Electrochemical cycling behavior of LiFePO4 cathode charged with different upper voltage limits

Electrochemical supercapacitors for energy storage and delivery

Editorial Electrochemical supercapacitors for energy storage and delivery:Advanced materials,technologies and applications q 1.Introduction In the effort to achieve a clean and sustainable world,energy storage and delivery have become one of today’s most important topics in globe research and development.In this regard,electro-chemical energy technologies such as batteries,fuel cells,and elec-trochemical supercapacitors have been recognized as the most important portion of the various energy storage and delivery tech-nologies.Among these technologies,supercapacitors,emerging as one of the most important energy storage and delivery devices for the 21st century,are particularly the most reliable and safe devices with extremely high power density and cycling stability in many applications including portable electronics,automobile vehicles,stationary power stations and energy storage devices,backup power supplies,etc.However,its challenges of low energy density as well as this low energy density induced high cost are the major drawbacks.To overcome these challenges,in recent years,there are tremendous efforts focusing on the development of new and cost-effective electrodes and electrolyte materials as well as electrode con?guration to improve the capacitance,the energy density of the next generation of supercapacitors. In order to benchmark the state of research in this area at this time,Applied Energy organized a special issue dedicated to recent research development in Supercapacitors.The articles in this spe-cial issue cover the most recent progress of supercapacitor research and development in terms of both fundamentals and applications with focuses on cutting edge research on new materi-als for system designs and practical deployment investigations.2.Background of supercapacitors Normally,the energy storage mechanism of supercapacitors is electrochemical in nature,but differs from that of batteries or fuel cells that rely on the coupling of Faradaic redox reactions.Instead,supercapacitors store and discharge energy dominantly through what is called electric double layer capacitance (EDLC).This occurs by employing two high surface area electrodes,that when charged,form a Helmholtz double layer at the interface between the con-ductive electrode materials and the electrolyte,as illustrated in Fig.1.The electrodes have opposing charges,and in this fashion energy is stored by the electrostatic charge separation.As a result of this energy storage mechanism,supercapacitors can charge and discharge in a matter of seconds while delivering immense power densities (typically in the 10–1000KW/kg).Their operational life-times are also an attractive feature,boasting in excess of 100,000charge and discharge cycles before needing replacement (ref).Owing to these advanced properties,supercapacitors have gained commercial success in certain applications that include dynamic load levelling and uninterruptable power supplies.However,due to their low energy density,large untapped markets remain,including the use of supercapacitors in electric vehicles,large scale energy storage units (grid),and small scale portable electronics.For supercapacitors to effectively penetrate these markets,further technological advances,such as those reported in this special issue are required. At the current state of research,a large body of research has been focused on increasing the energy density of supercapacitors by developing novel high surface area carbon materials,such as graphene,with unprecedented electric double layer capacitance.It is expected that the viability of supercapacitors could also be extended towards a wide range of applications if energy densities can be improved to more closely resemble those of batteries.To accomplish this,psuedocapacitors (or hybrid supercapacitors)are an emerging trend of research that includes compositing conven-tional EDLC electrodes with materials that contribute redox beha-viour during charge and discharge.These materials,with a high capacity to store energy must also be integrated into operational supercapacitor cell designs.These systems may then have their performance investigated and validated towards new,promising applications. 3.Research covered in this special issue In this special issue,13papers have been included covering the areas of electric double layer capacitance materials,psuedocapac-itor material,system design and application deployment.3.1.New high surface area EDLC materials Developing novel nano-structured electrode materials are one of the most active approaches in supercapacitors.For example,Article [1]reports the use of rice husks,a renewable resource,to prepare high surface area porous carbons that were used as EDLC https://www.360docs.net/doc/b18776323.html,/10.1016/j.apenergy.2015.05.0540306-2619/ó2015Published by Elsevier Ltd. q This paper is included in the Special Issue of Electrochemical Supercapacitors for Energy Storage and Conversion,Advanced Materials,Technologies and Applications edited by Dr.Jiujun Zhang,Dr.Lei Zhang,Dr.Radenka Maric,Dr.Zhongwei Chen,Dr.Aiping Yu and Prof.Yan.

