Method for producing aluminum alloy foil for positive electrode current collector of lithium ion secondary battery, aluminum alloy foil for lithium ion secondary battery positive electrode current collector and lithium ion secondary battery

摘要

PROBLEM TO BE SOLVED: To provide an aluminum alloy foil for a lithium ion secondary battery positive electrode collector, which has improved material strength.SOLUTION: The aluminum alloy foil for a lithium ion secondary battery positive electrode collector has enhanced material strength in comparison with that of a foil base material, and is obtained by casting alloy molten metal including 0.10-1.50 mass% of Mn, 0.20-1.50 mass% of Fe, with the proviso that the total amount of Mn and Fe is 1.30-2.10 mass%, and the remainder comprising Al and inevitable impurities by a semicontinuous casting process, then applying a homogenization treatment to the obtained ingot, applying hot rolling, cold rolling, intermediate annealing, and cold rolling to the homogenized ingot, and performing a heat treatment at 70-200°C for 10 min or more by using, as a base material, an aluminum alloy foil having a thickness of 5-25 m, obtained at a rolling-reduction ratio of 95% or more after the intermediate annealing.