Battery cell and battery module including the same

Abstract

A battery cell according to one embodiment of the present invention comprises: a battery case having a sealing portion having a structure in which an electrode assembly is mounted in a housing portion and the outer periphery is sealed; and an electrode lead electrically connected to an electrode tab included in the electrode assembly and protruding outwardly from the battery case via the sealing portion, wherein the sealing portion includes a gas exhaust portion located adjacent to at least one of the two sides of the electrode lead, and the gas exhaust portion is indented toward the electrode assembly with respect to the sealing portion, and the inner surface of the gas exhaust portion is located closer to the electrode assembly than the inner surface of the sealing portion.

Description

Technology Field

[0001] The present invention relates to a battery cell and a battery module including the same, and more specifically, to a battery cell and a battery module including the same that allows gas within the battery cell to be easily discharged in an induced direction and delays heat propagation between adjacent cells. Background Technology

[0002] With the increasing technological development and demand for mobile devices, the demand for secondary batteries as an energy source is rapidly increasing. In particular, secondary batteries are attracting significant interest as an energy source not only for mobile devices such as mobile phones, digital cameras, laptops, and wearable devices, but also for power devices such as electric bicycles, electric vehicles, and hybrid electric vehicles.

[0003] These secondary batteries are classified according to the shape of the battery case into cylindrical and prismatic batteries, in which the electrode assembly is embedded in a cylindrical or prismatic metal can, and pouch-type batteries, in which the electrode assembly is embedded in a pouch-type case made of an aluminum laminate sheet. Here, the electrode assembly embedded in the battery case is a power generation element capable of charging and discharging, consisting of a positive electrode, a negative electrode, and a separator structure interposed between the positive electrode and the negative electrode. It is classified into a jelly-roll type, which is wound with a separator interposed between long sheet-type positive and negative electrodes coated with active material, and a stack type, in which a plurality of positive and negative electrodes are sequentially stacked with a separator interposed between them.

[0004] Among these, pouch-type batteries, in particular those with a structure in which a stacked or stacked / folded electrode assembly is embedded in a pouch-type battery case made of aluminum laminate sheets, are seeing a gradual increase in usage due to reasons such as low manufacturing costs, small weight, and easy deformation.

[0005] However, as the energy density of battery cells has recently increased, there is a problem where the amount of gas generated inside the cell also increases. Conventional battery cells do not include components to vent the gas generated inside, so the cell may experience venting due to gas generation. In particular, when venting occurs in conventional battery cells, the gas is released through areas with weak sealing. Since this gas is flammable, it can heat adjacent cells, leading to ignition and explosion.

[0006] Accordingly, there is a growing need to develop battery cells that effectively discharge gas when venting occurs, while guiding the direction of gas discharge to minimize heat propagation. The problem to be solved

[0007] The problem to be solved by the present invention relates to a battery cell that delays heat propagation between adjacent cells while allowing gas within the battery cell to be easily discharged in an induced direction, and a battery module including the same.

[0008] The problems that the present invention aims to solve are not limited to those described above, and problems not mentioned will be clearly understood by those skilled in the art from this specification and the attached drawings. means of solving the problem

[0009] A battery cell according to one embodiment of the present invention comprises: a battery case having a sealing portion having a structure in which an electrode assembly is mounted in a housing portion and the outer periphery is sealed; and an electrode lead electrically connected to an electrode tab included in the electrode assembly and protruding outwardly from the battery case via the sealing portion, wherein the sealing portion includes a gas exhaust portion located in a portion excluding the portion where the electrode lead is located, and the gas exhaust portion is indented toward the electrode assembly with respect to the sealing portion, and the inner surface of the gas exhaust portion is located closer to the electrode assembly than the inner surface of the sealing portion.

[0010] The outer surface of the gas discharge portion may be located closer to the electrode assembly than the inner surface of the sealing portion.

[0011] The sealing strength of the above gas discharge part may be smaller than the sealing strength of the above sealing part.

[0012] The above gas discharge portion may have a sealing strength of 40% or more to 90% or less based on the sealing strength of the above sealing portion.

[0013] The thickness of the gas discharge portion may be the same as or smaller than the thickness of the sealing portion.

[0014] The above gas discharge portion may be positioned spaced apart from the electrode lead.

[0015] The space between the outer surface of the gas discharge portion and the sealing portion may be open toward the outside of the battery cell.

[0016] At least one of the upper and lower portions of the electrode lead may further include a lead film located in a portion corresponding to the sealing portion.

