锂离子电池论坛_锂离子电池工艺大全-经典
锂离子电池原理及工艺大全
锂离子电池是一种二次电池（充电电池），它主要依靠Li+ 在两个电极之间往返嵌入和脱嵌来工作，它主要有能量密度高，充电时间快，使用寿命长等特点。
随着能源汽车下游产业不断发展，锂离子电池的生产规正在不断扩大。
锂离子电池原理及工艺 - 大全2018锂离子电池简介一，锂离子电池的原理、配方和工艺流程•1、工作原理•1.1正极构造•LiCoO2 + 导电剂 + 粘合剂 (PVDF) + 集流体（铝箔）•1.2负极构造•石墨 + 导电剂 + 增稠剂 (CMC) + 粘结剂 (SBR) + 集流体（铜箔）•1.3工作原理•1.3.1 充电过程•一个电源给电池充电，此时正极上的电子e从通过外部电路跑到负极上，正锂离子Li+从正极“跳进”电解液里，“爬过”隔膜上弯弯曲曲的小洞，“游泳”到达负极，与早就跑过来的电子结合在一起。
此时：正负极物理反应为：•1.3.2 电池放电过程•放电有恒流放电和恒阻放电，恒流放电其实是在外电路加一个可以随电压变化而变化的可变电阻，恒阻放电的实质都是在电池正负极加一个电阻让电子通过。
由此可知，只要负极上的电子不能从负极跑到正极，电池就不会放电。
电子和Li+都是同时行动的，方向相同但路不同，放电时，电子从负极经过电子导体跑到正极，锂离子Li+从负极“跳进”电解液里，“爬过”隔膜上弯弯曲曲的小洞，“游泳”到达正极，与早就跑过来的电子结合在一起。
•1.3.3 充放电特性•电芯正极采用LiCoO2 、LiNiO2、LiMn2O2，其中LiCoO2本是一种层结构很稳定的晶型，但当从LiCoO2拿走x个Li离子后，其结构可能发生变化，但是否发生变化取决于x的大小。
通过研究发现当x >0.5时，Li1-xCoO2的结构表现为极其不稳定，会发生晶型瘫塌，其外部表现为电芯的压倒终结。
所以电芯在使用过程中应通过限制充电电压来控制Li1-xCoO2中的x值，一般充电电压不大于4.2V那么x小于0.5 ，这时Li1-xCoO2的晶型仍是稳定的。
【干货】锂离子电池工序大全详细解读
【干货】锂离子电池工序大全详细解读来源：新能源时代锂电池生产制造流程，凡在新能源领域的从业人员都能“信手拈来”。
但是，简单的流程能表达出锂电池制造工艺技术的种种艰辛吗？下面新能源时代（欢迎关注）公众号为大家介绍主要锂电池制程管控的要点。
（抛砖引玉）一部分正极配料（正极由活性物、导电剂、粘结剂组成）1、首先是对来料确认和烘烤，一般导电剂需≈120℃烘烤8h，粘结剂PVDF需≈80℃烘烤8h，活性物（LFP、NCM等）视来料状态和工艺而定是否需要烘烤干燥。
当前车间要求温度:≤40℃，湿度:≤25%RH。
2、干燥完成后，（湿法工艺）需要提前配好PVDF胶液（溶质PVDF，溶液NMP）。
PVDF胶液好坏对电池的内阻、电性能影响至关重要。
影响打胶的因素有温度、搅拌速度。
温度越高胶液配出来泛黄，影响粘结性；搅拌的速度太高容易将胶液打坏，具体的转速需要看分散盘的大小而定，一般情况下分散盘线速度在10-15m/s（对设备依赖性较高）。
此时要求搅拌罐需要开启循环水，温度:≤30℃.3、接下来是配正极浆料。
此时需要注意加料的顺序（先加活性物和导电剂慢搅混合、再加入胶液）、加料时间、加料比例，要严格按工艺执行。
其次需要严格控制设备公转和自转速度（一般分散线速度要在17m/s以上具体要看设备性能，不同厂家差别很大），搅拌的真空度、温度。
在此阶段需要定期检测浆料的粒度和粘度，而粒度和粘度跟固含量、材料性能、加料顺序和制程工艺关系紧密（此次不叙述，欢迎讨论）。
此时常规工艺要求温度:≤30℃，湿度:≤25%RH，真空度≤-0.085mpa。
4、浆料配完后就要将浆料转出至中转罐或涂布车间，浆料转出时需要对其过筛，目的就是过滤大颗粒物、沉淀和去除铁磁性等物质。
大颗粒影响涂布到最后可能导致电池自放过大或短路的风险；浆料铁磁性物质过高会导致电池自放电过大等不良。
此时的工艺要求是温度:≤40℃，湿度:≤25%RH，筛网≤100目，粒度≤15um（参数仅供参考）。
锂离子生产工艺流程
锂离子电池是一种常见的二次电池，具有高能量密度、长寿命和轻量化的特点，广泛应用于移动电子设备、电动汽车等领域。
锂离子电池的核心组成部分是正极材料、负极材料和电解液，其中正负极材料主要通过特定工艺生产得到。
下面将详细描述锂离子电池正负极材料的生产工艺流程：1.正极材料生产工艺流程：–原料准备：根据正极材料的配方，准备所需的原料，通常包括锂盐、过渡金属氧化物、导电剂等。
–混合：将经过粉碎和筛分处理后的原料按照一定比例混合均匀。
–烧结：将混合好的原料放入烧结炉中，在高温下进行烧结，使原料中的成分发生化学反应，并形成颗粒状物质。
–粉碎：将烧结后的颗粒物质进行粉碎处理，得到所需的正极材料粉末。
–表面处理：对正极材料粉末进行表面处理，包括涂覆一层保护膜，以提高正极材料的稳定性和电化学性能。
–干燥：将表面处理后的正极材料粉末进行干燥处理，去除水分和有机溶剂等。
–筛分：对干燥后的正极材料粉末进行筛分，以得到所需的颗粒大小范围。
2.负极材料生产工艺流程：–原料准备：根据负极材料的配方，准备所需的原料，通常包括石墨、导电剂等。
–混合：将经过粉碎和筛分处理后的原料按照一定比例混合均匀。
–制浆：将混合好的原料与溶剂混合，形成浆状物质。
–涂布：将制浆后的物质涂布在铜箔上，并通过压延等工艺使其均匀一致。
–干燥：将涂布在铜箔上的物质进行干燥处理，去除水分和有机溶剂等。
–烘烤：将干燥后的负极材料进行烘烤，使其形成致密的结构，提高电化学性能。
–切割：将烘烤后的负极材料进行切割，得到所需的形状和尺寸。
除了正负极材料的生产工艺外，锂离子电池还需要电解液的制备。
电解液主要由有机溶剂和锂盐组成，其生产工艺流程如下： - 原料准备：根据电解液的配方，准备所需的有机溶剂和锂盐。
- 混合：将有机溶剂和锂盐按一定比例混合，并进行搅拌使其充分溶解。
- 过滤：对混合好的电解液进行过滤处理，去除其中的杂质颗粒等。
- 脱水：对过滤后的电解液进行脱水处理，去除其中的水分和其他不纯物质。
锂离子电池论坛_碳热还原法制备具有高倍率放电性能的磷酸铁锂材料
碳热还原法制备具有高倍率放电性能的磷酸铁锂材料蒋永1，赵兵*1，焦正1，吴明红1，仲明阳1，栾健2，陈仁国2 （1. 上海大学环境与化学工程学院 上海 200444； 2. 泰州赛科电池有限公司 泰州225423）摘要：以FePO4为原料，采用聚乙烯醇（PVA）和苯化学气相沉积为碳源，制备粗糙多孔结构LiFePO4/C复合材料。
用XRD、SEM、HRTEM研究了材料的结构与碳的形态。
合成材料粒径1-2μm，颗粒分布比较均匀，电子电导率为2.4x10-2 S/cm。
电化学测试表明，700℃烧结10h合成样品具有较高的充放电容量和倍率放电性能，0.1C首次放电可逆容量达到155.4mAh/g，6C仍保持容量114.6 mAh/g，循环55次容量衰减0.28%每次，体现出了较好的循环性和大电流放电性能。
关键词 锂离子电池，LiFePO4，固相反应，碳热还原法A Carbon Thermal Reduction Method for preparing LiFePO4 with High-Rate ElectrochemicalPropertyJIANG Yong1, ZHAO Bing1, JIAO Zheng1, WU Ming-hong1, ZHONG Ming-yang1,LUAN Jian2, CHENG Ren-guo2(1. School of Environmental and Chemical Engineering, Shanghai University, Shanghai2004442. Taizhou Saike Battery Co., LTD, Taizhou, 225423 )AbstractAmorphous carbon-coated LiFePO4 cathode materials were synthesized by a solid-state reaction using inexpensive FePO4 as the iron precursor and polyvinyl alcohol (PVA) as the carbon sources. The chemical vapor deposition was also applied to reduce Fe (III) to Fe (II) using the benzene as the reductive agent. The effect of the sintering temperature on its structure and surface morphology of carbon was investigated by X-ray diffraction (XRD), field-emission scanning electron microscope (FESEM) and High resolution transmission electron microscope (HRTEM). The material has a single crystal globular structure with grain-size in the range 1-2μm, whose electron conductivity is about 2.4x10-2 S/cm. The tests of electrochemistry performance showed that the LiFePO4 prepared by carbon thermal reduction method with excellent rate capability. It showed 155.4 mAh/g at low discharge rate (0.1C). While it could maintain 114.6 mAh/g at high discharge rate (6C). A capacity fade of about 0.28% per cycle affected the material upon cycling.Keywords: Lithium ion batteries, LiFePO4, Solid-state reaction, Carbon thermal reduction method1 前言自1997年Goodenough[1]首次报道以来，LiFePO4作为新一代锂离子电池的阴极材料，以其高安全性、绿色环保、原材料便宜、循环性能好等独特的优势，极有可能替代目前市场上使用的各种材料，在电动汽车和大型储能设备上得到应用。
