigated by TEM(Fig.3).Both the NiCo2O4e MnO2NWs(Fig.3a)and Co3O4e MnO2NWs(Fig.3d) consist of numerous interconnected nanoparticles and present a mesoporous structure,which is ascribed to the successive release and lose of CO2and H2O during the thermal decomposition of precursor.It is well known that the mesoporous structures in nanosheets are important to facilitate the mass transport of elec-trolytes within the electrodes for fast redox reactions and double-layer charging/discharging.The porous structure will also greatly increase the electrode/electrolyte contact area,and thus further enhance the electrochemical performance.Fig.3b is an HRTEM image offirecracker-like NiCo2O4nanosheets.The spacing between adjacent fringes is~0.47nm,close to the theoretical interplane spacing of spinel NiCo2O4(111)planes.The selected area electron diffraction(SAED)pattern(Fig.3c)indicates the polycrystalline nature of the nanosheets,and the diffraction rings can be readily indexed to the(200),(311),(400),and(440)planes of the NiCo2O4 phase,which is consistent with the above XRD result.Fig.3e is an HRTEM image offirecracker-like Co3O4nanosheets.The lattice fringes show the structural characteristic of the cubic spinel Co3O4 crystal,in which the d-spacings of0.29and0.24nm correspond to the distance of the(220)and(311)planes,respectively.The SAED pattern shows well-defined diffraction rings,suggesting their polycrystalline characteristics.The nitrogen adsorption and desorption isotherms of the NiC-o2O4e MnO2and Co3O4e MnO2NWs are shown in Fig.4.The N2 adsorption e desorption isotherm is characteristic of type IV with a type H3hysteresis loop which mostly corresponds to the presence of aggregated particles with slit shape pores[24,25,26,27].The Brunauer e Emmett e Teller(BET)surface area values of the NiC-o2O4e MnO2and Co3O4e MnO2NWs are calculated to be60.02and 35.24m2gÀ1,respectively.The pore size distribution of the sample calculated by desorption isotherm using Barret e Joyner e Halenda (BJH)method is shown in inset of Fig.4.The average pore diameters of NiCo2O4e MnO2and Co3O4e MnO2NWs are found to be in the mesopore region.However,the pore size distribution maximum of the samples are centered at nearly same pore radii,for NiC-o2O4e MnO2NWs,it is centered at3.67nm,for Co3O4e MnO2NWs at3.29nm.These results show that mesopores of nearly same sizes originate from the nanostructures.The intensities of the pore size distribution in NiCo2O4e MnO2NWs are slightly higher than that of Co3O4e MnO2NWs,suggesting higher pore volumeof Fig.3.TEM images of the NiCo2O4e MnO2NWs(a)and Co3O4e MnO2NWs(d),HRTEM images of the NiCo2O4e MnO2NWs(b)and Co3O4e MnO2NWs(e),SAED patterns of the NiCo2O4e MnO2NWs(c)and Co3O4e MnO2NWs(f).M.Kuang et al./Journal of Power Sources270(2014)426e433429NiCo 2O 4e MnO 2NWs.The pore volume of Co 3O 4e MnO 2NWs is calculated as 0.082cm 3g À1,while the pore volume of NiC-o 2O 4e MnO 2NWs is up to 0.139cm 3g À1.In conclusion,high surface area and large pore volume are achieved for NiCo 2O 4e MnO 2NWs,so it is expected that the NiCo 2O 4e MnO 2NWs may exhibit improved electrochemical performance compared to Co 3O 4e MnO 2NWs,and further electrochemical measurements have been carried out to prove this hypothesis.3.2.Electrochemical performancesIn order to compare the contribution of NiCo 2O 4and Co 3O 4to the electrochemical performance of the electrode materials,cyclic voltammetry (CV),galvanostatic charge e discharge (GCD)and electrochemical impedance spectroscopy (EIS)measurements in a three-electrode system are employed.Representative CV curves for the NiCo 2O 4e MnO 2and Co 3O 4e MnO 2NWs in three electrode con figuration at different scan rates are shown in Fig.5a and b.As compared with CV curves of the NiCo 2O 4e MnO 2NWs,the Co 3O 4e MnO 2NWs has more distinct redox peaks.However,the area under the CV curve of the NiCo 2O 4e MnO 2NWs is clearly much larger than that of the Co 3O 4e MnO 2NWs at the same scan rate.It is well-known that the speci fic capacitance is proportional to the area of the CV curve [10,28].Thus,the NiCo 2O 4e MnO 2NWs has higher capacitances than the Co 3O 4e MnO 2NWs.In order to investigate the capability of the materials,the GCD tests of the NiCo 2O 4e MnO 2and Co 3O 4e MnO 2NWs are carried out at different constant current densities (Fig.5c and d).The curve of NiCo 2O 4e MnO 2NWs is linear and symmetric,indicating an ideal capacitor capable of reversible charging and discharging [29,30].In comparison,the curve of Co 3O 4e MnO 2NWs is distorted to some extent.Low internal resistance is very favorable in energy storage devices,which reduces energy waste during charging/discharging processes [31,32].The increase in the charging time represents the higher capacitance of the NiCo 2O 4e MnO 2NWs.According to the GCD curves,the speci fic capacitances of the electrodes are respectively calculated using the following equation [33]:C m ¼I D t m D Vwhere m ,I ,D t and D V are the weight (g)of the electroactive ma-terials,discharge current (A),the discharging time (s),and the discharging potential range (V),respectively.The speci fic capaci-tances of NiCo 2O 4e MnO 2and Co 3O 4e MnO 2NWs are 343F g À1and 192F g À1at a current density of 0.5A g À1,respectively,which is much higher than the pure MnO 2NWs (14F g À1),NiCo 2O 4nano-rods (102F g À1)and Co 3O 4nanosheets (77F g À1)(See Supplementary information,SI-6).Maximizing the utilization of active materials is always considered as a challenge because only the surface of oxides can be utilized for charge storage.Up to now,the NiCo 2O 4-based electrodes with various substrates and nano-structure have been prepared to improve the utilization of NiCo 2O 4.Thus,the comparison of the speci fic capacitance based on the mass of NiCo 2O 4(the mass of NiCo 2O 4was obtained by chemical anal-ysis)alone between this work and previous reports is summarized (See Supplementary information,Table S1).According to the comparison in Table S1,it can be obtained that the speci fic capac-itance based on the in our work is 798F g À1,indicating that the speci fic capacitance of firecracker-like NiCo 2O 4e MnO 2NWs nano-structure in this work can actually be higher than many NiCo 2O 4nanostructures-based supercapacitors previously reported.The speci fic capacitance of NiCo 2O 4e MnO 2and Co 3O 4e MnO 2NWs electrodes at various current densities is shown in Fig.5e.We observe that the speci fic capacitance for both electrodes decreases with an increase in the current density from 0.5A g À1to 8A g À1.This is a common phenomenon,caused by the insuf ficient time available for ion diffusion at high current density [34].In addition,the NiCo 2O 4e MnO 2NWs maintains its 75.3%capacitance as the current density is increased from 0.5to 8A g À1,while the Co 3O 4e MnO 2NWs lose 30%of its capacity in the same condition,indicating that the NiCo 2O 4e MnO 2NWs have better rate capability,in good accordance with the CV tests.The EIS analysis has been recognized as one of the principal methods for examining the fundamental behavior of electrode materials,which not only provides useful information on the electrochemical frequency of the system but also allows for the measurement of redox reaction resistance and equivalent series resistance of the electrode [15,35].Typical Nyquist plots of the NiCo 2O 4e MnO 2and Co 3O 4e MnO 2NWs electrode are shown in Fig.5f.The two impedance spectra