高温诱发锂离子电池热失控仿真研究

Simulation research on thermal runaway of lithium ion batteries induced by high temperature

为提高锂离子电池安全性,减少锂离子电池热失控安全事故,以某商用18650三元锂离子电池为研究对象,利用COMSOL Multiphysics 5.6建立三维高温诱发热失控模型,通过对比不同诱发温度、不同换热条件下的温升曲线,探究诱导温度、换热系数对锂离子电池热失控行为的影响规律。结果表明:不同温度条件下,诱导温度越高,热失控温度峰值越高,出现热失控时刻越早;不同换热条件下,对流换热系数越大,热失控时刻越早,达到峰值后温度下降梯度越大。此外,正极材料参与反应可作为热失控现象的关键特征。

In order to improve the safety of lithium ion batteries and reduce safety accidents caused by thermal runaway of lithium ion batteries,this paper uses a commercial 18650 ternary lithium ion battery as the research object,and establishes a three-dimensional thermal runaway model induced by high temperature through COMSOL Multiphysics 5.6.By comparing temperature rise curves under different induced temperatures and different heat transfer conditions,the influence of induction temperature and heat transfer coefficient on the thermal runaway of lithium ion batteries is analyzed and explored.The results show that under different temperatures,the higher the induced temperature is,the higher the thermal runaway temperature peak is and the earlier the thermal runaway occurs.Under different heat transfer conditions,the larger the convective heat transfer coefficient is,the earlier the thermal runaway occurs and the larger the temperature drop gradient is after reaching the peak.Besides,the participation of cathode materials in the reaction can be regarded as a key characteristic of thermal runaway.