Numerical study of thermal runaway caused by local overheating of LiFePO4 battery

Thermal runaway of battery leads to a serious consequence, such as explosion, in which the variation of temperature is the key parameter needed to be controlled.Therefore, by using the validated 3D model, this paper discussed the impact of discharge rate and convection heat transfer coefficient on the behavior of thermal runaway, which is caused by the local overheating.Results showed that, a high discharge rate could increase the rate of temperature rise and decrease the triggering time of thermal runaway.It changed from 895 s to 771 s when the discharge rate increased from 0.5 C to 4 C. Increasing the convection heat transfer coefficient was an effective way to mitigate the thermal runaway.Compared to 15 W/(m 2 •K), the highest temperature of battery could decrease by 40 °C and the triggering time could be delayed by 280 s when the convection heat transfer coefficient was 75 W/(m 2 •K).The result obtained in this paper could provide guidance to understand the characteristic of thermal runaway.