are composed of a semicircular arc in the high-frequency range and a straight line in the low-frequency range.The intersection of the plot at the x -axis repre-sents the solution resistance (R s ),which includes the following three terms:the resistance of the KOH aqueous solution,the intrinsic resistance of the electroactive materials and the contact resistance at the interface between electroactive materials and current collector [31,36].As can be seen from the inset,the calcu-lated R s values are 0.46and 0.48U for NiCo 2O 4e MnO 2and Co 3O 4e MnO 2NWs electrode,respectively,it's much lowerthanFig.4.Nitrogen adsorption and desorption isotherms for the NiCo 2O 4e MnO 2NWs (a)and Co 3O 4e MnO 2NWs (b).The insets show the corresponding BJH pore size distributions.M.Kuang et al./Journal of Power Sources 270(2014)426e 433430that of pure NiCo 2O 4and Co 3O 4(See Supplementary information,SI-7).At the high frequencies,semicircles can be observed for both with the diameters representing the charge-transfer resis-tance (R ct ).R ct can be directly measured from the Nyquist plots as the semicircular arc diameter.The calculated R ct values for NiC-o 2O 4e MnO 2and Co 3O 4e MnO 2NWs electrode are 0.8U and 1.6U respectively.The NiCo 2O 4e MnO 2NWs electrodes have a low R ct value compared with the Co 3O 4e MnO 2NWs electrode,resulting in an improved charge transfer performance for the electrode.The straight line in the low-frequency range is called the Warburg resistance (W),which is caused by the frequency dependence of ion diffusion/transport from the electrolyte to the electrode surface [37,38].As shown in Fig.5f,NiCo 2O 4e MnO 2NWs electrode has a smaller Warburg region,presenting a minor Warburg resistance.It implies that the highly porous NiCo 2O 4e MnO 2NWs electrode is able to facilitate the penetration of electrolyte,leading to fast diffusion of electrolyte into the pores of NiCo 2O 4[39].It can be seen that the slope of the straight line for NiCo 2O 4e MnO 2NWs electrode are much larger than that of the Co 3O 4e MnO 2NWs electrode.Thisobservation indicates that the NiCo 2O 4e MnO 2NWs electrode has much lower diffusive resistance than that of the Co 3O 4e MnO 2NWs.Long cycle life for the supercapacitors is an important parameter for their practical application.Supercapacitors should work steadily and safely,which requires the speci fic capacitance of electrode ma-terials to change as little as possible.The relationship of the speci fic capacitance and Coulombic ef ficiency against cycling number of the NiCo 2O 4e MnO 2NWs electrode is shown in Fig.6a.The speci fic capacitance of NiCo 2O 4e MnO 2NWs electrode decreases gradually with increasing cycle numbers and its capacitance retention is 89.7%after 3000cycles.Such excellent cycling stability is mainly attributed to the following aspects.First,the synergistic contribution from NiCo 2O 4and MnO 2,both the firecracker-like NiCo 2O 4nanosheets and the MnO 2nanowires can have redox reactions with anions and cations from the electrolyte,respectively,accounting for the elec-trochemical charge storage.Second,the MnO 2nanowires provides a direct pathway for electron transport while the partial connected NiCo 2O 4nanosheets with high speci fic surface area provide more electronic transmission channels (as schematically illustratedinFig.5.Electrochemical evaluations of the NiCo 2O 4e MnO 2and Co 3O 4e MnO 2NWs:(a,b)CV curves,(c,d)charge e discharge curves,(e)capacitances versus current densities,and (f)Nyquist plots (Insert show the enlarged part of Nyquist plots and equivalent circuit for the electrochemical impedance spectrum).M.Kuang et al./Journal of Power Sources 270(2014)426e 433431Fig.6b).Third,the firecracker-like NiCo 2O 4e MnO 2possess higher pore volume,which is probably more bene ficial to double-layer capacitor.Furthermore,the more porous of firecracker-like NiC-o 2O 4e MnO 2also provides more channel for electrolyte.So the cycle performance can be enhanced by the fast ion diffusion in the one-dimensional nanoporous architecture.After long-term cycling,the firecracker-like NiCo 2O 4e MnO 2NWs are overall preserved with little structure deformation,as shown in Fig.6c and d.On the other hand,it is noted that the Coulombic ef-ficiency of the NiCo 2O 4e MnO 2NWs can maintain almost 93%after long-term cycling.These results demonstrate the as-prepared NiC-o 2O 4e MnO 2NWs are very stable as an active electrode material.By contrast,Co 3O 4e MnO 2NWs electrode lose 26.2%of its capacitance after 3000cycles with the same current density (See Supplementary Information,SI-8)and the structure of firecracker-like Co 3O 4e MnO 2NWs is slight destroyed after 3000cycles.The as-assembled NiCo 2O 4e MnO 2//AG asymmetric cell is measured at different potential windows in a 2M KOH aqueous electrolyte at a scan rate of 40mV s À1,and the resulted CV curves are exhibited in Fig.7a.The CV curves show a quasi-rectangular shape from 1.0V to 1.4V.At a potential window of 1.6V,the CV curve shows a distortion and a slight hump around 1.6V.This in-dicates that some irreversible reactions happen when the potential window is higher than 1.4V.Thus,the optimum working potential window for this asymmetric supercapacitor is from 0to 1.4V Fig.7b shows the typical CV curves of the asymmetric cell in the voltage window from 0to 1.4V at the scan rates of 5,10,20,50and 100mV s À1.The CV pro file of the asymmetric cell remains relatively quasi-rectangular at a high scan rate of 100mV s À1,demonstrating good charge/discharge properties and rate capability of the asym-metric supercapacitor [7,40].To further evaluate the electro-chemical performance of the asymmetric cell,galvanostaticFig.6.(a)Variation of capacitance with cycle number at 5A g À1,(b)schematic of the charge storage advantage of the NiCo 2O 4e MnO 2NWs,(c)and (d)SEM images of the NiCo 2O 4e MnO 2NWs before and after 3000cycles.Fig.7.(a)CV curves of the NiCo 2O 4e MnO 2//AG asymmetric supercapacitor cell measured at different potential windows in 2M KOH electrolyte,(b)CV curves of the NiC-o 2O 4e MnO 2//AG asymmetric supercapacitor cell measured at different scan rates,(c)charge e discharge curves of the NiCo 2O 4e MnO 2//AG asymmetric supercapacitor,(d)a Ragone plot of the NiCo 2O 4e MnO 2//AG asymmetric supercapacitor.M.Kuang et al./Journal of Power Sources 270(2014)426e 433432charge e discharge tests are performed.As shown in Fig.7c,these typical triangular-shape charge/discharge curves exhibit good symmetry and fairly linear slopes at different current densities, again demonstrating the ideal capacitive characteristic.The specific capacitance of the NiCo2O4e MnO2//AG asymmetric cell is calcu-lated to be31.3F gÀ1based on the total weight of the electrodes at a current density of0.25A gÀ1,and still maintains at24F gÀ1when the current density increases by as much as16times(4A gÀ1).To further illustrate the energy and power property of this asymmetric supercapacitor,a Ragone plot is shown in Fig.7.This device shows a high energy density of9.4Wh kgÀ1at a power density of 175W kgÀ1,while maintaining a high energy density of 5.8Wh kgÀ1at a power density of2500W kgÀ1.This result shows a much improved energy density at high power density compared with a Ni e Co oxide//AC asymmetric device(12Wh kgÀ1at 95W kgÀ1)[41],a MnO2-modified diatomites//MnO2-modified diatomites symmetric device(3.75Wh kgÀ1at250W kgÀ1)[42],a CNT//CNT symmetric