BATTERY MODULE, BATTERY RACK INCLUDING BATTERY MODULE, AND ENERGY STORAGE SYSTEM INCLUDING BATTERY RACK

A battery module includes a plurality of battery cells, a module case configured to accommodate the plurality of battery cells and having inner cooling channels formed at both sides of the plurality of battery cells. At least one opening is provided at both side surfaces of the module case to face the inner cooling channels of the module case and a pair of film members is mounted to both side surfaces of the module case to cover the at least one opening, the pair of film members being melted over a predetermined temperature to open the at least one opening.