摘要 |
The present invention provides an electrolytic copper foil which is excellent in the extension property and can endure the change in the expansion and contraction at the fine units while having high strength, and a method of producing the same. Specifically, the electrolytic copper foil for a negative electrode collector in a secondary battery, wherein in a nominal stress strain curve, a tensile strength is 45 to 70 kg/mm2, and a value of the tensile strength is greater than a value of a breaking stress, and an extension rate is 5% or more. |