[0017] A battery module according to another embodiment of the present invention includes the battery cell described above.

[0018] The above battery cells may be stacked such that the gas discharge portion is adjacent to the bottom surface.

[0019] The above battery cells may be stacked in a direction such that the gas discharge portion is located on the lower side of the electrode lead. Effects of the invention

[0020] According to the embodiments, the present invention relates to a battery cell and a battery module including the same, wherein the gas within the battery cell is easily discharged in an induced direction, and heat propagation between adjacent cells can be delayed.

[0021] The effects of the present invention are not limited to the effects described above, and unmentioned effects will be clearly understood by those skilled in the art from this specification and the accompanying drawings. Brief explanation of the drawing

[0022] Figure 1 is a top view of a battery cell according to a comparative example. Figure 2 is an enlarged view of the battery cell end of Figure 1. Figure 3 is a diagram showing the path through which gas is discharged from the end of the battery cell of Figure 1. FIG. 4 is a top view of a battery cell according to one embodiment of the present invention. Figure 5 is an enlarged view of the battery cell end of Figure 4. Figure 6 is a diagram showing the path through which gas is discharged from the end of the battery cell of Figure 4. Figure 7 is an enlarged view of the gas exhaust portion formed at the end of the battery cell of Figure 4. Specific details for implementing the invention

[0023] Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. The present invention may be embodied in various different forms and is not limited to the embodiments described herein.

[0024] To clearly explain the present invention, parts unrelated to the explanation have been omitted, and the same reference numerals are used for identical or similar components throughout the specification.

[0025] Furthermore, the size and thickness of each component shown in the drawings are depicted arbitrarily for convenience of explanation, and thus the present invention is not necessarily limited to what is illustrated. Thicknesses have been enlarged in the drawings to clearly represent various layers and regions. Additionally, for convenience of explanation, the thickness of some layers and regions has been exaggerated in the drawings.

[0026] Furthermore, throughout the specification, when a part is described as “comprising” a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0027] Additionally, throughout the specification, "planar" means when the subject part is viewed from above, and "cross-sectional" means when the cross-section obtained by vertically cutting the subject part is viewed from the side.

[0028] FIG. 1 is a top view of a battery cell according to a comparative example. FIG. 2 is an enlarged view of the end portion of the battery cell of FIG. 1.

[0029] Referring to FIGS. 1 and 2, a battery cell (10) according to a comparative example includes a battery case (20) in which an electrode assembly (11) is mounted in a storage portion (21) and a sealing portion (25) with a sealed outer periphery is included. Additionally, a conventional battery cell (10) includes an electrode lead (30) that protrudes outwardly from the battery case (20) via the sealing portion (25), and a lead film (40) is positioned between the upper and lower portions of the electrode lead (30) and the sealing portion (25).

[0030] Figure 3 is a diagram showing the path through which gas is discharged from the end of the battery cell of Figure 1.

[0031] Referring to FIGS. 2 and FIGS. 3, when the internal pressure rises due to gas generation inside the battery cell (10), the battery cell (10) according to the comparative example may have a fractured portion (25V) formed in the portion where the electrode lead (30) is located, which is the part with the weakest sealing strength. Here, the fractured portion (25V) may be a part where the sealing surface of the sealing portion (25) is opened, ruptured, or fractured due to the rise in internal pressure of the battery cell (10).

[0032] However, in the case of the battery cell (10) according to the comparative example, there is a problem in that the sealing portion (25) where the electrode lead (30) is located is damaged. In addition, the portion where the electrode lead (30) is located is located very close to the electrode lead of an adjacent battery cell, so the high-temperature flammable gas discharged from the rupture portion (25V) can rapidly heat the adjacent battery cell. Accordingly, there is a problem in that heat propagation between battery cells (10) can occur more easily in a battery module including the battery cell (10) according to the comparative example.

[0033] In addition, in the battery cell (10), the part where the sealing strength is weakest in the sealing part (25) is the part where the electrode lead (30) is located, or the internal pressure of the battery cell (10) for the formation of the fracture part (25V) is relatively high, so there is a problem that the gas discharge time inside the battery cell (10) may be excessively delayed.

[0035] Hereinafter, a battery cell according to an embodiment of the present invention will be described. However, the description herein will be based on one of the two ends of the battery cell, but is not necessarily limited thereto, and the other end may also be described in the same or similar manner.

[0036] FIG. 4 is a top view of a battery cell according to an embodiment of the present invention. FIG. 5 is an enlarged view of the end portion of the battery cell of FIG. 4.

