【摘要】 锂离子电池的极化内阻是不可逆热测试的关键参数。为了更准确地计算极化内阻,针对三元软包锂离子动力电池,进行了HPPC测试、熵热系数测试、充放电温升测试,采用两种方法对极化内阻进行了计算,一种是通过电压变化量除以电流得到,另一种是通过建立二阶RC模型,结合HPPC测试工况辨识得到。根据两种方法得到的极化内阻,结合Bernardi生热速率模型公式对电池进行了1C充电和0.5C、1C、2C放电下的温度场仿真,并与红外热成像仪记录到的温度分布进行了对比。结果表明:根据二阶RC模型得到的极化内阻进行的仿真与实验数据吻合较好,说明利用二阶RC模型得到的极化内阻更加适用于电池持续充放电过程中的热分析。模型很好地模拟了电池不同充放电倍率下的温度场信息,对电池热分析及热管理可起到指导作用。更多还原

【Abstract】 The polarization resistance of lithium-ion batteries is the key parameter for irreversible heat testing. In order to obtain more precise results of polarization resistance, hybrid pulse power characterization(HPPC) test, entropy thermal coefficient test, and the temperature measurements of the cell in charging and discharging were carried out for a soft-packed NCM lithium-ion battery. Two methods were used to calculate the polarization resistance. One was obtained by dividing the amount of voltage change by the current, the other was identified by establishing a second-order RC model combined with the HPPC test condition. The temperature field simulation under 1 C charging and 0.5 C,1 C and 2 C discharge was carried out by combining with Bernardi’s heat generation rate model formula,and compared with the temperature distribution recorded by the infrared thermal imager. The results show that the polarization resistance obtained by second-order RC model is in good agreement with the experimental data, which indicates that the polarization resistance obtained by the second-order RC model is more suitable for the thermal analysis of the battery’s continuous charge-discharge process.The model simulates well the temperature field information under different charge-discharge ratios of the battery, which plays a key role in the thermal analysis and thermal management of the battery.更多还原