The feasibility of using a rechargeable MnO2 cathode with a metal hydride anode

The feasibility of using a manganese dioxide cathode with a metal hydride anode is discussed. MnO(2) cathodes doped with bismuth compounds were rechargeable. The cathode material was prepared in its discharged state from MnO and bismuth compounds, thus matching the metal hydride anode in terms of initial state of charge, formation cycles and balance of self-discharge. It is believed that the presence of bismuth in the cathode prevents formation of spinel manganese oxide and lowers the activation energy (overpotential) for the second electron reduction and oxidation of MnO(2). Hydrogen recombination with MnO(2) was also studied to enable balancing of the self discharge rates of cathode and anode during storage.