device(6.1Wh kgÀ1at195W kgÀ1)[43],a NiO//carbon asymmetric device(~10Wh kgÀ1at30W kgÀ1)[44],a TiO2-CNT//CNT asymmetric device(4.47Wh kgÀ1at50W kgÀ1) [45],and a LiMn2O4//MnFe2O4asymmetric device(5.5Wh kgÀ1at 1080W kgÀ1)[46].4.ConclusionIn summary,to bypass the lower electrical conductivity by Co3O4e MnO2NWs electrode,we have successfully fabricated firecrackers-like NiCo2O4e MnO2NWs via the simple co-precipitation method followed by annealing in atmosphere.Elec-trochemical measurements reveal that the NiCo2O4e MnO2NWs electrode exhibits much higher specific capacitance and better rate capability compared with Co3O4e MnO2NWs electrode.Specif-ically,the NiCo2O4e MnO2NWs electrode displays a high specific capacitance of343F gÀ1at current density of0.5A gÀ1,excellent cycle stability with capacitance retention of89.7%at5A gÀ1after 3000cycles.Furthermore,the NiCo2O4e MnO2//AG asymmetric cell delivers an energy density of9.4Wh kgÀ1and a maximum power density of2.5kW kgÀ1,indicating a promising potential application as an effective candidate for supercapacitors.The superior capaci-tive performance of NiCo2O4e MnO2NWs electrode is attributed to the high electrical conductivity,short electron transporting path, with Ni-substitution and good contact.AcknowledgmentsThe authors gratefully acknowledge thefinancial supports provided by National Natural Science Foundation of China(Grant no.51104194),Doctoral Fund of Ministry of Education of China (20110191120014),No.43Scientific Research Foundation for the Returned Overseas Chinese Scholars,National Key laboratory of Fundamental Science of Micro/Nano-device and System Technol-ogy(2013MS06,Chongqing University),State Education Ministry and Fundamental Research Funds for the Central Universities (Project no.CDJZR12248801,CDJZR12135501,and CDJZR13130035, Chongqing University,PR China).Appendix A.Supplementary dataSupplementary data related to this article can be found at http:// /10.1016/j.jpowsour.2014.07.144.References[1]M.Huang,Y.Zhang,F.Li,L.Zhang,R.S.Ruoff,Z.Wen,Q.Liu,Sci.Rep.4(2014)3878,1e7.[2]Y.Liu,D.Yan,R.Zhuo,S.Li,Z.Wu,J.Wang,P.Ren,P.Yan,Z.Geng,J.PowerSources242(2013)78e85.[3] C.Liu,Z.Yu,D.Neff,A.Zhamu,B.Z.Jang,Nano Lett.10(2010)4863e4868.[4]M.-G.Jeong,K.Zhuo,S.Cherevko,W.-J.Kim,C.-H.Chung,J.Power Sources244(2013)806e811.[5]M.Huang,Y.Zhang,F.Li,L.Zhang,Z.Wen,Q.Liu,J.Power Sources252(2014)98e106.[6]S.Wu,W.Chen,L.Yan,J.Mater.Chem.A2(2014)2765e2772.[7]P.Yang,Y.Li,Z.Lin,Y.Ding,S.Yue,C.P.Wong,X.Cai,S.Tan,W.Mai,J.Mater.Chem.A2(2014)595e599.[8]Y.Luo,D.Kong,J.Luo,S.Chen,D.Zhang,K.Qiu,X.Qi,H.Zhang,C.M.Li,T.Yu,RSC Adv.3(2013)14413e14422.[9]J.Li,W.Zhao, F.Huang, A.Manivannan,N.Wu,Nanoscale3(2011)5103e5109.[10]J.-H.Zhong,A.-L.Wang,G.-R.Li,J.-W.Wang,Y.-N.Ou,Y.-X.Tong,J.Mater.Chem.22(2012)5656e5665.[11]L.Jiang,R.Zou,W.Li,J.Sun,X.Hu,Y.Xue,G.He,J.Hu,J.Mater.Chem.A1(2013)478e481.[12]P.Roy,S.Berger,P.Schmuki,Angew.Chem.Int.Ed.50(2011)2904e2939.[13]X.Lu,M.Yu,G.Wang,T.Zhai,S.Xie,Y.Ling,Y.Tong,Y.Li,Adv.Mater.25(2013)267e272.[14]Y.Wang,Z.Hong,M.Wei,Y.Xia,Adv.Funct.Mater.22(2012)5185e5193.[15]L.Huang,D.Chen,Y.Ding,S.Feng,Z.L.Wang,M.Liu,Nano Lett.13(2013)3135e3139.[16]X.Liu,S.Shi,Q.Xiong,L.Li,Y.Zhang,H.Tang,C.Gu,X.Wang,J.Tu,ACS Appl.Mater.Interfaces5(2013)8790e8795.[17] C.Yuan,J.Li,L.Hou,X.Zhang,L.Shen,X.W.Lou,Adv.Funct.Mater.22(2012)4592e4597.[18] C.Yuan,J.Li,L.Hou,J.Lin,X.Zhang,S.Xiong,J.Mater.Chem.A1(2013)11145e11151.[19] C.Yuan,J.Li,L.Hou,J.Lin,G.Pang,L.Zhang,L.Lian,X.Zhang,RSC Adv.3(2013)18573e18578.[20] C.-T.Hsu,C.-C.Hu,J.Power Sources242(2013)662e671.[21]H.Jiang,J.Ma,C.Li,mun.48(2012)4465e4467.[22]R.Zou,K.Xu,T.Wang,G.He,Q.Liu,X.Liu,Z.Zhang,J.Hu,J.Mater.Chem.a1(2013)8560e8566.[23]H.Wang,X.Wang,ACS Appl.Mater.Interfaces5(2013)6255e6260.[24]H.Jiang,C.Li,T.Sun,J.Ma,mun.48(2012)2606e2608.[25]Y.Qin,F.Zhang,Y.Chen,Y.Zhou,J.Li,A.Zhu,Y.Luo,Y.Tian,J.Yang,J.Phys.Chem.C116(2012)11994e12000.[26]G.Zhang,W.Li,K.Xie, F.Yu,H.Huang,Adv.Funct.Mater.23(2013)3675e3681.[27]Z.Zhang,H.Che,Y.Wang,L.Song,Z.Zhong,F.Su,Catal.Sci.Technol.2(2012)1953e1960.[28]H.Chen,J.Jiang,L.Zhang,H.Wan,T.Qi, D.Xia,Nanoscale5(2013)8879e8883.[29]Y.Jin,H.Chen,M.Chen,N.Liu,Q.Li,ACS Appl.Mater.Interfaces5(2013)3408e3416.[30]P.Yang,Y.Ding,Z.Lin,Z.Chen,Y.Li,P.Qiang,M.Ebrahimi,W.Mai,C.P.Wong,Z.L.Wang,Nano Lett.14(2014)731e736.[31]G.Zhu,Z.He,J.Chen,J.Zhao,X.Feng,Y.Ma,Q.Fan,L.Wang,W.Huang,Nanoscale6(2014)1079e1085.[32]G.Zhang,X.W.Lou,Adv.Mater.25(2013)976e979.[33]M.Hakamada, A.Moriguchi,M.Mabuchi,J.Power Sources245(2014)324e330.[34]G.Zhang,X.W.Lou,Sci.Rep.3(2013)1470e1476.[35]Z.Tang,C.-h.Tang,H.Gong,Adv.Funct.Mater.22(2012)1272e1278.[36]J.Zhang,X.S.Zhao,Carbon52(2013)1e9.[37]T.Zhai,F.Wang,M.Yu,S.Xie,C.Liang,C.Li,F.Xiao,R.Tang,Q.Wu,X.Lu,Y.Tong,Nanoscale5(2013)6790e6796.[38]Q.Wang,J.Xu,X.Wang,B.Liu,X.Hou,G.Yu,P.Wang,D.Chen,G.Shen,ChemElectroChem1(2014)559e564.[39] A.Ramadoss,S.J.Kim,Carbon63(2013)434e445.[40]J.-G.Wang,Y.Yang,Z.-H.Huang, F.Kang,Electrochim.Acta56(2011)9240e9247.[41] C.Tang,Z.Tang,H.Gong,J.Electrochem.Soc.159(2012)A651e A656.[42]Y.X.Zhang,M.Huang,F.Li,X.L.Wang,Z.Q.Wen,J.Power Sources246(2014)449e456.[43]Q.Wang,Z.H.Wen,J.H.Li,Adv.Funct.Mater.16(2006)2141e2146.[44] D.-W.Wang,F.Li,H.-M.Cheng,J.Power Sources185(2008)1563e1568.[45]X.Sun,M.Xie,J.J.Travis,G.Wang,H.Sun,J.Lian,S.M.George,J.Phys.Chem.C117(2013)22497e22508.[46]Y.-P.Lin,N.-L.Wu,J.Power Sources196(2011)851e854.M.Kuang et al./Journal of Power Sources270(2014)426e433433。
常用中英文翻译
主柜rectifier整流容器Rectifier container可控硅Thyristor二极管diode压敏电阻surge arrestor陶瓷绕线电阻wire wound resistor in ceramic casing 电容器capacitor端子terminal热敏电阻thermistor操作过电压保护operation overvoltage protection换向保护commutation protection接地小母排mini earthing busbar水管water pipe水冷散热器water cooling heat sink螺钉bolt螺母nut喉箍hose clamp水温变送器water temperature transducer水压变送器water pressure transducer电接点水压表electrical contact water pressure gauge 电接点水温表electrical contact water temp meter臂温arm temperature脉冲变压器pulse transformer脉冲板pulse trigger card脉冲隔离板Pulse isolation card可控硅阳极Thyristor anode可控硅阴极Thyristor cathode可控硅控制极/可控硅门极Thyristor control electrode/ Thyristor gate pole触发电压trigger voltage快速熔断器high speed fuse三角形接法Delta connection星形接法Star connection连接方式connecting method绝缘板Insulation board胶木板bakelite plate不锈钢stainless steel碳钢carbon steel直流正极母排DC positive busbar直流负极母排DC negative busbar交流进线AC incoming涡流vortex均流检测Current sharing measuring臂电流检测arm current measuring均流仪current sharing meter陶瓷绝缘子ceramic insulator脉冲线pulse wire控制柜Control panel交流AC220V交流AC100V直流DC+24V电源变压器Power supply transformer加法器Totalizer四路继电器板4-route relay card中间继电器Intermediate relay时间继电器Time relay变送器/电量隔离传感器Transducer 同步Sync.缺反馈No feedback封脉冲Block pulse控制角Control angle导通角Conductive angle给定Set实际显示Actual display档位仪Step indicator档位Step升档Raise step降挡Lower step主板Control card触发板Trigger card功放板Power amplifier card电源板Power supply card6脉波6 pulse谐波Harmonic示波器Oscilloscope万用表Multimeter螺丝刀Screwdriver负载Load电解槽Electrolyzer重接地Heavy grouding轻接地Light grouding接地保护Grouding protection油温高Oil temperature high油位低Oil level low有载调压开关On-load tap chager (OL TC) 电机Motor整流变压器Rectifier transformer交流反馈AC feedbackDCS连锁DCS interlock跳闸Trip延时Delay极化柜Polarization rectifier / CPU(加拿大) 控制电源Control power supply极化启动Polarization start极化停止Polarization stop稳流/稳压constant current / constant voltage 本空/远控Local control / remote control手动/自动Manual / Automatic文本显示器Text display触摸屏Touch panel/ LCP（比利时bigan2）控制器Controller故障报警Fault alarm状态Status直流刀开关DC switch直流刀开关分状态DC switch open直流刀开关合状态DC switch closed三相电源3-phase power supply相序Phase sequence行程开关/限位开关Limit switch接触器Contactor空气开关Air switch断路器Breaker嵌入式压板式纯水器DM water cooler纯水DM water冷却水cooling water电阻率Resistivity电导率Conductivity付水循环水Cooling water阀门V alve兆帕MPa千安KA千伏安KV A容量Capacity功率因素Power factor有功active power无功reactive power短路电流Short circuit current网侧/一次侧电压Primary side voltage阀侧/二次侧电压Secondary side voltage一次侧进线Primary side incoming油水冷却oil water cooling油风冷却oil air cooling水泵water pump油泵oil pump工艺DCS Process DCS湿度检测仪Temp. meter桥臂Bridge arm供电Power supply变电站Substation通讯Communication通讯转换开关Communication selector switch上位机computer触摸屏和上位机常用的数据以及显示的翻译，苏威项目都可以作为参考。
