A manganese-hydrogen battery with potential for grid-scale energy storage

Batteries including lithium-ion, lead-acid, redox-flow and liquid-metal batteries show promise for grid-scale storage, but they are still far from meeting the grid's storage needs such as low cost, long cycle life, reliable safety and reasonable energy density for cost and footprint reduction. Here, we report a rechargeable manganese-hydrogen battery, where the cathode is cycled between soluble Mn2+ and solid MnO2 with a two-electron reaction, and the anode is cycled between H-2 gas and H2O through well-known catalytic reactions of hydrogen evolution and oxidation. This battery chemistry exhibits a discharge voltage of similar to 1.3 V, a rate capability of 100 mA cm(-2) (36s of discharge) and a lifetime of more than 10,000 cycles without decay. We achieve a gravimetric energy density of similar to 139 Wh kg(-1) (volumetric energy density of similar to 210 Whl(-1)), with the theoretical gravimetric energy density of similar to 174 Wh kg(-1) (volumetric energy density of similar to 263 Whl(-1)) in a 4M MnSO4 electrolyte. The manganese-hydrogen battery involves low-cost abundant materials and has the potential to be scaled up for large-scale energy storage.