A secondary battery includes an electrode assembly including a first electrode, a second electrode, and a separator between the first electrode and the second electrode, a case accommodating the electrode assembly, a cap assembly including a cap plate having a first through-hole and coupled to the case and a short-circuiting member electrically coupled to one of the first and second electrodes, and a displacement plate in the first through-hole and spaced from a bottom surface of the short-circuiting member at a first position, and configured to be separated from the first through-hole and to contact the bottom surface of the short-circuiting member at a second position.