Abstract: A rechargeable alkaline manganese cell provided, having improved capacity and improved energy density. The cell is anode limited, and each of the anode and cathode is physically dimensioned so that the anode has a capacity in the range of from about 55% to 100% of the theoretical one electron capacity of the cathode. The gravimetric energy density of the cell exceeds 70 Wh/kg, and the volumetric energy density of the cell exceeds 200 Wh/liter. Each of the anode and cathode may comprise additional additives. For example, the cathode may include additional hydrophobic materials and a porous additive such as carbon black so as to improve gas transport of hydrogen gas into the cathode where it is oxidized; and the anode may comprise hydrogen gassing inhibitors as well as hydrogen gas recombing agents.

Abstract: Porous electrodes for use in fuel cells and other electrochemical cells are disclosed. Principally, the electrodes a catalytically active layer on a porous conductive substrate, which catalytically active layer is derived from non-noble metals. The loading of the catalytically active layer is lower in terms of weight of catalyst per unit area of geometrical electrode surface than heretofore. Several alternative methods of forming the electrode are taught, including impregnating a porous conductive substrate with a metal salt solution, followed by chemical or thermal formation of the porous catalytically active layer; or mixing the catalytically active material with the material of the porous conductive substrate, followed by fabrication of the electrode; or depositing pyrolitic carbon from the gas phase onto a porous conductive substrate, at elevated temperatures in a gas atmosphere. The electrode may also have a porous metallic current collector, and also a further gas diffusion layer.