| abstract |
An object of the present invention is to provide a perforated metal foil which enables performing pre-doping with high efficiency and has high strength, a negative electrode for a secondary battery, and a positive electrode for a secondary battery. A perforated metal foil has a plurality of through-holes in a thickness direction of a metal foil, in which an average opening ratio by the through-holes is 0.5% to 10%, a number density of the through-holes is 50 to 200 holes/mm<sup>2</sup>, and the metal foil is a foil selected from the group consisting of a copper foil, a silver foil, a gold foil, a platinum foil, a stainless steel foil, a titanium foil, a tantalum foil, a molybdenum foil, a niobium foil, a zirconium foil, a tungsten foil, a beryllium copper foil, a phosphor bronze foil, a brass foil, a nickel silver foil, a tin foil, a zinc foil, an iron foil, a nickel foil, a Permalloy foil, a nichrome foil, a 42 alloy foil, a Kovar foil, a Monel foil, an Inconel foil, and a Hastelloy foil, or a foil formed by laminating a foil selected from this group and a metal of a different type from the selected foil. |