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

A battery module includes a plurality of battery cells, a module case configured to accommodate the plurality of battery cells, an air intake unit provided to one side of the module case and configured to guide an air into the module case to cool the plurality of battery cells, an air discharge unit provided to the other side of the module case and configured to discharge the air introduced into the module case through the air intake unit to the outside of the module case, and at least one sheet member attached to an inner wall of the module case between the air discharge unit and the air intake unit and configured to expand at a predetermined temperature or above to seal an inner space of the module case.