Ultrathin and super-tough membrane for anti-dendrite separator in aqueous zinc-ion batteries

Rechargeable aqueous zinc-ion batteries have emerged as potential alternatives to lithium-ion batteries in grid energy storage due to their intrinsic safety, economy, and high capacity of zinc anode. Unfortunately, dendrite growth, limited reversibility, and corrosion of metal zinc anodes in aqueous systems seriously hamper the application of zinc-ion batteries. Herein, ultrathin and high-toughness membranes composed of eco-friendly biomass nanofibers are constructed for substituting glass-fiber separators in rechargeable zinc-ion batteries. The presence of this robust biomass membrane lowers separator thickness to 9 μm, which can prevent the pierce of zinc dendrite, manipulate crystallographic orientation during zinc deposition, and improve the anti-corrosion property of zinc. Thus, this robust biomass membrane enables excellent electrochemical performance and sheds light on a multifunctional design for improving metal zinc anode performance from separators beyond zinc itself.