In an embodiment, a secondary ZnMnO.sub.2 battery comprises a battery housing, a MnO.sub.2 cathode, a Zn anode, and an electrolyte solution. The MnO.sub.2 cathode, the Zn anode, and the electrolyte solution are disposed within the battery housing, and the MnO.sub.2 cathode comprises a MnO.sub.2 cathode mixture and a current collector. The MnO.sub.2 cathode mixture is in electrical contact with at least a portion of an outer surface of the current collector, and the MnO.sub.2 cathode has a porosity of from about 5 vol. % to about 90 vol. %, based on the total volume of the MnO.sub.2 cathode mixture of the MnO.sub.2 cathode.

Provided is a highly reliable nickel-zinc battery including a separator exhibiting hydroxide ion conductivity and water impermeability. The nickel-zinc battery includes a positive electrode containing nickel hydroxide and/or nickel oxyhydroxide; a positive-electrode electrolytic solution in which the positive electrode is immersed, the electrolytic solution containing an alkali metal hydroxide; a negative electrode containing zinc and/or zinc oxide; a negative-electrode electrolytic solution in which the negative electrode is immersed, the electrolytic solution containing an alkali metal hydroxide; a hermetic container accommodating the positive electrode, the positive-electrode electrolytic solution, the negative electrode, and the negative-electrode electrolytic solution; and the separator exhibiting hydroxide ion conductivity and water impermeability and disposed in the hermetic container so as to separate a positive-electrode chamber from a negative-electrode chamber. The alkali metal hydroxide concentration of the positive-electrode electrolytic solution differs from that of the negative-electrode electrolytic solution.

Provided is a highly reliable nickel-zinc battery including a separator exhibiting hydroxide ion conductivity and water impermeability. The nickel-zinc battery includes a positive electrode containing nickel hydroxide and/or nickel oxyhydroxide; a positive-electrode electrolytic solution in which the positive electrode is immersed, the electrolytic solution containing an alkali metal hydroxide; a negative electrode containing zinc and/or zinc oxide; a negative-electrode electrolytic solution in which the negative electrode is immersed, the electrolytic solution containing an alkali metal hydroxide; a hermetic container accommodating the positive electrode, the positive-electrode electrolytic solution, the negative electrode, and the negative-electrode electrolytic solution; and the separator exhibiting hydroxide ion conductivity and water impermeability and disposed in the hermetic container so as to separate a positive-electrode chamber from a negative-electrode chamber. The alkali metal hydroxide concentration of the positive-electrode electrolytic solution differs from that of the negative-electrode electrolytic solution.

A rechargeable battery module that effectively imparts a curvature using a rechargeable battery formed as a pin-shaped rechargeable battery with a very small diameter is provided. The rechargeable battery module includes a plurality of rechargeable batteries arranged in parallel, wherein each rechargeable battery comprises a case and terminals that extend from respective ends of the case along a length direction of the case. The module includes a plurality of caps, wherein each cap is coupled to an end of a rechargeable battery of the plurality of rechargeable batteries and is electrically connected to one of the terminals of the rechargeable battery. The module also includes a connector on each cap connecting adjacent caps coupled to corresponding rechargeable batteries. The adjacent caps are moveable relative to the connector such that a curvature between the corresponding rechargeable batteries changes in a direction crossing the length direction.

A rechargeable battery module that effectively imparts a curvature using a rechargeable battery formed as a pin-shaped rechargeable battery with a very small diameter is provided. The rechargeable battery module includes a plurality of rechargeable batteries arranged in parallel, wherein each rechargeable battery comprises a case and terminals that extend from respective ends of the case along a length direction of the case. The module includes a plurality of caps, wherein each cap is coupled to an end of a rechargeable battery of the plurality of rechargeable batteries and is electrically connected to one of the terminals of the rechargeable battery. The module also includes a connector on each cap connecting adjacent caps coupled to corresponding rechargeable batteries. The adjacent caps are moveable relative to the connector such that a curvature between the corresponding rechargeable batteries changes in a direction crossing the length direction.

A secondary alkaline battery using manganese dioxide is described. The battery includes a mixed cathode material with birnessite-phase manganese dioxide or electrolytic manganese dioxide (EMD), a bismuth compound and a copper compound selected from the group consisting of elemental copper and a copper salt. In some embodiments, a conductive carbon and/or a binder may also be included.

A secondary alkaline battery using manganese dioxide is described. The battery includes a mixed cathode material with birnessite-phase manganese dioxide or electrolytic manganese dioxide (EMD), a bismuth compound and a copper compound selected from the group consisting of elemental copper and a copper salt. In some embodiments, a conductive carbon and/or a binder may also be included.

Provided is a highly reliable nickel-zinc battery, which includes a separator exhibiting hydroxide ion conductivity and water impermeability. The separator is disposed in a hermetic container to separate a positive-electrode chamber from a negative-electrode chamber. The positive-electrode chamber has an extra positive-electrode space having a volume that meets part of a variation in amount of water in association with the positive electrode reaction, and the negative-electrode chamber has an extra negative-electrode space having a volume that meets part of a variation in amount of water in association with the negative electrode reaction. The battery further includes a gas-liquid flow channel that connects the extra positive-electrode space to the extra negative-electrode space, and the gas-liquid flow channel allows the electrolytic solution and gas in the positive-electrode and negative-electrode chambers to pass through the flow channel in response to a variation in amount of water caused by charge and discharge reactions.

Provided is a highly reliable nickel-zinc battery, which includes a separator exhibiting hydroxide ion conductivity and water impermeability. The separator is disposed in a hermetic container to separate a positive-electrode chamber from a negative-electrode chamber. The positive-electrode chamber has an extra positive-electrode space having a volume that meets part of a variation in amount of water in association with the positive electrode reaction, and the negative-electrode chamber has an extra negative-electrode space having a volume that meets part of a variation in amount of water in association with the negative electrode reaction. The battery further includes a gas-liquid flow channel that connects the extra positive-electrode space to the extra negative-electrode space, and the gas-liquid flow channel allows the electrolytic solution and gas in the positive-electrode and negative-electrode chambers to pass through the flow channel in response to a variation in amount of water caused by charge and discharge reactions.

Provided is a highly reliable nickel-zinc battery including a separator exhibiting hydroxide ion conductivity and water impermeability. The nickel-zinc battery includes a positive electrode containing nickel hydroxide and/or nickel oxyhydroxide; a positive-electrode electrolytic solution in which the positive electrode is immersed, the electrolytic solution containing an alkali metal hydroxide; a negative electrode containing zinc and/or zinc oxide; a negative-electrode electrolytic solution in which the negative electrode is immersed, the electrolytic solution containing an alkali metal hydroxide; a hermetic container accommodating the positive electrode, the positive-electrode electrolytic solution, the negative electrode, and the negative-electrode electrolytic solution; and the separator exhibiting hydroxide ion conductivity and water impermeability and disposed in the hermetic container so as to separate a positive-electrode chamber from a negative-electrode chamber. The alkali metal hydroxide concentration of the positive-electrode electrolytic solution differs from that of the negative-electrode electrolytic solution.