ALUMINUM ALLOY SHEET FOR BATTERY CASE AND METHOD FOR PRODUCING THE SAME

PROBLEM TO BE SOLVED: To provide an aluminum alloy sheet for a battery case excellent in pressure resistance and laser weldability and a suitable method for producing the same.SOLUTION: The aluminum alloy sheet for a battery case comprises 0.10-0.60 mass% of Si, 0.05-0.60 mass% of Fe, more than 0.70 mass% and less than 1.0 mass% of Cu, 0.10-1.80 mass% of Mn, more than 0.70 mass% and not more than 1.5 mass% of Mg, more than 0.10 mass% and less than 0.20 mass% of Zr, and 0.03-0.25 mass% of Ti, with the balance of Al and unavoidable impurities, wherein artificial aging treatment is not performed prior to case molding. Further, 0.02 mass% or less of B and 0.35 mass% or less of Cr can be contained. A battery case is produced from the aluminum alloy sheet by performing aging treatment after the aluminum alloy sheet is molded into a case. The battery case is excellent in pressure resistance because a sufficient intermediate phase of AlCuMg is developed due to the aging treatment, and is capable of high-speed laser welding because the Cu content achieves the specific amount above.