内阻是评价电池性能的重要指标之一,内阻的测试包括交流内阻(ACIR)与直流内阻(DCIR)。交流内阻与欧姆阻抗接近,直流内阻则包含了欧姆电阻和活化电阻。锂离子电池的直流内阻与电池的功率性能直接相关,且关系到电池系统的发热性能、电动汽车的爬坡能力,对电池系统的相关设计有着重要的指导意义,在实际应用中也多用直流内阻来评价电池的健康度和寿命预测等。因此直流内阻测试结果的准确性至关重要。对不同条件下的直流内阻进行了测试对比,测试结果表明,电池SOC状态,脉冲电流,脉冲时间,测试温度以及使用工况都对电池直流内阻有较大的影响。

Internal resistance is one of the most important indicators for evaluating battery performance,and internal resistance tests include AC internal resistance(ACIR)and DCIR.AC internal resistance is close to ohm impedance,while DC internal resistance includes ohm resistance and activation resistance.The DC resistance of lithium-ion battery is directly related to the power performance of the battery,and is related to the thermal performance of the battery system,the climbing ability of electric vehicles,which has important guiding significance to the design of the battery system,and in practical applications we also uses the DC internal resistance to evaluate the health of the battery and predict the life of the battery.The accuracy of DC internal resistance test results is therefore critical.In this paper,the test and comparison of DC internal resistance under different conditions show that the state of battery SOC,pulse current,pulse time,test temperature and operating conditions all have a great influence on the DC internal resistance.