Fabrication of fire‐response functional separators with microcapsule fire extinguishing agent for lithium‐ion battery safety

Fire safety issues hinder the large-scale application of lithium-ion batteries (LiBs). Here, a new type fire-response separators is prepared by loading microcapsule fire extinguishing agent on surface separator. The shell will break automatically at certain temperature and release when thermal runaway LiBs occurs, which can quickly absorb heat through endothermic reaction ensure not burn or explode. porosity separator 53.6%, electrolyte uptake 132% ionic conductivity 1.00 mS cm-1. initial specific capacity 2643 mAh g-1 4°C retention rate 93% after 200 cycles for NCM523 battery based drop to room in 20 seconds, ensures other adjacent LiBs. This work proposes active protection concept solve problem