1 . A battery cell, comprising:
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 included in the electrode assembly and protruding out of the battery case via the sealing portion; and a lead film located at a portion corresponding to the sealing portion in at least one of an upper portion and a lower portion of the electrode lead, wherein a gas discharge guiding unit is inserted in the lead film, the battery case includes a cover portion extending from the sealing portion, and the cover portion is located on the lead film and protrudes in an outer direction of the battery case.
2 . The battery cell according to claim 1 ,
wherein the cover portion is located on the gas discharge guiding unit.
3 . The battery cell according to claim 2 ,
wherein the gas discharge guiding unit is located in a portion corresponding to a center of the cover portion.
4 . The battery cell according to claim 2 ,
wherein based on a direction perpendicular to the protruding direction of the electrode lead, a length of the cover portion is equal to or greater than a length of the gas discharge guiding unit.
5 . The battery cell according to claim 4 ,
wherein based on the direction perpendicular to the protruding direction of the electrode lead, the length of the cover portion is equal to or smaller than a length of the lead film.
6 . The battery cell according to claim 1 ,
wherein based on the protruding direction of the electrode lead, an end of the cover portion is located outer than an end of the lead film.
7 . The battery cell according to claim 6 ,
wherein based on the protruding direction of the electrode lead, an end of the electrode lead is located outer than the end of the cover portion.
8 . The battery cell according to claim 6 ,
wherein the cover portion is bent in a direction away from the lead film based on the sealing portion.
9 . The battery cell according to claim 1 ,
wherein the gas discharge guiding unit extends along the protruding direction of the electrode lead, and an end of the gas discharge guiding unit adjacent to an outer side of the battery case is surrounded with the lead film.
10 . The battery cell according to claim 9 ,
wherein an end of the gas discharge guiding unit adjacent to an inner side of the battery case is exposed inside the battery case.
11 . The battery cell according to claim 1 ,
wherein a gas discharge path is formed at an interface between the gas discharge guiding unit and the lead film.
12 . The battery cell according to claim 11 ,
wherein an adhesive force between the gas discharge guiding unit and the lead film is smaller than an adhesive force between the lead film and the electrode lead or an adhesive force between the lead film and the sealing portion.
13 . The battery cell according to claim 12 ,
wherein the gas discharge guiding unit is a film layer made of polyimide or polyethylene terephthalate.
14 . The battery cell according to claim 12 ,
wherein the gas discharge guiding unit is a coating layer made of liquid resin.
15 . The battery cell according to claim 12 ,
wherein the gas discharge guiding unit further includes a getter material containing calcium oxide (CaO), lithium chloride (LiCl), silica (SiO 2 ), barium oxide (BaO), barium (Ba), or calcium (Ca).
16 . The battery cell according to claim 1 ,
wherein the gas discharge guiding unit is located on the electrode lead, and an adhesive layer is formed between the gas discharge guiding unit and the electrode lead.
17 . The battery cell according to claim 16 ,
wherein an adhesive force between the gas discharge guiding unit and the lead film is smaller than either an adhesive force between the adhesive layer and the gas discharge guiding unit or an adhesive force between the adhesive layer and the electrode lead.
18 . The battery cell according to claim 17 ,
wherein the adhesive layer is made of an adhesive tape or an adhesive binder.
19 . (canceled)
20 . (canceled)
21 . The battery cell according to claim 1 ,
wherein the gas discharge guiding unit has gas permeability of 40 Barrer or more at 60° C.
22 . A battery module, comprising the battery cell according to claim 1 .