Aluminum alloy foil and method for manufacturing same

1. An aluminum alloy foil, comprising:

0.8 to 2.0 mass % of Fe, 0.05 to 0.2 mass % of Si, and 0.0025 to 0.5 mass % of Cu, with the rest consisting of Al and unavoidable impurities, wherein

the aluminum alloy foil has an average crystal grain size of 20 μm or less, and

a number of intermetallic compounds existing in the aluminum alloy foil, the intermetallic compounds having a circle equivalent diameter of 1.0 to 5.0 μm, is 1.0×10 4 grains/mm 2 or more.

2. The aluminum alloy foil of claim 1 , wherein an average value of tensile strength of the aluminum alloy foil in 0 degrees, 45 degrees, and 90 degrees with respect to the rolling direction is 100 N/mm 2 or higher.

3. A formed packaging material comprising the aluminum alloy foil of claim 1 .

4. The formed packaging material of claim 3 , further comprising:

a synthetic resin film laminated on one side of the aluminum alloy foil, and

a heat sealing layer laminated on an other side of the aluminum alloy foil.

5. A secondary battery comprising the formed packaging material of claim 4 .

6. A package container for medicine comprising the formed packaging material of claim 4 .

7. A method for manufacturing the aluminum alloy foil of claim 1 , comprising the steps of:

performing a homogeneous retention of an aluminum alloy ingot comprising 0.8 to 2.0 mass % of Fe, 0.05 to 0.2 mass % of Si, and 0.0025 to 0.5 mass % of Cu, with the rest consisting of Al and unavoidable impurities at 430° C. or higher and 540° C. or lower for 1 hour or longer and 6 hours or shorter;

performing a hot rolling immediately after the homogeneous retention, and a cold rolling after the hot rolling;

performing an intermediate annealing by retaining at 350° C. or higher in between the cold rolling;

performing the cold rolling at a cold rolling rate of 95% or higher from after the intermediate annealing until achieving final foil thickness; and

performing final annealing after the cold rolling to obtain the aluminum alloy foil.