Battery Cell and Battery Cell Manufacturing Apparatus

A battery cell includes 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; an electrode lead electrically connected to an electrode tab of the electrode assembly and protruding out of the battery case; and a lead film located at a portion corresponding to the sealing portion in one of an upper portion and a lower portion of the electrode lead. The lead film has a dented portion recessed in an inner direction of the battery case. The dented portion is opened toward outside of the battery case. The sealing portion located on a gas inlet portion of the dented portion has a recessed sealing portion recessed outward from an inner side of the battery case, and the recessed sealing portion does not overlap with a part of the gas inlet portion on a plane.