A Bio‐Inspired Multifunctional Hydrogel Network with Toughly Interfacial Chemistry for Highly Reversible Flexible Zinc Batteries

Abstract Flexible and high‐performance aqueous zinc‐ion batteries (ZIBs), coupled with low cost and safe, are considered as one of the most promising energy storage candidates for wearable electronics. Hydrogel electrolytes present a compelling alternative to liquid electrolytes due to their remarkable flexibility and clear advantages in mitigating parasitic side reactions. However, hydrogel electrolytes suffer from poor mechanical properties and interfacial chemistry, which limits them to suppressed performance levels in flexible ZIBs, especially under harsh mechanical strains. Herein, a bio‐inspired multifunctional hydrogel electrolyte network (polyacrylamide (PAM)/trehalose) with improved mechanical and adhesive properties was developed via a simple trehalose network‐repairing strategy to stabilize the interfacial chemistry for dendrite‐free and long‐life flexible ZIBs. As a result, the trehalose‐modified PAM hydrogel exhibits a superior strength and stretchability up to 100 kPa and 5338 %, respectively, as well as strong adhesive properties to various substrates. Also, the PAM/trehalose hydrogel electrolyte provides superior anti‐corrosion capability for Zn anode and regulates Zn nucleation/growth, resulting in achieving a high Coulombic efficiency of 98.8 %, and long‐term stability over 2400 h. Importantly, the flexible Zn//MnO 2 pouch cell exhibits excellent cycling performance under different bending conditions, which offers a great potential in flexible energy‐related applications and beyond.