Dual‑Diol Synergized Electrolyte for Wide‑Temperature Hydrogel Zn‑Ion Batteries

Abstract

Aqueous zinc‐ion batteries (AZIBs) feature low cost, superior safety, and eco‐friendliness, promising extensive prospects for next‐generation electrochemical energy storage. Nevertheless, inferior interfacial stability, uncontrollable Zn dendrite formation, and poor temperature tolerance severely hinder their practical exploitation in flexible electronic devices. Herein, glycerol (Gly) and ethylene glycol (EG) are incorporated into a polyacrylamide (PAM) hydrogel matrix via a facile one‐pot route to fabricate a wide‐temperature‐tolerant PAM‐based composite hydrogel electrolyte (PAM/Gly/EG). Benefiting from the synergistic effect of the two diols, the hydroxyl‐rich structure reconstructs the intrinsic hydrogen bond network of confined water, while coordination interactions modulate the solvation configuration of Zn 2+ , thereby fundamentally restraining Zn dendrite propagation and parasitic hydrogen evolution. The resultant Zn||Zn symmetric cell delivers a long stable lifespan over 3000 h at 1 mA·cm −2 , and sustains steady cycling for 500 h at −20°C and 300 h at 50°C. This synergistic diol modification strategy affords a feasible avenue for structural optimization and practical deployment of wide‐temperature flexible AZIBs.