Abstract: To provide a manganese-iridium composite oxide, a manganese-iridium composite oxide and a manganese-iridium composite oxide electrode material, having high catalytic activity produced at low cost, to be used as an anode catalyst for oxygen evolution in water electrolysis, and their production methods. A manganese-iridium composite oxide, which has an iridium metal content ratio (iridium/(manganese+indium)) of 0.1 atomic % or more and 30 atomic % or less, and has interplanar spacings of at least 0.243±0.002 nm, 0.214±0.002 nm, 0.165±0.002 nm, 0.140±0.002 nm, and a manganese-iridium composite oxide electrode material comprising an electrically conductive substrate constituted by fibers at least part of which are covered with the above manganese-iridium composite oxide.

Abstract: To provide electrolytic manganese dioxide excellent in packing property and high-rate discharge characteristics when used as a cathode material for alkaline dry cells. Electrolytic manganese dioxide in which the half-value width of the (110) plane in XRD measurement using CuK? line as the radiation source is at least 1.8° and less than 2.2°, the peak intensity ratio of X-ray diffraction peaks (110)/(021) is at least 0.70 and at most 1.00, and the JIS-pH (JIS K1467) is at least 1.5 and less than 5.0; a method for producing the electrolytic manganese dioxide; and its application.

Abstract: A manganese oxide, a manganese oxide/carbon mixture and a manganese oxide composite electrode material, having high catalytic activity produced at low cost, to be used as an anode catalyst for oxygen evolution in water electrolysis, and their production methods, are provided. A manganese oxide for an oxygen evolution electrode catalyst in water electrolysis is provided, which is a manganese oxide having a metallic valence of higher than 3.0 and at most 4.0, having an average primary particle size of at most 80 nm and an average secondary particle size of at most 25 ?m, a manganese oxide/carbon mixture for an oxygen evolution electrode catalyst in water electrolysis, having a proportion of manganese oxide to the total of the manganese oxide and electrically conductive carbon of from 0.5 to 40 wt %, and a manganese oxide composite electrode material which includes an electrically conductive substrate constituted by fibers.

Abstract: To provide electrolytic manganese dioxide excellent in packing property and high-rate discharge characteristics when used as a cathode material for alkaline dry cells. Electrolytic manganese dioxide in which the half-value width of the (110) plane in XRD measurement using CuK? line as the radiation source is at least 1.8° and less than 2.2°, the peak intensity ratio of X-ray diffraction peaks (110)/(021) is at least 0.70 and at most 1.00, and the JIS-pH (JIS K1467) is at least 1.5 and less than 5.0; a method for producing the electrolytic manganese dioxide; and its application.

Abstract: The object of the present invention is to provide electrolytic manganese dioxide excellent in the middle rate discharge characteristic as compared with conventional electrolytic manganese dioxide, and a method for its production and its application. Electrolytic manganese dioxide characterized in that the potential as measured in a 40 wt % KOH aqueous solution by using a mercury/mercury oxide reference electrode as a standard is higher than 250 mV and less than 310 mV, and the volume of pores having a pore diameter of at least 2 nm and at most 50 nm is at most 0.0055 cm3/g. Of such electrolytic manganese dioxide, the volume of pores having a pore diameter of at least 2 nm and at most 200 nm is preferably at most 0.0555 cm3/g.

Abstract: The invention provides electrolytic a manganese dioxide with a BET specific surface area of 20 to 60 m2/g, and a volume of at least 0.023 cm3/g for pores with pore diameters of 2 to 200 nm. Also provided is a method for producing an electrolytic manganese dioxide including a step of suspending a manganese oxide in a sulfuric acid-manganese sulfate mixed solution to obtain the electrolytic manganese dioxide, wherein a manganese oxide particles are continuously mixed with a sulfuric acid-manganese sulfate mixed solution, for a manganese oxide particle concentration of 5 to 200 mg/L in the sulfuric acid-manganese sulfate mixed solution. Still further provided is a method for producing a lithium-manganese complex oxide, including a step of mixing the electrolytic manganese dioxide with a lithium compound and heat treating the mixture to obtain a lithium-manganese complex oxide.