[0037] Referring to FIGS. 4 and 5, a battery cell (100) according to one embodiment of the present invention comprises: a battery case (200) having a sealing portion (250) having a structure in which an electrode assembly (110) is mounted in a storage portion (210) and the outer periphery is sealed; an electrode lead (300) electrically connected to an electrode tab (not shown) included in the electrode assembly (110) and protruding outwardly from the battery case (200) via the sealing portion (250); and a lead film (400) located in a portion corresponding to the sealing portion (250) at least one of the upper and lower portions of the electrode lead (300).

[0038] The battery case (200) may be a laminate sheet comprising a resin layer and a metal layer. More specifically, the battery case (200) may be made of a laminate sheet and may consist of an outer resin layer forming the outermost layer, a barrier metal layer that prevents the penetration of material, and an inner resin layer for sealing.

[0039] The electrode assembly (110) may be formed in a jelly-roll type (wound type), stack type (laminated type), or composite type (stacked / folded type) structure. More specifically, the electrode assembly (110) may be composed of an anode, a cathode, and a separator placed between them.

[0040] The electrode lead (300) is electrically connected to an electrode tab (not shown) included in the electrode assembly (110) and protrudes outwardly from the battery case (200) via a sealing portion (250). Additionally, a lead film (400) is located at a portion corresponding to the sealing portion (250) in at least one of the upper and lower portions of the electrode lead (300).

[0041] Accordingly, the lead film (400) can prevent a short circuit from occurring in the electrode lead (300) during heat fusion or press fusion together with the sealing part (250), while also improving the sealing performance between the sealing part (250) and the electrode lead (300).

[0042] FIG. 6 is a diagram showing the path through which gas is discharged from the end of the battery cell of FIG. 4. FIG. 7 is an enlarged diagram showing the gas discharge section formed at the end of the battery cell of FIG. 4.

[0043] Referring to FIGS. 5 and 6, in the battery cell (100) according to the present embodiment, the sealing portion (250) includes a gas discharge portion (255) located in a portion excluding the portion where the electrode lead (300) is located. Here, the gas discharge portion (255) may be a portion where the sealing surface of the sealing portion (250) is opened, ruptured, or broken due to an increase in internal pressure of the battery cell (100).

[0044] More specifically, with respect to the upper or lower surface of the battery cell (100), the gas exhaust portion (255) may be located on at least one of the two sides of the electrode lead (300) in the sealing portion (250). Additionally, the gas exhaust portion (255) may be located in the sealing portion (250) but spaced apart from the electrode lead (300).

[0045] For example, the gas discharge portion (255) may be located on the same side as the electrode lead (300) in the sealing portion (250), and the gas discharge portion (255) may be located between the portion of the sealing portion (250) where the electrode lead (300) is located and the end of the sealing portion (250). In particular, in the sealing portion (250), the gas discharge portion (255) may be located closer to the end of the sealing portion (250) than to the electrode lead (300).

[0046] Accordingly, as shown in FIG. 6, when the internal pressure of the battery cell (100) rises, the gas discharged is not discharged to the sealing portion (250) where the electrode lead (300) is located, but can be discharged through the gas discharge portion (255) located in the portion excluding the portion where the electrode lead (300) is located. That is, the gas discharge portion (255) can guide the discharge direction of the gas discharged when the internal pressure of the battery cell (100) rises in a specific direction.

[0047] Referring to FIGS. 5 and 7, in the battery cell (100) according to the present embodiment, the gas exhaust portion (255) may be recessed toward the electrode assembly (110) with respect to the sealing portion (250). In other words, the gas exhaust portion (255) may be recessed in the opposite direction to the direction in which the electrode lead (300) protrudes with respect to the sealing portion (250).

[0048] Referring to FIG. 7, the gas discharge portion (255) may be recessed toward the electrode assembly (110) with respect to the outer surface (B) of the sealing portion (250). More preferably, the gas discharge portion (255) may be recessed toward the electrode assembly (110) with respect to the inner surface (A) of the sealing portion (250).

[0049] Here, the degree of internal pressure required at the time of gas discharge of the battery cell (100) can be reduced as the inner surface (A') of the gas discharge portion (255) is located closer to the electrode assembly (110). In other words, the closer the inner surface (A') of the gas discharge portion (255) is located to the electrode assembly (110) than the inner surface (A) of the sealing portion (250), the more pressure can be applied to the inner surface (A') of the gas discharge portion (255) according to the expansion behavior of the battery cell (100).

