Decoupling electrolytes towards stable and high-energy rechargeable aqueous zinc–manganese dioxide batteries

Aqueous battery systems feature high safety, but they usually suffer from low voltage and low energy density, restricting their applications in large-scale storage. Here, we propose an electrolyte-decoupling strategy to maximize the full potential of Zn–MnO 2 batteries by simultaneously enabling the optimal redox chemistry of both the Zn and MnO 2 electrodes. The decoupled Zn–MnO 2 battery exhibits an open-circuit voltage of 2.83 V (in contrast to the typical voltage of 1.5 V in conventional Zn–MnO 2 batteries), as well as cyclability with only 2% capacity fading after deep cycling for 200 h. Benefiting from the full utilization of MnO 2 , the Zn–MnO 2 battery is also able to maintain approximately 100% of its capacity at various discharge current densities. We also demonstrate the feasibility of integrating the Zn–MnO 2 battery with a wind and photovoltaic hybrid power generating system. This electrolyte-decoupling strategy is shown to be applicable for other high-performance zinc-based aqueous batteries such as Zn–Cu and Zn–Ag batteries.