压缩载荷下两种圆柱锂电池的安全性研究

Study on safety of two kinds cylindrical lithium batteries under compressive load

分析了圆柱形18650和21700两种锂离子电池,受到压缩载荷时的安全性。利用万能试验机、示波器和红外热像仪记录了压缩过程中电池的力学响应、电压变化和温度变化。结果表明,2种电池的力学响应和电压变化具有相同的趋势。利用有限元软件模拟了2种电池的平面压缩过程,与实验测得的力学特性具有很好的一致性。进一步模拟了10 mm直径圆柱压头作用下不同荷电状态电池的局部压缩,发现2种电池都表现出了荷电状态硬化现象,而且在局部压缩载荷下,2种电池都表现出比平面压缩载荷下更小的承载能力。研究结果对于优化电池布局和提升电池使用安全性具有参考价值。

Taking cylindrical 18650 and 21700 lithium-ion batteries as experimental objects,the safety of the two batteries under compressive load was analyzed.A universal testing machine,an oscilloscope and an infrared thermal imager were used to record the mechanical response,voltage change and temperature change of the battery during the compression process.The results show that the mechanical response and voltage change of the two batteries have the same trend.The finite element software was used to simulate the plane compression process of the two batteries,and the mechanical properties are in good agreement with the experimentally measured mechanical properties.The obtained model was further used to simulate the local compression of batteries with different states of charge under the action of a 10 mm diameter cylindrical indenter,and it was found that both batteries exhibited state of charge hardening.Moreover,under local compressive load,both batteries show a smaller load-bearing capacity than under plane compressive load.The research results of this paper have reference significance for optimizing battery layout and improving battery safety.