三元锂电池组最优寿命均衡策略设计及试验验证

Design and Experimental Verification of Optimal Life Balance Strategy for Ternary Lithium Battery Pack

为了充分发挥在采用电池均衡方法有效解决电池成组一致性问题的能力,以三元锂电池组寿命提高为目标,完成均衡方案的设计。实验结果证明该策略在电池组一致性提升方面具有显著成效,可行性较高。研究结果表明:最慢单体容量衰减特性在55%~15%SOC区间呈现,电池容量衰减速率随着ΔDOD的提升而逐渐加快。容量衰减系数F_C在SOC均值达到最高值时达到最大,F_C随着ΔDOD的增大而不断提高,确定单体电池最佳区间对应的SOC均值和ΔDOD分别为40%、80%。循环实验验证测试可有效改善电池组的一致性,同时各单体电池容量经250次循环处理之后几乎相同,均衡效果表现较为优异,容量一致性减至0.0012,缩减0.0051。文中所设计的寿命均衡策略实现了长时间尺度范围的电池组容量一致性优化。

In order to maximize the ability of the battery equalization method to effectively improve battery group consistency,the equalization scheme is designed to improve the life of ternary lithium battery packs.The experimental results show that the strategy is effective and feasible in improving the consistency of the battery pack.The results show that the slowest cell capacity attenuation occurs in the range of 55%-15%SOC,and the cell capacity attenuation rate increases gradually with the increase of ADOD.The capacity attenuation coefficient Fc reaches the maximum when the mean value of SOC reaches the maximum,and the Fc increases with the increase of ADOD.The mean value of SOC and△DOD corresponding to the optimal range of a single battery are 40%and 80%,respectively.Cyclic testing can effectively improve the consistency of the battery pack.Meanwhile,the capacity of each cell is almost the same after 250 cycles,and the balancing performance is relatively good,with the capacity consistency reduced to 0.0012.The life balancing strategy designed in this paper achieves consistent optimization of battery pack capacity over a long time scale.