锰酸锂电池储存后容量衰减机理  

Capacity fading mechanism of LiMn_2O_4 cell after storage

作　　者：刘云建[1,2,3] 宋杨 魏洪兵 王彩娟 赵永 金挺 李新海[3] 郭华军[3] 

机构地区：[1]吴江出入境检验检疫局,吴江215200 [2]江苏大学材料科学与工程学院,镇江212013 [3]中南大学冶金科学与工程学院,长沙410083

出　　处：《中国有色金属学报》2011年第11期2812-2818,共7页The Chinese Journal of Nonferrous Metals

基　　金：国家重点基础研究发展计划资助项目(2007CB613607);国家质检总局科研项目(2008IK260-6);江苏省自然科学基金资助项目(BK2011530);江苏大学高级人才启动基金(10JDG041)

摘　　要：采用商品化的LiMn2O4制作锰酸锂/石墨电池,研究其储存性能,并对储存前后的正极、负极和电解液进行表征分析。结果表明:半荷电常温储存一个月,电池容量衰减3.7%,循环性能得到改善。X射线衍射和透射电镜结果表明:LiMn2O4晶格发生收缩,正极表面形成一层固体电解质(SEI)膜。交流阻抗研究表明:正极阻抗由储存前的62.69Ω增大到储存后的84.64Ω,负极阻抗由储存前的183.1Ω增大到储存后的301Ω。红外光谱分析表明:电解液溶剂和电解质盐均不同程度地发生了分解,锰酸锂电池储存后容量衰减主要是由电极极化、Mn溶解、电解液分解、负极SEI膜增厚等原因造成。The power battery was manufactured with the commercial LiMn2O4 and graphite.The storage performance of LiMn2O4 battery was tested.The cathode,anode and electrolyte before and after storage were characterized.The result shows that the capacity fading ratio of LiMn2O4 battery at half-charged state is 3.7%,but the cycling performance is improved after storage.XRD results show that the crystal lattice of LiMn2O4 shrinks.TEM results show that the surface of LiMn2O4 particles is covered with SEI film.The cathode impedance increases from 62.69 Ω to 84.64 Ω and that of anode increases from 183.1 Ω to 301 Ω.FT-IR results show that the solvent and solutes of electrolyte decompose at a certain degree after storage.The polarization,Mn dissolution,electrolyte decomposition and the incrassation of anode SEI are responsible for the capacity fading of LiMn2O4 battery after storage.

关 键 词：锰酸锂电池 储存 容量衰减 机理 

分 类 号：TM912.2[电气工程—电力电子与电力传动]