To provide electrolytic manganese dioxide excellent in low rate characteristics and middle rate characteristics when used as a cathode material for alkaline manganese dry cells, and a method for its production. Electrolytic manganese dioxide of which the apparent density is at least 4.0 g/cm.sup.3 and at most 4.3 g/cm.sup.3, and the mode particle size is at least 30 ?m and at most 100 ?m; a method for its production and its application.

To provide electrolytic manganese dioxide excellent in low rate characteristics and middle rate characteristics when used as a cathode material for alkaline manganese dry cells, and a method for its production. Electrolytic manganese dioxide of which the apparent density is at least 4.0 g/cm.sup.3 and at most 4.3 g/cm.sup.3, and the mode particle size is at least 30 ?m and at most 100 ?m; a method for its production and its application.

This application relates to oxide particles, preferably transition metal oxide particles, made via the application of a voltage across an electrolyte solution. The electrolyte solution includes a transition metal salt dissolved in water, and preferably also includes a compound for increasing the electrical conductivity of the electrolyte. The particles made by the processes disclosed herein, can have sizes in the micrometer or nanometer ranges. The oxide particles can have a variety of uses, including for charge storage devices. As an example, manganese oxide particles, and methods for making the same, are disclosed for a variety of uses including lithium ion batteries.

This application relates to oxide particles, preferably transition metal oxide particles, made via the application of a voltage across an electrolyte solution. The electrolyte solution includes a transition metal salt dissolved in water, and preferably also includes a compound for increasing the electrical conductivity of the electrolyte. The particles made by the processes disclosed herein, can have sizes in the micrometer or nanometer ranges. The oxide particles can have a variety of uses, including for charge storage devices. As an example, manganese oxide particles, and methods for making the same, are disclosed for a variety of uses including lithium ion batteries.

It is an object of the present invention to provide a catalyst having high catalytic activity for oxygen reduction reaction, hydrogen evolution reaction, and the like, particularly a catalyst employing platinum group particles having a small particle diameter. A layered manganese oxide comprising platinum group metal particles between layers. A method for producing a layered manganese oxide comprising platinum group metal particles between layers, or platinum group metal particles, the method comprising introducing a platinum group complex between layers of a layered manganese oxide and reducing the introduced platinum group complex by electrolysis, wherein a potential applied to the platinum group complex is changed in a positive direction and a negative direction.

It is an object of the present invention to provide a catalyst having high catalytic activity for oxygen reduction reaction, hydrogen evolution reaction, and the like, particularly a catalyst employing platinum group particles having a small particle diameter. A layered manganese oxide comprising platinum group metal particles between layers. A method for producing a layered manganese oxide comprising platinum group metal particles between layers, or platinum group metal particles, the method comprising introducing a platinum group complex between layers of a layered manganese oxide and reducing the introduced platinum group complex by electrolysis, wherein a potential applied to the platinum group complex is changed in a positive direction and a negative direction.

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.

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.

An electrolytic cell and a method of electrochemical oxidation of manganese(II) ions to manganese(III) ions in the electrolytic cell are described. The electrolytic cell comprises (1) an electrolyte solution of manganese(II) ions in a solution of 9 to 15 molar sulfuric acid; (2) a cathode immersed in the electrolyte solution; and (3) an anode immersed in the electrolyte solution and spaced apart from the cathode. Various anode materials are described including vitreous carbon, reticulated vitreous carbon, and woven carbon fibers.

An electrolytic cell and a method of electrochemical oxidation of manganese(II) ions to manganese(III) ions in the electrolytic cell are described. The electrolytic cell comprises (1) an electrolyte solution of manganese(II) ions in a solution of 9 to 15 molar sulfuric acid; (2) a cathode immersed in the electrolyte solution; and (3) an anode immersed in the electrolyte solution and spaced apart from the cathode. Various anode materials are described including vitreous carbon, reticulated vitreous carbon, and woven carbon fibers.