BATTERY MODULE HAVING FLAME DISCHARGING-PREVENTION STRUCTURE, BATTERY PACK COMPRISING SAME, VEHICLE, AND POWER STORAGE SYSTEM

A battery module according to an embodiment of the present disclosure includes a sub module including a plurality of battery cells, a lower housing to receive the sub module therein and having an opening, a first housing cover coupled to the lower housing, covering the opening of the lower housing, and having a gas inlet, a second housing cover coupled to the first housing cover from above to form a gas receiving space therebetween, and having a gas outlet, and a variable partition structure using hinges installed in the gas receiving space to partition the gas receiving space to define a gas exhaust path to increase a movement path of a flame entering together with gas occurred in the sub module and entering the gas receiving space through the gas inlet.