Pouch-type battery cell and manufacturing method thereof

Abstract

A pouch-type battery cell according to an embodiment of the present invention may include an electrode assembly housed between a pair of cases including a first resin layer forming an innermost layer, a second resin layer forming an outermost layer, and a metal layer laminated between the first and second resin layers. The pouch-type battery cell may include: a cup portion formed in at least one of the pair of cases to house the electrode assembly; an insulating sealing portion sealing the first resin layers of the pair of cases; a folding portion in which an end portion of one of the pair of cases is folded to cover an end portion of the other case; and a metal sealing portion formed in the folding portion sealing the metal layers of the pair of cases.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0087829, filed July 15, 2022, and all contents disclosed in the documents of that Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a pouch-type battery cell in which an electrode assembly is housed between a pair of cases including a first resin layer forming the innermost layer, a second resin layer forming the outermost layer, and a metal layer laminated between the first and second resin layers, and a manufacturing method thereof. [Background technology]

[0003] Recently, secondary batteries have been attracting attention as a power source for electric vehicles (EVs) and hybrid electric vehicles (HEVs), which have been proposed as a solution to address air pollution caused by existing gasoline and diesel vehicles that use fossil fuels.

[0004] While small mobile devices use one, two or three secondary batteries, medium to large devices such as electric vehicles require high output and large capacity, so they use a battery module in which a number of secondary batteries are electrically connected or a battery pack in which a number of battery modules are electrically connected to each other.

[0005] Among secondary batteries currently in commercial use, lithium secondary batteries are the most popular, and lithium secondary batteries can be classified into can-type, prismatic-type, and pouch-type batteries depending on the type of their exterior materials. Among these, pouch-type secondary batteries are widely used in medium- to large-sized battery modules due to their advantages of high energy density and ease of stacking.

[0006] Meanwhile, with the recent increase in demand for secondary battery modules installed in vehicles, customer requirements for stability are gradually increasing. However, while customers are demanding an increase in the energy density of battery cells within the limited space of a secondary battery module, this also raises the problem of increased stability risks regarding fire and explosion of the battery cells.

[0007] In general, a pouch-type battery cell has a structure in which an electrode assembly is housed in a pouch-type battery case, and a sealing portion is formed at an end of the battery case.

[0008] When a battery cell exceeds its critical temperature due to abnormal heat generation, the temperature rises rapidly, which can cause thermal propagation (TP) between other surrounding battery cells, resulting in safety issues. Therefore, to prevent or sufficiently delay such thermal propagation, it is necessary to create a sealing part with higher heat resistance and sealing strength. Summary of the Invention [Problem to be solved by the invention]

[0009] SUMMARY OF THE INVENTION One problem to be solved by the present invention is to provide a pouch-type battery cell in which the sealing portion has high heat resistance and sealing strength, and a method for manufacturing the same. [Means for solving the problem]

[0010] A pouch-type battery cell according to an embodiment of the present invention may include an electrode assembly housed between a pair of cases including a first resin layer forming an innermost layer, a second resin layer forming an outermost layer, and a metal layer laminated between the first and second resin layers. The pouch-type battery cell may include: a cup portion formed in at least one of the pair of cases to house the electrode assembly; an insulating sealing portion sealing the first resin layers of the pair of cases; a folding portion in which an end portion of one of the pair of cases is folded to cover an end portion of the other case; and a metal sealing portion formed in the folding portion sealing the metal layers of the pair of cases.

[0011] The metal sealing portion may be positioned outside the insulating sealing portion.

[0012] The metal sealing portion may include a first metal sealing portion in which one side of the metal layer of the other case is sealed with the metal layer of the one case; and a second metal sealing portion in which the other side of the metal layer of the other case is sealed with the metal layer of the one case.

[0013] The first resin layer and the second resin layer may be excluded from the metal sealing portion.

[0014] The first resin layer may be excluded from the metal sealing portion, and the second resin layer may be excluded from either one of the outer surfaces on both sides of the folding portion.

[0015] The metal layer may include a stainless steel material.

[0016] A method for manufacturing a pouch-type battery cell according to an embodiment of the present invention may include the steps of: accommodating the electrode assembly in a cup portion formed in at least one of the pair of cases; sealing the first resin layers of the pair of cases together; forming a folding portion by folding an end portion of one of the pair of cases to cover an end portion of the other case; and sealing the metal layer at the folding portion.

[0017] When sealing the first resin layers together, the first resin layers may be heat-sealed to each other, and when sealing the metal layers together, the metal layers may be laser-welded to each other.