锂离子电池制造工艺及各工序品质控制要点
锂离子电池制造工艺及各工序品质控制要点Lithium-ion batteries have become ubiquitous in our modern lives, powering everything from smartphones to electric vehicles. The manufacturing process of lithium-ionbatteries involves several key stages that are essentialfor ensuring high-quality products. In this response, Iwill outline the main processes involved in lithium-ion battery manufacturing and discuss the key points of quality control for each stage.原材料的选择和准备是制造锂离子电池的第一步。
正极材料通常采用锂铁磷酸盐、锰酸锂或钴酸锂等化合物，而负极则使用石墨材料。
电解液也是一个关键因素，一般由有机溶剂和锂盐组成。
在这个阶段，质量控制的重点是确保原材料的纯度和稳定性。
The first step in manufacturing lithium-ion batteries isthe selection and preparation of raw materials. Positive electrode materials typically consist of compounds such as lithium iron phosphate, lithium manganese oxide, or lithium cobalt oxide, while graphite materials are commonly usedfor the negative electrode. Additionally, the electrolyte is a crucial component and usually consists of organic solvents and lithium salts. At this stage, quality control focuses on ensuring the purity and stability of the raw materials.接下来是制备正负极片的工序。
锂离子电池论坛_大容量锰酸锂动力电池的研制
大容量锰酸锂动力电池的研制3王先友13, 易四勇1, 肖 琼2(11湘潭大学化学学院,湖南湘潭411105;21湖南海星高科动力电池有限公司,湖南长沙410013)[摘要] 用尖晶石型LiMn 2O 4材料做正极活性物质,石墨做负极材料,成功研制额定容量为20Ah 的4860110型锂离子动力电池1重点讨论了大容量动力型20Ah 锂离子电池的产品设计、质量监控、制造工艺过程和性能检测1特别是研究了电池的功率特性及储存性能1试验表明,大容量4860110型电池115C 倍率的放电比功率达140W/kg ,比能量达9115Wh/kg ,以013C (6A )循环180次后容量保持率约为9116%1关 键 词:动力电池;锂离子电池;性能;研制中图分类号:TM912 文献标识码:A 文章编号:100025900(2009)022*******The Design and Manufacture of High C apacityLi 2ion Pow er B attery with LiMn 2O 4C athodeW A N G X ian 2you 13, Y I S i 2yong 1, X IA O Qiong 2(11Depart ment of Chemistry ,Xiangtan University ,Xiangtan 411105;21Hunan Haixing high 2tech power batteries Co 1Ltd ,Changsha 410013China )【Abstract 】 4860110size Li 2ion power battery with 20Ah nominal capacity was designed and fabricatedwith spinel LiMn 2O 4cathode and graphite anode 1This paper focused on the design ,manufacture ,perform 2ance testing and quality control of high power Li 2ion batteries ,especially emphasized on power property andstorage characteristics of the battery 1The results showed that the specific power of 4860110battery at arate of 115C is 140W/kg ,specific energy is 9115Wh/kg ,013C (6A )discharge capacity retains about9116%after 180cycles 1K ey w ords : power battery ;Li 2ion battery ;performance ;research and development随着人们对于环境保护的加强,汽车尾气带来的环境污染已经引起了广泛的关注,为了根治汽车尾气对环境造成的污染,电动汽车的研究、开发,乃至产业化成为全世界关注的问题1然而,制约电动汽车发展的最大瓶颈就是动力电池1作为电动车应用的动力电池应具有以下特点[1～3]:1)高能量和高功率;2)高能量密度;3)优良的循环性能,使用寿命长;4)能快速充放电,抗过充过放电能力好;5)安全可靠;6)成本低;7)无公害1目前在纯电动车上应用的电池主要是铅酸电池1虽然铅酸电池污染严重,而且低的质量比能量和体积比能量,使其难以满足纯电动车的要求1但由于铅酸电池具有开路电压高(210V )、成本低廉、使用可靠、大电流放电性能良好、原材料丰富及铅回收率高等优点,使得铅酸电池在电动车上得到广泛应用;燃料电池是车载动力最经济、最环保的解决方案,但是要实现商业化还有许多问题需要解决,如价格昂贵的Pt 催化剂、氢的储存和运输等,限制了其在电动车上的应用;锂离子电池是近年来发展起来的一种新型绿色环保电池,具有能量密度高,自放电小,循环寿命长,无记忆效应和环境污染小等优点,在电子工业、通信产业和计算机上被广泛使用,但作为动力电池应用方面,因为动力电池特殊的使用环境,对电池提出了更高的要求,虽然锂电池的保护电路已经比较成熟,但对动力电池而言,要真正保证安全,正极材料的选择十分关键1,在锂离子电池中使用量最多的正极材料有以下几种:钴酸锂(Li 2CoO 2)、锰酸锂(LiMn 2O 4)、镍钴锰酸锂(LiCo x Ni y Mn z O 2)以及磷酸铁锂(LiFePO 4),金属钒氧化物[4](MVO )等1近年来的研究发现以尖晶石锰酸锂作为正极材料的锂离子动力电池不但安全性能好,而且第31卷第2期2009年6月 湘 潭 大 学 自 然 科 学 学 报Natural Science Journal of Xiangtan University Vol 131No 12J un 120093收稿日期:2008210221 基金项目:“十一五”国防基础研究项目(A3720061186) 通信作者:王先友(1962— ),男,湖南湘乡人,教授,博士生导师1E 2mail :wxianyou @yahoo 1com具有很好的大电流放电特性[5],电池的循环寿命较长,因此,锰酸锂作正极活性物质的锂离子电池是目前最具竞争力的动力电池[6～8]1虽然目前国内外关于小容量的锂离子动力电池已有报道,但关于高功率大容量的锂离子动力电池制备技术的报道较少,本文用尖晶石型LiMn 2O 4材料做正极活性物质,设计和制造了额定容量为20Ah 的4860110型锂离子动力电池,并对其性能进行了测试11 实验正极活性物质用尖晶石型LiMn 2O 4,将LiMn 2O 4、导电剂、粘结剂以及溶剂按一定比例混合,涂敷在铝箔上,经过烘干、碾压、剪裁等工艺制成正极极片;再以铜箔为负极集流体,石墨为负极活性物质,按制备正极极片相同的工艺制备负极极片;将正、负极片及隔膜(Celegard 2325)卷绕后装入电池壳体中,注入电解液(电解液为广州天赐公司1mol/L Li PF 6/EC +EMC +D EC ,含成膜添加剂),再经过化成工艺,得锂离子动力电池1单体电池的充放电性能、循环性能和储存性能等检测采用兰电电池性能测试仪(武汉金诺L AND );单体电池的内阻测试采用RBM 2200智能电池内阻测试仪(深圳超思思)12 