Abstract:

There is a risk of thermal runaway of power battery after collisions of electric vehicles. This paper analyzed extrusion thermal runaway based on a Li-NiCoMnO2 (NCM) power battery to obtain damage tolerance of battery. The cells of battery were extruded in different directions to analyze the extrusion resistance and the
failure mode of the extrusion thermal runaway. Modules were extruded respectively in two directions to analyze the extrusion failure mode. The results show that the electric cell is more prone to extrusion and failure in length direction than that in width and height directions. The extrusion failure mode is uncertain. The extrusion damage tolerance is 10 mm. The modules are more prone in length direction than that in width and height directions to thermal runaway being consistent with battery cells. The results can provide references for the safety layout design and for the simulation failure determination of power battery packs.

Key words: electric vehicle (EV) , vehicle collision , Li-ion power battery ,  thermal runaway , extrusion failure ,  damage tolerance