Patent ID: 7258951

Claim:
A method for making a lithium secondary battery comprising: forming a positive electrode by coating a lithium metal oxide on a positive current collector; forming a negative electrode by coating carbonaceous materials or SnO 2 on a negative current collector, the negative current collector is made of a Cu-based alloy with a thickness of 20 μm or less and the Cu-based alloy comprises at least four materials selected from the group consisting of boron, cobalt, nickel, titanium, magnesium, tin, zinc, chromium, manganese, iron, vanadium, aluminum, zirconium, niobium, and bismuth, wherein at least three of the four materials are nickel, titanium and magnesium and the Cu-based alloy further comprises a copper-based material selected from the group consisting of copper, copper/nickel, copper/titanium, and copper/nickel/titanium, wherein the Cu-based alloy is produced by a plating process into a foil shape; interposing a separator between the positive and negative electrodes; and injecting an electrolyte to immerse the positive and negative electrodes and the separator.