Dynamic Cross‐Linking Network Construction of Flexible Hydrogel Electrolyte Enabling Dendrite‐Free Zinc Anode

Abstract Aqueous zinc‐ion batteries (AZIBs) are highly promising for flexible electronics and advanced energy storage due to their eco‐efficiency, safety, and low cost. However, their practical application is limited by severe zinc dendrite growth, side reactions, and mechanical instability associated with conventional electrolytes. Herein, a novel chondroitin sulfate‐functionalized polyacrylamide (PAM‐CS) hydrogel electrolyte to address these challenges is presented. The PAM‐CS hydrogel integrates multiple functional groups, including hydroxyl (─OH), strongly electronegative sulfonic acid (─SO ₃ ⁻ ), and carboxylic acid (─COO ⁻ ) groups, which form hydrogen bonds with free water molecules to reduce their activity and suppress side reactions. Furthermore, the strongly electronegative groups (─SO ₃ ⁻ and ─COO ⁻ ) construct dynamic coordination networks by strong electrostatic interactions, which enable fast Zn ² ⁺ migration and promote uniform Zn ² ⁺ deposition. As a result, the Zn||PAM‐CS||Zn symmetric cell demonstrates stable cycling for over 1200 h at 1 mA cm ⁻² /1 mAh cm ⁻² , while the Zn||PAM‐CS||NH ₄ V ₄ O ₁₀ full cell exhibits an outstanding rate performance and specific capacity of 87 mAh g ⁻¹ at a high current density of 5 A g ⁻¹ . Additionally, a flexible pouch battery using PAM‐CS exhibits robust performance under mechanical stress, including bending, puncture, and cutting, showcasing its potential for wearable electronics.