Multiparameter Comprehensive Thermal Runaway Warning Model of Lithium-Ion Battery under Overcharge Condition

With the gradual popularization of new energy vehicles, fire accident reports are common. Overcharge is one of the main causes of an accident, which has the characteristics of sudden occurrence, no obvious signs, and difficulty in stopping the spread of fire. Therefore, herein, the law of safety change of pouch batteries after overcharging is studied and the expressions of the thermal runaway stage are derived based on the voltage, temperature, and temperature difference as the main parameters through thermal runaway experimental data, and then a three-stage overcharge warning strategy based on multiple parameters is constructed to build a warning model. The early warning model can predict the overcharge stage of batteries and provide the remaining time before thermal runaway, which is implemented and verified.