基于COMSOL的锂离子电池热失控仿真与防控

动力电池是新能源汽车关键部件，为进一步探究其热失控机理及影响因素，总结热失控发展过程，利用COMSOL软件构建锂离子电池单体模型，结合仿真实验结果详细分析其影响因素，并提出一款利用隔热罩、隔热盖板、隔热底座和可滑动扩容盒延缓热失控效果的可延缓热失控的汽车电池包。研究结果表明：热失控过程大致分为加热阶段、喷射和燃烧阶段、熄灭阶段，受4种副反应产热影响；在超过445.08K的高温环境下，长时间工作的锂离子电池易发生热失控，失控热源关键在正极活性材料与电解液分解反应；当电池实际温度超过500 K时，温度若无法及时控制将导致火灾事故发生；同时，对流传热系数越高，电池温度变化越快；初始温度越高，热失控可能性越大。

Thermal Runaway Simulation and Prevention and Control of Lithium-Ion Batteries Based on COMSOL

To further explore the thermal runaway of power battery and summarize the development process, a battery monomer model was constructed by COMSOL software, and the influencing factors were analyzed in detail combined with the simulation results. An automotive battery pack that can retard thermal runaway was proposed. Results showed that the thermal runaway process could be roughly divided into heating phase, injection and combustion phase, and quenching phase, which was affected by four kinds of side reactions of heat production. Under the high temperature environment of over 445.08 K, the lithium-ion battery working for a long time was prone to thermal runaway, and the key source of runaway heat was the decomposition reaction between the cathode active material and electrolyte. When the actual temperature of the battery exceeded 500 K, the temperature would lead to a fire accident if it cannot be controlled in time. The higher the convective heat transfer coefficient, the faster the battery temperature changed; the higher the initial temperature, the greater the possibility of thermal runaway.