Liquid_Exfoliation_of_Layered_Materials
DOI: 10.1126/science.1226419, (2013);340 Science et al.Valeria Nicolosi Liquid Exfoliation of Layered MaterialsThis copy is for your personal, non-commercial use only.clicking here.colleagues, clients, or customers by , you can order high-quality copies for your If you wish to distribute this article to othershere.following the guidelines can be obtained by Permission to republish or repurpose articles or portions of articles): July 3, 2013 (this information is current as of The following resources related to this article are available online at/content/340/6139/1226419.full.html version of this article at:including high-resolution figures, can be found in the online Updated information and services, /content/340/6139/1226419.full.html#ref-list-1, 8 of which can be accessed free:cites 136 articles This article/cgi/collection/chemistry Chemistrysubject collections:This article appears in the following registered trademark of AAAS.is a Science 2013 by the American Association for the Advancement of Science; all rights reserved. The title Copyright American Association for the Advancement of Science, 1200 New York Avenue NW, Washington, DC 20005. (print ISSN 0036-8075; online ISSN 1095-9203) is published weekly, except the last week in December, by the Science o n J u l y 3, 2013w w w .s c i e n c e m a g .o r g D o w n l o a d e d f r o mThe list of author affi liations is available in the full article online.*Corresponding author. E-mail: colemaj@tcd.ieLiquid Exfoliation of Layered MaterialsValeria Nicolosi, Manish Chhowalla, Mercouri G. Kanatzidis, Michael S. Strano, Jonathan N. Coleman*Background: Since at least 400 C.E., when the Mayans fi rst used layered clays to make dyes, people have been harnessing the properties of layered materials. This gradually developed into scientifi c research, leading to the elucidation of the laminar structure of layered materials, detailed understand-ing of their properties, and eventually experiments to exfoliate or delaminate them into individual, atomically thin nanosheets. This culminated in the discovery of graphene, resulting in a new explosion of interest in two-dimensional materials.Layered materials consist of two-dimensional platelets weakly stacked to form three-dimensional structures. The archetypal example is graphite, which consists of stacked graphene monolayers. How-ever, there are many others: from MoS 2 and layered clays to more exotic examples such as MoO 3, GaTe, and Bi 2Se 3. These materials display a wide range of electronic, optical, mechanical, and electrochemi-cal properties. Over the past decade, a number of methods have been developed to exfoliate layered materials in order to produce monolayer nanosheets. Such exfoliation creates extremely high-aspect-ratio nanosheets with enormous surface area, which are ideal for applications that require surface activity. More importantly, however, the two-dimensional confi nement of electrons upon exfoliation leads to unprecedented optical and electrical properties.Advances: An important advance has been the discovery that layered crystals can be exfoliated in liquids. There are a number of methods to do this that involve oxidation, ion intercalation/exchange, or surface passivation by solvents. However, all result in liquid dispersions containing large quantities of nanosheets. This brings considerable advantages: Liquid exfoliation allows the formation of thin fi lms and composites, is potentially scaleable, and may facilitate processing by using standard technologies such as reel-to-reel manufacturing.Although much work has focused on liquid exfoliation of graphene, such processes have also been demonstrated for a host of other materials, including MoS 2 and other related structures, lay-ered oxides, and clays. The resultant liquid dispersions have been formed into fi lms, hybrids, and composites for a range of applications.Outlook: There is little doubt that the main advances are in the future. Multifunctional composites based on metal and polymer matrices will be developed that will result in enhanced mechanical, electrical, and barrier properties. Applications in energy generation and storage will abound, with layered materials appearing as electrodes or active elements in devices such as displays, solar cells, and batteries. Particularly impor-tant will be the use of MoS 2 for water splitting and metal oxides as hydrogen evolution catalysts. In addition, two-dimensional materials will fi nd important roles in printed electronics as dielectrics, optoelectronic devices, and transistors.To achieve this, much needs to be done. Production rates need to be increased dramatically, the degree of exfoliation improved, and methods to control nanosheet properties devel-oped. The range of layered materials that can be exfoliated must be expanded, even as methods for chemical modifi cation must be developed. Success in these areas will lead to a family of materials that will dominate nanomaterials science in the 21st century.21 JUNE 2013 VOL 340 SCIENCE 1420ARTICLE OUTLINE Why Exfoliate?Large-Scale Exfoliation in Liquids?PioneersRecent Advances in Liquid Exfoliation Potential Applications of Liquid-Exfoliated Nanosheets OutlookADDITIONAL RESOURCESJ. N. Coleman et al ., Two-dimensional nanosheets produced by liquid exfoliation of layered materials. Science 331, 568–571 (2011). doi:10.1126/science.1194975K. Varoon et al ., Dispersible exfoliated zeolite nanosheets and their application as a selective membrane. Science 334, 72–75 (2011). doi:10.1126/science.1208891READ THE FULL ARTICLE ONLINE /10.1126/science.1226419Liquid exfoliation of layered crystals allows the production of suspensions of two-dimensional nanosheets, which can be formed into a range of structures. (A ) MoS 2 powder. (B ) WS 2 dispersed in surfactant solution. (C ) An e xfoliate d MoS 2 nanosheet. (D ) A hybrid material consisting of WS 2 nanosheets embedded in a network of carbon nanotubes.Published by AAASo n J u l y 3, 2013w w w .s c i e n c e m a g .o r g D o w n l o a d e d f r o mLiquid Exfoliation of Layered Materials Valeria Nicolosi,1,2Manish Chhowalla,3Mercouri G.Kanatzidis,4Michael S.Strano,5Jonathan N.Coleman1*Not all crystals form atomic bonds in three yered crystals,for instance,are those that form strong chemical bonds in-plane but display weak out-of-plane bonding.This allows them to be exfoliated into so-called nanosheets,which can be micrometers wide but less than a nanometer thick.Such exfoliation leads to materials with extraordinary values of crystal surface area,in excess of1000square meters per gram.This can result in dramatically enhanced surface activity,leading to important applications,such as electrodes in supercapacitors or batteries. Another result of exfoliation is quantum