大容量锂离子电池的并联性能评估与等价性分析

Parallel Performance Evaluation and Equivalence Analysis of High-Capacity Lithium Ion Battery

为研究大容量锂离子电池在并联方式制约下的性能估计和评价方法,首先,基于不同循环条件和不同电池参数差异条件的并联电池实验,分析了支路电流不平衡的起因和结果;选取简化的并联等效电路模型,详细分析了不同充电阶段的支路荷电状态(state of charge,SOC)累积特性,提出了并联电池电流不平衡的等效计算方法;建立了以并联电池交叉点前的平均电流、放电末端的电流极值和整体容量利用率等参数为基础的电池组综合性能评价指标;阐述了并联电池组和单体电池的等价范围,对延长并联电池使用寿命和成组筛选等应用提供了参考。

To research the performance estimation and evaluation method for high-capacity lithium-ion battery under parallel operation mode,firstly,based on the experiments of parallel lithium-ion batteries under different cyclic condition and various battery parameter differences the cause and result of imbalanced branch currents are analyzed; secondly,selecting simplified parallel equivalent circuit model the cumulative characteristics of the state of charge （SOC） of branches during different charging stages are analyzed in detail,and an equivalent calculation method for current imbalance of parallel lithium-ion batteries is proposed; thirdly,a comprehensive performance evaluation index system,based on such parameters as the average current before the current crosspoint of parallel batteries,the extreme value of current at the end of discharging and the overall capacity utilization,is established; finally,the equivalent range of parallel lithium-ion battery bank and single lithium-ion battery,which can be referential for increase of service life of parallel lithium-ion batteries and groupwise screening of lithium-ion batteries,are expounded.