[0018] The end portions of the pair of cases include exposed regions where the first resin layer is removed and the metal layer is exposed to the inside, and the exposed region of one case can cover the exposed region of the other case during the step of forming the folding portion.

[0019] When sealing the metal layers together, a laser may be irradiated onto one of the outer surfaces of both sides of the folded portion from which the second resin layer is removed. [Effects of the Invention]

[0020] According to a preferred embodiment of the present invention, a metal sealing portion is formed at the folded portion, which allows the pouch-type battery cell to maintain its sealing strength even at high temperatures and pressures, thereby preventing or sufficiently delaying thermal propagation (TP) from occurring in other battery cells when an abnormally high temperature occurs in the electrode assembly.

[0021] In addition, since an insulating sealing portion is formed inside the metal sealing portion, the case can be kept insulated from the electrode assembly and the electrolyte.

[0022] In addition, since the metal sealing portion is double sealed, the sealing strength of the metal sealing portion may be further increased.

[0023] Furthermore, the ratio of the gap between the metal layers to the thickness of the folded portion is smaller than when the folded portion is not formed, so the quality of the laser welding can be improved.

[0024] In addition, the present invention may include other effects that can be easily predicted by a person skilled in the art from the configuration of the preferred embodiment of the present invention. [Brief explanation of the drawings]

[0025] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention described below, serve to further understand the technical concept of the present invention. Therefore, the present invention should not be interpreted as being limited solely to the matters depicted in such drawings. [Figure 1] 1 is a perspective view illustrating a case and an electrode assembly of a pouch-type battery cell according to a first embodiment of the present invention; [Figure 2] 1 is a cross-sectional view of a pouch-type battery cell according to a first embodiment of the present invention. [Figure 3] FIG. 4 is a cross-sectional view of a pouch-type battery cell according to a second embodiment of the present invention. [Figure 4] FIG. 10 is an enlarged cross-sectional view of a folding portion of a pouch-type battery cell according to a third embodiment of the present invention. [Figure 5] FIG. 10 is a cross-sectional view of a pouch-type battery cell according to a comparative example. [Figure 6] FIG. 10 is a flowchart of a method for manufacturing a pouch-type battery cell according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0026]

[0030] The present invention will now be described in detail with reference to the accompanying drawings, in which:

[0031] A preferred embodiment of the present invention will be described in detail so that those skilled in the art can easily implement the present invention; however, the present invention may be embodied in various different forms and should not be construed as being limited to the following embodiments.

[0027] In order to clearly explain the present invention, detailed descriptions of parts that are not relevant to the description or related known technologies that may obscure the gist of the present invention are omitted, and when referring to components in each drawing in this specification, the same or similar reference symbols are used throughout the specification to refer to the same or similar components.

[0028] Furthermore, the terms and words used in this specification and claims should not be interpreted in a limited way to their ordinary or dictionary meanings, but should be interpreted in a way that is consistent with the technical idea of the present invention, based on the principle that the inventors can appropriately define the concepts of terms in order to best explain their invention.

[0029] FIG. 1 is a perspective view illustrating a case and an electrode assembly of a pouch-type battery cell according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view of the pouch-type battery cell according to the first embodiment of the present invention.

[0030] The pouch-type battery cell 10 according to the first embodiment of the present invention may include a pair of cases 100 and an electrode assembly 200 housed between the pair of cases 100. More specifically, the pair of cases 100 may be sealed together with an electrolyte to form the pouch-type battery cell 10.

[0031] The electrode assembly 200 may include a positive electrode, a negative electrode, and a separator interposed between the positive and negative electrodes to insulate them. The type of electrode assembly 10 is not limited. For example, the electrode assembly 200 may be a stick-type electrode assembly in which a positive electrode and a negative electrode are stacked on top of each other with a separator interposed therebetween. For another example, the electrode assembly 200 may be a jelly-roll-type electrode assembly in which sheet-type positive and negative electrodes are wound together with a separator interposed therebetween.

[0032] The pair of cases 100 may have an overall pouch shape and provide a storage space in which the electrode assembly 200 can be stored.

[0033] The pair of cases 100 may be connected to each other at one side, and the connected portion may form the folding portion 105. That is, the pair of cases 100 may be connected as a single unit by the folding portion 105. However, the present invention is not limited to this, and the pair of cases 100 may of course be separate, individual members.

[0034] Each case 100 may include a first resin layer 101, a second resin layer 102, and a metal layer 103. That is, the case 100 may be manufactured by molding a laminate film including the first resin layer 101, the second resin layer 102, and the metal layer 103.

[0035] The first resin layer 101 can form the innermost layer of the case 100 .