confinement of electrons in two dimensions,transforming the electron band structure to yield new types of electronic and magnetic materials.Exfoliated materials also have a range of applications in composites as molecularly thin barriers or as reinforcing or conductive fillers.Here,we review exfoliation—especially in the liquid phase—as a transformative process in material science,yielding new and exotic materials,which are radically different from their bulk,layered counterparts.I n1824,Thomas H.W ebb heated a mineral sim-ilar to mica and,by means of thermal ex-foliation,transformed it into what is today a valuable commodity,with applications as an ion exchange resin,an insulating material,and a structural binder in cement.He named the mineral“vermiculite”for its wormlike appear-ance upon exfoliation(Fig.1),from the Latin vermiculare meaning“to breed worms.”Almost 200years later,in2004,Geim and Novosolov showed that thin transparent adhesive tape could be used to exfoliate graphite into single atomic layers of graphene and demonstrated atomical-ly thin devices(1).As a process,exfoliation of layered solids has had a transformative effect on materials science and technology by opening up properties found in the two-dimensional(2D) exfoliated forms,not necessarily seen in their bulk counterparts.Layered materials are defined as solids with strong in-plane chemical bonds but weak out-of-plane,van der Waals bonds.Such materials can be sheared parallel or expanded normal to the in-plane direction.In the extreme limit,these processes yield nanometer-thin—even atomically thin—sheets that are not at all characteristic of the bulk precursor.This production of extremely thin sheets from layered precursors is known as exfoliation or delamination,although in this work we will use the former term.The sheets produced are generally referred to as nanosheets, where“nano”refers to the magnitude of the thick-ness.Although in the ideal case such nanosheets consist of single monolayers,they are often man-ifested as incompletely exfoliated flakes compris-ing a small number(<10)of stacked monolayers.There are many types of layered materials,whichcan be grouped into diverse families(Fig.1).The simplest are the atomically thin,hexagonalsheets of graphene(1–3)and hexagonal boronnitride(h-BN)(4).Transition metal dichalco-genides(TMDs)(such as MoS2and WSe2)(5,6)and metal halides(such as PbI2and MgBr2)(7)have near-identical structures and consist ofa plane of metal atoms sandwiched betweenplanes of halide/chalcogen yered me-tal oxides(such as MnO2,MoO3,and LaNb2O7)(8–11)and layered double hydroxides(LDHs)[such as Mg6Al2(OH)16](8,12)represent a di-verse class of materials with a large variety ofstructures.Similarly,layered silicates,or clays,are minerals and exist as many different types,with well-known examples being montmorilloniteor the micas(13,14).Generally,oxides,LDH,and clay nanosheets are charged and are accom-panied by charge-balancing ions(8,14).Otherinteresting families are the layered III-VIs(suchas InSe and GaS)(15),the layered V-VIs(such asBi2Te3and Sb2Se3)(16),the metal trichalcogenides,and metal trihalides.Although many other lay-ered materials exist(Table1),all share a planar,anisotropic bonding and therefore the potentialto be exfoliated into nanosheets.One substantial advantage of layered materi-als is their diversity.Even before exfoliation,themany families of layered materials display a verybroad spectrum of properties.For example,TMDs(5,6)occur as more than40different types de-pending on the combination of chalcogen(S,Se,or Te)and transition metal(5,6).Depending onthe coordination and oxidation state of the metalatoms,or doping of the lattice,TMDs can be me-tallic,semimetallic,or semiconducting(6).In ad-dition,these materials display interesting electronicbehavior,such as superconductivity or charge-density wave effects(6).Similarly,the many dif-ferent types of layered metal oxides have interestingelectronic,electrochemical,and photonic proper-ties(8).These materials have been fabricated intotransistors,battery electrodes,and magneto-opticdevices(8–10).Thus,even as bulk crystals,lay-ered materials are an interesting and potentiallyuseful material class.This makes them an excitingstarting material for exfoliation into nanosheets.As we will see below,exfoliation dramaticallyenhances the range of properties displayed by analready diverse material type.Why Exfoliate?The simplest effect of exfoliation is to dramati-cally increase the accessible surface area of amaterial.For surface-active or catalytic materials,this can radically enhance their chemical andphysical reactivity.The ion exchange ability ofminerals such as vermiculite to purify water at1000meq/kg depends on its near106-fold increasein surface area after expansion(13).In structuralmechanics,the strength and stiffness of compositesincrease as the thickness of planar fillers,such asclay or graphite,decreases(17).When heat causesexfoliation,a layered material can be used as anintumescent(or thermally expansive)material.Hence,vermiculite and graphite are used for fireretardation in paints and firestop pillows be-cause they reduce their density upon heating andproduce an ash of low thermal conductivity.As interest in nanotechnology has intensi-fied in recent decades,another important advan-tage of exfoliation has emerged.In a layeredcrystal,the electronic wave function extendsin three dimensions.However,after exfoliationelectrons are constrained to adopt a2D wavefunction,thus modifying the electronic bandstructure.Graphite can be transformed into agraphene monolayer after exfoliation,with elec-tronic properties that differ greatly from any othermaterial(1).These include an enormously highcarrier mobility and other exciting properties,such as Klein tunnelling and the half-integer quan-tum Hall effect(1,3).Likewise,the propertiesof MoS2depend strongly on exfoliation state.The bandgap of MoS2changes on exfoliationfrom1.3eV for the bulk crystal to1.9eV foran exfoliated nanosheet.Because the bandgapchanges monotonically with number of mono-layers per nanosheet,this allows the electronicresponse to be chosen at will(18).In addition,although multilayer MoS2is not photolumines-cent,exfoliation-induced changes in its electron-ic structure lead to photoluminescent behaviorin exfoliated monolayers(19).Similar behavioris expected in other layered semiconductors(5).Large-Scale Exfoliation in Liquids?The exfoliation of graphite demonstrated by Geimand Novolosov was achieved essentially by rubbinggraphite on a surface(1).Such mechanical ex-foliation remains the source of the highest-qualitygraphene samples available and has resultedin some major advances(1).However,it suffersfrom low yield and a production rate that is not1School of Physics and Centre for Research on Adaptive Nano-structures and Nanodevices,Trinity College,Dublin,D2Dublin,Ireland.2School of Chemistry,Trinity College,Dublin,D2Dublin,Ireland.3Materials Science and Engineering,Rutgers University,Piscataway,NJ08901,USA.4Department of Chemistry,North-western University,Evanston,IL60208,USA.5Department ofChemical Engineering,Massachusetts Institute of Technology,Cambridge,MA02139,USA.