三元锂电池内阻特性的研究

Study on DC resistance characteristics of ternary lithium batteries

以2.9 Ah三元锂电池为实验对象,参考FreedomCAR功率辅助型混合动力车电池测试手册,利用HPPC混合脉冲功率测试方法测试不同脉冲电流大小、不同脉冲时间长度下充放电过程中的内阻,实验温度为25℃,得出充放电状态下内阻的变化规律。实验结果表明,随着SOC的增加,充放电过程的内阻都呈现减小趋势,放电过程的内阻R值高于充电过程的内阻R值,且SOC=0.3后,放电过程的R值趋于稳定状态;随着脉冲电流大小的增加,内阻R值减小;随着脉冲时间的增加,内阻R值增加;SOC=0.1和SOC=0.2时的内阻R值明显大于SOC=0.3到SOC=0.9时的R值。

2.9 Ah ternary lithium batteries were taken as the experimental object, the manual FreedomCAR power auxiliary hybrid battery test was taken as a reference. HPPC mix pulse current pulse power testing method was used to test different sizes, different pulse length under internal resistance in the process of charging and discharging. At the experiment temperature 25 ℃, it is concluded the changing rule of the resistance to charge and discharge condition. The experimental results show that with the increase of SOC, the internal resistance of the charge and discharge process tends to decrease, and the resistance of the process is higher than that of the resistance of the charging process. After SOC=0.3, the discharge process the R value of the resistance decreases with the increase of the pulse current. The resistance increases with the increase of the pulse time. The resistance R value of SOC=0.1 and SOC=0.2 is significantly greater than the R value of SOC=0.3 to SOC=0.9.