The frequent accidents of power lithium-ion battery have become the major reason to hinder the development of electric vehicles. In this paper, the thermal runaway process for a 32650 battery is analyzed based on 300°C oven heating experiment in adiabatic rate calorimeter, the rise of temperature, the drop of voltage and the leakage of electrolyte are observed before exploding, which could be used as predictor variables for thermal runaway warning. A large number of smoke releases and diffuses after explosion, which could be utilized as a criterion for determining the explosion. And a lumped chemical reaction kinetics model coupled with three-dimensional heat transfer model is constructed for further discussion. The thermal runaway process of the battery could be accurately calculated by the coupled model. Thermal radiation plays a more important role in heat transfer than heat convection in the process of thermal runaway. The explosion happens when the temperature achieves around 230°C, and the active material mainly starts to decompose at this moment.

中文翻译：

---

32650 锂离子电池热失控期间内部短路和排气的详细有限元模型

动力锂离子电池事故频发已成为阻碍电动汽车发展的主要原因。本文通过绝热量热仪中300°C烘箱加热实验分析了32650电池的热失控过程，在爆炸前观察了温度升高、电压下降和电解液泄漏情况，可用于作为热失控警告的预测变量。爆炸后有大量的烟雾释放和扩散，可作为判断爆炸的标准。并建立了一个集总化学反应动力学模型与三维传热模型相结合以供进一步讨论。通过耦合模型可以准确计算电池的热失控过程。在热失控过程中，热辐射在传热中的作用比热对流更重要。当温度达到230°C左右时发生爆炸，此时活性物质主要开始分解。