*Corresponding author.E-mail:colemaj@tcd.ie SCIENCE VOL34021JUNE20131226419-1o n J u l y 3 , 2 0 1 3 w w w . s c i e n c e m a g . o r g D o w n l o a d e d f r o mtechnologically scalable in its current form.One possible solution is the exfoliation of lay-ered compounds in liquids to give large quan-tities of dispersed nanosheets.This should allow for methods to obtain sizable quantities of 2D materials that can be processed by using exist-ing industrial techniques,such as reel-to-reel manufacturing.Here,we briefly outline the four main liquid exfoliation techniques for layered materials (schematics are provided in Fig.2,and examples of exfoliated nanosheets are pro-vided in Fig.3).One of the oldest methods of exfoliating lay-ered crystals with low reductive potential is oxi-dation and subsequent dispersion into suitable solvents.The best example is that of graphite (20),in which treatment with oxidizers such as sulphuric acid and potassium permanganate results in ad-dition of hydroxyl and epoxide groups to the basal plane.The resulting hydrophillicity allows water intercalation and large-scale exfoliation to yield graphene oxide upon ultrasonication.The dispersed flakes are predominantly monolayers,typically hundreds of nanometers across,and sta-bilized against reaggregation by a negative sur-face charge at concentrations of up to 1mg/ml.Dispersed graphene oxide can be chemically re-duced in the liquid phase but will then aggregate unless surfactant or polymer stabilizers are present.Although reduction removes most of the oxides,structural defects remain,rendering the properties of oxidatively produced graphene substantially different from pristine graphene.Layered materials can also strongly adsorb guest molecules into the spacing between lay-ers,creating what are called inclusion complexes.This forms the basis of another exfoliation meth-od that is widely applied to layered materials,including graphite (21)and TMDs (22,23).Intercalation,often of ionic species,increases the layer spacing,weakening the interlayer ad-hesion and reducing the energy barrier to exfolia-tion.Intercalants such as n -butyllithium (22,23)or IBr (21)can transfer charge to the layers,re-sulting in a further reduction of interlayer bind-ing.Subsequent treatment such as thermal shock (21)or ultrasonication (22,23)in a liquid com-pletes the exfoliation process.The exfoliated nanosheets can be stabilized electrostatically by a surface charge (23)or by surfactant addition (21).In the case of MoS 2,this method tends to give highly exfoliated nanosheets (22).However,ion intercalation –based methods have drawbacks associated with their sensitivity to ambient condi-tions (22–24).Ion exchange methods take advantage of the fact that LDHs,clays,and some metal oxidesFig.1.Crystalstructures,natural-ly occurring forms,and exfoliated products for four example layered materials.(A )Graphite consists of alternating stacks of hexagonally ar-ranged carbon atoms (black spheres),(B )is a naturally occurring mineral,and (C )exfoliates to single atomic layers of carbon called graphene.(D )Vermicu-lite is a layered silicate hydrate (typ-ically Mg 1.8Fe 0.9Al 4.3SiO 10(OH)2•4(H 2O)that (E )is found naturally as a min-eral and (F )can be exfoliated,for example,upon heating.Silicon atoms are in blue,oxygen atoms are in red,Al/Mg/Fe atoms are in yellow,and interlayer counterions are in black (H and H 2O not shown).(G )MoS 2is a layered arrangement of S and Mo atoms (chalcogen atoms are in yellow,and transition metal are in green)that (H )is found naturally as the mineral molybdenite and (I )can be exfoliated to MoS 2monolayers.(J )Layered manganese dioxide (man-ganese atoms are in yellow,oxygen is in red,and interlayer counterions are in black)occurs naturally (K )as birnessite and (L )can be exfoliated to give MnO 2nanosheets.(C),(I),and (L)are adapted from (48),(87),and (58),respectively.The layer spac-ings for each material are graphite,0.35nm;vermiculite,1.5nm;MoS 2,0.6nm;and MnO 2,0.45nm.21JUNE 2013VOL 340SCIENCE1226419-2REVIEWo n J u l y 3, 2013w w w .s c i e n c e m a g .o r g D o w n l o a d e d f r o mTable 1.Referenced table of families of layered compounds,including structures and information on exfoliation methods,potential applications,and availablility.This table is not exhaustive.Crystal structures were obtained from the CrystalMaker Library (/library/index.html).Graphi t eTop viewSide viewF amily of layered compound StructureExfoliation methodApplicationsCommercial availabilitySonication in surfactantsolution (30, 50–53)Sonication in solvents (27, 45–48)Sonication in polymersolutions (54, 55)Graphene oxide (20,88)Many (1, 89)Widely availableMoS 2top viewMoS 2 side viewSingle-layer transistor (92)Batteries (63, 64)Top-gatephototransistors (93)Thermo-electrics (29, 58)Superconducting composites (94)Raw materials mostly available (purity issues)h-BNTop viewNitrogen BoronSide viewSonication in surfactant solution (58)Sonication in solvents (29, 56)Sonication in polymer solutions (54)Sonication in surfactant solution (58)Sonication in solvents (29, 59, 60)Sonication in polymer solutions (54)Ion intercalation (91)Composites (57)Device substrates (90)YesTransition metal ChalcogenTransition metal dichalcogenides (TMDs) SCIENCE VOL 34021JUNE 20131226419-3REVIEWo n J u l y 3, 2013w w w .s c i e n c e m a g .o r g D o w n l o a d e d f r o mTiTe 3top viewMnPS 3top viewTiTe 3side viewMnPS 3 side viewBatteries (96)No, only by synthesisIon intercalation (95)Wide band-gap semiconductors (97)Magnetic properties (98)No, only by synthesisIntercalation (75)Transition metal ChalcogenTransition metal Chalcogen PhosphorusTransition metal trichalcogenides (TMDs)AMo 3X 3, NbX 3, TiX 3, and TaX 3 (X = S, Se, or Te)Metal phosphorous trichalcogenides (MPX 3), such as MnPS 3, CdPS 3, NiPS 3, ZnPS 3, and Mn 0.5Fe 0.5PS 321JUNE 2013VOL 340SCIENCE 1226419-4REVIEWo n J u l y 3, 2013w w w .s c i e n c e m a g .o r g D o w n l o a d e d f r o mtop viewCrCl PbCl top viewMoCl CrCl 3 side viewPbCl 4 side viewNo (synthesis required)No (synthesis required)No (synthesis required)Ion intercalation (7)Polymer intercalation(99)Ion intercalation (100)Polymer intercalation (99)Ion intercalation (101)Transition metal HalideTransition metal Heavy metal Halide AmmoniumMetal halidesTransition-metal dihalides*Metal MX 3 halides, such as αRuCl 3, CrCl 3, and BiI 3†Layer-type halides with composition MX 4, MX 5, MX 6‡MoCl 2 top 2 side view3top viewHalide SCIENCE VOL 34021JUNE 20131226419-5REVIEWo n J u l y 3, 2013w w w .s c i e n c e m a g .o r g D o w n l o a d e d f r o mNa x (Mn 4+,Mn 3+)2O 4(birnessite) top viewNa x (Mn 4+,Mn 3+)2O 4 (birnessite) side viewVanadium oxide (V 2O 5) top viewV 2O 5 side viewSome raw materials available (purity issues)Most compounds are not availableSupercapacitors (106)Batteries (107)Catalysts (108)Dielectrics (109)Ferroelectrics (109)Ti oxidesIon intercalation (102)Mn oxidesSonication in surfactantsolution (58); Ion intercalation (103)Nb oxidesIon intercalation (104)Va oxidesPolymer intercalation (105)Transition metal Oxygen CatonVanadium OxygenOxidesTransition metal oxides : Ti oxides, Ti 0.91O 2, Ti 0.87O 2, Ti 3O 7, Ti 4O 9, Ti 5O 11; Nb oxides,Nb 3O 8, Nb 6O 17, HNb 3O 8;§ Mn oxides, MnO 2, Ti 3O 7, Na x (Mn 4+,Mn 3+)2O 421JUNE 2013VOL 340SCIENCE 1226419-6REVIEWo n J u l y 3, 2013w w w .s c i e n c e m a g .o r g D o w n l o a d e d f r o mMoO 3top viewMoO 3 side viewSr 2RuO 4 top viewSr 2RuO 4 side viewYesNo (only by synthesis)No (only by synthesis)Ion intercalation (110)Polymer intercalation(111)Intercalation with liquid crystals (115)Ion intercalation (protonation