Aramid nanofiber-based porous membrane for suppressing dendrite growth of metal-ion batteries with enhanced electrochemistry performance

• The large-scale fabrication of aramid nanofiber membrane (ANFM) with proper porous size was proposed. • The ANFM displayed superior mechanical properties and impressively wettability for organic electrolyte. • Simultaneously suppression of lithium dendrites and remarkable improvement of cycle life were achieved for ANFM separator. • Li-ion batteries can operate stability at a high temperature (150℃) environment. Huge volume changes, uncontrolled side-reactions with electrolytes and irregular dendrite induced short-circuits have impeded practical application in rechargeable batteries based on metallic electrodes including lithium (Li), sodium (Na) and aluminum (Al). Separator with superior mechanical strength represent attractive alternatives to inhibit metal-dendrite growth while preventing capacity fading by stabilizing the solid electrolyte interphase (SEI). However, the challenge of simultaneous retaining high thermal resistance and good electrolyte wettability still have been not overcome in commonly used separators. Here we show that these key properties can be acquired in a porous membrane fabricated from Kevlar microfiber-derived aramid nanofibers ( ANFs ) prepared in a facile and scalable vacuum filtration method. The obtained ANFs membrane ( ANFM ), which yields mechanically strong that are markedly effective in inhibit dendrite growth as well as provides good electrolyte wettability to ensure excellent electrochemistry performance. Benefitting from these merits, ANFM guarantee stable cycling of Li-ion or Na-ion rechargeable batteries paired with conventional intercalating cathodes (LiCoO 4 and Na 2 Ti 3 O 7 ) even at a high operated temperature (150 ℃ for Li-ion battery). Replacing polyolefins-based separator with an ANFM appear to offer a major step towards dendrite-free Li /Na batteries and potentially other metal-ion batteries.