RECHARGEABLE BATTERY

A rechargeable battery according to one embodiment of the present invention includes: an electrode assembly having a separator interposed between a first electrode and a second electrode; a case including an upper case having an open lower portion and a penetration hole in the upper portion thereof, and a lower case having an open upper portion to seal the lower portion of the upper case, and accommodating the electrode assembly therein; and a cap plate coupled to the upper case so as to seal the penetration hole and electrically insulated from the upper case, wherein the upper case and the lower case are coupled such that partial regions overlap, and an upper end of the lower case protrudes inwardly and is latched and fixed to the outside of the upper case.