A Porous Kevlar Separator for Impact‐Tolerant Lithium‐Ion Batteries

The use of Kevlar separators with high mechanical strength and thermal stability enhances the safety of lithium‐ion batteries. However, the dense structure formed by entangled aramid nanofibers (ANFs) networks via extensive hydrogen bonds limits porosity, resulting in low ionic conductivity. Here, we present a simple fabrication method, using a porogen‐containing ANF dispersion and vacuum‐assisted filtration, to prepare a porous Kevlar separator. The removal of the porogen embedded within the membrane creates a porous structure. This Kevlar separator demonstrates high ionic conductivity, outstanding thermal stability, flame retardance, and excellent electrolyte wettability. The assembled lithium‐ion batteries not only demonstrate excellent electrochemical performance but also offer good impact resistance to mitigate mechanical abuse.