热辐射触发锂离子电池热失效行为及其射流热特性

Thermal failure behaviors and the heat efflux characteristics of Li-ion batteries triggered by thermal radiation

实验研究了辐射加热器非接触式触发动力锂离子电池热失效过程中的温度特性、质量损失、产热行为变化等特性及其空间射流温度与热流分布特性。以50 Ah的Li(Ni_(0.6)Co_(0.2)Mn_(0.2))O_(2)电池为对象,基于锂离子电池燃烧实验平台进行。结果表明:电池热失控实验过程中发生了2次喷发现象,电池表面最高温度为489.2℃;最高温升速率为27.7 K·s^(-1);最大质量损失速率为32.7 g·s^(-1);电池本体总产热量为1.05 MJ;环境最高温度为705.3℃;烟气总释放热为6.56 MJ·m^(-2);射流空间环境最高温度比电池表面最高温度高。这表明,高温高速的易燃气体会加剧热失控危害的风险。本结果有助于电池失效初期预警、热失控抑制、火灾风险控制。

This paper experimentally investigated the temperature characteristics,the mass loss,the change characteristics of heat production behaviors,the spatial efflux temperature and heat flow distribution characteristics for non-contact trigger power lithium-ion batteries of radiant heater during thermal failure.Batteries of 50 Ah Li(Ni_(0.6)Co_(0.2)Mn_(0.2))O_(2)were taken as the research object to carry out relevant tests based on a lithium-ion battery combustion experiment platform.The results show that 2 eruptions occurred during the battery thermal runaway experiment;The battery surface maximum temperature is 489.2°C;the highest average temperature rise rate is 27.7 K·s^(-1);the maximum mass loss rate is 32.7 g·s^(-1);the battery body total heat release is 1.05 MJ;the highest ambient temperature is 705.3°C,the flue gas total heat release is 6.56 MJ·m^(-2),and the maximum ambient temperature of efflux space is higher than the maximum temperature of battery surface.These mean that the flammable gas with high temperature and high-speed aggravate the risk of thermal runaway.These results have significances for the early warning of battery failure,the thermal runaway suppression,and the fire risk control.