JESD22-A105C-Power and Temperature Cycling

STANDARD Power and Temperature Cycling JESD22-A105C (Revision of JESD22-A105-B) JANUARY 2004, Reaffirmed January 2011 JEDEC SOLID STATE TECHNOLOGY ASSOCIATION

NOTICE JEDEC standards and publications contain material that has been prepared, reviewed, and approved through the JEDEC Board of Directors level and subsequently reviewed and approved by the JEDEC legal counsel. JEDEC standards and publications are designed to serve the public interest through eliminating misunderstandings between manufacturers and purchasers, facilitating interchangeability and improvement of products, and assisting the purchaser in selecting and obtaining with minimum delay the proper product for use by those other than JEDEC members, whether the standard is to be used either domestically or internationally. JEDEC standards and publications are adopted without regard to whether or not their adoption may involve patents or articles, materials, or processes. By such action JEDEC does not assume any liability to any patent owner, nor does it assume any obligation whatever to parties adopting the JEDEC standards or publications. The information included in JEDEC standards and publications represents a sound approach to product specification and application, principally from the solid state device manufacturer viewpoint. Within the JEDEC organization there are procedures whereby a JEDEC standard or publication may be further processed and ultimately become an ANSI standard. No claims to be in conformance with this standard may be made unless all requirements stated in the standard are met. Inquiries, comments, and suggestions relative to the content of this JEDEC standard or publication should be addressed to JEDEC at the address below, or refer to https://www.360docs.net/doc/b18776323.html, under Standards and Documents for alternative contact information. Published by ?JEDEC Solid State Technology Association 2011 3103 North 10th Street Suite 240 South Arlington, VA 22201-2107 This document may be downloaded free of charge; however JEDEC retains the copyright on this material. By downloading this file the individual agrees not to charge for or resell the resulting material. PRICE: Contact JEDEC Printed in the U.S.A. All rights reserved

Nanomaterial-based electrochemical

Nanomaterial-based electrochemical biosensors Joseph Wang DOI:10.1039/b414248a The unique properties of nanoscale materials offer excellent prospects for interfacing biological recognition events with electronic signal transduction and for designing a new generation of bioelectronic devices exhibiting novel functions.In this Highlight I address recent research that has led to powerful nanomaterial-based electrical biosensing devices and examine future prospects and challenges.New nanoparticle-based signal amplification and coding strategies for bioaffinity assays are discussed,along with carbon-nanotube molecular wires for achieving efficient electrical communication with redox enzyme and nanowire-based label-free DNA sensors. 1.Why nanomaterials? The buzzword‘‘nanotechnology’’is now around us everywhere.Nanotechnology has recently become one of the most exciting forefront fields in analytical chemistry.Nanotechnology is defined as the creation of functional materials, devices and systems through control of matter at the1–100nm scale.A wide variety of nanoscale materials of differ-ent sizes,shapes and compositions are now available.1The huge interest in nanomaterials is driven by their many desirable properties.In particular,the ability to tailor the size and structure and hence the properties of nanomaterials offers excellent prospects for designing novel sensing systems and enhancing the performance of the bioanalytical assay. The goal of this article is to highlight recent advances in nanomaterials for such electrical sensing devices. 2.Nanoparticles,nanowires and nanotubes Research efforts on metal and metal semiconductor nanoparticles have flour-ished in recent years.2,3Metal nano-particles are generally defined as isolable particles between1and50nm in size,that are prevented from agglo-merating by protecting shells.Owing to their small size such nanoparticles have physical,electronic and chemical proper-ties that are different from those of bulk metals.Such properties strongly depend on the number and kind of atoms that make up the particle.Several reviews have addressed the synthesis and proper- ties of nanoparticles.2,3Typically,such particles are prepared by chemical reduc- tion of the corresponding transition metal salts in the presence of a stabilizer (capping agent such as citrate or thiol) which binds to their surface to impart high stability and rich linking chemistry and provide the desired charge and solubility properties.Designer particles, including colloidal gold or inorganic nanocrystals have found broad applica- tions in many forms of biological tagging schemes.For example,colloidal quan- tum dots have been widely used for optical bioassays because their light emitting properties can be broadly tuned through size variation.4Recent years have witnessed the development of powerful electrochemical bioassays based on nanoparticle labels and ampli- fication platforms. One-dimensional(1-D)nanostruc- tures,such as carbon nanotubes(CNT) and semiconductor-or conducting- polymer nanowires,are particularly attractive for bioelectronic detection. Because of the high surface-to-volume ratio and novel electron transport pro- perties of these nanostructures,their elec- tronic conductance is strongly influenced by minor surface perturbations(such as those associated with the binding of macromolecules).Such1-D materials thus offer the prospect of rapid(real- time)and sensitive label-free bioelectro- nic detection,and massive redundancy in nanosensor arrays.The extreme smallness of these nanomaterials would allow packing a huge number of sensing elements onto a small footprint of an array device.Metal and conducting polymer nanowires can be readily prepared by a template-directed electro- chemical synthesis involving electro- deposition into the pores of a membrane template.5Carbon nanotubes (CNT)are particularly exciting1-D nanomaterials that have generated a considerable interest owing to their unique structure-dependent electronic and mechanical properties.6CNT can be divided into single-wall carbon- nanotubes(SWCNT)and multi-wall carbon-nanotubes(MWCNT).SWCNT possess a cylindrical nanostructure (with a high aspect ratio),formed by rolling up a single graphite sheet into a tube.SWCNT can thus be viewed as molecular wires with every atom on the surface.MWCNT comprise of an array of such nanotubes that are concentrically nested like rings of a tree trunk.The remarkable properties of CNT suggest the possibility of developing superior electrochemical sensing devices,ranging from amperometric enzyme electrodes to label-free DNA hybridization bio- sensors.7The tailored electronic con- ductivity of conducting polymers, coupled with their ease of processing/ modification and rich chemistry,make them extremely attractive as1-D sensing materials.Newly introduced CNT/ conducting-polymer nanowire mate- rials,8based on incorporating oxidized CNT as the charge-balancing dopants i-SECTION:HIGHLIGHT https://www.360docs.net/doc/b18776323.html,/analyst|The Analyst

