Abstract: An aluminum-alloy foil that enables to satisfy both of high elongation and high strength even in the case of reducing the foil thickness. The chemical composition of the aluminum-alloy foil contains, in mass %, Fe: 1.0% or more and 2.0% or less, Cu: 0.1% or more and 0.5% or less, and Mn: 0.05% or less, the remainder being Al and unavoidable impurities. The aluminum-alloy foil has a foil thickness of 20 ?m or less, and satisfies the relation El?100×t/UTS. Here, t represents a foil thickness (?m), UTS represents a tensile strength (MPa), and El represents an elongation (%).

Abstract: A current-collector metal foil has at least at least one roughened surface and numerous recessed parts are present on the roughened surface. Each recessed part has an edge part that surrounds a bottom-surface part and is raised above the bottom-surface part. The average Feret diameter Lave of the recessed parts is 0.5-50 ?m. The current-collector metal foil is suitable for use, e.g., as an electrode current collector for a lithium-ion secondary battery, a sodium secondary battery, an electric double-layer capacitor, or a lithium-ion capacitor.

Abstract: An aluminum-alloy foil that enables to satisfy both of high elongation and high strength even in the case of reducing the foil thickness. The chemical composition of the aluminum-alloy foil contains, in mass %, Fe: 1.0% or more and 2.0% or less, Cu: 0.1% or more and 0.5% or less, and Mn: 0.05% or less, the remainder being Al and unavoidable impurities. The aluminum-alloy foil has a foil thickness of 20 ?m or less, and satisfies the relation El?100×t/UTS. Here, t represents a foil thickness (?m), UTS represents a tensile strength (MPa), and El represents an elongation (%).

Abstract: A high-strength, highly-elongatable aluminum-alloy foil contains, in mass %, Fe: 1.0% or more and 2.0% or less and Mn: 0.05% or less, and unavoidable impurities. The aluminum-alloy foil has an average crystal-grain size at a foil surface of 2.5 ?m or less, and a ratio of the surface-area percentages of the crystal orientations A{112}<111>/A{101}<121> is 3.0 or more. A{112}<111> is the percentage, with respect to the total surface area, of the surface areas of crystal grains in which the crystal orientation is in a range within 15° from {112}<111> in an orientation-mapping image of the foil surface produced by electron backscatter diffraction. A{101}<121> is the percentage, with respect to the total surface area, of the surface areas of the crystal grains in which the crystal orientation is in a range within 15° from {101}<121> in the orientation-mapping image.

Abstract: At least one foil surface of an aluminum foil is roughened; and in arithmetic mean roughnesses Ra, stipulated in JIS B 0601:2001, of the roughened surface(s), A, which is the arithmetic mean roughness Ra measured in a direction at a right angle to a rolling direction during foil rolling, and B, which is the arithmetic mean roughness Ra measured in a direction parallel to the rolling direction during foil rolling, satisfy the following relationships: 0.15 ?m?A?2.0 ?m; 0.15 ?m?B?2.0 ?m; and 0.5?B/A?1.5. Preferably 50-1000 ?g/m2 of oil is adhered to the roughened foil surface. The oil is preferably rolling oil.

Abstract: A current-collector metal foil has at least at least one roughened surface and numerous recessed parts are present on the roughened surface. Each recessed part has an edge part that surrounds a bottom-surface part and is raised above the bottom-surface part.. The average Feret diameter Lave of the recessed parts is 0.5-50 ?m. The current-collector metal foil is suitable for use, e.g., as an electrode current collector for a lithium-ion secondary battery, a sodium secondary battery, an electric double-layer capacitor, or a lithium-ion capacitor.

Abstract: At least one foil surface of an aluminum foil is roughened; and in arithmetic mean roughnesses Ra, stipulated in JIS B 0601:2001, of the roughened surface(s), A, which is the arithmetic mean roughness Ra measured in a direction at a right angle to a rolling direction during foil rolling, and B, which is the arithmetic mean roughness Ra measured in a direction parallel to the rolling direction during foil rolling, satisfy the following relationships: 0.15 ?m?A?2.0 ?m; 0.15 ?m?B?2.0 ?m; and 0.5?B/A?1.5. Preferably 50-1000 ?g/m2 of oil is adhered to the roughened foil surface. The oil is preferably rolling oil.