Advanced Eutectogel Electrolyte for High-Performance and Wide-Temperature Flexible Zinc-Air Batteries

Despite ongoing challenges, achieving further breakthroughs in the development of gel polymer electrolytes with a wide temperature range, excellent liquid retention capability and enhanced anode compatibility in flexible zinc-air batteries (FZABs) remains a significant objective. This study presents a significant advancement in the development of choline chloride/ethylene glycol-polyvinyl alcohol (ChCl/EG-PVA) eutectogel electrolyte, tailored for high-performance operation across a wide temperature range. Systematic in-situ and ex-situ characterizations and theoretical simulations confirm the formation of robust hydrogen bonding and denser polymer cross-linked networks within the prepared eutectogel, leading to enhanced liquid retention ability (93.7 % after 96 h exposure to air) and ion transport capacity (ionic conductivity of 171.3 mS cm^-1). Additionally, the zincophilicity nature of the choline cation in eutectogel effectively suppresses dendrites growth. The assembled FZAB utilizing this eutectogel electrolyte achieves a peak power density of 109.3 mW cm^-2 and a cycle life of 90 h. Notably, the power density of FZAB is maintained as high as 38.2 mW cm^-2 at -40 °C and 63.2 mW cm^-2 at 50 °C, demonstrating its prominent suitability for applications in extreme temperature conditions. The design of eutectogel provides a novel way to achieve the high-performance FZAB.