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 alkaline battery includes an anode comprising zinc, a cathode, and separator disposed between the anode and the cathode. The separator comprises a water-insoluble metal hydroxide. For example, the water-insoluble metal hydroxide can be magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, or any combination thereof. The separator comprising the water-insoluble metal hydroxide can serve to capture a portion of any zincate ions produced at the anode prior to the zincate ions passing through the separator to the cathode.

A rechargeable alkaline battery includes an anode comprising zinc, a cathode, and separator disposed between the anode and the cathode. The separator comprises a water-insoluble metal hydroxide. For example, the water-insoluble metal hydroxide can be magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, or any combination thereof. The separator comprising the water-insoluble metal hydroxide can serve to capture a portion of any zincate ions produced at the anode prior to the zincate ions passing through the separator to the cathode.

A bipolar battery having at least two electrochemical cells electrically arranged in series includes a housing, an electrolyte, a bipolar electrode, an anode, a cathode, and first and second microporous separators. The bipolar electrode comprises a first anode material and a first cathode material. The first cathode and anode materials are disposed on opposite faces of a current collector. The anode comprises a second anode material comprising: a zinc compound, a zinc oxide compound, and a binder, and the cathode comprises a second cathode material comprising: a manganese oxide, a conductive carbon, and a copper compound. The first cathode material faces the second anode material, and the first anode material faces the second cathode material. The first microporous separator is disposed between the first cathode material and the second anode material, and the second microporous separator is disposed between the first anode material and the second cathode material.

A bipolar battery having at least two electrochemical cells electrically arranged in series includes a housing, an electrolyte, a bipolar electrode, an anode, a cathode, and first and second microporous separators. The bipolar electrode comprises a first anode material and a first cathode material. The first cathode and anode materials are disposed on opposite faces of a current collector. The anode comprises a second anode material comprising: a zinc compound, a zinc oxide compound, and a binder, and the cathode comprises a second cathode material comprising: a manganese oxide, a conductive carbon, and a copper compound. The first cathode material faces the second anode material, and the first anode material faces the second cathode material. The first microporous separator is disposed between the first cathode material and the second anode material, and the second microporous separator is disposed between the first anode material and the second cathode material.

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.

An alkaline dry battery includes a bottomed cylindrical battery case; a positive electrode packed in the battery case and including n hollow cylindrical pellets; a negative electrode disposed in a hollow portion of the pellets; a separator interposed between the positive electrode and the negative electrode; and an alkaline electrolytic solution. The positive electrode includes manganese dioxide and a conductive agent, n is an integer of 1 or more, and an average density of manganese dioxide of the positive electrode is 2.80 to 3.00 g/cm.sup.3. The density d.sub.c of manganese dioxide in the center portion in the height direction of the positive electrode is 98% or less of an average value d.sub.e of density of manganese dioxide in each of both end portions.

The present invention proposes an electrode thin film and a method for manufacturing the electrode thin film. The method includes: determining a height between a first roller and a substrate and a coating speed for the first roller coating a first metal nanowire suspension liquid onto the substrate based on a suspension property of the first metal nanowire suspension liquid; coating, by using the first roller, the first metal nanowire suspension liquid onto the substrate with the coating speed to form a wetting film on the substrate; and controlling a first temperature of the substrate heating the wetting film based on the suspension property of the first metal nanowire suspension liquid to dry the wetting film as the electrode thin film. The first temperature makes a dewetting speed of the wetting film higher than a drying speed of the wetting film.

Disclosed are a method of manufacturing a secondary battery having an electrode assembly sealed therein including: (a) sealing a battery case after introducing an electrode assembly having a structure, in which a separator is interposed between a positive electrode and a negative electrode, and an electrolyte thereinto; and (b) removing gases generated at an abnormal operation state of a battery or high temperature from an internal battery environment by pressing both sides of the battery case having the electrode assembly embedded therein in the sealing (a) to increase internal pressure of the battery case in the sealing, wherein the electrode assembly includes a spinel-structure lithium nickel manganese composite oxide as a positive electrode active material and a lithium metal oxide as a negative electrode active material.