and ion exchange) (116)Amine surfactant (TBA +) under sonication (117)Ion intercalation (protonation and ion exchange) (114)Electrochromics (112)Light emitting diodes (113)Ferroelectrics (118)Photochromic (119)Photoluminescent (120)Layered trirutile phases HMWO (M = Nb, Ta), such as (HNbWO 6 and HTaWO 6)Hydrogen OxygenTransition metal StrontiumRutheniumOxygenOxidesTrioxides, such as MoO 3, TaO 3, and hydrated WO 3Perovskites and niobates, such as Sr 2RuO 4KCa 2Nb 3O 10, H 2W 2O 7, LaNb 2O 7, La 0.90Eu 0.05Nb 2O 7, Eu 0.56Ta 2O 7, Sr 2RuO 4, Sr 3Ru 2O 7, SrTa 2O 7, Bi 2SrTa 2O 9, Ca 2Nb 3O 10, Sr 2Nb 3O 10, NaCaTa 3O 10, CaLaNb 2TiO 10, La 2Ti 2NbO 10, and Ba 5Ta 4O15 SCIENCE VOL 34021JUNE 20131226419-7REVIEWo n J u l y 3, 2013w w w .s c i e n c e m a g .o r g D o w n l o a d e d f r o mTi 2Sb 2O top viewTi 2Sb 2O side viewFeOCl top viewFeOCl side viewNo (only by synthesis)No (only by synthesis)To our knowledge, these have never been exfoliatedIon intercalation (122)Superconductivity (121)Magnetic properties (121)Catalyst (redox properties) (121)Batteries (121)Batteries (123)Transition metal Pnictide CationTransition metal Halide OxygenOxidesOxychalcogenides and oxypnictides: Oxychalcogenides, LaOCuCh(Ch, chalcogenide) and derivatives, Sr 2MO 2Cu 2-δS 2 (M = Mn, Co, Ni),Sr 2MnO 2Cu 2m -0.5S m +1 (m = 1-3), Sr 4Mn 3O 7.5Cu 2Ch 2 (Ch=S, Se); oxypnictides, LaOFeAs II Oxyhalides of transition metals, such as VOCl, CrOCl, FeOCl, NbO 2F, WO 2Cl 2, and FeMoO 4Cl 21JUNE 2013VOL 340SCIENCE 1226419-8REVIEWo n J u l y 3, 2013w w w .s c i e n c e m a g .o r g D o w n l o a d e d f r o mLayered ␣ and ␥ zirconiumphosphates and phosphonatesGaSe top viewGaSe side viewCaHPO 4 top viewCaHPO 4 side viewSome available (maybe purity issues), mostly synthesizedNo (only by synthesis)Ion intercalation (124)Surfactant (125)Nonlinear optical properties, poor thermal conductivity (126)Intercalation (127)Exfoliation in water/acetone mixtures (128)Drug delivery (127)Semiconductor for dye sensitized solar cells (129)S/Se/Te Ga/InOxygen Phosphorus Cation WaterIII–VI layered semiconductorGaX (X = S, Se, Te); InX (X = S, Se Te)¶α-M IV phosphates, α-M IV (O 3P–OH)2·H 2O; and α-Metal IV phosphonates, M IV (O 3P–R)2·n H 2O# o n J u l y 3, 2013w w w .s c i e n c e m a g .o r g D o w n l o a d e d f r o mVermiculite top viewVermiculiteside viewKaolite top viewKaolite side viewNatural minerals,available on themarket Dispersion in water(13)Intercalation (130)Polymer intercalation(131)Catalysis (130)Composites (131)Lightweightnanocomposites forstructural applications(132)Clay-dye complexesand photoactivematerials (131)Organoclays as ionicand electronicconductors (compositeswith conductivepolymers) (131)Thermal and barrierpropertiesnanocomposites (133)Aluminum Oxygen Silicon OH-Oxygen Silicon Cation Intercalates/-C/-OHClays(layered silicates)2:1 Layered silicates**:Smectites, M n+x/n.yH2O[Al4-xMgx](Si8)O20(OH)4;talc, [(Mg3)(Si2O5)2(OH)2];vermiculite, [Mg6.Si6Al2/O20(OH)4] [M n+1/n] (Mg6);biotite [(MgFe)3(Si3Al)O10(OH)2]K;phlogopite, [(Mg6)(Si6Al2)O20(OH)4]Ba;fluorphlogopite, [Mg11/4(Si6Al2)O20F4][(M2+)3/2;margarite, [(Al2)(Si2Al2)O10(OH)2]Ca;and muscovite, [(Al2)(Si3Al)O10(OH)2]K1:1 Layered Silicates ††: Kaolite,[Al4Si4O10](OH)8; halloysite,Al4Si4O10(OH)8.4H2OonJuly3,213www.sciencemag.orgDownloadedfromBrucite (Mg 2+x , Mg 3+x (OH)2 (A n–)x/n . yH 2O)top viewBrucite (Mg 2+x , Mg 3+x (OH)2 (A n–)x/n . yH 2O) side viewTi3C2No, only bysynthesisYesIntercalation (134)Surfactant-assistedexfoliation and intercalation ofmolecules (135)Surfactant exfoliation (136)Solvent exfoliation in DMF (137)Functionalizationfollowed by exfoliation in solvents (138)Biocompatible–bio-hybrids/drug delivery (12, 134)Bionanocomposites with functional and structural properties (139)Extra oxygen and hydrogen at layers surface are present as a consequence of the exfoliation treatment with HF (66, 67).Batteries andsupercapacitors (140)Carbon TitaniumOxygenHydrogenCationLayered double hydroxides (LDHs)Ternary transition metal carbides and nitridesGeneral formula: M(II)1–x M(III)x (OH)2(A n –)x /n . yH 2O, where M(II) = divalent cation; M(III) = trivalent cation; A = interlayer anion; and n – = charge on interlayer anion‡‡Derivatives from MAX phases, where M = transition metal; A = Al or Si;and X=C or N§§Oxygen Hydrogen*These are iso-structural with TMDs.†These are defect CdI2structure types.‡These are heavy metal halides (perovskite type)structurally similar to transition metal dihalides withorganic ammonium interlayers.§Protons emplaced between 2D of Nb 3O 8–anion nanosheets composed of NbO 6octahedra.‖They contain oxide layers separated by distinct layers,which contain the softer chalcogenide (S,Se,and Te)or pnictide (P,As,Sb,and Bi).¶The building block has a trigonal structure,consisting of a pair of (M 3X 3)rings linked by M –M yers interact through van der Waals forces between the X outermost planes.#R is an organic radical,and n is the number of water molecules that can be intercalated in the interlayer region.**The 2:1notation means that the layers consist of two tetrahedral silicate sheets sandwiching one octahedral sheet.††Layer consists of one tetrahedral silicate sheets and one octahedral sheet.‡‡The structure of LDHs can be described by considering Mg(OH)2,which consists of Mg 2+ions coordinated octahedrally by hydroxyl groups.The octahedral units share edges to form infinite,charge neutral layers.In an LDH,isomorphous replacement of a fraction of the Mg 2+ions with a trivalent cation,such as Al 3+,occurs and generates a positive charge on the layers that necessitates the presence of interlayer,charge-balancing,anions.The remaining free space of the interlayer is occupied by water of crystallization.§§Layered M 2X,M 3X 2,M 4X 3,where M =transition metal and X =C or N,can be obtained after removal of the A layer with hydrofluoric acid (HF).o n J u l y 3, 2013w w w .s c i e n c e m a g .o r g D o w n l o a d e d f r o m。
英汉互译中的技巧-力学专业
On Some Mechanics Problems in One Dimensional NanostructureCarbon nanotubes and copper nanowires are so promising nano-components that their mechanical properties have received more and more attention over the past decade. In studying the nano-components, molecular dynamics simulations can only predict the dynamics results case by case and can hardly reveal the relation between multiple physical variables. On the other hand, it is still an open problem whether the continuum mechanics is valid to those discrete nano-components by nature. If not, is it possible to get any modified approach to deal with nano-components?The objective of this dissertation is to check the validity of the continuum mechanics, especially the continuum dynamics, for the nano-structures of one dimension, such as the carbon nanotubes and copper nanowires, with help of molecular dynamics simulations. The studies presented in the dissertation include the dispersion of both flexural and longitudinal waves in carbon nanotubes, the buckling of both single-walled and multi-walled carbon nanotubes, the impact of carbon nanotubes with a rigid wall, the size effect on the effective Young’s modulus of copper nanowires, the dynamic buckling of copper nanowires and the effect of temperature in nano-scale problems. The results and the main contributions of the dissertation are as following.1. The flexural wave propagation in single-walled carbon nanotubes was studied