A rechargeable battery includes an electrode assembly having a positive electrode, a negative electrode, and a separator located between the positive electrode and the negative electrode; a case housing the electrode assembly, the case having an opening; a cap assembly including a cap plate coupled to the opening of the case and a vent member on the cap plate adapted to discharge a gas from the case; and a separation member located between the electrode assembly and the cap plate to prevent the electrode assembly from significantly moving toward the cap plate.