Molecular‐Ionic Coupling Enables Solvation‐Regulated Hydrogel Electrolytes to Stabilize Zinc Anodes

ABSTRACT Hydrogel electrolytes are promising candidates for stabilizing Zn metal anodes in aqueous Zn‐ion batteries (AZIBs), yet their practical application remains hindered by water‐induced side reactions and nonuniform Zn 2+ transport. Herein, a polyacrylamide‐based hydrogel electrolyte (PAMPS) is developed by integrating glycerol and 2‐acrylamido‐2‐methylpropane sulfonic acid (AMPS) to achieve multiscale regulation of the electrolyte environment. Through molecular‐ionic coupling, glycerol‐mediated hydrogen‐bond regulation redistributes water states, while the introduced sulfonate groups modulate the local Zn 2+ environment through outer‐sphere interactions, thereby promoting Zn 2+ transport and uniform Zn deposition. This combined regulation simultaneously tailors water structure, the local Zn 2+ environment, and ion transport pathways within the hydrogel matrix. As a result, the optimized PAMPS electrolyte delivers a high ionic conductivity of 27.3 mS cm −1 and accelerated Zn 2+ transport kinetics, effectively suppressing parasitic interfacial reactions and enabling uniform Zn deposition. Consequently, Zn||Zn symmetric cells exhibit extremely stable cycling for 2000 h at 2 mA cm −2 / 2mAh cm −2 . Moreover, Zn||NH 4 V 4 O 10 full cells retain 75.9% of their initial capacity over 2000 cycles at 1 A g −1 . This work demonstrates an effective electrolyte‐engineering strategy for enhancing the durability of AZIBs through the coordinated regulation of water activity, Zn 2+ solvation structure, and ion transport behavior.