A rechargeable solid-state proton battery with an intercalating cathode and an anode containing a hydrogen-storage material

Rechargeable proton batteries have been fabricated with the configuration Zn+ZnSO4·7H2O//solid-state proton conductor//C+electrolyte+intercalating PbO2+V2O5. The solid-state proton conductor is phosphotungstic acid (H3PW12O40·nH2O) or a H3PW12O40·nH2O+Al2(SO4)3·16H2O composite. The maximum cell voltage is ∼1.8 V at full charge. The cell can run for more than 300 h at low current drain (2.5 μA cm−2). Further, the cell can withstand 20 to 30 cycles. The addition of a metal hydride in the anode side enhances the rechargeability and the addition of a small amount of Al2(SO4)3·16H2O in the H3PW12O40·nH2O electrolyte improves the performance of the battery.