BATTERY MODULE HAVING STRUCTURE CAPABLE OF PREVENTING INFLOW OF AIR INTO MODULE WHEN THERMAL RUNAWAY OCCURS AND BATTERY PACK INCLUDING SAME

Disclosed is a battery module, which includes a cell stack having a plurality of battery cells; a module case configured to accommodate the cell stack; a pair of module covers configured to cover openings at both sides of the module case; and a ventilation unit installed through the module cover. The ventilation unit includes a one-way venting valve disposed at a center of a perforation hole formed through the module cover; a first hole sealing portion attached onto an inner wall of the perforation hole; and a second hole sealing portion attached onto an outer circumference of the one-way venting valve.