A universal strategy towards high–energy aqueous multivalent–ion batteries

Abstract Rechargeable multivalent metal ( e.g ., Ca, Mg or, Al) batteries are ideal candidates for large–scale electrochemical energy storage due to their intrinsic low cost. However, practical application is hampered by the reversibility, dendrite growth at anodes, sluggish multivalent–ion kinetics in oxide cathodes and, poor electrode compatibility with non–aqueous organic–based electrolytes. To circumvent these issues, here we report various aqueous comprising of concentrated gel electrolytes, sulfur–containing anodes high-voltage as alternative systems batteries. This rationally designed battery chemistry enables satisfactory specific energy, favorable reversibility and improved safety. As a demonstration model, room–temperature calcium-ion/sulfur| |metal full cell 110 Wh kg –1 remarkable cycling stability. Molecular dynamics modeling experimental investigations reveal that side reactions could be significantly restrained through suppressed water activity formation protective inorganic solid electrolyte interphase. The unique redox system also demonstrated magnesium–ion/sulfur||metal aluminum–ion/sulfur||metal cells.