through the use of the continuum mechanics and the molecular dynamics simulation based on the Terroff-Brenner potential. The study focuses on the wave dispersion caused not only by the rotary inertia and the shear deformation in the model of a traditional Timoshenko beam, but also by the non-local elasticity characterizing the microstructure of a carbon nanotube in a wide frequency range up to THz. For this purpose, the study starts with the dynamic equation of a generalized Timoshenko beam made of the non-local elastic material, and then gives the dispersion relations of the flexural wave in the non-local elastic Timoshenko beam, the traditional Timoshenko beam and the Euler beam, respectively. Afterwards, it presents the molecular dynamics simulations for the flexural wave propagation in an armchair (5,5) and an armchair (10,10) single-walled carbon nanotubes for a wide range of wave numbers. The simulation results show that the Euler beam holds for describing the dispersion of flexural waves in these two single-walled carbon nanotubes only when the wave number is small. The Timoshenko beam provides a better prediction for the dispersion of flexural waves in the two single-walled carbon nanotubes when the wave number becomes a little bit large. Only the non-local elastic Timoshenko beam is able to predict the decrease of phase velocity when the wave number is so large that the microstructure of carbon nanotubes has a significant influence on the flexural wave dispersion. The work has been published in Physical Review B. The referee wrote: “This is an extremely interesting paper which would, most likely, makea significant contribution and impact t o the study of dynamic behavior of CNTs”.2. The study on the longitudinal wave propagation and dispersion in single-walled carbon nanotubes was presented through the use of the continuum mechanics and the molecular dynamics simulation based on the Terroff-Brenner potential. The study focuses on the effects of non-local elasticity characterizing the microstructure on thewave dispersion of single-walled carbon nanotubes. The study begins with the numerical simulation of molecular dynamics for the longitudinal wave of single-walled carbon nanotubes. Then, it presents the wave dispersion relations based on the models of rods or shells, made of either the elastic materials or the non-local elastic materials so as to characterize the micro-structure, for the carbon nanotubes. Among them, only the model of non-local elastic shell is able to get a good agreement with the molecular dynamics in a wide frequency range up to THz. The study shows that both the micro-structure and the coupling of longitudinal wave and radial motion play an important role in the wave dispersion of carbon nanotubes. The work has been published in Nanotechnology.题目：一维纳米结构的若干力学问题碳纳米管、铜纳米线是构成未来纳米器件的重要元素，如何了解和描述其力学特性成为人们近几十年非常关注的科学问题。
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碳纳米片作为超级电容器电极材料摘要：碳纳米片由1 - 7层主要是垂直朝向衬底的石墨烯层组成。
碳纳米片的厚度和形态的变化取决于前面生长和衬底温度。
他们有一个超低平面电阻率。
碳纳米片的电容可在标准的电化学三电极电解电池下用循环伏安法测量,其中包含铂对电极和标准汞/硫酸亚汞参比电极在6MH2 SO4电解液。
作为工作电极,碳纳米片的电容被发现是单位面积0.076 F厘米−2。
用数学模型来模拟一个包含碳纳米片作为电极材料并被发现是1.49×104 F的虚拟超级电容器单元的总可能电容。
1.介绍这里说的超级电容器(supercapacitor or ultracapacitor)与传统的超级电容相比，前者具有超高电容。
超级电容器的电容通过电化学双层建立(EDLC)[1 - 3]。
超级电容器和电池对于便携式电子设备,风力发电和电动汽车(EV)[4]来说都是至关重要的能源/电力存储设备。
电动汽车产业的发展主要依靠生活的进步,快速充电、大容量电池。
电池和超级电容器并不是相互替换,而且在电动汽车的传动系的系统有不同的作用。
电池依靠化学反应和电解质离子扩散产生/储存能量而且可以提供的能量比超级电容器更多。
超级电容器的存储/释放能量取决于电化学双层,设备上避免了化学反应所以可以快速充电和放电。
超级电容器可以重复使用多年而不退化和在电解质/电极中不含重离子,因此,它是一种环保设备。
超级电容器的大电容量源于高导电材料的比表面积很高。
传统超级电容器由活性炭颗粒或碳纤维组成。
这些碳材料理论上有很高的比表面积(1000 - 2000平方米克−1)。
相应地计算单位表面积活性炭材料的电容是10- 15F厘米−2。
因此,超级电容器用活性炭材料作为电极,具有更高的理论电容值(100 - 300 F g−1)相比普通电容器(大约F或pF)和内阻比电池内阻少得多。
此外,多达40%的能源可以恢复。
通过在supercapacitor-bus制动。
根据Pandolfo和Hollenkamp[5]和Obreja[6]的评论,传统碳超级电容器有一个1 - 10(Whkg−1)的比能和0.5-10 (kWkg−1)的功率系数。
几十甚至上百公斤的超级电容器也需要一个电动汽车。
传统的铅酸电池通常是30 - 40 Whkg−1和现代锂电池120 Whkg−1,因此,重要的是要提高EDLC物理极限和减少体重。
两个因素限制超级电容器的容值：孔隙分布和电极材料的电阻。
为了改善电极性能,材料的孔隙分布应该优化。
电极的电阻是另一种常见的限制约束。
为了增加功率系数,电极材料的体电阻和界面电阻应该最小化。
几种碳纳米材料,如碳纳米管(碳纳米管、单壁和多壁)和石墨烯作为超级电容器电极材料[7 - 9]吸引了研究兴趣。
碳纳米结构都是由sp2-bonded碳。
石墨烯是一种单原子层的碳六角形结构(10、11)。
碳纳米管是一个管状几何由一个或多个石墨烯层组成。
理论和实验测量结果表明,碳纳米管和石墨烯中对电子转移有超低的电阻率[12]。
在室温下,石墨烯片的电阻率为10−6厘米(少于银的电阻率)。
一个石墨烯片的比表面积可达到接近2630平方米克−1[7]。
研究在麻省理工学院LEES项目带领下，已演示了30 Whkg−1超级电容器。
石墨烯超级电容器的研究,由罗夫和同事(7、15)最近报道,化学修饰石墨烯(CMG)可以在水溶液中获得非常高单位电容(137 Fg−1)。
Nanogate碳®[16]能够获得30 - 75 Whkg−1。
这个碳质材料,由石墨结构夹层距离0.375nm的预热石油焦产生。
人们建议,化学气相沉积是制作高质量的石墨烯薄膜(10、11)的最好技术,如发展碳纳米片的王等人[19]运用的射频等离子体增强化学汽相淀积。
碳纳米片是二维石墨片由1 – 7层石墨烯层(平均三层),通常终止在一个石墨烯片(20、21)。
碳纳米片的比表面积可用BET方法测量(18、19、22)并且被发现约1100平方米克−1。
通过改变沉积时间,中枢神经系统高度可以发生从100纳米到> 10 m改变。
中枢神经系统的形态可通过调整衬底温度和采用不同的前体进行调节。
中枢神经系统可以合成大量纯形式(杂质< 100 ppm,由粒子诱导的x射线辐射,PIXE)[22]。
垂直对齐碳纳米片是二维纳米片,代表三维纳米孔。
衬底偏压电场的对齐中枢神经系统有序,平行平面几何300纳米宽,1米高[22]。
在这项研究中,中枢神经系统的电容的测量是通过用一个数学模型--一个标准的包含6MH2SO4电化学环境和经验值来评估一个虚拟EDLC。
2.方法碳纳米片由之前被报道的(18 - 23)等离子体增强化学气相沉积(PECVD)系统制作。
简而言之,在沉积过程中,400 - 1200 W 射频(RF,13.56 MHz)功率电感耦合到沉积室通过在一个石英窗口放置平面盘绕的射频天线。
先驱气体甲烷(CH4)是作为碳源并且混合着氢气(H2)作为载气。
感应等离子体的密度capacitive-coupled系统的10倍。
其他典型的沉积参数：衬底温度、在600-950◦C之间变化、燃烧室压力、在20至200毫托之间变化。
碳纳米片已经可以在没有任何特殊的预处理或催化剂的情况下，成功地覆盖在Si, W, Mo, Zr, Ti, Hf, Nb, Ta, Cr, 304不锈钢、二氧化硅和氧化铝等上。
图1显示了在100毫托总压强,680◦C 衬底温度,和900 W功率60% H2、40%CH4碳纳米片的扫描电子显微镜(SEM)典型图像。
图1中的插图是石墨烯的原理图。
图1 b显示纳米片大致垂直于衬底,发展情况下,高0.6米。
如图1所示b,纳米片的边缘非常薄(< 1nm),也被高分辨率透射电子显微镜(17 - 19、22)证实。
图2演示了碳纳米片均匀覆盖在碳纤维上。
图2中的插图是一个碳布由大量的碳纤维组成。
图2 b是碳纳米层覆盖的碳纤维的SEM图像。
CNS涂料大大扩大碳纤维的比表面积。
在这里,CNS在传统的沉积碳纸(请参见图3 a和b)中作为电容测量的工作电极。
碳纸是由聚丙烯腈碳纤维(PAN)组成。
碳化纤维之间绑定(残留胶)用于造纸制浆过程。
循环伏安法(CV)是一种评估EDLC电容器新材料有效的技术。
在这项研究中,CV实验涉及扫描一个碳纳米片连接间工作电极之间的可能工作电压(V),和一个参考电极,同时记录流过电极的时间电流(i)。
充电/放电电流(i)与电容(C)和扫描速率(dV / dt)C = i /(dV / dt)有关。
在真实的应用中,EDLC电容器是二电极器件。
然而,为了理解单个电极的材料性能(阳极和阴极),这是一个科学的必要性用参考电极。
潜在应用的工作电极和反电极可以分离。
霍洛维茨和希尔[24]有一个关于恒电位电化学电路(也称为电压钳位)简洁的解释,这是基于运算放大器的反馈。
一个由GamryTM 制造的商业稳压器被用于这项研究。
碳纳米片成为一个定制的由聚四氟乙烯塑料构成的工作电极。
样品接触面积是0.78平方厘米(1厘米直径)。
对电极由铂箔制成。
参比电极是一个标准的汞/硫酸亚汞电极缩写“MSE Hg-Hg2SO4-SO42−)和电解质是6-mole硫酸酸(硫酸)。
3.结果与讨论图4显示了附加到工作电极(阳极)的CV碳纳米片块样品在不同扫描速率(25、50、100、100、150、250和300 mVs−1)。
x轴是在工作电极和参比电极之间的差分电压(V)。
y轴是流过工作电极的测量电流(i)。
从理论上讲,一个理想的电容器将生成一个完美的矩形轮廓,因此电容C(或者i)应该在线性充电/放电中保持常数(dV / dt =常数)。
这个循环电压图的概要在低扫描率(25 mV s−1)时接近矩形,这表明它接近理想EDLC电容器。
在本系列实验,材料经过充电/放电循环停在0.6 v。
CV平面图保持半长方形形状300 mV s−1。
材料的电容在不同扫描速率几乎是相同的。
这个现象表示材料在快速充电/放电应用中可能会性能良好。
在高扫描速率(> 50 mV s−1),材料的电容随低到高电压增加。
换句话说,电容的材料取决于外加电压,从而偏离理想的电容器。
在扫描速率为(dV / dt)50 mV s−1,最大放电电流(I)是3 mA，从而使C = I /(dV / dt)= 0.06 f .碳纳米片沉积在碳纸的接触面积s =0.782平方厘米。
因此CNS产量C / S F = 0.0764厘米−2测试区域。
在这项研究中,开发了一个数学模型来评估理想的超级电容器材料。
如图5所示,超级电容器的半径R和高度H,可以由碳纳米片形成的“三明治”阿基米德螺旋得到。
三明治是中心对称几何。
垫包含两个电流收集器,它连接到扭转极化电压。
它有一个绝缘层作为离子渗透分离器。
碳纳米片作为电极材料被填满。
左边角落插图是板的横截面示意图(筛选区中间的图)。
三明治是d的厚度及其旋转路径遵循一个阿基米德螺旋模式。
如果我们假设内壁和外壁电流收集器是电绝缘和绕组完全压缩,把(N)的数量可以通过电容的比值估算半径和垫厚度,即R / d。
评估一个超级电容器的电容,我们可以应用下面的简化模型来表示有包装板结构的截面:内表面的轮廓纳米片满足从原点开始的阿基米德螺旋方程,用r表示从起始点的距离和角度,分别和a= d / 2是一个常数。
因此,我们可以估计三明治板的总长度计算的积分长度阿基米德螺旋使用以下公式:其中ϕ= 2 N,N = R / d。
Matlab脚本开发评价L各种输入。
超级电容器设备与R = 3厘米,H = 13.8厘米,滚在一个三明治板与d = 100,设备的电容值需要计算两个电容器。
设备capac-itance 1/2每个电极的电容两系列。
这给了,作为参考,一个商业超级电容器设备(麦克斯韦Boostcap®电容,BCAP3000-P270-T04)的气缸高度H = 13.8厘米,一个外径d = 60.0毫米,有一个电容3000.0 F,然而,直接比较商业产品的新概念是不合适的。
通过使用一个水电解质(硫酸),最大CV测试电压(0.6 V)远低于实际的工作电压。
营利性设备,像Boostcap®,使用非水有机电解质(如乙腈)能维持工作电压2.5 v .由于储能是用来评估EDLC设备一个目标,在同一工作电压电极材料的电容比较是有意义。
4.总结本研究评估作为电化学双层电容器的电极材料碳纳米片(EDLC)。
碳纳米片是由石墨烯或1 - 7层的sp2碳同石墨结构。
他们可以长到一个面积大于1 m×1米,厚度小于1nm。
碳n 纳米片通过inductive-coupled等离子体增强化学汽沉积(ICP-CVD)覆盖在传统碳纸或碳纤维布上。