基于等效热模型的锂电池容量衰减特性研究

Research on Capacity Fading Characteristics of Li-ion Battery Based on Equivalent Thermal Model

在动力锂电池的循环使用过程中,温度对其容量衰减有直接影响,而电池结构的密封性导致其内部真实温度无法直接测量。针对此问题,通过测量电池表面及环境温度并运用等效热模型估计其内部的真实温度,构建电池容量衰减与内部温度的ETM-Arrhenius模型,预测锂电池在循环使用中的容量衰减特性。对锂电池进行不同温度下的循环寿命试验,结果表明,该模型能在长期循环中准确预测锂电池容量的衰减程度。

Temperature has a direct impact on the capacity fading of a power Li-ion battery during its lifecycle.However,its real inner temperature cannot be directly measured due to the sealed structure.To solve this problem,the inner temperature of a battery is estimated by measuring the battery surface and ambient temperature with the application of an equivalent thermal model(ETM).Then,an ETM-Arrhenius model is built based on the capacity fading and inner temperature to predict the capacity fading characteristics of the Li-ion battery during its lifecycle.The cycle life test on the Li-ion battery was conducted at different temperatures,and results show that the proposed ETM-Arrhenius model can accurately predict the capacity fading degree of the Li-ion battery during its long-term lifecycle.