Review on Cathode Stabilization by Electrolyte Engineering in Aqueous Batteries

Abstract The stability of cathode materials is a crucial factor that influence the overall performance of aqueous batteries. Electrolyte greatly influences on the stability of cathode material due to the complexed electrochemical–chemical reactions at the interfaces. Therefore, electrolyte engineering is a direct and powerful way to solve various problems at aqueous electrolyte interfaces. In this review article, we firstly summarized the fading mechanisms of different kinds of state-of-the-art aqueous battery cathodes including manganese/vanadium-based material, chalcogen and halogen materials, Prussian blue analogues, and Ni(OH) 2 cathodes. Afterward, we reviewed recent progresses on electrolyte engineering on the stability of cathode materials such as bulk electrolyte modification, electrolyte additives, water-in-salt electrolytes, and hydrogel electrolytes. Finally, we proposed the issues that should be concerned in future electrolyte design for highly state aqueous battery cathodes.