Synergistic dual-network design of a nanocomposite hydrogel electrolyte for durable and flexible zinc–air batteries

Flexible and wearable electronics demand energy storage solutions that combine high performance, stability, and mechanical flexibility. Flexible aqueous zinc-air batteries (FAZABs) are a promising candidate, but their performance is often limited by conventional liquid electrolytes, which suffer from issues like leakage, evaporation, and poor cycling stability. This study introduces a dual-network gel electrolyte, nano-PAS/PVA, designed for FAZABs. Functionalized with sulfonate groups and electrolyte additives, nano-PAS/PVA significantly enhances ionic conductivity, mechanical strength, and electrolyte retention, overcoming key limitations of traditional polymer electrolytes like polyacrylamide (PAM). Its dual-network architecture facilitates efficient energy dissipation through sacrificial bond fracture. FAZABs employing nano-PAS/PVA achieve a cycle life exceeding 350 h at 1 mA·cm⁻² significantly outperforming PAM-based counterparts. The electrolyte exhibits high ionic conductivity (148.14 mS·cm⁻¹) and outstanding mechanical properties (318 kPa tensile strength, 2311 % strain), maintaining stable performance under bending. Combined density functional theory (DFT) calculations and molecular dynamics (MD) simulations reveal that sulfonate groups in nano-PAS/PVA promote uniform zinc plating through dual mechanisms: By reconstructing Zn²⁺ solvation sheaths to suppress hydrogen evolution reactions (HER) while modulating interfacial energies to direct Zn(002)-oriented deposition. Supported by Distribution of relaxation times (DRT) analysis and multiscale simulations, this work provides a robust electrolyte platform enabling durable and efficient wearable energy devices.