This disclosure provides
aluminum foil and a method for forming the same. The method includes: performing a multi-stage formation process on the
aluminum foil, the multi-stage formation process including three to eight stages; wherein, for
aluminum foil with a target formation withstand
voltage greater than or equal to 145V and less than or equal to 185V, a first mixture of
ammonium adipate and
ammonium dihydrogen
phosphate is used in the first stage of formation; for aluminum foil with a target formation withstand
voltage greater than or equal to 105V and less than 145V, a second mixture of
ammonium adipate and
ammonium dihydrogen phosphate is used in the second stage of formation; for aluminum foil with a target formation withstand
voltage greater than or equal to 65V and less than 105V, a third mixture of
ammonium adipate and
ammonium dihydrogen phosphate is used in the third stage of formation. By introducing
ammonium dihydrogen phosphate in advance during the main formation stage for aluminum foils with different target formation withstand voltage ranges, and utilizing its electrochemical behavior at specific formation stages, the density and
chemical stability of the
oxide film are optimized, significantly improving the hydration resistance of the aluminum foil.