uncivilized behavior

Uncivilized behavior of Chinese tourists “You see, it’s common, most people didn’t care”said by one female tourist who is just throwing trash on the San Ya beach which has already been reduced to a dumping ground. When the beautiful island meets holiday crowd, under the hustling and bustling scene, we absolutely startled by the carving “Dao ci yi you”, dumbling beer bottles, spilling peels and half-burned branches. These facts are still far from enough.Uncivilized behavior makes headlines in the National Day holidays. At the memorable flag-raising ceremony at Tiananmen Square on October 1, over 120,000 participants left five tons of trash behind after showing their respect to the country. Sometimes, you could not find a place to sit –men take up all the benches in the park, lying full-length and blissfully snoring the afternoon away.Spitting, talking loudly and random littering are frequent scenes in tourist attractions. Countless visitors allow their children to use the city streets as a toilet, even though there is a toilet nearby. Newsstand and bookshop proprietors also suffer from bad-mannered people who tear the wrappers off magazines and read the contents without buying them. Bookstore visitors ignore the signs of asking them to rest only in designated areas instead of sitting on the stairwell. Similar stories are testing the tolerance of public opinion almost every day. We could be denied those undesirable manner. Nevertheless, it will be more persuasive to point out that China's tourism industry is not developing in a gradual way, but in a blowout manner. Growing wealth enables more Chinese people to seek leisure and fulfillment from traveling. Considering China's large population, some problems and challenges must emerge at the same time.We might be disappointed but not be desperate. Objectively speaking, before the national holiday, civilized traveling aroused surges of attention such as Wechat hot debate, media focus, screen exposure, which is beyond the past several years.Under the supervision of public opinion, the index of civilized golden week presents positive improvement. However,it’s still a serious short board that reflects on Chinese social moral deficiency. Not only should we take it seriously, but also wake up the consciousness of citizen responsibility and turn it in to action to make up. Forming harmonious social morality as if human’s maturation. We need time. I do believe the enlightened public moral education combined with perfected facilities will take several generations to nurture civilized behavior and display a positive image of Chinese tourists.

