METHOD FOR MANUFACTURING NEGATIVE ELECTRODE COLLECTOR COPPER FOIL, NEGATIVE ELECTRODE COLLECTOR COPPER FOIL, NEGATIVE ELECTRODE FOR LITHIUM ION SECONDARY BATTERY, AND LITHIUM ION SECONDARY BATTERY

摘要

PROBLEM TO BE SOLVED: To provide a negative electrode collector copper foil having less generation of cracks in cutting.SOLUTION: In a method of manufacturing a negative electrode collector copper foil which is cut off and becomes a negative electrode collector copper foil piece at a negative electrode of a lithium ion secondary battery, after applying hot rolling, cold rolling and the final cold rolling to a copper ingot added with Zr, a heating treatment process is provided in which heat treatment for one hour or more and six hours or less are applied at a temperature of 80°C or more and 500°C or less, and the negative electrode collector copper foil containing Zr is obtained.