电极及电池设计动力电池在使用过程中,电池本身产生的热量将直接影响电池性能,为了满足大电流放电的要求,同时为提高其循环性能,设计和制备时采用以下措施来保证大容量锂离子动力电池的性能:1)电池设计时,尽量减小极片间的空隙,提高导热性能,以避免热量的积聚,阻止内压升高,提高充电效率;2)电池采用厚基体、薄电极结构,以减小电极的欧姆电阻,以提高其高功率放电性能[9];3)为了确保电池在充放电循环中不掉粉粒、不溶胀脱粉,成膜结构不会被破坏1在极片制备过程中严格控制涂膜的温度和湿度等环境因素;4)严格控制辊压极片厚度的均匀性,避免出现正负极片与隔膜间局部点接触;5)电池正极在放电时容易膨胀,从而影响正极容量和降低寿命1低正极极片厚度方法,提高正极极片的均匀性,并保持良好的卷绕紧密度的方法来解决正极膨胀,改善其循环寿命;6)4860110电池采用多卷芯结构设计,通过合理设计极片长度,避免因正负极不能很好对应而造成的析锂现象1此外,严格控制卷绕工艺,使卷绕松紧度达到前后均匀一致,卷绕后隔膜、极片均不折皱,保证了电池低的内阻及性能稳定,使得电池既能够大电流放电又可以减少充放过程中热量的产生[10],从而保证其较长的循环寿命1表1为根据上述设计思路设计的大容量锂离子动力电池的基本参数1所设计的锂离子动力电池要求在115C (30A )的大电流工作的情况下,具有较高的比功率和比能量1表1 大容量锂离子动力电池的设计参数T ab 11 The m ain design parameters of high capacity Li 2ion pow er b attery正极活性物质LiMn 2O 4负极活性物质石墨外形尺寸/mm48×60×110容量/Ah≥20内阻/m Ω≤10115C 持续放电功率/(W/kg )≥120115C 持续放电能量/(Wh/kg )≥903 电池性能测试311 电池的容量特性单体电池在常温下以6A (013C )恒流充电到412V 后转恒压充电,当充电电流小于014A 时停止001 湘 潭 大 学 自 然 科 学 学 报 充电(以下试验均用该方法充电),而后以6A 恒流放电到310V ,图1为电池013C 首次充放电曲线1从图1可见,电池013C 充电容量为21138Ah ,其中恒流充电容量为18164Ah ,恒流充电容量占总图1 20Ah 锂离子电池首次充放电曲线Fig 11 The first charge 2discharge curves of 20Ah Li 2ion battery 充电容量的8712%;首次放电容量为21113Ah ,首次充放电效率达9818%,中值电压为318279V 1312 电池的内阻及其放电特性采用RBM 2200智能电池内阻测试仪检测,电池的内阻为7m Ω,低于表1中规定的R ≤10m Ω的要求1作为电动工具用电源,应具有良好的大电流持续放电能力,图2给出了常温下单体电池不同倍率的放电曲线1图2为20Ah 锂离子电池不同倍率下的放电曲线,电池在同等充电制度(013C )下充满电,分别在不同放电倍率,即以2～20A 电流放电1从图2可知,随着放电倍率的增加,放电初期电压下降速度加快,放电平台电压下降,放电平台的降低使得放电容量随之降低,这是因为随着放电电流的增加,图2 20Ah 锂离子电池不同倍率放电曲线Fig 12 The discharge curves of 20Ah Li 2ion battery at different rates 电池的欧姆电压降升高,以及电池的电化学极化和浓差极化增大1随着放电电流的增大,放电容量逐步减小,电池放电中值电压亦减小12A 和20A 放电容量分别为21142Ah 和20124Ah ,电流增大10倍,容量减小515%1电池显示出优良的倍率放电性能1313 大电流放电性能对于动力电池来说,电动车在爬坡和加速时需要较大的瞬时功率,因此大电流性能是一个重要指标1图3是制备的动力电池在室温下以30A 电流的放电曲线1图3记录了20Ah 锂离子电池在013C 充电制度下充满电,以30A 的电流进行大电流放电的情况1图3 20Ah 锂离子电池大电流放电曲线Fig 13 The high 2current discharge curve of 20Ah Li 2ion battery 从图3可知,在30A 的大电流情况下,电池放电容量高达1916Ah ,为额定容量的98%1其放电平台为315V ,显示出电池有优良的大电流放电性能;同时,制作的4860110型电池重量约为750g ,由此得出电池115C 倍率的放电比功率为140W/kg ,比能量为9115Wh/kg ,满足表1的设计要求,适合做电动车用动力电源1314 荷电保持与容量恢复能力为了检测上述方型电池的自放电性能,对其进行了荷电保持与容量恢复能力测试,电池的荷电保持能力测试方法为单体电池在常温充电后以开路状态搁置28d ,之后将电池以6A (013C )恒流放电,根据储存后放电容量得出,可以表达为额定容量的百分数1电池的荷电保持能力结果如图4所示,将经过荷电保持能力测试的电池在常温条件下以013C 倍率进行充放电,所放出容量为额定容量的百分数即为其容量恢复能力1锂离子电池容量恢复能力见图51101第2期 王先友,等 大容量锰酸锂动力电池的研制 图4 20h 锂离子电池搁置28d 后013C 放电曲线 图5 20Ah 锂离子电池搁置28d 后容量恢复曲线Fig 14 The 013C discharge curve of 20Ah Fig 15The Capacity recovery curve after28daysLi 2ion battery after 28days storage storage of 20Ah Li 2ion battery由图5可知,电池充满电搁置28d 后放电,放电容量为16196Ah ,约为额定容量的85%;由图1可知,电池013C 倍率下初始容量为21113Ah ,因此,电池的自放电率约为每天017%1图6为对经过荷电保持能力测试的电池在常温下013C 充电后的放电曲线,由图可知放电容量为18187Ah ,由此得出,电池的容量恢复能力为9413%1符合电动汽车用锂离子蓄电池荷电保持率应不低于额定值的80%,容量恢复能力应不低于额定值的90%的标准1315 循环寿命图6 20Ah 锂离子电池013C 循环特性Fig 16 The cycle curve of 20Ah Li 2ion battery with 013rate 动力电池因其充放电频率高,放电后不能及时充电等等,对电池的循环性能提出了更高的要求,动力电池必须具有良好的循环寿命,以满足电动工具的使用要求1图6为电池在室温条件下以013C 倍率进行循环实验的循环曲线1由图6可以看出,电池在013C 倍率下放电的稳定性比较好,容量衰减较少,电池的首次放电容量为20173Ah ,经过6A 循环180次以后,放电容量保持在19Ah ,约为额定容量的95%,对应初始循环容量20173Ah ,容量保持率为9116%1电池显示出良好的循环性能1316 安全性能为考察电池的安全性能,我们根据电动汽车用锂离子蓄电池标准,对电池进行了外部短路、过充、针刺以及加热试验1测试要求及结果见表2表2 锂离子动力电池安全试验评估T ab 12 S afety evalu ation of the lithium ion pow er b attery项 目试验条件要求结果测试结果过充电3C ,10V 不爆炸、不起火不爆炸、不起火外部短路阻值小于5m Ω不爆炸、不起火不爆炸、不起火针刺φ3mm 钢针刺破短路不爆炸、不起火不爆炸、不起火加热85℃,120min不爆炸、不起火不爆炸、不起火 从表2可以看出,电池安全性能良好,符合QC 2T 74322006电动汽车用锂离子蓄电池标准的要求14 结论用LiMn 2O 4作正极活物质,石墨作负极活性物质,用Celgard2325作隔膜,用1mol/L Li PF 6/EC +201 湘 潭 大 学 自 然 科 学 学 报 2009年EMC +DEC 作电解液,设计和制备了额定容量为20Ah 的4860110型锂离子动力锂离子电池,测试结果表明:1)电池初次放电容量达到21113Ah ,电池的内阻仅为7m Ω1电极的涂覆量达到电池容量设计的要求,同时电极不掉粉,符合电池装配的要求12)电池180次循环容量保持约为额定容量的95%,为初始容量的9116%,电池显示出良好的循环性能13)电池在室温储存28d ,自放电率约为每天017%,容量恢复能力达9413%,符合电动汽车用锂离子蓄电池标准要求14)电池115C 倍率放电比功率为140W/kg ,比能量达9115Wh/kg ,适合做电动车用动力电源15)电池安全性能良好,符合QC 2T 74322006电动汽车用锂离子蓄电池标准的要求1参 考 文 献[1] 胡信国1动力电池进展[J ]1电池工业,2007,12(2):113-1181[2] 李诚芳1电动自行车及其电池[J ]1电池工业,2004,9(3):125-1301[3] 崔萌佳,戴永年,姚耀春,等1电动车用动力电池的研究概况[J ]1昆明理工大学学报(理工版),2004,29(6):122-1261[4] 王先友,曹俊琪,王欣等1碳包覆对Li/CuV2O6电池性能的影响[J ]1湘潭大学自然科学学报,2008,30(3):103-1081[5] 郭炳琨,徐徽,王先友,等1锂离子电池[M ]1长沙:中南大学出版社,2002:47-751[6] 余国华,肖斌1大容量动力型锂离子电池的研制与生产[J ]1电池工业,2007,12(2):78-841[7] 伊欣1动力型锂离子电池的正极材料选择[J ]1科技园地,2007(5):29-311[8] LIAN G R F ,W AN G Z X ,GUO H J ,et al 1Fabrication and electrochemical properties of lithium 2ion batteries for power tools[J ]1Journal ofPower S ources ,2008,184:598-6031[9] 孟蕊,邱瑞珍,高俊奎1电动工具用锂离子电池的开发和性能研究[J ]1电源技术,2007,131(1):30-331[10] 黄坤1锂离子电池的工艺探讨[J ]1电池,2000,30(5):217-2181责任编辑:朱美香301第2期 王先友,等 大容量锰酸锂动力电池的研制 。
