BATTERY PACK COMPRISING EXTINGUISHMENT UNIT

A battery pack includes at least one battery module arranged in one direction and having a cell assembly including a plurality of secondary batteries arranged in one direction; and a fire extinguishing unit having a fire extinguishing tank configured to contain a fire extinguishing agent therein, a pipe connected to the fire extinguishing tank to supply the fire extinguishing agent from the tire extinguishing tank to the at least one battery module, and a fire extinguishing valve configured so that, when an internal gas of the battery module is heated over a predetermined temperature, an inner configuration of the fire extinguishing valve is partially deformed by the heated internal gas to open an output hole thereof so as to supply the fire extinguishing agent from the fire extinguishing tank into the battery module.