A secondary battery includes: an electrode assembly including a first electrode plate, a second electrode plate, and a separator; an electrode tab electrically connected to the electrode assembly; a current collector plate electrically connected to the electrode tab; a case accommodating the electrode assembly, the electrode tab, the current collector plate, and an electrolyte therein; a cap plate sealing the case and including a safety vent at one region; and a current interruption device connected to the safety vent and the electrode tab.