BATTERY MODULE HAVING STRUCTURE CAPABLE OF RAPID COOLING, AND ESS COMPRISING SAME

A battery module includes a sub module including a cell stack having a plurality of battery cells and a pair of bus bar frames respectively coupled to one side and the other side of the cell stack; a module housing configured to accommodate the sub module and configured to have an air inlet and an air outlet formed to circulate air; a sprinkler provided through the module housing at one side of the cell stack in a stacking direction; and an outlet closing device configured to move by a buoyancy generated by a cooling water introduced into the module housing through the sprinkler so that the air outlet is closed.