Wearing “body armor” on zinc anodes for robust aqueous zinc-ion batteries

Abstract

Rechargeable aqueous zinc batteries (ZIBs) are promising devices for sustainable energy storage, yet their application is hindered by uncontrollable Zn dendrite growth and parasitic reactions. Herein, a flexible membrane comprising aramid nanofibers (ANFs) and cellulose nanofibers (CNFs) is developed as an interlayer between the Zn anode and the separator. The ANF/CNF (AC) membrane exhibits a dense and uniform microstructure, abundant zincophilic polar groups, and excellent mechanical properties. Simulations and experimental results reveal that the AC interlayer facilitates the desolvation of Zn²⁺, increases the Zn²⁺ transference number, reduces the deposition barrier and homogenizes the ion flux. Consequently, the AC interlayer can effectively inhibit Zn dendrite formation and side reactions. The Zn-symmetric cell with the AC interlayer demonstrates stable cycling for over 1760 h at 2 mA cm⁻², which significantly outperforms those without the interlayer. Furthermore, the AC interlayer enhances both the rate performance and the cycling stability of ZIBs and ensures notable stability and safety under external forces in pouch batteries. This work offers a facile yet effective interlayer engineering strategy for the fabrication of robust aqueous ZIBs.