Rolled copper foil, method for producing the same, and lithium ion secondary battery negative electrode using the rolled copper foil

摘要

The invention provides a rolled copper foil and a manufacturing method thereof, and a negative electrode of the lithium ion secondary battery using the same. The rolled copper foil not only is of high intensity, high heat resistance, high conductive rate and good processing ability and the like, and has high tightness of the resin contained in a negative electrode active material layer without applying coarse processing such as plating of electro-deposition particles on a surface of the copper foil. The rolled copper foil is characterized by comprising Cr, preferably 0.20 to 0.40 weight% Cr, and an average atomic radius is smaller than the atomic radius of Cu when the total of (atomic radius) of each component element plus (atom%) is taken as the average atomic radius of all the component elements; elements (except for Cr) which have functions of enhanced intensity and/or heat resistance, preferably one or more elements from an element ground formed by Ag, Sn, In, Ti and Zn, and the remaining parts are composed of Cu and unavoidable impurities.