[0050] That is, when gas is discharged through a gas discharge portion (255) formed in a position such as in the present embodiment, the degree of internal pressure required at the time of gas discharge of the battery cell (100) can be reduced. In particular, the closer the inner surface (A') of the gas discharge portion (255) is to the electrode assembly (110) than the inner surface (A) of the sealing portion (250), the more the degree of internal pressure required at the time of gas discharge of the battery cell (100) can be reduced.

[0051] For example, the inner surface (A') of the gas discharge section (255) may be located closer to the electrode assembly (110) than the inner surface (A) of the sealing section (250). For another example, the outer surface (B') of the gas discharge section (255) may be located closer to the electrode assembly (110) than the inner surface (A) of the sealing section. For yet another example, the inner surface (A') of the gas discharge section (255) may be located closer to the electrode assembly (110) than the inner surface (A) of the sealing section (250), while the outer surface (B') of the gas discharge section (255) may be located closer to the electrode assembly (110) than the inner surface of the sealing section. Here, the inner surface (A') of the gas discharge section (255) may be located closer to the electrode assembly (110) than the outer surface (B') of the gas discharge section (255).

[0052] However, the positions of the inner surface (A') and outer surface (B') of the gas discharge portion (255) are not limited to those of the sealing portion (250), and if the gas discharge portion (255) is located closer to the electrode assembly (110) than the inner surface (A) of the sealing portion (250), it is included in this embodiment.

[0053] Accordingly, the battery cell (100) according to the present embodiment can adjust the position of the inner surface (A') and the outer surface (B') of the gas discharge part (255) based on the inner surface (A) of the sealing part (250) to control the timing at which gas inside the battery cell (100) is discharged through the gas discharge part (255).

[0054] Additionally, the space between the outer surface (B') of the gas discharge section (255) and the sealing section (250) may be open toward the outside of the battery cell (100). In other words, the space between the outer surface (B') of the gas discharge section (255) and the sealing section (250) may be a part that is not fused during thermal fusion or press fusion.

[0055] Referring to FIGS. 5 and 7, the space between the outer surface (B') of the gas discharge section (255) and the sealing section (250) may have a first width (d1) of the portion of the gas discharge section (255) that is indented relative to the sealing section (250) and a second width (d2) between the outer surface (B') of the gas discharge section (255) and the outer surface (B) of the sealing section (250).

[0056] The gas discharge section (255) can control the degree of gas discharge by adjusting the first width (d1). For example, the gas discharge section (255) can reduce the degree of gas discharge as the first width (d1) is relatively smaller, and increase the degree of gas discharge as the first width (d1) is relatively larger.

[0057] Accordingly, the battery cell (100) according to the present embodiment can control the degree to which gas inside the battery cell (100) is discharged through the gas discharge portion (255) by adjusting the first width (d1) between the outer surface (B') of the gas discharge portion (255) and the sealing portion (250).

[0058] In contrast, if the first width (d1) between the outer surface (B') of the gas discharge portion (255) and the sealing portion (250) is excessively small or large, the degree of gas discharge due to the increase in internal pressure of the battery cell (100) may be excessively small, resulting in reduced gas discharge efficiency, or it may be excessively large, making it difficult to prevent ignition and explosion due to heat propagation between adjacent battery cells (100).

[0059] Additionally, the gas discharge section (255) can adjust the gas discharge timing by adjusting the second width (d2). For example, the gas discharge section (255) may delay the gas discharge timing as the second width (d2) is relatively smaller, and may expedite the gas discharge timing as the second width (d2) is relatively larger.

[0060] Accordingly, the battery cell (100) according to the present embodiment can control the degree and / or timing of gas discharged from inside the battery cell (100) through the gas discharge part (255) by adjusting the second width (d2) between the outer surface (B') of the gas discharge part (255) and the outer surface (B) of the sealing part (250).

[0061] In contrast, if the second width (d2) between the outer surface (B') of the gas discharge part (255) and the sealing part (250) is excessively small or large, the gas discharge time due to the increase in internal pressure of the battery cell (100) is excessively early, resulting in a very short lifespan of the battery cell (100), or it is excessively slow, making it difficult to prevent ignition and explosion due to heat propagation between adjacent battery cells (100).

[0062] Additionally, the sealing strength of the gas discharge section (255) may be smaller than the sealing strength of the sealing section (250). The sealing strength may be defined as the magnitude of the pressure required for the gas discharge section (255) or the sealing section (250) to break.

