Abstract: Lithium-ion traction batteries are considered to be a key component of new energy vehicles. It has advantages as high energy density, low self-discharge rate, and long service life. The internal and external mechanism and external characteristics of “overcharge-to-thermal runaway” of new energy vehicle traction batteries are illustrated. A new method of prevention and control technology of overcharge and the induced thermal runaway is put forward. Firstly, the internal and external factors of overcharge and the main characterizations of heat generation and gas release are introduced. The reaction mechanisms and characteristic stage division of overcharge thermal runaway under different trigger conditions are summarized. The common electrochemical and thermodynamic modeling methods for traction battery under overcharge-to-thermal runaway are also described. Henceforth, common technologies and the advantages/disadvantages of the current traction battery for preventing and controlling thermal runaway are explained. Finally, based on the big data platform of new energy vehicles and the actual vehicle operating data, a six-step analysis method of overcharge-induced thermal runaway of traction battery is put forward, where future research on the prevention and control of traction battery overcharge thermal runaway for the safe operation in real scenarios is enlightened. The lack of Chinese review paper is filled in this field.

Key words: electric vehicles, lithium-ion traction batteries, overcharge, thermal runaway, safety prevention and control