Abstract: An object of the present invention is to provide electrolytic manganese dioxide to be used as a cathode active material for an alkali-manganese dry cell, which has a high alkali potential and is provided with a high reactivity and packing efficiency as a cathode for the cell, and which is excellent in the middle rate discharge characteristic, and electrolytic manganese dioxide excellent in the high rate discharge characteristic and the middle rate discharge characteristic, which will not cause corrosion of metal materials, and a method for its production. In the present invention, electrolytic manganese dioxide having an alkali potential of at least 280 mV and less than 310 mV, and FWHM of at least 2.2° and at most 2.9°, is used. It is preferred that of the electrolytic manganese dioxide, the (110)/(021) peak intensity ratio in the X-ray diffraction peaks is at least 0.50 and at most 0.80, and the (110) interplanar spacing is at least 4.00 ? and at most 4.06 ?.

Abstract: The object of the present invention is to provide electrolytic manganese dioxide excellent in the middle rate discharge characteristic as compared with conventional electrolytic manganese dioxide, and a method for its production and its application. Electrolytic manganese dioxide characterized in that the potential as measured in a 40 wt % KOH aqueous solution by using a mercury/mercury oxide reference electrode as a standard is higher than 250 mV and less than 310 mV, and the volume of pores having a pore diameter of at least 2 nm and at most 50 nm is at most 0.0055 cm3/g. Of such electrolytic manganese dioxide, the volume of pores having a pore diameter of at least 2 nm and at most 200 nm is preferably at most 0.0555 cm3/g.

Abstract: Disclosed is an electrolytic manganese dioxide having an alkali potential of at least 310 mV, a full width at half maximum of the (110) plane in the XRD measurement using the CuK? line as the light source of from 2.2° to 3.0°, and a (110)/(021) peak intensity ratio in the X-ray diffraction spectrum of from 0.5 to 0.80. Also disclosed is a method for producing electrolytic manganese dioxide by electrolysis in an aqueous solution of a sulfuric acid/manganese sulfate mixture.

Abstract: Disclosed is an electrolytic manganese dioxide having an alkali potential of at least 310 mV, a full width at half maximum of the (110) plane in the XRD measurement using the CuK? line as the light source of from 2.2o to 3.0o, and a (110)/(021) peak intensity ratio in the X-ray diffraction spectrum of from 0.5 to 0.80. Also disclosed is a method for producing electrolytic manganese dioxide by electrolysis in an aqueous solution of a sulfuric acid/manganese sulfate mixture.

Abstract: Electrolytic manganese dioxide characterized by having a surface sulfate (SO4) content of smaller than 0.10% by weight and a JIS-pH value, as measured according to JIS K1467, of at least 1.5 but smaller than 3.5, preferably at least 2.1 but smaller than 3.2 is provided. Preferably 3% to 25% in number of the fine particles of the manganese dioxide have a particle diameter of not larger than 1 ?m. A battery provided with a cathode made from the electrolytic manganese dioxide as active material exhibits good high-rate discharge characteristics and good resistance to metal corrosion.

Abstract: The invention provides electrolytic a manganese dioxide with a BET specific surface area of 20 to 60 m2/g, and a volume of at least 0.023 cm3/g for pores with pore diameters of 2 to 200 nm. Also provided is a method for producing an electrolytic manganese dioxide including a step of suspending a manganese oxide in a sulfuric acid-manganese sulfate mixed solution to obtain the electrolytic manganese dioxide, wherein a manganese oxide particles are continuously mixed with a sulfuric acid-manganese sulfate mixed solution, for a manganese oxide particle concentration of 5 to 200 mg/L in the sulfuric acid-manganese sulfate mixed solution. Still further provided is a method for producing a lithium-manganese complex oxide, including a step of mixing the electrolytic manganese dioxide with a lithium compound and heat treating the mixture to obtain a lithium-manganese complex oxide.

