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). 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 and a cycle life of 90 h. Notably, the power density of FZAB is maintained as high as 38.2 mW cm at -40 °C and 63.2 mW cm 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.