锂离子电池论坛_磷酸铁锂材料焙烧制备、合成问题
磷酸铁锂材料焙烧制备、合成问题！2007-12-15 16:43磷酸铁锂 LiFePO4（磷酸亚铁锂）材料的焙烧设备：两种窑炉可以解决烧结工艺技术问题！实现工业化生产！技术方法：压块烧结法＼粉末烧结法＼气氛烧结法＼连续烧结法＼间歇烧结法＼真空烧结法＼微波合成法时间温度：４ｈ-１２ｈ左右/５７３-７７３Ｋ左右/９２３-１０２３ｋ左右材料合成：锂源：碳酸锂（Li2CO3）氢氧化锂（LiOH）铁源：草酸亚铁（FeC2O4·2H2O）、醋酸亚铁〔Fe（CH3COO）2〕、磷酸铁〔FePO4·2H2O〕铁粉（4微米）、氧化铁（Fe2O3）磷酸根：磷酸氢铵〔（NH4）2HPO4〕、磷酸二氢铵*〔NH4H2PO4〕、磷酸铵〔（NH4）3PO4〕、碳源：葡萄糖*、蔗糖、碳石墨、Super P、酚醛树脂、碳黑混合原料：磷酸二氢锂（LiH2PO4）、磷酸亚铁（FeHPO4）产品性能：１＼物理指标：温度高，粒度大，粒球好．（在合理温度范围内）２＼电性能：温度高，电容量大．超过合理温度，容量反而小．循环性都不错．文献工艺:(1)取一定摩尔比的Li2CO3,FeC2O4·2H2O,(NH4)2HPO4,置于玛瑙罐中,加入适当比例的玛瑙球,球料比为 0.5-1.0,球磨至混料均匀.然后把混合物放在石英舟中,放入管式炉中于氮气保护下升温.先以5℃/min 升至300℃,后以10℃/min 升至 480-800-20-℃,保温 20 h 后自然冷却.即:1h升温至300℃,50min升温至800℃,保温20h.总体时间约24h,与4#炉一次烧结时间大体一致.(2)以Li2CO3,FeC2O4·2H2O和(NH4) 2HPO4为前驱物按化学计量比混合,采用固相反应法合成LiFePO4.反应分二步进行:第一步,预分解前驱物:前驱物经研磨或加分散剂超声分散后在350℃反应6h后随炉冷却得到中间产物;第二步,高温反应过程:将中间产物研磨,压片,在675℃反应12h,随炉冷却得到LiFePO4.为防止二价铁的氧化,以上反应均在纯净的氮气流中进行.在前驱物中加入适量的蔗糖作为碳源,采用与合成LiFePO4相同的步骤即可获得表面覆碳的LiFePO4(下面简写成LiFePO4/C).(3) 以FeC2O4·2H2O, Li2CO3,MnCO3和(NH4) H2PO4为原料,按化学计量比配比混合,以无水乙醇为介质进行球磨,干燥后转入管式炉中( 上海电炉厂) ,在通入氩气情况下于给定温度煅烧24h,冷却得到.反应时间与4#炉大致一致.极片制作:正极片采用压片法制取,正极膜的组成为 [活性物质]:[乙炔黑]:[聚四氟乙烯]=75:20:5.(4)研磨时液相(丙酮溶液)保护.两步法合成,总时间32h.(5)按一定摩尔比称量LiCO3,FeC2O4·2H2O 和NH4H2PO4,加入适量的葡萄糖作为导电剂前驱物,在玛瑙研钵中加入丙酮进行湿磨. 待原料混合均匀后,放入石英坩锅中,在N2气气氛下于350 ℃预热12 h,使原料完全分解. 冷却后充分研磨,混匀. 分别在400 ～850 ℃的温度范围内焙烧24 h. 缓慢降温,冷却后经研磨得到LiFePO4 / C 复合正极材料. 研磨时液相(丙酮溶液)保护.极片制作:正极活性物质:乙炔黑:60%的聚四氟乙烯乳液(PTFE)按质量比为80: 15: 5混合.电压范围为2. 8 ～ 4. 2 V.图形分析:200 ℃之前的失重主要是析出原料中的结晶水,对应DSC 曲线上一个较小的吸热峰;200 ～250 ℃的温度范围内存在2 个较强的吸热峰,根据热力学数据可知,这分别对应原料中FeC2O4的分解及NH4H2PO4的熔融,同时伴随着质量损失;250 ～350 ℃的区间内有一个较宽的放热峰,同时在TG 曲线上存在失重,由此可预测在此区间内,各物质之间可能发生如下反应:NH4H2PO4 + Li2CO3 → Li3PO4 + NH3↑ + CO2↑ + H2O↑ (1)FeO + NH4H2PO4 → Fe3 ( PO4)2+ H2O↑ + NH3↑ (2)由于固相反应是极为复杂的复相反应,因此并不排除其它反应的可能性. 为了保证反应完全,应适当延长在350 ℃下预烧的时间. 400 ℃后的温度区间内,基本上没有失重,但却存在热量上的变化,这说明随着温度的升高,发生了新的固相反应以及反应产物不断的进行晶型转化或完成晶格规整,因此应选择在400 ℃ 之后的温度范围内合成目标产物. 葡萄糖的无氧热分解失重过程一般发生在200 ～350 ℃较宽的温度区间内,且实验中所用葡萄糖的量较少,故不再对其过程进行分析.文献中最佳温度750℃.(6)溶胶-凝胶法:先合成Fe(OH)2,吸附PO43-,干燥后加还原剂C.总时间13h.极片配比:70:20;10.(7)以Li2CO3,,FeC2O4·2H2O和(NH4) 2HPO4为前驱物按化学计量比混合,采用固相反应法合成LiFePO4.反应分二步进行:第一步,预分解前驱物:前驱物经研磨或加分散剂超声分散后在350℃反应6h后随炉冷却得到中间产物;第二步,高温反应过程:将中间产物研磨,压片,在675℃反应12h,随炉冷却得到LiFePO4.为防止二价铁的氧化,以上反应均在纯净的氮气流中进行.在前驱物中加入适量的蔗糖作为碳源,采用与合成LiFePO4相同的步骤即可获得表面覆碳的LiFePO4(下面简写成LiFePO4/C).两步法合成.极片制作:73:21;6Anderson[14]指出首次循环容量衰减主要由以下两种因素决定,而且这两种因素之间互相影响:(1)锂在单个LiFePO4活性颗粒中的脱嵌/嵌入机理;(2)电极的形貌(如颗粒的大小,形态分布).问题:覆碳量是怎么确定的.(8) 实验所用试剂分别为Fe(CO2)2·2H2O(自制),Li2CO3 (AR 级)和NH4H2PO4 ( AR 级). 按照LiFePO4摩尔配比称取原料,在N2气中于400 ℃下保温12 h,预合成LiFePO4.然后加入质量分数为5%的聚乙烯醇的溶液,球化预合成料,最后将粉体料置入炉膛中,通入N2气进行合成,合成温度为600 ～800 ℃,保温16 h,然后随炉冷却至室温.两步法合成,400℃预合成,PAN球化烧结,总时间28h.极片配比:75;17:8.(9)原料为乙酸锂,草酸亚铁,磷酸二氢铵,液体乙醇做保护和分散剂,气氛保护下60℃干燥.加入2%的铁粉压片,微波合成.正极活性物质:导电性乙炔黑:聚四氟乙烯=75:20:5 .(10)将草酸镍,草酸亚铁,碳酸锂,磷酸氢二氨按LiNixFe1 - xPO4的化学计量配比,其中x 为Ni 的摩尔分数, x 值分别为0,0. 01,0. 03,0. 05,0. 07 和0. 10. 球磨6 h 混合后,在氮气气氛下先以5℃ / min 升到300℃恒温3 h,再以5℃ / min 升到600℃恒温24 h,反应完成后随炉冷却.分段升温,以300℃为界,总时间30h左右.极片配比:75:20;5.(11)偏钒酸铵,草酸亚铁,碳酸锂,磷酸氢二氨按化学计量配比, 球磨6h混合后, 在氮气气氛下,先以5℃升到300℃恒温3h,再以5℃ 升到600℃恒温24h,反应完成后随炉冷却.分段升温法,总时间27h.极片配比;75:20:5(12)分段升温,300℃为界,总时间27h.。
锂离子电池论坛_高功率磷酸铁锂电池
Lawrence Berkeley NationalLaboratory(University of California,University of California) Year Paper LBNLThe development of low cost LiFePO4-based high power lithium-ionbatteriesJoongpyo Shim Azucena SierraKathryn A.StriebelThis paper is posted at the eScholarship Repository,University of California./lbnl/LBNL-54098Copyright c 2003by the authors.The development of low cost LiFePO4-based high power lithium-ionbatteriesAbstractThe cycling performance of low-cost LiFePO4-based high-power lithium-ion cells was investigated and the components were analyzed after cycling to determine capacity fade mechanisms.Pouch type LiFePO4/natural graphite cells were assembled and evaluated by constant C/2cycling,pulse-power and impedance measurements.From post-test electrochemical analysis after cycling, active materials,LiFePO4and natural graphite,showed no degradation struc-turally or electrochemically.The main reasons for the capacity fade of cell were lithium inventory loss by side reaction and possible lithium deposition on the anode.THE