| 摘要 |
PROBLEM TO BE SOLVED: To provide a current collector made out of an aluminum foil for a secondary cell, which is hardly dissolved into electrolyte. SOLUTION: This current collector is made out of an aluminum foil, in which its purity is 99%, and its weight percentage is equal to or more than 70% by weight. In this aluminum foil, the total content of specified impure elements formed out of a group composed of indium, tin, antimony, thallium, lead, bismuth, magnesium, silicon, copper, and of manganese, is less than 0.1% by weight at the surface layer as thin as 0.1 μm measured from its surface. In the whole of the aluminum foil, the total content of these specified impure elements and impurity including iron, chromium, zinc, nickel, titanium, and potassium, is preferably less than 2% by weight. The aluminum foil thus mentioned above, can be obtained out of aluminum ingots by means of hot rolling, primary cold rolling, intermediate annealing and secondary cold rolling. This current collector is preferably used for the positive electrode of a lithium ion cell or a polymer cell. |
