不同工况下锂电池热特性影响因素实验研究

Research of influencing factors for thermal characteristics of lithium battery under different working conditions

针对电动汽车在日常运行过程中由于加速、爬坡、路面状况不良等原因导致电池模块内单体电池电压、电流分布不均匀的现象,利用高精密电池测试仪与恒温水浴联用的方法,研究LiCo_(1/3)Mn_(1/3)Ni_(1/3)O_2三元正极材料锂电池在不同环境温度、荷电状态、放电倍率以及循环次数下电池内阻的变化规律以及不同环境温度、荷电状态下温熵系数的变化规律。实验结果表明,不同的工作状态对单体电池的内阻、熵变的影响效果不同,因此,有必要对电池模块内电压、电流的分布状况进行实时监测,并添加散热系统。

The phenomenon of nonuniform current and voltage distribution also occurs under electric vehicles accelerating, climbing or driving on a bad road conditions. The laws between resistance with ambient temperature, SOC, discharge rate and cycle life were studied by the combination of the high-precision test instrument with the water tanks. Meanwhile, the variation law of entropy coefficient in different ambient temperatures and SOC was also discussed. The experimental results show different working conditions have different influence on the total internal resistance and entropy coefficient. It is necessary to monitor the distribution of module voltage and current at real time.