DEVELOPMENT OF LOW COST LiFePO4-BASEDHIGH POWER LITHIUM-ION BATTERIESJoongpyo Shim, Azucena Sierra, Kathryn A. Striebel Environmental Energy Technologies Division, Lawrence Berkeley National LaboratoryBerkeley, CA 94720 USAABSTRACTThe cycling performance of low-cost LiFePO4-based high-powerlithium-ion cells was investigated and the components were analyzed aftercycling to determine capacity fade mechanisms. Pouch typeLiFePO4/natural graphite cells were assembled and evaluated by constantC/2 cycling, pulse-power and impedance measurements. From post-testelectrochemical analysis after cycling, active materials, LiFePO4 andnatural graphite, showed no degradation structurally or electrochemically.The main reasons for the capacity fade of cell were lithium inventory lossby side reaction and possible lithium deposition on the anode.INTRODUCTIONMuch research has been devoted to the study of rechargeable lithium batteries for application in hybrid electric vehicles (HEVs), where low price, long calendar life, safety and high power capability are required [1,2]. The active materials found in consumer-size lithium batteries, such as the synthetic graphite MCMB and LiCoO2, will need to be replaced with lower cost materials such as natural graphite and cathode materials, such as those containing iron and manganese.In the Batteries for Advanced Transportation Technologies (BATT) program sponsored by Department of Energy (DOE), we have been studying the LiFePO4/natural graphite cell with a liquid electrolyte, as a low-cost baseline cell for application in EV, HEV or FCEV’s. In previous work, we reported a limited cycle life for this cell system due to the consumption of the cycleable lithium at the anode by side reaction [3]. This was determined from post-test electrochemical analysis of the electrodes removed from the cycled cells [4]. In this work, we report on the addition of a carbon coating to the Al current collector which results in 2.5 times increased cell cycle life for 100% DOD cycling at C/2. In addition, the area specific impedance (ASI) of our pouch cells has dropped by an order of magnitude. This brings this technology into the realm of possibility for applications requiring high power as well as high-energy.EXPERIMENTALThe twelve-cm2 pouch cells contained LiFePO4 cathodes and natural graphite anodes. The cathodes were prepared from 82% carbon-coated LiFePO4 from the University of Montreal, 8% conducting carbon and 10% PVdF binder (Kureha). The NMP slurries of were cast onto either bare Al current collectors or carbon-coated Al (C/Al) current collectors. The C/Al were prepared in our lab with very thin coatings of Shawiniganblack and PVdF from the same type of slurry. These were dried extensively before preparing the cathodes. The anodes were prepared from SL20 natural graphite (Superior Graphite) and 10% PVdF binder (Kureha) on bare copper current collectors. The 10mAh pouch cells were assembled with Celgard 2500 and 1M LiPF6+EC/DEC (1/1) electrolyte in an Ar-filled glovebox. Two formation cycles were carried out at C/25 to form a smooth SEI layer on the anode. Cycle-life testing was carried out with constant cycling (C/2) between 2.5 and 4.0V. A reference performance test (RPT) with high pulse of discharge 5C and charge 3.75C was carried out every 80 cycles to monitor the pulse power capability of the cell. More details of the manufacturing process and test protocol were described in previous work [5]. After cycling, the pouch cell was disassembled in the fully discharged state and each electrode was washed in DEC before electrochemical and other analysis in the glovebox. Electrochemical analysis of the electrode components before and after cycling was carried out in half-cells with Li reference and counter electrodes and the same electrolyte.RESULTS AND DISCUSSIONThe C/Al used in this work contained a layer less than 10 µm thick with a loading of about 0.1 mg/cm2. The performance of LiFePO4 cathodes prepared on C/Al and Al current collectors is compared in Fig. 1 which shows discharge voltage profiles for discharge rates from C/5 to 5C. The LiFePO4 cathode on Al foil (left figure) shows large ohmic drops at high rates in the region of the flat plateau and a large decrease