Modular Interfacial Engineering via Nanofiber‐Reinforced Hydrogels for Stabilizing Zn Anodes Toward High‐Performance Zn‐Based Batteries

Aqueous zinc‐ion batteries (AZIBs) have attracted increasing interest as candidates for next‐generation energy storage, benefiting from intrinsic safety, cost advantages, and high energy density. Nevertheless, unstable interfaces at Zn anodes frequently lead to dendritic deposition, corrosion, and hydrogen evolution, limiting practical application. Herein, a modular interfacial engineering approach is developed by constructing a fiber‐reinforced hydrogel protective layer on Zn anodes, where electrospun polyacrylonitrile (PAN) fibers and a crosslinked acrylamide/2‐acrylamido‐2‐methylpropane sulfonic acid (PAAm/AMPS) hydrogel network are architected as two orthogonal yet synergistic interfacial modules. The PAN fiber scaffold provides mechanical reinforcement while simultaneously regulating water activity to mitigate corrosion and hydrogen evolution. Meanwhile, the PAAm/AMPS hydrogel promotes uniform ion distribution and enhances ionic conductivity by offering continuous pathways for Zn 2+ transport, thereby effectively reducing interfacial polarization. Consequently, the PAN‐H protected Zn anode (Zn@PAN‐H) exhibits exceptional durability, sustaining stable cycling for over 5000 h at 2 mA cm −2 and maintaining reliable operation for 350 h at 10 mA cm −2 . When assembled with a sodium vanadate cathode, the resulting full cell preserves a high‐specific capacity of 194.8 mAh g −1 at 5 A g −1 after 1000 cycles. These results highlight the effectiveness of the modular interfacial design in stabilizing Zn metal anodes and facilitating the development of high‐performance AZIBs.