Rolled copper foil for negative electrode current collector of secondary battery, negative electrode of secondary battery and secondary battery using the rolled copper, and method for manufacturing rolled copper foil for negative electrode current collector of secondary battery

Abstract

The present invention is intended to provide a rolled copper foil for a secondary battery negative electrode current collector which can satisfactorily suppress rupture of the copper foil caused by stress generation or the like due to volume change of an active material. A rolled copper foil for a secondary battery negative electrode current collector, wherein a tensile strength in a direction parallel to the rolling direction is 600 MPa or more, and a breaking elongation in the direction parallel to the rolling direction is 2.0% or more; and wherein a tensile strength in a direction orthogonal to the rolling direction is 640 MPa or more, and a breaking elongation in the direction orthogonal to the rolling direction is 3.5% or more.

Dependencies are inferred from the claim text.