RECHARGEABLE BATTERY

A rechargeable battery includes an electrode assembly including a first electrode plate, a second electrode plate, and a separator between the first and second electrode plates; a first collector plate and a second collector plate electrically coupled to the first electrode plate and the second electrode plate, respectively; a case accommodating the electrode assembly and the first and second collector plates; and a cap assembly coupled to the case, wherein the cap assembly comprises a cap plate sealing the case, and wherein a reinforcing protrusion part is on the cap plate extending along a length of the cap plate.