of specific capacity as rate is increased. The very thin carbon layer on the current collector (C/Al) appears to greatly reduce the contact resistance between electrode layer and current collector. Ohmic resistance of these cathodes, calculated from voltage increase at the end of discharge, decreased almost 80% (196Ω−cm2Æ ~40Ω−cm2).The cycle performance of LiFePO4/natural graphite pouch cells prepared from these two types of cathode is compared in Fig. 2. Both cyclability and coulombic efficiency are significantly improved with the use of the C/Al in the cathode. Part of the improvement can be traced directly to the lower impedance of the cells with the C/Al. Fig. 3 shows the ASI (area specific impedance) of the pouch cells, which is calculated from RPT, before and after cycling. The ASI of cell with the C/Al in the LiFePO4 cathode is significantly lower than cell with normal LiFePO4 cathode, but more significantly, this low impedance is maintained during cycling. The ASI of the improved cell after 400 cycles is much lower than that of old cell after 80 cycles. However, the improved cell still has high capacity fade rate of about 0.1%/cycle. Our target for these pouch cells is 0.05%/cycle or a loss of 20% of the C/2 capacity loss after 400 cycles. In order to gain more insight into the capacity fade in these cells, they were taken apart as discussed above and the electrodes were examined in half-cells against lithium. Electrochemical DiagnosticsMany different mechanisms have been invoked for the explanation of capacity fade occurring in lithium-ion cells, most concerning the stability of one or both of the electrodes. Our lab has examined several mechanisms for power and capacity fade observed in high-power lithium-ion cells containing Co-doped LiNiO2 and graphite, such as 1) degradation of active material, 2) impedance rise of cell by formation of SEI layer,3) lithium inventory loss by side reaction, 4) loss of carbon as conductive additive from cathode, etc. [6-10]. In our previous work with the LiNi0.8Co0.15Al0.05O2 cells, performance loss was found to be a combination of loss of lithium inventory and structural degradation of the cathode active material and impedance characteristics. In contrast, our early studies of LiFePO4/natural graphite cells showed that lithium inventory loss and structural degradation of the anode were most important. The LiFePO4 was found to be exceptional stable to long-term cycling [11,12].The LiFePO4(C/Al)/natural graphite cell was cycled 400 times and then fully discharged at C/25 before disassembly in the glovebox for electrochemical diagnostic analysis. The potential profiles during the C/25 cycling of the anode and cathode against lithium metal in excess electrolyte are compared with those from fresh electrodes in Fig.4. The C/25 capacities of fresh and cycled electrodes indicate how much lithium can be cycled into and out of the active material without ohmic effects. This gives a measure of the structural stability and reversibility of active material. In Fig. 4, the C/25 capacities of cycled anode and cathode are almost same with fresh electrodes. The data show that these active materials are electrochemically stable during 400 cycles. This result for natural graphite is consistent with those from literature for other types of graphite [11-13]. The C/25 behavior of the LiFePO4(C/Al) cathode again shows excellent stability, in contrast to the structural degradation and phase segregation seen with the LiNi0.8Co0.15Al0.05O2 cathodes [10].The electrode samples were also measured at high rate to look at the changes in electrode impedance characteristics. The 5C profiles (Fig. 4) from the cycled cathodes also compare very well with those from the fresh LiFePO4(C/Al) cathodes, in contrast to previous results for cathodes with un-coated current collectors [12]. The carbon coating appears to ensure maintenance of a low contact resistance with the LiFePO4active material. This is a direct reflection of the stable cell impedance shown in Fig. 3. The cycled anodes also showed excellent capacity and no significant impedance rise with cycling when compared to the fresh anodes.These analyses have eliminated all of the capacity/power fade mechanisms proposed