高温和荷电状态对锂离子电池单体力学响应的耦合影响

Influence of coupling of elevated temperature and state of charge on mechanical response of Li-ion battery cells

针对锂离子电池机械完整性在高温环境下的研究需求,本文对不同荷电状态(SOC)的圆柱型锂离子电池单体进行高温搁置和高温循环处理,并对处理后的电池单体进行径向挤压试验。试验结果表明:高SOC的电池单体经40℃以上的高温搁置后受压时往往会因结构软化而提早发生内短路,搁置温度越高电池抗变形能力越低;高温短期循环会提高电池单体的抗变形能力。

To meet the research demand of lithium-ion batteries under high temperature,cylindrical lithium-ion battery cells with different State Of Charge(SOC)were placed at elevated temperature for rest and cycle,and then these battery cells were compressed in radial direction in this paper. The experiment results indicate that the cells with a high SOC tend to be short-circuited early under compression after resting at a temperature of 40 ℃ or higher. This is due to the structural softening of the cells. The higher the rest temperature,the lower the resistance of the high SOC cells to deformation. Short cycling under high temperature would increase the resistance of the cells to deformation.