Organic-inorganic hybrid hydrogel electrolyte for high-performance quasi-solid-state zinc-air batteries

Flexible aqueous zinc-air batteries with high energy density and safety have garnered significant attention. Gel polymer electrolytes have emerged as the preferred option over conventional liquid electrolytes due to their ability to prevent electrolyte leakage. In this study, a composite PANa-PVP-TiO₂(NH₂) hydrogel with high alkaline resistance and ionic conductivity is designed, where the inorganic TiO₂(NH₂) nanoparticles are evenly distributed and integrated into the organic dual network of polyacrylate sodium and polyvinyl pyrrolidone. The organic-inorganic hybrid structure enhances the absorption and retention capabilities for electrolyte solution, leading to impressive ionic conductivity of the gel polymer electrolyte throughout the operation of flexible aqueous zinc-air batteries. Additionally, the incorporation of TiO₂(NH₂) nanoparticles and the dual network construction effectively strengthen the mechanical strength and flexibility of the gel polymer electrolyte, suppressing by-products and zinc dendrite formation. The enhancements lead to the extended cycling longevity of zinc symmetric batteries and excellent power density, as well as the prolonged cycle life of flexible aqueous zinc-air batteries.