above, except for the consumption of cycleable Li from the cell. The measure of lithium loss is demonstrated in Fig. 5. The first charge of the cycled cathode, in a half-cell against lithium, reveals how much cycleable lithium is remaining in the cell after cycling. We are fairly confident that since the cell was discharged at slow rate before disassembly and the anode samples tend to show voltages greater than 1.5V vs. Li, that there is no cycleable Li remaining in the anode. Comparison of this first charge capacity with the full capacity on the second cycle (shown in Fig 4 and 5) shows that the LiFePO4 cathode contains only 55% of the original Li content after formation and cycling. Part of this, about 24%, was lost during the anode formation process and the balance of about 21% was lost during cycling. From results of Figs 4 and 5, we conclude that the main reason for the capacity fade in these LiFePO4/natural graphite pouch cells is the loss of cycleable lithium. This type of loss is usually associated with the continual formation of the SEI, which is possibly preceded by the dissolution of the SEI. We did observe a significant amount of gassing in these pouch cells during cycling, suggesting the continual oxidation of the electrolyte solvent(s). The fact that the impedance of the anode was not compromised during this side-reaction also suggests that the SEI is maintaining a fairly steady thickness, or at least is maintaining a high conductivity.The cyclability curves in Fig. 2 show small but sharp drops in capacity at the 80 cycle intervals where the RPT tests are carried out, suggesting that the high current pulses in this measurement may be exacerbating the capacity loss in the cell. The high overpotentials developed during the 10-second 3.75C charge pulses at high SOC could lead to lithium deposition on a low conductivity anode. This is especially apparent for the cell without the C/Al in the cathode. To investigate the effect of the RPT measurements on the capacity maintenance in these cells, we replaced the RPT with a full-spectrum impedance measurement to keep track of the increases in cell resistances during cycling. The AC perturbation employed potential swings of only ± 10 mV and is not expected to lead to large overpotentials or Li deposition. However, as is shown in Fig. 6, the cyclability and coulombic efficiency are essentially the same whether subjected to the RPT pulses or not. Both of these cells contained the C/Al in the cathode. However, comparison of the impedance changes in Fig. 7 shows that impedance of the cell subjected to the RPT is much higher than the cell without RPT after 80 cycles, even though the impedances of fresh cells (small figure in Fig. 7) were quite similar. Further analysis of the anodes after cycling will be carried out to understand this added sources of degradation, which could be quite significant to the application of the LiFePO4/natural graphite cell in a high-power pulse application such as the HEV..CONCLUSIONSThe addition of a carbon-coated current collector to the cathode of the LiFePO4/natural graphite cell lead to 2.5 times improvement in cyclability. In addition, the cell impedance was reduced by an order of magnitude and the impedance rise during cycling was only a few percent. Post-test electrochemical analysis of cycled electrodes showed that these electrodes did not lose their original capacity when provided a large source of Li, even after 400 cycles. However, it was revealed, in the half-cell studies of the cathode, that 21% of cycleable lithium was consumed during cycling. Cells cycled with and without periodic high-current-pulse RPT measurements showed similar cyclability but a faster rate of impedance rise during cycling for the cell subjected to the RPT. This could possibly result from lithium deposition during the charging pulses at high SOC. Spectroscopic analysis of the anode surfaces will be carried out to further understand the side-reactions going on in this cell.ACKNOWLEDGEMENTSWe acknowledge the supply of electrode materials from Hydro-Quebec, U. de Montreal and Superior Graphite. This work was supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of FreedomCAR and Vehicle Technologies of the U.S. Department