[0063] Here, the gas discharge portion (255) may have a sealing strength of 40% or more to 90% or less based on the sealing strength of the sealing portion (250). More specifically, the gas discharge portion (255) may have a sealing strength of 43% or more to 89% or less based on the sealing strength of the sealing portion (250). For example, the gas discharge portion (255) may have a sealing strength of 45% or more to 87% or less based on the sealing strength of the sealing portion (250). Here, the sealing strength of the sealing portion (250) may refer to the sealing strength of the sealing portion (250) in the part where the electrode lead (300) is located.

[0064] Accordingly, the battery cell (100) according to the present embodiment has a sealing strength of the gas discharge part (255) that is included within the range described above, so that when the internal pressure of the battery cell (100) rises, gas can be discharged through the gas discharge part (255) rather than the sealing part (250).

[0065] In contrast, if the sealing strength of the gas discharge part (255) is less than 40%, the gas discharge time due to the increase in internal pressure of the battery cell (100) becomes excessively fast, and there is a problem that the lifespan of the battery cell (100) becomes very short. Also, if the sealing strength of the gas discharge part (255) exceeds 90%, the gas discharge time becomes excessively slow, and it may be difficult to prevent ignition and explosion due to heat propagation between adjacent battery cells (100).

[0066] In addition, in this embodiment, the thickness of the gas discharge portion (255) may be equal to or smaller than the thickness of the sealing portion (250). More specifically, as the thickness of the gas discharge portion (255) becomes smaller than the thickness of the sealing portion (250), the sealing strength of the gas discharge portion (255) may become smaller than the sealing strength of the sealing portion (250). For example, as shown in FIGS. 5 to 7, the thickness of the gas discharge portion (255) may be smaller than the thickness of the sealing portion (250). However, this is not limited thereto, and the thickness of the gas discharge portion (255) may be appropriately adjusted considering the gas discharge timing.

[0067] Accordingly, the battery cell (100) according to the present embodiment can adjust the thickness of the gas discharge portion (255) based on the thickness of the sealing portion (250) to control the timing at which gas inside the battery cell (100) is discharged through the gas discharge portion (255).

[0069] A battery module according to another embodiment of the present invention includes the battery cell (100) described above. In particular, in the battery module, the battery cell (100) may be stacked in a direction in which the side not having the electrode lead (300) is in contact with the bottom surface. Here, the battery cell (100) may be stacked in a direction in which the gas exhaust portion (255) is adjacent to the bottom surface. At this time, the battery cell (100) may be stacked in a direction in which the gas exhaust portion (255) is located below the electrode lead (300).

[0070] Accordingly, in this embodiment, the gas discharge portion (255) of the battery cell (100) is located adjacent to the bottom surface, so that when the internal pressure of the battery cell (100) rises, the gas discharged through the gas discharge portion (255) can be discharged toward the bottom surface. That is, in this embodiment, the gas discharged from some of the battery cells (100) is discharged toward the bottom surface, thereby minimizing damage caused by the high-temperature flammable gas discharged from the battery cell (100) to adjacent battery cells (100), and effectively delaying heat propagation to adjacent battery cells (100).

[0072] The content of the present invention is explained below through more specific embodiments, but the following embodiments are intended to illustrate the invention and the scope of the invention is not limited thereto.

[0074] <Example 1>

[0075] A battery cell was manufactured by alternately stacking positive and negative electrodes in the order, housing an electrode assembly in a battery case with a separator interposed between the positive electrode and the negative electrode, and sealing the outer surface of the battery case.

[0076] Here, in the sealing portion where the electrode lead is located, a gas exhaust portion is formed in the portion excluding the portion where the electrode lead is located. In particular, the gas exhaust portion is indented toward the interior of the battery case with respect to the outer surface of the sealing portion, as in the battery cell of FIGS. 5 to 7.

[0078] <Example 2>

[0079] In the above Example 1, the gas discharge portion is recessed toward the interior of the battery case with respect to the outer surface of the sealing portion, at a depth 1.38 times the depth to which the gas discharge portion of Example 1 is recessed. Except for this point, a battery cell was manufactured in the same manner as in Example 1.

[0081] <Experimental Example - Measurement of Sealing Strength at the Time of Venting>

[0082] For the battery cells of Example 1 and Example 2, the point at which fracture occurs in the sealing portion of each battery cell was determined using Computer-Aided Engineering (CAE) simulation, and the results are shown in Table 1. Here, the sealing strength at the time of venting may refer to the sealing strength of the gas exhaust portion relative to the sealing strength of the portion where the electrode lead is located.

