Rechargeable battery and manufacturing method of the same

A method for manufacturing a rechargeable battery, comprising:

• slitting a metal sheet into a unit sheet of a predetermined size;
• forming the unit sheet into a pipe of a cylinder having a side seam portion by rolling the unit sheet, and overlapping and bonding both ends of the unit sheet, said pipe having a bent portion attached directly to said side seam portion;
• forming the cylinder pipe into a rectangular pipe, said rectangular pipe includes a pair of narrow surfaces facing each other and a pair of wide surfaces facing each other, said narrow surfaces have a shorter width than said wide surfaces;
• forming a flange by deforming one end portion of the rectangular pipe;
• forming a can of a rechargeable battery having a bottom seam portion where the flange and the curl of the bottom plate are bonded;
• inserting an electrode assembly having a positive electrode, negative electrode and separator into the can and combining a cap assembly to the can by connecting the cap assembly to the electrode assembly, said electrode assembly includes a plane portion facing the pair of wide surfaces, and a convex portion facing the pair of narrow surfaces;
• and
• inserting a plurality of inserting member consisting of four inserting members inserted into spaces formed between a corner vertically connecting the wide surface and the narrow surface of the pipe and the convex portion of the electrode assembly, each of the plurality of inserting members includes a concave portion entirely in direct contact with a portion of the convex portion of the electrode assembly, each of the plurality of inserting members includes a first plane portion in direct contact with the narrow surface of the pipe, and each of the plurality of inserting members includes a second plane in direct contact with the wide surface of the pipe, said concave portion shape has a concave shape and said convex portion has a convex shape, no space, void or cavity exists between the rectangular pipe and the electrode assembly, the plurality of inserting members is in direct physical contact with solely said separator of the electrode assembly and not in contact with the positive or negative electrode of the electrode assembly,
• wherein solely one of the four inserting portions consists of first and second sub-plane portions, said second sub-plane portion is in direct contact with solely the wide surface of the pipe and the first sub-plane is in direct contact with solely the bent portion of the pipe, the first and second sub-plane portions form a step that has a same shape and size as the bent portion.