低气压环境轴向压缩锂离子电池的机械性能

Mechanical properties of axially compressed Li-ion battery under low-pressure environment

锂离子电池在低气压环境下的安全性能研究对电池安全管理的改进十分重要。将环境压力设定为50 kPa和95 kPa,对荷电状态(SOC)为25%的21700型锂离子电池进行轴向挤压实验,探究两种气压环境下电池的载荷、电压和温度的变化特征,分析电池轴向压缩下的失效过程,研究电池在低气压环境下受到轴向压缩的机械性能。21700型锂离子电池在低气压环境下,失效模量和结构压溃应力高于常压情况,电池发生失效的位移随着气压的降低,增长了0.4 mm。电池失效后所达到的最高温度随着气压的降低,升高了4℃,内部损坏程度也比常压情况大。

The research on the safety performance of Li-ion battery under low-pressure environment was very important for the improvement of battery safety management.The environmental pressures were set to 50 kPa and 95 kPa,the axial extrusion experiments were performed on a 21700 type Li-ion battery with a state of charge(SOC)of 25%.The variation characteristics of the load,voltage and temperature of the battery under two air pressure environments were explored,the failure process of the battery under axial compression was analyzed,the mechanical properties of the battery under axial compression and low-pressure environment were studied.The failure modulus and structural crushing stress of the 21700 type Li-ion battery under low-pressure environment were significantly higher than those in normal pressure situation,the displacement of the battery failure increased by 0.4 mm with the decrease of air pressure.The maximum temperature reached after the battery failure increased by 4℃with the decrease of air pressure,the damage degree inside the battery was also greater than that under normal pressure.