Opportunities and challenges of eutectic electrolytes for advanced zinc-iodine batteries

Abstract Aqueous zinc-iodine batteries have garnered extensive attention due to their low cost, high safety, long lifespan and desirable energy density. However, their performance is limited by the severe shuttle effect and side reactions, which impede operability, energy density and cycling stability. This perspective begins by outlining the configuration of zinc-iodine batteries, detailing their chemical redox mechanism and associated challenges. It then shifts focus to zinc salt-based eutectic electrolytes, exploring their fundamental properties and potential applications in zinc batteries. The role and functions of eutectic electrolytes in zinc-iodine batteries are emphasized in following, highlighting their achievements in enhancing stability and energy density. Given that research on eutectic electrolytes is still in its infancy, remaining challenges and future directions are also discussed, offering insights for the rational design of advanced eutectic electrolytes and zinc-iodine batteries.