车用圆柱锂电池及模组的机械完整性

Mechanical integrity of cylindrical automotive lithium-ion batteries and modules

为了获取能高效准确探究锂离子电池(LIBs)及模组机械完整性的方法,通过实验探究各荷电状态(SOC)下圆柱锂电池单体在受到不同方向机械外载作用下的机械响应及电化学失效情况.基于实验结果提出均质化电池单体材料模型,建立具有SOC相关性、各向异性的电池单体模型,并提出适用于该模型的2种电池单体失效力学判据.基于该单体模型获取2种典型堆积形式下的电池模组模型,并提出基于该细致模组模型的均质化建模方法,进一步提取出特定堆积方式下的电池模组均质化材料模型,建立相应的均质化电池模组模型,并通过电池模组力学加载实验进行验证.实验结果显示,该均质化电池模组模型能够高效并准确地预测电池模组在复合机械加载条件下的响应.

In order to provide a highly accessible method to explore the mechanical integrity of automotive cylindrical lithium-ion batteries(LIBs)and battery modules,a series of multidirectional loading tests for LIBs at various states of charge(SOC)were conducted to figure out both mechanical and electrochemical response of the LIBs when subjected to mechanical abuse.An homogeneous material model for battery cells was proposed and mechanical model of single LIB with both SOC dependence and anisotropy was established,in terms of the analytic results of experimental data.Two mechanical short-circuit criteria,practical for above-mentioned single LIB model,were proposed and calibrated.Detailed battery module models of two specific packing modes were established based on the single battery model.Homogenization method of the detailed battery module model was illustrated and homogeneous battery module material model was developed.According to the homogeneous material model,homogeneous battery module models of two different packing modes were developed and verified by the mechanical loading experiments of the battery modules.Experimental results show that this homogeneous battery module can predict the performance under multi-direction mechanical abuse precisely with less computing effort.