Low-cost and high safe manganese-based aqueous battery for grid energy storage and conversion

As an effective energy storage technology, rechargeable batteries have long been considered as a promising solution for grid integration of intermittent renewables (such as solar and wind energy). However, their wide application is still limited by safety issue and high cost. Herein, a new battery chemistry is proposed to satisfy the requirements of grid energy storage. We report a simple Cu-Mn battery, which is composed of two separated current collectors in an H₂SO₄-CuSO₄-MnSO₄ electrolyte without using any membrane. The Cu-Mn battery shows an energy density of 40.8 Wh L^-1, a super-long life of 10,000 cycles (without obvious capacity decay) and negligible self-discharge. And the capital cost of US$ 11.9 kWh^-1 based on electrolyte is lower than any previous batteries. More importantly, the battery can still work smoothly during thermal abuse test and drill-through test, showing high safe nature. Furthermore, a combination system integrating the Cu-Mn battery and hydrogen evolution is also proposed, which is able to avoid the generation of explosive H₂/O₂ mixture, and presents an efficient approach for grid energy storage and conversion.