Method for producing aluminum foil
View Patent ↗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: R 1 R 2 R 3 R 4 N.X (wherein R 1 to R 4 independently represent an alkyl group and X represents a counteranion for the quaternary ammonium cation), and then the film is removed from the substrate.
1. A method for producing an aluminum foil, 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: R 1 R 2 R 3 R 4 N.X (wherein R 1 to R 4 independently represent an alkyl group and X represents a counteranion for the quaternary ammonium cation), and
the film is then removed from the substrate,
wherein the aluminum foil has a first surface, that is closer to the substrate, and a second surface,
wherein the aluminum foil has a cross-sectional configuration whose crystal structure increases in width from the first surface towards the second surface,
wherein an Ra of the first surface is 1 to 10 μm,
wherein, before a washing, the second surface has first concentrations of S and Cl, and the first surface has second concentrations of S and Cl more than the first concentrations of S and Cl.
2. A production method according to claim 1 , characterized in that the dialkyl sulfone is dimethyl sulfone.
3. An electrolytic aluminum foil characterized by having an aluminum content of 97.0 to 99.9 mass %, S and Cl contents of 1.5 mass % or less each, a Vickers hardness of 40 to 120 Hv, and a thickness of 1 to 15 μm,
wherein the aluminum foil has a first surface, that is closer to a substrate, and a second surface,
wherein the aluminum foil has a cross-sectional configuration whose crystal structure increases in width from the first surface towards the second surface,
wherein an Ra of the first surface is 1 to 10 μm,
wherein, before a washing, the second surface has first concentrations of S and Cl, and the first surface has second concentrations of S and Cl more than the first concentrations of S and Cl.
4. A positive electrode current collector for an electrical storage device, characterized by comprising an electrolytic aluminum foil according to claim 3 .
5. An electrode for an electrical storage device, characterized by comprising an electrode active material supported on an electrolytic aluminum foil according to claim 3 .
6. An electrical storage device characterized by being configured using an electrode for an electrical storage device according to claim 5 .
7. A method for producing an aluminum foil, 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: R 1 R 2 R 3 R 4 N.X (wherein R 1 to R 4 independently represent an alkyl group and X represents a counteranion for the quaternary ammonium cation), and
the film is then removed from the substrate,
wherein the aluminum foil has a first surface, that is closer to the substrate, and a second surface,
wherein the aluminum foil has a cross-sectional configuration whose crystal structure increases in width from the first surface towards the second surface,
wherein an Ra of the first surface is 1 to 10 μm,
wherein, after a washing, the second surface has first concentrations of S and Cl, and the first surface has the first concentrations of S and Cl.
8. An electrolytic aluminum foil characterized by having an aluminum content of 97.0 to 99.9 mass %, S and Cl contents of 1.5 mass % or less each, a Vickers hardness of 40 to 120 Hv, and a thickness of 1 to 15 μm,
wherein the aluminum foil has a first surface, that is closer to a substrate, and a second surface,
wherein the aluminum foil has a cross-sectional configuration whose crystal structure increases in width from the first surface towards the second surface,
wherein an Ra of the first surface is 1 to 10 μm,
wherein, after a washing, the second surface has first concentrations of S and Cl, and the first surface has the first concentrations of S and Cl.