Abstract: An object of the present invention is to provide electrolytic manganese dioxide to be used as a cathode active material for an alkali-manganese dry cell, which has a high alkali potential and is provided with a high reactivity and packing efficiency as a cathode for the cell, and which is excellent in the middle rate discharge characteristic, and electrolytic manganese dioxide excellent in the high rate discharge characteristic and the middle rate discharge characteristic, which will not cause corrosion of metal materials, and a method for its production. In the present invention, electrolytic manganese dioxide having an alkali potential of at least 280 mV and less than 310 mV, and FWHM of at least 2.2° and at most 2.9°, is used. It is preferred that of the electrolytic manganese dioxide, the (110)/(021) peak intensity ratio in the X-ray diffraction peaks is at least 0.50 and at most 0.80, and the (110) interplanar spacing is at least 4.00 ? and at most 4.06 ?.

Abstract: To provide electrolytic manganese dioxide to be used as a cathode active material for an alkali-manganese dry cell, which has a high alkali potential and is provided with a high reactivity and packing efficiency as a cathode for the cell. Electrolytic manganese dioxide having an alkali potential of at least 310 mV, FWHM of at least 2.2° and at most 3.0°, and a (110)/(021) peak intensity ratio in the X-ray diffraction peaks of at least 0.50 and at most 0.80, is used. The (110) interplanar spacing of the electrolytic manganese dioxide is preferably at least 4.00 ? and at most 4.06 ?. Particularly when the alkali potential is at least 350 mV and at most 400 mV, the molar ratio of structural water contained (H2O/MnO2) is preferably at least 0.20. It can be produced by electrolysis at a low sulfuric acid concentration at the initial stage of the electrolysis and at a high sulfuric acid concentration at a later stage. It is preferred to further carry out sulfuric acid treatment.

Abstract: Electrolytic manganese dioxide characterized by having a surface sulfate (SO4) content of smaller than 0.10% by weight and a JIS-pH value, as measured according to JIS K1467, of at least 1.5 but smaller than 3.5, preferably at least 2.1 but smaller than 3.2 is provided. Preferably 3% to 25% in number of the fine particles of the manganese dioxide have a particle diameter of not larger than 1 ?m. A battery provided with a cathode made from the electrolytic manganese dioxide as active material exhibits good high-rate discharge characteristics and good resistance to metal corrosion.

Abstract: A cathode of sufficiently low hydrogen overvoltage is provided which is useful in electrolysis of water or of an aqueous alkali metal chloride solution such as a sodium chloride solution. A process for producing the cathode is also provided. The low hydrogen overvoltage cathode has an electroconductive base material coated with an alloy layer containing nickel and molybdenum, the alloy layer containing the nickel at a content ranging from 35 to 90% by weight and the molybdenum at a content ranging from 10 to 65% by weight. The alloy laser has an X-ray diffraction (CuK.alpha. line) pattern with a main peak at an angle ranging from 42 to 45.degree. with a peak half width ranging from 0.4 to 7.degree.. One process for producing the low hydrogen overvoltage cathode of the present invention involves plating an electroconductive base material by an arc discharge type ion plating method.

Abstract: A novel cathode of low hydrogen overvoltage is provided which is useful for electrolysis of water and electrolysis of an aqueous alkali metal chloride such as sodium chloride. A process for producing the cathode is also provided. The low hydrogen overvoltage cathode comprises an electroconductive base material; and a coating layer containing at least one organic compound selected from the group consisting of amino acids, monocarboxylic acids, dicarboxylic acids, monoamines, diamines, triamines, and tetramines, and derivatives thereof at a content of from 0.5% to 18% by weight in terms of carbon, and a metal component selected from the group consisting of nickel, nickel-iron, nickel-cobalt, and nickel-indium at an indium content ranging from 1% to 90% by weight.

Abstract: A low hydrogen overvoltage cathode is provided which comprises an electroconductive base material coated with an alloy layer containing cobalt and tin at least at a content of tin ranging from 0.01 to 95% by weight. A process is also provided for producing the low hydrogen voltage cathode, wherein cobalt and tin at least are electrolytically co-deposited onto a surface of an electroconductive base material from a plating bath containing cobalt ions, tin ions, and a complexing agent.