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.

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.