细水雾抑制18650型锂离子电池热失控实验研究

Experimental study on thermal runaway of 18650 lithium-ion battery inhibited by water mist

为研究细水雾灭火系统对18650型锂电池热失控的抑制效果,利用自设计实验平台进行抑爆实验,对比初爆与燃爆两个关键点及有无外部热源的温度变化图。研究表明,细水雾能够明显抑制18650型锂电池热失控,但施加细水雾的时间点对抑制效果影响较大,初爆后施加细水雾能够有效抑制,在燃爆后施加细水雾10s内温度降低200℃以上,但由于锂电池内部电解液复燃的特点,温度回升。温升速率的变化使得电池初爆的时间和温度分别提前了67.4%和44.4%,据此提出通过探测18650型锂电池初爆释放气体发现热失控发生并在最短时间内移除异常行为电池来控制电池热失控及其热量的异常传播。

This paper intends to study the effect of the water mist fire extinguishing systems on the thermal runaway of the 18650 lithium-ion battery.A self-designed experimental platform is employed to perform the explosion suppression experiment,which compares the two key points of the initial blast and violent explosion and examines whether there are the temperature changes of the external heat source.The results show that the water mist can obviously inhibit the thermal runaway of the 18650 lithium-ion battery,however the time point of the application of the water mist has great influence on the inhibitory effect.After the initial blast,the application of the water mist can have effective inhibition.If the water mist is applied after the violent explosion,the temperature will decrease more than 200℃in 10 s.However,on account of the characteristics regarding the reburning of electrolyte in lithium battery,the temperature will rise again.The change of the increasing rate of temperature brings forward the time and temperature of the initial blast of the battery for 67.4%and 44.4%respectively.According to this,it is proposed that,by detecting the release gas of the first blast of the 18650 lithium-ion battery,the occurrence of thermal runaway can be detected and the battery with abnormal behavior can be removed in the shortest time,so that the thermal runaway of the battery and the abnormal propagation of heat can be controlled.