[0083] Example 1 Example 2 Sealing strength (%) at the time of venting 85 49

[0084] <Analysis of Experimental Results>

[0085] Referring to Table 1 and Figures 5 to 7, as in Examples 1 and 2, when a gas discharge portion (255) is included in the sealing portion (250), it can be seen that when the internal pressure of the battery cell (100) rises, the gas discharge portion (255), rather than the sealing portion (250), breaks. Additionally, in Examples 1 and 2, the sealing strength at the time when the gas discharge portion (255) breaks is 85% and 49%, respectively, which can be seen to be relatively lower compared to the sealing strength of the sealing portion (250) where the electrode lead (300) is located.

[0086] Accordingly, as in Examples 1 and 2, when the gas discharge portion (255) is included in the sealing portion (250), it can be confirmed that the sealing strength at the point when the gas is vented when the internal pressure of the battery cell (100) rises is relatively lower. That is, in the case of Examples 1 and 2, when the internal pressure of the battery cell (100) rises, the gas can be discharged to the outside more quickly than in the battery cell (10) of the comparative example that does not have the gas discharge portion (255).

[0087] In particular, when comparing Example 1 and Example 2, if the depth at which the gas discharge portion (255) is indented is greater than the depth of Example 1 as in Example 2, it can be confirmed that the sealing strength at the point where the gas discharge portion (255) breaks is relatively low.

[0088] Accordingly, as in Example 2, it can be confirmed that the greater the depth to which the gas discharge portion (255) is indented, the lower the sealing strength at the point when the gas is vented when the internal pressure of the battery cell (100) rises. That is, as in Example 2, the greater the depth to which the gas discharge portion (255) is indented, the more quickly the gas can be discharged to the outside when the internal pressure of the battery cell (100) rises.

[0090] Meanwhile, one or more of the battery modules according to the present embodiment may be packaged within a pack case to form a battery pack.

[0091] The battery module and battery pack containing the same described above can be applied to various devices. Such devices may be applied to means of transportation such as electric bicycles, electric vehicles, and hybrid vehicles, but the present invention is not limited thereto and can be applied to various devices capable of using the battery module and battery pack containing the same, and this also falls within the scope of the rights of the present invention.

[0092] Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention as defined in the following claims also fall within the scope of the present invention. Explanation of the symbols

[0093] 100: Battery cell 110: Electrode assembly 200: Battery case 210: Storage compartment 250: Sealing part 255: Gas exhaust part 300: Electrode Lead 400: Lead film

Claims

Claim 1 A battery case comprising a sealing portion having a structure in which an electrode assembly is mounted in a housing portion and the outer periphery is sealed; and an electrode lead electrically connected to an electrode tab included in the electrode assembly and protruding outwardly from the battery case via the sealing portion, wherein the sealing portion includes a gas exhaust portion located in a portion excluding the portion where the electrode lead is located, wherein the gas exhaust portion is indented toward the electrode assembly relative to the sealing portion, wherein the inner surface of the gas exhaust portion is located closer to the electrode assembly than the inner surface of the sealing portion, and the outer surface of the gas exhaust portion is located closer to the electrode assembly than the inner surface of the sealing portion, and the width between the outer surface of the gas exhaust portion and the outer surface of the sealing portion is greater than the width of the sealing portion. Claim 2 delete Claim 3 In claim 1, the sealing strength of the gas discharge portion is smaller than the sealing strength of the sealing portion of the battery cell. Claim 4 In paragraph 3, the gas discharge portion is a battery cell having a sealing strength of 40% or more to 90% or less based on the sealing strength of the sealing portion. Claim 5 In paragraph 4, the thickness of the gas discharge portion is equal to or smaller than the thickness of the sealing portion of the battery cell. Claim 6 In claim 1, the gas discharge portion is a battery cell located spaced apart from the electrode lead. Claim 7 In claim 1, the space between the outer surface of the gas discharge portion and the sealing portion is open toward the outside of the battery cell. Claim 8 A battery cell according to claim 1, further comprising a lead film located in a portion corresponding to the sealing portion at least one of the upper and lower portions of the electrode lead. Claim 9 A battery module comprising the battery cell of claim 1. Claim 10 In claim 9, the battery cell is a battery module in which the gas exhaust portion is stacked in a direction adjacent to the bottom surface. Claim 11 In claim 10, the battery cell is a battery module in which the gas exhaust portion is stacked in a direction such that the lower side of the electrode lead is located.

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