不同充电机制锂离子电池老化行为分析

闫晟睿 孙笑寒 王丹 刘晓蕾130013） （中国第一汽车股份有限公司 新能源开发院，长春

摘要：不同的充电机制会影响锂离子电池的充电时间、循环寿命和安全性能。锂离子电池充电普遍采用阶梯式充电策略。研究并选取合适的充电策略将提高锂离子电池的经济性，在保证安全性能的前提下降低电动汽车用户对于充电时间的焦虑。锂离子电池在充放电过程中，由于锂离子的嵌入和脱嵌，会导致正极负极

活性材料损失（LAM）和可用锂离子存量损失（LLI）。通过容量增量分析方法（IC）结合扫描电子显微镜（SEM）, X射线光电子能谱（XPS）分析，研究了不同充电机制对锂离子电池老化行为的影响，研究发现两种策略对电池老化的机理相近，但不同充电机制将会导致电池内阻增长率不同，进而影响电池和整车的功率性能。

关键词：锂离子电池 老化行为容量增量法 充电机制

中图分类号：U461.7 文献标识码：B 10.19710/J.cnki.1003-8817.20200371

DOI: The Aging Behavior Analysis of Lithium-ion Batteries Using Different Charging Strategy

Yan Shengrui, Sun Xiaohan, Wang Dan, Liu Xiaolei

（New Energy Development Institute, China FAW Co., Ltd., Changchun 130013）

Abstract：different charging mechanisms will affect the charging time, cycle life and safety of lithium- ion batteries. The lithium- ion batteries generally adopts a stepped charging strategy. Research and selecting appropriate charging strategies will improve the economy of lithium-ion batteries and ensure safety, relieve electric vehicle users from the anxiety of charging time under the premise of ensuring safety. During the charging and discharging process of lithium ion batteries, the intercalation and deintercalation of lithium ions will cause the loss of positive and negative active materials (LAM) and the loss of available lithium ion inventory (LLI). This article uses the Incremental Capacity analysis method (IC) combined with Scanning Electron Microscope (SEM) and X-ray Photoelectron Spectroscopy (XPS), to analyze the influence of different charging mechanisms on the aging behavior of lithium- ion batteries. The study shows that the two strategies have similar mechanisms for battery aging, but different charging mechanisms will result in different growth rates of battery internal resistance, which further affects the power performance of the battery and the vehicle. The method in this paper is of great significance to the analysis of lithium-ion battery charging behavior. Key words: Lithium-ion battery, Aging behavior, Incremental Capacity (IC) method, Charging mechanism

1 前言

三元锂离子电池因其比能量高，比功率大，耐低温性能良好，允许大倍率充电，目前已经广泛应[1]。寿命是评估电池性用于纯电动汽车动力系统能的重要指标之一，电池可用容量会随着循环使用逐渐下降，电池长期处于大倍率充放电状态下会缩短其寿命，合适的充放电策略可以减缓这种变化，从而节约成本。因此，研究锂离子电池循环使用过程中充放电倍率对其容量衰减的影响具有重要意义。

不同的充放电倍率对锂离子电池衰减机理的