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. [ABSTRACT FROM AUTHOR]