Non-Metal Ion Co-Insertion Chemistry in Aqueous Zn/MnO₂ Batteries

The co-insertion of dual ions can often offer enhanced electrochemical performance for the aqueous zinc batteries. Although the insertion of non-metallic ions has been achieved in aqueous zinc batteries, the co-insertion chemistry of non-metallic cations is still a challenge. Here, a reversible H⁺/NH₄⁺ co-insertion/extraction mechanism was developed in an aqueous Zn/MnO₂ battery system. The synergistic effect between the dual cations endows the aqueous batteries with the fast kinetics of ion diffusion and the reversible structure evolution of MnO₂. As a result, the Zn/MnO₂ battery displays excellent rate capability and cycling performance. This work will pave the way toward the design of aqueous rechargeable batteries with non-metallic ions.