A battery module, including a cell stack having a first battery cell and a second battery cell; a first bus bar connected to the cell stack and having a first polarity; a second bus bar connected to the cell stack and having a second polarity opposite to the first polarity; a short-circuit unit that moves toward the first bus bar and the second bus bar in response to receiving an expanding force caused by a volume increase of the first battery cell and the second battery cell, so that the first bus bar and the second bus bar are electrically connected to generate a short circuit; and a cartridge that at least partially accommodates each of the first bus bar, the second bus bar and the short-circuit unit.