方形锂离子电池热失控情况下的热管理研究

为了研究某种方形锂离子电池中单个电芯发生热失控事故时电池的整体性能,本文利用ANSYS软件进行热仿真分析,同时通过实验对电池中单个电芯进行过充强制其发生热失控分析热失控。模拟过程中根据电池箱中电芯和冷却装置的结构特性对电池三维模型进行简化,通过设置均匀热流密度内热源来模拟电池发热过程。热失控实验时对单个电芯进行强制性的过充使电芯发生热失控至电芯过压保护。结合模拟仿真和热失控实验中电池系统的温度分布情况,模拟结果和实验结果十分接近从而验证了仿真模型的准确性。根据热失控仿真结果中的电池系统温度分布云图,该型电池的冷却装置能够保证在单个电芯发生热失控的情况下整个电池的安全性。

Thermal Management of a Square Lithium Ion Battery in Thermal Out of Control

In order to study the overall performance of the prismatic lithium when single core exists a thermal runaway accident, ANSYS software was used to analysis the thermal simulations. At the same time, the single cell in the battery is overcharged to force the thermal runaway for analysing it through the experiment. The three-dimensional model of the battery is simplified according to the structural characteristics of the battery cells and the cooling device in the battery box. The heat generation process of the battery is simulated by setting a heat source with uniform heat flow density during the simulation. In the thermal runaway experiment, a forced overcharging of a single cell causes thermal runaway of the cell to overvoltage protection. Combined with the temperature distribution of the battery system in the simulation and thermal runaway experiments, the simulation results are close to the experimental results to verify the accuracy of the simulation model. According to the temperature distribution diagram of the battery system in the thermal runaway simulation result, the cooling device of the battery can ensure the safety of the entire battery in the case of thermal runaway of a single battery core.