A battery cell according to an embodiment of the present invention comprises: a battery case including a reception part in which an electrode assembly is mounted and a sealing part having a structure in which an outer periphery has been sealed; an electrode lead which is electrically connected to an electrode tab included in the electrode assembly and protrudes out of the battery case through the sealing part; and a lead film positioned at a part corresponding to the sealing part in at least one of the upper portion and the lower portion of the electrode lead, wherein the lead film has a recessed part recessed toward the inside of the battery case, and the recessed part is open to the outside of the battery case; and the sealing part positioned on a gas introduction part of the recessed part includes a recessed sealing part recessed in a direction from the inside to the outside of the battery case, and the recessed sealing part does not overlap any part of the gas introduction part on a plane.