A secondary battery, comprising: a first aluminum foil having a surface coated with a positive terminal material, and a plurality of first notches being formed at first preset locations along a length of the first aluminum foil, each of the first notches having a depth ranging from one half to three fourths of a width of the first aluminum foil, each of the first notches being covered by a first adhesive tape adhered with the first aluminum foil, thereby preventing the first aluminum foil from being cracked along the first notches while being pulled, and a plurality of first electrode lugs being provided along the length of the first aluminum foil at locations different from the first preset locations of the first notches, all the first electrode lugs being connected in parallel to serve as a positive terminal of the secondary battery for increasing a charging/discharging current; a second aluminum foil having a surface coated with a negative terminal material, and a plurality of second notches being formed at second preset locations along a length of the second aluminum foil, each of the second notches having a depth ranging from one half to three fourths of a width of the second aluminum foil, each of the second notches being covered by a second adhesive tape adhered with the second aluminum foil, thereby preventing the second aluminum foil from being cracked along the second notches while being pulled, and a plurality of second electrode lugs being provided along the length of the second aluminum foil at locations different from the second preset locations of the second notches, all the second electrode lugs being connected in parallel to serve as a negative terminal of the secondary battery for increasing the charging/discharging current; a separation film disposed between the first aluminum foil and the second aluminum foil to form a trilayer structure, the trilayer structure being wound into a predetermined shape; a case for accommodating and sealing the trilayer structure in the predetermined shape; and an electrolyte filled in the case. a first aluminum foil having a surface coated with a positive terminal material, and a plurality of first notches being formed at first preset locations along a length of the first aluminum foil, each of the first notches having a depth ranging from one half to three fourths of a width of the first aluminum foil, each of the first notches being covered by a first adhesive tape adhered with the first aluminum foil, thereby preventing the first aluminum foil from being cracked along the first notches while being pulled, and a plurality of first electrode lugs being provided along the length of the first aluminum foil at locations different from the first preset locations of the first notches, all the first electrode lugs being connected in parallel to serve as a positive terminal of the secondary battery for increasing a charging/discharging current; a second aluminum foil having a surface coated with a negative terminal material, and a plurality of second notches being formed at second preset locations along a length of the second aluminum foil, each of the second notches having a depth ranging from one half to three fourths of a width of the second aluminum foil, each of the second notches being covered by a second adhesive tape adhered with the second aluminum foil, thereby preventing the second aluminum foil from being cracked along the second notches while being pulled, and a plurality of second electrode lugs being provided along the length of the second aluminum foil at locations different from the second preset locations of the second notches, all the second electrode lugs being connected in parallel to serve as a negative terminal of the secondary battery for increasing the charging/discharging current; a separation film disposed between the first aluminum foil and the second aluminum foil to form a trilayer structure, the trilayer structure being wound into a predetermined shape; a case for accommodating and sealing the trilayer structure in the predetermined shape; and an electrolyte filled in the case.