Composite foil for negative electrode current collector of non-aqueous electrolyte secondary battery and manufacturing method thereof, and negative electrode current collector, non-aqueous electrolyte secondary battery electrode and non-aqueous electrolyte secondary battery using the composite foil

摘要

Disclosed is a composite foil which exhibits high tensile strength even after a high-temperature heat treatment and is suitably used as a current collector for nonaqueous electrolyte secondary batteries. Specifically disclosed are composite foils (1) and (2) below. In such composite foils, a cobalt plating layer or a cobalt-nickel alloy plating layer is preferably formed on the surface of a copper foil so that it has a thickness of 0.5-5.0 mum. (1) A composite foil obtained by forming a cobalt plating layer on the surface of a copper foil. (2) A composite foil obtained by forming a cobalt-nickel alloy plating layer on the surface of a copper foil.