三元锂离子动力电池衰减机理  

Fade Mechanism of Ternary Lithium Ion Power Battery

作　　者：杨涛 刘文凤 马梦月 董红玉[2] 杨书廷[2] YANG Tao;LIU Wenfeng;MA Mengyue;DONG Hongyu;YANG Shuting(He′nan Lithium Power Co.,Ltd;School of Chemistry and Chemical Engineering,He′nan Normal University;The Battery Research Institute of Henan,Xinxiang,He′nan 453000,China)

机构地区：[1]河南锂动电源有限公司 [2]河南师范大学化学化学学院 [3]河南电池研究院有限公司,河南新乡453000

出　　处：《应用化学》2020年第10期1181-1186,共6页Chinese Journal of Applied Chemistry

摘　　要：失效分析是通过剖析电池循环过程中复杂的物理和化学变化引起的失效现象,优化材料制备和电池制作工艺,提升电池性能的有效途径。通过对3.0~4.2 V电压范围1C循环1000周镍钴锰酸锂(NCM,LiNi 0.5 Co 0.2 Mn 0.3 O 2)三元锂离子动力电池拆解分析后发现,正极容量损失约为2.73%,负极容量损失约为2.4%。对比正负极片循环前后X射线衍射和场发射扫描电子显微镜分析发现,正极容量损失主要由正极颗粒破碎和结构转变引起的,负极衰减主要由循环过程中Li+持续脱嵌导致石墨层状结构损伤引起的。正极过渡金属阳离子溶解并沉积在负极,催化电解液/电极界面副反应,导致负极过度成膜,活性锂损失,影响电极过程动力学也是电池失效的原因之一。Failure analysis is an effective way to analyze the failure phenomena caused by complex physical and chemical changes during battery cycling,optimize the material preparation and the manufacturing processes of battery,and improve the cycle performance.In this paper,after dismantling and analyzing the ternary nickel cobalt manganese(NCM,LiNi 0.5 Co 0.2 Mn 0.3 O 2)lithium ion power battery(NCM LIPB)at 1 C in the voltage range of 3~4.2 V for 1000 cycles,it is found that the capacity loss of the cathode electrode is about 2.73%,and the capacity loss of anode electrode is about 2.4%.Comparing the X-ray diffraction and field emission scanning electronic microscope results of cathode and anode electrodes before and after cycling,capacity fade of cathode is mainly caused by the breakage of particles and the structural transformation of the NCM layer.The capacity fade of anode is generated by the damage of graphite layer structure,which is caused by the continuous Li+de-intercalation during cycling.Moreover,the positive transition cation dissolves and deposits on the surface of electrodes,and catalyzes the side reaction of electrolyte/electrode interface to result in excessive film formation and loss of active lithium,which affects the dynamics of electrode process,one of the reasons for battery failure.

关 键 词：三元正极 失效机理 离子溶出 动力电池 锂离子电池 

分 类 号：O646[理学—物理化学]