Battery Cell and Battery Module Including the Same

Disclosed is a battery cell including a battery case having an accommodation portion in which an electrode assembly is mounted, and a sealing portion formed by sealing an outer periphery thereof. A gas discharge unit can be inserted into the sealing portion and fused together with the sealing portion. The gas discharge unit including a first layer and a second layer and having a folded structure based on a first border line such that the gas discharge unit is open toward the inside of the battery case and the first layer becomes an outer surface of the gas discharge unit. The first layer and the sealing portion being in contact with each other.