Detachable polymer lithium ion battery and assembling method thereof

The invention discloses a detachable polymer lithium ion battery. The detachable polymer lithium ion battery comprises at least two parallel polymer lithium ion battery cells, and an upper stainless steel sheet, a lower stainless steel sheet, a top shell and a bottom shell which are connected fixedly to form a cell containing cavity, wherein the two sides and the bottoms of the upper stainless steel sheet and the lower stainless steel sheet are inwards bent respectively to form side connection edges and inserting teeth; inserting grooves corresponding to the inserting teeth are formed in the bottom shell; the tops of the upper stainless steel sheet and the lower stainless steel sheet are in injection molding connection with the top shell; and the lap joint parts of the side connection edges on the two sides of the upper stainless steel sheet and the lower stainless steel sheet are welded together. The invention provides a cell packaging structure which has high packaging precision and maximized capacity density and low cost; the two or more than two polymer cells are overlapped and connected in parallel and are welded, and then are welded on a protection plate; and a battery shell packaging structure is combined by a plastic shell and a metal shell and the packaging size is saved, so that the battery packaging structure is more compact.