Thin and Robust Separator with Directed Zn2+ Migration Channel for a Stable and Dendrites-Free Zn Anode

Abstract

The irregular dendrite growth and unfavorable adverse reactions on the Zn anode has emerged as a non-negligible obstacle for broad deployment of aqueous zinc-ion batteries (AZIBs). Herein, a thin and robust separator (LFP_1:1) composed of lyocell fibrillated fibers and polyethylene terephthalate (PET) fibers that features a light weight, cost effectiveness, and being mass-producible is developed by a paper-making method to inhibit the undesirable adverse reactions and achieve an exceptional stable Zn anode. The LFP_1:1 separator offers abundant polar functional groups, small and uniform pore structure, and high mechanical strength, which is beneficial to constructing specific migration channels for Zn²⁺ and suppressing adverse reactions, promoting uniform Zn deposition, and resisting dendrite penetration. As verified by the experimental results, the Zn//Zn symmetric cell furnished with the LFP_1:1 separator displays prolonged lifespan up to 1452 h in 3 M Zn(CF₃SO₃)₂ electrolyte at 1 mA·cm^–2 without dendrite or byproducts, which is superior than that with GF separator. Moreover, the assembled Zn//V₂O₅ full cell with the LFP_1:1 separator also demonstrates an outstanding cycling stability with 77.8% capacity retention at 1 A·g^–1 after 1000 cycles. This work sheds light on a promising and large-scale producible method for the development of advanced separator materials for high performance AZIBs.