锂离子电池低温循环老化的空间分布与特征  

Distribution and characteristics of degradation of lithium ion batteries cycled at low temperature

作　　者：刘中孝 葛昊[1] 李哲[1,2] 张雅琨[3] 张剑波 LIU Zhongxiao;GE Hao;LI Zhe;ZHANG Yakun;ZHANG Jianbo(State Key Laboratory of Automotive Safety and Energy,Tsinghua University,Beijing 100084,China;Beijing Co-Innovation Center for Electric Vehicles,Beijing Institute of Technology,Beijing 100081,China;CH-AUTO Technology Co.Ltd,Beijing 101300,China)

机构地区：[1]汽车安全与节能国家重点实验室,清华大学,中国北京100084 [2]北京电动车辆协同创新中心,北京理工大学,中国北京100081 [3]北京长城华冠汽车科技股份有限公司,中国北京100081

出　　处：《汽车安全与节能学报》2019年第4期502-510,共9页Journal of Automotive Safety and Energy

基　　金：国家自然科学基金资助项目(51577104,U1864214);科技部重点研发资助项目(2017YFB0102201)

摘　　要：为探究锂离子电池的低温循环性能与电池老化后的分布与特征,设计了低温循环的正交实验,通过主因分析、解体物化分析的方法分别探究了影响电池低温循环老化的主次因素、老化后的析锂分布特征。研究结果表明:影响电池低温老化的3个重要因素的主次顺序为温度>充电电流>充电截止电压;析锂电池的老化分布特征为:中间电极层比外侧电极层析锂多,同一电极层内的负极极耳位置和中心位置比同一电极层内其他位置析锂更多。电池内电流密度的分布是电池析锂分布的主要原因,电池内电流密度较大位置的电位更易低于析锂电位而发生析锂,电池设计时应使电流密度均匀分布。Orthogonal experiments were utilized to explore the characteristics and distribution of degradation of lithium ion batteries cycled at low temperature.The main aging factors and internal lithium plating distribution were investigated with the statistical method and post-mortem physical-chemical analysis,respectively.The results showed that the order of the 3 important aging factors are the ambient temperature>charge current>charge cut-off voltage.The amount of lithium plated in center electrodes is greater than that in the outer electrodes.The amount of lithium plated in central area and the area near the negative tab is greater than that on other areas in the same electrode layer.The main reason for such lithium plating distribution is attributed to the non-uniformity in the current density in the battery,as the voltage at areas with larger current density reaches the lithium plating potential easier.Therefore,to alleviate degradation from lithium plating,an effective measure is to design battery with more uniform current density distribution.

关 键 词：锂离子电池 低温循环 析锂 主因分析 老化分布 

分 类 号：TM911[电气工程—电力电子与电力传动]