A secondary battery, comprising:
- a plurality of first aluminum foils respectively having a surface coated with a positive terminal material, each two adjacent foils of the first aluminum foils being separated by a first preset gap and connected with each other by a first adhesive tape to form a first interconnected foil layer, each foil of the first aluminum foils having a first electrode lug, and 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 plurality of second aluminum foils respectively having a surface coated with a negative terminal material, each two adjacent foils of the second aluminum foils being separated by a second preset gap and connected with each other by a second adhesive tape to form a second interconnected foil layer, each foil of the second aluminum foils having a second electrode lug, and 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 being located between the first interconnected foil layer and the second interconnected foil layer 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.