Abstract: The relevant research on the safety characteristics of lithium- ion batteries after impact extrusion was summarized from both experimental and simulation perspectives at home and abroad in recent years, and the four influencing factors as punch shape, mechanical loading method, mechanical loading position, and SOC state was analyzed. The analysis results showed that the larger the internal short-circuit area of the lithium-ion battery, the more marginal the impact extrusion position and the higher the SOC, the higher the temperature at failure, the faster the voltage drop and the easier the thermal runaway; and the larger the strain of the lithium- ion battery, the smaller the internal resistance. According to the change law of the voltage, temperature, internal resistance and other safety characteristics parameters of lithium battery before thermal runaway by impact extrusion, an early warning identification method of lithium battery safety status is established, which is extremely necessary to prevent thermal runaway safety accidents caused by impact extrusion of new energy vehicles.

Key words: lithium- ion battery, impact extrusion, safety characteristics, thermal runaway, safety analysis