基于多米诺效应的锂离子电池热释放速率分析方法

常用实验手段测得单节锂离子电池热释放速率无法真实反映航空运输包装件内大量锂离子电池因发生多米诺效应导致热量散失及传递过程间歇性变化。本文提出一种基于多米诺效应的锂离子电池热释放速率等效分析方法,即通过自主设计的实验平台对3×3排布的典型18650型锂离子电池热失控后发生的多米诺效应及各节电池表面温度进行分析。利用FLUENT使用标准18650型锂离子电池热释放速率曲线用于同等实验条件下的锂离子电池热失控传播仿真模拟,采用二分法逐次修正标准热释放速率、使仿真和实验的锂离子电池表面温度相符。将获得等效的锂离子电池热释放速率曲线再次应用于仿真,得到各电池的最高温度及达到最高温度的时间和实验数据相吻合,验证了修正后的等效热释放速率模型可靠性。该方法可适用于各型号及不同数量包装件内锂离子电池热释放速率获取,指导航空运输锂离子电池火灾防控工程实际。

Analysis method of heat release rate of lithium-ion battery based on domino effect

The heat release rate of single lithium-ion battery measured by the commonly used experimental method is not able to reflect the heat losses caused by the domino effect and the intermittent changes during the transfer process of a large number of lithium-ion batteries within the air transport package.This paper,instead,proposes a method of equivalent analysis for the heat release rate of lithium-ion battery based on domino effect.Namely,the domino effect and the surface temperature of each battery after the thermal runaway of typical 18650 lithium-ion battery in 3 × 3 configuration were analyzed with the help of independently designed experimental platform.Using FLUENT to use the standard 18650 lithium-ion battery heat release rate curve for the same experimental conditions of lithium-ion battery thermal runaway simulation.Then dichotomy was used to revise the standard heat release rate to accord the surface temperature of the lithium-ion battery in simulation and in experiment to obtain equivalent heat release rate curve of lithium-ion battery to apply to further simulation.It turned out that the maximum temperature of each battery and the time to reach maximum temperature coincided with the experimental data,verifying the reliability of the revised equivalent heat release rate model.This method can be applied to obtain heat release rate of various types of lithium-ion batteries in different amount of package,therefore guiding the fire prevention and control project in the air transport of lithium-ion battery in practice.