受限空间环境压力对三元锂离子电池热失控影响

Influence of environmental pressure in confined space on thermal runaway of ternary lithium ion battery

为研究三元锂离子电池在空运低压环境中的安全性,通过自主设计搭建的封闭式变压实验舱开展相关实验,对不同荷电状态(SOC)下的三元锂离子电池在不同压力环境(101,80,60,40 kPa)下的热失控特性进行研究,采集电池热失控过程中的温度以及实验舱内的压力变化,并对热失控后实验舱内的气体成分进行分析。结果表明:三元锂离子电池热稳定性随着SOC的升高而下降,常压下100%SOC的电池热失控温度可达650.8℃,初始环境压力越低,相同SOC的电池热失控最高温度越低。随着环境压力的降低,相同SOC的电池在热失控后会生成更多CO,且电解液占比升高。研究结果可为锂离子电池空运安全性研究提供理论依据。

In order to study the safety of ternary lithium ion battery in the low pressure environment of air transportation,the relevant experiments were carried out by using the self-designed closed variable pressure experiment,and the thermal runaway characteristics of ternary lithium ion battery under different state of charge(SOC)and different pressure environments(101,80,60,40 kPa)were studied.The temperature of battery during the thermal runaway process and the pressure variation in the experimental chamber were collected,and the gas composition in the experimental chamber after thermal runaway was analyzed.The results showed that the thermal stability of ternary lithium ion battery decreased with the increase of SOC,and the thermal runaway temperature of battery with 100%SOC under the normal pressure could reach 650.8℃.The lower the initial environmental pressure,the lower the maximum thermal runaway temperature of battery with the same SOC.With the decrease of environmental pressure,the battery with the same SOC would generate more CO after thermal runaway,and the proportion of electrolyte would increase.The results can provide theoretical basis for the research on the air transportation safety of lithium ion battery.