Patent ID: 8557418

Claim:
A rechargeable battery comprising: a case containing an electrode assembly; a cap plate coupled to the case and sealing an opening of the case; a first electrode terminal connected to a first electrode of the electrode assembly and electrically connected to the case; a second electrode terminal connected to a second electrode of the electrode assembly and electrically insulated from the case when a pressure inside the case is less than a threshold pressure; and a short-circuit unit comprising a short-circuit member connected to the second electrode terminal, the short-circuit unit adapted to short-circuit the second electrode terminal to the case by swelling a portion of the case to contact and electrically connect to the short-circuit member when the pressure inside the case is equal to or greater than the threshold pressure, wherein the short-circuit unit further comprises a swelling induction unit comprising the portion of the case, the portion of the case having a thickness that is less than a thickness of another portion of the case surrounding the portion, and wherein the short-circuit member faces and is contactable with an outer surface of the portion of the case.