Interfacial H-Bonding Enables Fatigue-Resistant Gel Electrolytes for Flexible Zinc–Ion Batteries

The insufficient interfacial adhesion between the electrode and electrolyte, which compromises the stability of ion transport under dynamic mechanical conditions, remains a critical technical challenge for flexible zinc–ion batteries (ZIBs). Dynamic hydrogen bonding and hydrophobic inclusion can effectively enhance the adhesion between gel molecules and electrodes. Here, a cyclodextrin (CD)-modified polyacrylamide/carboxymethyl cellulose (PAM/CMC) dual-network gel electrolyte with fatigue resistance is successfully developed, which is based on the host–guest interactions from CD. This design effectively resolves the separation problem caused by interfacial slippage in conventional gel electrolytes under repeated bending, exhibiting an enhanced interfacial load-bearing capacity of 11 N, high stretchability of 162%, and retained structural integrity after folding cycles. Notably, the PAM/CMC/CD gel delivers a breakthrough ionic conductivity of 32.01 mS cm –1 and a Zn 2+ transference number of 0.9062. Interfacial H-bonds regulate Zn 2+ solvation structures, reducing coordination numbers and desolvation energy to 4.54 eV. Simultaneously, they suppress Zn dendrite growth by promoting preferential (002) plane deposition, evidenced by a higher adsorption energy (−2.97 eV) versus the (100) plane. The assembled Zn||Zn symmetric batteries have only 1.8% capacity decay after 1200 h of cycling, and the Zn||MnO 2 full batteries retain a specific capacity of 275 mAh g –1 after 120 cycles at 0.2 A g –1, exhibiting robust electrochemical stability even under repeated mechanical deformation. This work overcomes critical challenges in interfacial stability and mechanical endurance for flexible ZIBs, providing a reliable energy storage solution for wearable electronics.