Reconstructing Solvation and Interface Dynamics for High‐Performance Hydrogel Polymer Zn‐S Batteries

ABSTRACT In this work, an agarose‐polyacrylamide hydrogel electrolyte (APE) with an interpenetrating and hierarchically porous network is introduced to reconstruct solvation and interface dynamics for a high‐performance Zn‐S batteries. This structure results in a high ionic conductivity of 42.1 mS cm −1 and a Zn 2+ transference number of 0.64. Molecular dynamics reveal that most H 2 O and SO 4 2− are excluded from the outer Helmholtz plane, forming an optimized electric double layer on Zn surface. Consequently, a prolonged 1200 h Zn plating/stripping behavior is obtained with 1 mAh cm −2 at 1 mA cm −2 , and a high Zn plating of 20 mAh cm −2 at 5 mA cm −2 . Furthermore, APE modulates the nucleation mode of ZnS, converting the originally sluggish and non‐uniform progressive nucleation into a rapid and uniform instantaneous nucleation. As a result, this hydrogel Zn‐S batteries deliver a capacity of 895 mAh g −1 and 91% capacity retention within 300 cycles at 5 A g −1 .