过充电条件下锂离子电池热失控数值模拟

采用数值模拟方法研究了过充电流（1C、2C、3C和4C）对三元锂离子电池热失控行为的影响.基于多物理场耦合方法建立了过充电条件下锂离子电池三维电-热耦合模型，对电池发生热失控的临界时间，临界温度以及热分布进行了模拟计算.模拟结果与试验测量结果符合较好，各个测试点处的温度和热失控临界点的误差小于8%.过充电流对锂离子电池热失控的临界温度、临界时间以及电池内外部温差有较大影响:过充电流越大，电池发生热失控的时间越短，临界温度越高，区域温差越大，内外部温差越大. 

Thermal Runaway Analysis of Lithium-Ion Battery with Overcharge

In order to study the influence of overcharge current on thermal runaway, numerical model was adopted to calculate the effects of different currents (1C, 2C, 3C and 4C) on thermal runaway under overcharge conditions. A three-dimensional electrochemical-thermal model based on Multiphysics coupling method was built and critical temperature, critical time and heat distribution of thermal runaway with different currents were calculated. Model feasibility was also verified, the error between simulation and experiment was less than 8%. Overcharge has remarkable effects on the thermal runaway of lithium-ion battery in various ways. Results show that the greater the overcharge current is, the shorter the thermal runaway time will be, the higher the critical temperature will become, and the larger the temperature differences between different parts of and the surface and the interior of the battery will be.