CELL ASSEMBLY UNIT AND BATTERY PACK INCLUDING THE SAME

A battery pack includes a cell assembly unit including a plurality of battery cells and a bus bar configured to electrically connect the plurality of battery cells, a frame unit accommodating the cell assembly unit, a bracket unit fixing the cell assembly unit to the frame unit, wherein the bracket unit and the frame unit form a flow path through which a gas is discharged, and a reverse flow prevention member disposed between the bus bar and the bracket unit, the reverse flow prevention member including a plurality of gas permeation holes, each of which extends from one end facing the bus bar and leads to another end facing the flow path.