Hitachi Metals, Ltd.

Setsuo Andou

Atsushi Okamoto

Hiroyuki Hoshi

An object of the present invention is to provide an aluminum foil that can make a positive electrode current collector thinner for size reduction and higher energy density of electrical storage devices, be produced easily and has a low surface resistance. An aluminum foil of the present invention as a means for achieving the object is characterized in that carbonaceous particles are dispersed and supported therein. The aluminum foil with carbonaceous particles dispersed and supported therein of the present invention can be produced by electrolysis.

Aluminum foil with carbonaceous particles dispersed and supported therein

A method for producing an aluminum foil of the present invention is characterized in that an aluminum film is formed on a surface of a substrate by electrolysis using a plating solution containing at least (1) a dialkyl sulfone, (2) an aluminum halide, and (3) at least one nitrogen-containing compound selected from the group consisting of an ammonium halide, a hydrogen halide salt of a primary amine, a hydrogen halide salt of a secondary amine, a hydrogen halide salt of a tertiary amine, and a quaternary ammonium salt represented by the general formula: RRRRN.X (Rto Rindependently represent an alkyl group and are the same as or different from one another, and X represents a counteranion for the quaternary ammonium cation), then the film is separated from the substrate to obtain an aluminum foil, and the obtained aluminum foil is subjected to a heat treatment.

Method for producing aluminum foil

An object of the present invention is to provide a method for producing a high-ductility, high-purity aluminum foil at a high film formation rate by electrolysis using a plating solution having a low chlorine concentration. A method for producing an aluminum foil of the present invention as a means for achieving the object is characterized in that an aluminum film is formed on a surface of a substrate by electrolysis using a plating solution at least containing (1) a dialkyl sulfone, (2) an aluminum halide, and (3) at least one nitrogen-containing compound selected from the group consisting of an ammonium halide, a hydrogen halide salt of a primary amine, a hydrogen halide salt of a secondary amine, a hydrogen halide salt of a tertiary amine, and a quaternary ammonium salt represented by a general formula: RRRRN.X (wherein Rto Rindependently represent an alkyl group and X represents a counteranion for the quaternary ammonium cation), and then the film is removed from the substrate.

A plating film is provided with enough hardness before anodic oxidation, which is hard to be damaged during handling, and also the production method of the plating film. This problem can be solved by an aluminum plating film with aluminum concentration of 98 wt. % or lower, and with a Vickers hardness of 250 or higher. The hardness is increased by containing oxygen, carbon, sulfur, and a halogen element as impurities. The impurity concentration is controlled by adjusting the current density, the plating temperature, or the plating bath composition.

Growing community of inventors

Kagoshima, Japan

Setsuo Andou