SOLID-STATE METAL HYDRIDE BATTERIES USING TETRAMETHYLAMMONIUM HYDROXIDE PENTAHYDRATE

A new solid electrolyte, tetramethylammonium hydroxide pentahydrate, was applied to a nickel oxyhydroxide-metal hydride (NiOOH/MH) battery and a manganese dioxide-metal hydride (MnO2/MH) battery, which were prepared by impregnating the melt of the solid electrolyte into the battery components. The NiOOH/MH and MnO2/MH batteries were dischargeable even at 10 mA cm-2 and 2 mA cm-2, respectively. No appreciable decrease in discharged capacity for both batteries was observed up to 200 cycles. Both batteries showed poor charge retention performance, resulting from the decreased density of the oxidized metal ions near the surface of the active material particles on their positive electrodes due to diffusion of protons and conduction of electrons.