Thermal runaway and combustion of LiFeO4 lithium-ion battery induced by electric-thermal coupling abuse

Thermal runaway and combustion of batteries under external heating and external heating-external short circuit coupling abuse are studied in this work. Thermal runaway occurs to battery under external heating. Lots of smokes are ejected out of the battery after thermal runaway. High-temperature electric conductor ignites the flammable and explosive gases after the open of safety valve under coupling abuse. But, state of charge decreases, which induces lower maximum temperature and less violent exothermic side reactions after thermal runaway. It takes shorter time to open the safety valve under coupling abuse. The color of flame is saffron yellow during fast discharging. It changes to white after discharging current decreases to 0 A. Fast discharging affects the gas components after the open of safety valve. The heat from external heating contributes much more to the accumulated heat of battery compared to external short circuit. With the increase of external resistance, the combustion lasts shorter and is less violent, but the exothermic side reactions increase after thermal runaway. With the increase of triggering time of ESC, the combustion lasts longer, but the exothermic side reactions decrease after thermal runaway. • Thermal behavior of LiFeO 4 battery under electric-thermal coupling abuse is studied. • External heating coupling external short circuit causes LiFeO 4 battery combustion. • Contribution of heat from external heating and external short circuit is found.