Enhancing Flexibility and Durability of Zinc–Air Batteries with Double Cross-Linked Gel Electrolytes

Advanced electrolytes are critical for enhancing the performance, flexibility, and durability of zinc–air batteries (ZABs). An innovative double cross-linked network approach for gel polymer electrolytes (GPEs) has been introduced utilizing poly(vinyl alcohol) (PVA), potassium carbonate (K₂CO₃), potassium hydroxide (KOH), and polyacrylamide (PAAm). The double cross-linking, facilitated by PVA-K₂CO₃ and PAAm, enhances the mechanical strength and electrochemical stability of the GPEs. Compared with conventional PVA-KOH GPEs, these double cross-linked GPEs demonstrate improved water retention, higher ionic conductivity, and superior mechanical properties. Additionally, the double cross-linked structure effectively inhibits zinc dendrite formation during battery cycling, resulting in longer ZAB lifespans. ZABs assembled with these GPEs exhibit high flexibility, notable power density, and remarkable cycling stability, positioning them as promising candidates for flexible energy storage devices. Solid-state ZABs using PAAm-PVA GPEs achieve a power density of 148 mW cm^–2, a specific capacity of 762 mAh g^–1, a cycling stability of 86 h, and outstanding flexibility.