Review on Cathode Stabilization by Electrolyte Engineering in Aqueous Batteries

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.