仁爱英语八年级下Unit 6 Enjoy Cycling Topic 3 Section C-课件内容介绍和使用说明

新课标第一网系列资料https://www.360docs.net/doc/b18776323.html, 课件内容介绍和使用说明 本课件是为仁爱英语八年级下学期Unit 6 Topic 3 Section C 编写的教学课件。这是第六单元第三话题的第三课时。本课重点是进行阅读和写作的训练，继续学习与自行车和交通安全有关的话题。短文1a部分介绍自行车在人们生活中的作用以及骑自行车的人在路上的交通安全守则；课文第3部分则是对1a的拓展，让学生辨别哪些行为在路上是安全的，哪些是不安全的。本课教学中继续强化学生遵守交通规则、安全意识和珍爱生命意识。本课件的教学程序安排如下： 复习——①复习巩固if引导的条件状语从句，强调“主将从现”原则。（幻灯片2） ②学生课堂竞赛，用英语说出尽可能多交通规则以及违反这些规则的后 果，运用“if”从句。（幻灯片3） 导入——学生谈论：保持道路交通安全应做与不应做的事。（幻灯片4） 呈现——呈现1a，读前活动：谈论骑自行车应该知道的安全事项。（幻灯片5） 巩固——①学生阅读短文，找出各段的主题句。（幻灯片6） ②阅读短文，从短文中找出生词并利用图片、读音规则来学习。（幻灯片 7、8） ③观看flash动画，巩固对1a内容理解。（幻灯片9） ④学生根据短文内容回答1c的问题。（幻灯片10） ⑤学生听1a录音，然后找出短文中提到的骑自行车的安全守则。（幻灯片 11） ⑥呈现关键词，学生复述短文。（幻灯片12） 练习——①呈现课本第2部分内容，学生选词完成句子，并巩固1a的知识。（幻灯片13） ②课堂练习，巩固本课重要知识点。（幻灯片14） ③完成一篇与交通知识有关的短文填空。（幻灯片15） 拓展——①看图讨论图中哪些人物的行为能做，哪些不能做，并完成短文。（幻灯片16、17） ②学生根据提示讨论如何写短文。（幻灯片18） 小结——归纳本课重点。（幻灯片19、20）

TPO4-leture1-animal behavior

Listen to part of a lecture in a biology class. The class is discussing animal behavior. Okay Ok , the next kind of animal behavior I want to talk about might be familiar to you. You may have seen, for example, a bird that's in a the middle of a mating ritual. and suddenly it stops and prines preens . You know, takes a few moments to straight straighten its feathers. and then returns to the mating ritual. This kind of behavior, this doing something that seems completely out of place. It's is what we call a displacement activity. Displacement activities are activities that animals engaged animal's engaging in when they have conflicting drives. If we take our example for from a minute ago if the bird is afraid of its mate, it's conflicted. It wants to mate, but it's also afraid and wants to run away. So instead, it starts grooming itself. So the displacement activity the grooming, the straightening of its feathers seems to be an irrelevant behavior. So what do you think another example of the a displacement activity might be? How about an animal that , um, instead of fighting its enemy or running away, it attacks a plant or a bush. That's a really good suggestion, Carol Karl . But that's called redirecting. The animal is redirecting its behavior to another object. In this case, the plant or the bush. But that's not an irrelevant or inappropriate behavior. The behavior makes sense. it's appropriate under the circumstances, but what doesn't make sense is the object behaviors direct the behavior's directed towards. Okay Ok , who else? Carol? I think I've read in another class about an experiment were where an object that the animal was afraid of was put next to its food. next to the animal's food. And the animal, it was conflicted between confronting the object and eating the food, so instead

雅思口语话题-cycling自行车

雅思口语话题-cycling自行车 上海环球雅思 环球雅思的刘薇老师与考生分享“Can you ride a bike?”这一常见雅思口语话题的 回答方法，一起来看一下吧 雅思口语话题cycling的答法1 Sure. I learnt bicycling when I was only 7 years old before entering theprimary school. My coach was nobody but my father who was proved to be abrilliant trainer. As far as I remembered, at the very beginning, I fell fromthe bike for numerous times and made the left knee hurt. However, my fatherencouraged me to overcome obstacles/difficulties. Soon I found I could handlethe bike smoothly and effortlessly. 雅思口语话题cycling的答法2 Sure. I learnt bicycling when I was only 7years old before entering the primary school. My coach was nobody but my fatherwho was proved to be a brilliant trainer. Now I ride the bike for schoolcommuting. Bicycling as an exercise is less demanding in space and time butextremely helpful in increasing muscle strength and flexibility. While as atransportation, it’s economical and eco-friendly. The benefits of bike riding Bike riding can offer lots of benefits forbody health It can increase the ….. cardiovascular fitness muscle strength and heart health balance and flexibility endurance and stamina ittakes a lot of stamina to run a marathon a less stressful exercise, especially goodfor protection of joints