of Energy under Contract No. DE-AC03-76SF00098.REFERENCES1. T.Q. Duong, J. Power Sources , 89, 244 (2000).2. N. Terada, T. Yanagi, S. Arai, M. Yoshikawa, K. Ohta, N. Nakajima, and N. Arai, J. Power Sources, 100, 80 (2001).3. J. Shim, A. Sierra, K.A. Striebel, abstract #370, IMLB 11, Monterey, USA, June 20024. J. Shim, A. Sierra, K.A. Striebel, abstract #123, ECS meeting, Salt Lake City, USA, Oct. 20025. J. Shim, K.A. Striebel, J. Power Sources , 122, 188 (2003).6. X. Zhang, P.N. Ross, R. Kostecki, F. Kong, S. Sloop, J.B. Kerr, K.A. Striebel, E.J. Cairns, F. McLarnon, J. Electrochem. Soc ., 148, A463 (2001).7. J. Shim, R. Kostecki, T. Richardson, X. Song, K.A. Striebel, J. Power Sources , 112 222, (2002)8. R. Kostecki, F. McLarnon, J. Power Sources , 119-121, 550 (2002).9. R. Kostecki, F. McLarnon, Electrochem. Solid-State Lett ., 5, A164 (2002).10. K.A. Striebel, J. Shim, E.J. Cairns, R. Kostecki, Y.-J. Lee, J. Reimer, T.J. Richardson, P.N. Ross, X. Song, G. V. Zhuang, J. Electrochem. Soc , submitted.11. K.A. Striebel, A. Guerfi, J. Shim, M. Armand, M. Gauthier, K. Zaghib, J. Power Sources , 119-121, 951 (2003).12. J. Shim, K.A. Striebel, J. Power Sources , 119-121, 955 (2003).13. D. P. Abraham, J. Liu, C. H. Chen, Y. E. Hyung, M. Stoll, N. Elsen, S. MacLaren, R. Twesten, R. Haasch, E. Sammann, I. Petrov, K. Amine, G. Henriksen, J. Power Sources , 119-121, 511(2003).2.42.62.833.23.43.604080120160Specific capacity(mAh/g)E v s . L i /L i +(V )2.42.62.833.23.43.604080120160Specific capacity(mAh/g)E v s . L i /L i +(V )Fig. 1. Discharging voltage profiles of LiFePO 4 cathodes on only Al foil (left) and carbon-coated Al foil (right) for various C rates. Charging rate C/2.0204060801000100200300400Cycle NoC a p a c i t y r e t e n t i o n (%)0.9911.011.02E f f i c i e n c yFig. 2. Cyclability and efficiency of pouch lithium-ion cells for constant C/2 cycling0100200300400500600700800020406080100Depth of discharge (%)A S I (Ωc m 2)Fig. 3. ASI (area specific impedance) of pouch cells, which was calculated from RPT00.20.40.60.810100200300400Specific capacity (mAh/g)E v s . L i /L i +(V )2.42.62.833.23.43.63.8404080120160Specific capacity (mAh/g)E v s . L i /L i +(V )Fig. 4. Post-electrochemical test of electrodes in half-cell against fresh Li metal2.42.62.833.23.43.63.84020406080100120140160Specific capacity (mAh/g)E v s . L i /L i +(V )Fig. 5. Voltage profile of cycled cathode at C/25 in half-cell against fresh Li metal020406080100C a p a c i t y r e t e n t i o n (%)E f f i c i e n c ycycling 02468101214Z'Z "Fig. 7. Impedance plots of cells with and without RPT before and after cyclingLBNL-54098Keywords : LiFePO4, natural graphite, lithium-ion battery, diagnostics。
锂离子电池论坛_ATL电池的化成
锂电芯电池的化成
锂电芯的化成是电池的初使化,使电芯的活性物质激活，即是一个能量转换的过程。
锂电芯的化成是一个非常复杂的过程，同时也是影响电池性能很重要的一道工序，因为在Li+第一次充电时，Li+第一次插入到石墨中，会在电池内发生电化学反应, 在电池首次充电过程中不可避免地要在碳负极与电解液的相界面上、形成覆盖在碳电极表面的钝化薄层，人们称之为固体电解质相界面或称SEI膜(SOLID ELECTROLYTE INTERFACE）。
SEI膜的形成一方面消耗了电池中有限的锂离子，这就需要使用更多的含锂正极极料来补偿初次充电过程中的锂消耗; 另一方面也增加了电极/电解液界面的电阻造成一定的电压滞后。
SEI膜机制的基本内容：
⑴在一定的负极电位下，电极/电解液相界面的锂离子与电解液中的溶剂分子等发生不可逆反应；
⑵不可逆反应主要发生在电池首次充电过程中；
⑶电极表面完全被SEI膜覆盖后，不可逆反应即停止；
⑷一旦形成稳定的SEI膜，充放电过程可多次循环进行。
由此可见SEI膜形成的质量、稳定性、界面的优化是决定电池寿命不可忽视的重要因素。
化成的工艺条件：
⑴机器：目前，ATL使用的是杭州可靠仪器厂提供的锂电芯化成机器。
⑵化成温度：目前ATL采用45℃的高温化成。
⑶化成的流程
目前，我们采用的流程如下：
第一循环：0.1C恒流充到3.4V，然后0.5C充电至4.2V，再恒压到0.05C，0.5C放电至3.0V；
第二循环：0.5C恒流充到4.2V，恒压至0.05C，然后0.5C放电55min.。
锂离子电池制造工艺及各工序品质控制要点
锂离子电池制造工艺及各工序品质控制要点1.引言1.1 概述锂离子电池作为一种高效、轻便且可靠的电力储存装置，广泛应用于手机、电动汽车、无人机等领域。
随着市场需求的增长和技术进步，锂离子电池制造工艺也在不断改进和完善。
本文将重点探讨锂离子电池制造工艺及各工序品质控制要点，并结合品质监控技术应用案例分析，为相关行业提供有益的参考和指导。
1.2 研究背景随着科学技术的不断发展，人们对新能源的需求越来越迫切。
锂离子电池由于其高能量密度、长寿命以及环境友好的特点，成为了新能源领域最具潜力的能量转换和储存设备之一。
然而，在实际生产过程中，由于工艺参数和原材料质量等因素的影响，锂离子电池存在一些品质问题，如容量衰减、内阻增加等。
因此，研究锂离子电池制造工艺及各工序品质控制要点，对于提高产品品质和性能具有重要意义。
1.3 目的和意义本文旨在系统地介绍锂离子电池制造工艺及各工序品质控制要点，并探讨传统监控技术与先进监测技术的应用案例。
具体目标如下：1) 概述锂离子电池制造工艺的步骤总览，包括正极材料制备、负极材料制备等关键工序；2) 分析各工序品质控制的概述，重点关注切割与成型工艺控制要点、电解液充注工序控制要点等；3) 通过案例分析，比较传统监控技术与先进监测技术在品质监控中的应用优劣；4) 总结研究结果并展望未来锂离子电池制造领域可能的发展方向。
通过本文的撰写和发布，期望能够为锂离子电池行业相关从业人员和研究者提供一份全面而有实际指导意义的参考资料，进一步推动相关技术的发展和创新。
同时，也为其他新能源领域的生产工艺和品质控制提供借鉴与启发。
2.锂离子电池制造工艺:2.1 步骤总览:锂离子电池的制造过程通常包括正极材料制备、负极材料制备、电解液配方及充注、装配以及封装等步骤。
这些步骤相互关联，每个步骤的质量控制都非常重要，以确保最终产品的性能和安全性。
2.2 步骤一: 正极材料制备:正极材料是锂离子电池中的重要部分，其性能直接影响到电池的容量和循环寿命。