[0036] The first resin layer 101 located in the cup portion 110 of the pair of cases 100 may be in direct contact with or adjacent to the electrode assembly 200 and the electrolyte. Therefore, the first resin layer 101 may have high insulating properties and corrosion resistance. For example, the first resin layer 101 may include a polypropylene (PP) material. However, the present invention is not limited thereto, and those skilled in the art may appropriately select the material of the first resin layer 101.

[0037] The first resin layers 101 located at the end portions 120 of the pair of cases 100 may be sealed together to form the insulating sealing portion 140, which will be described in detail below.

[0038] The second resin layer 102 may form the outermost layer of the case 100. The second resin layer 102 may protect the pouch-type battery cell 10 from external friction and impact while electrically insulating the electrode assembly 200 from the outside. For example, the second resin layer 102 may include a polyethylene terephthalate (PET) material. However, the second resin layer 102 is not limited thereto, and a person skilled in the art may appropriately select the material for the second resin layer 102.

[0039] The metal layer 103 may be laminated between the first resin layer 101 and the second resin layer 102. The metal layer 103 ensures the mechanical strength of the case 100 and can prevent leakage of the electrolyte by blocking the entry and exit of external gases or moisture.

[0040] The metal layer 103 may include a stainless steel (STS) material. The melting point of stainless steel is approximately 1400°C, so stainless steel has higher heat resistance than aluminum (Al) used in conventional pouch-type battery cells.

[0041] The metal layers 103 located at the end portions 120 of the pair of cases 100 may be sealed to each other to form a metal sealing portion 150, which will be described in detail below.

[0042] At least one of the pair of cases 100 may be formed with a cup portion 110 for accommodating the electrode assembly 200. The cup portion 110 may be formed by depression molding in a laminate film that is the base material of the case 100.

[0043] In this embodiment, each of the pair of cases 100 may have a cup portion 110. The electrode assembly 200 may be accommodated in an accommodating space formed by the pair of cup portions 110 communicating with each other.

[0044] The pair of cases 100 may include a terminal portion 120 located around the cup portion 110. The terminal portion 120 may be called a terrace portion. The terminal portions 120 of the pair of cases 100 may be sealed while in contact with each other, thereby sealing the electrode assembly 200 within the pair of cases 100.

[0045] For example, if a pair of cases 100 are integrally formed, the folding portion 105 may be folded so that the end portions 120 of the pair of cases 100 come into contact with each other. In this case, the end portions 120 that come into contact with each other may form three sides of the pouch-type battery cell 10, and the folding portion 105 may form the remaining side. Therefore, the pouch-type battery cell 10 may have sealing portions 140, 150 formed on the three sides.

[0046] As another example, when the pair of cases 100 are separated from each other, the end portions 120 of the pair of cases 100 may be arranged to contact each other. In this case, the end portions 120 that are in contact with each other may form the four sides of the pouch-type battery cell 10. The pouch-type battery cell 10 may have sealing portions 140, 150 formed on the four sides.

[0047] Meanwhile, the pouch-type battery cell 10 may include a folded portion 130 in which the end portion 120 of one case 100A of the pair of cases 100 is folded over to cover the end portion 120 of the other case 100B.

[0048] More specifically, the end portion 120 of one case 100A may be hemmed along the end of the end portion 120 of the other case 100B. For this reason, the end portion 120 of one case 100A may be formed wider than the end portion 120 of the other case 100B. More specifically, the end portion 120 of one case 100A may be formed longer in the overall length and width directions than the end portion 120 of the other case 100B.

[0049] The first line L1 and the second line L2 shown in Fig. 1 are exemplary lines along which the pouch-shaped battery cell 10 is folded during hemming. The first line L1 may be aligned with the overall length of the pouch-shaped battery cell 10, and the second line L2 may be aligned with the overall width of the pouch-shaped battery cell 10. The first line L1 and the second line L2 may correspond to the ends of the end portion 120 of another case 100B.

[0050] The first line L1 and the second line L2 can be folded sequentially or in reverse order. The corner where the first line L1 and the second line L2 overlap at the end portion 120 of one case 100A may be folded twice. However, this is not a limitation, and a person skilled in the art should be able to cut the corner into an appropriate shape.

[0051] Meanwhile, the pouch-type battery cell 10 may include an insulating sealing portion 140 and a metal sealing portion 150 .

[0052] The insulating sealing portion 140 may be formed by sealing the first resin layers 101 of the pair of cases 100 together. More specifically, the first resin layers 101 of the end portions 120 of the pair of cases 100 may be heat-sealed to each other to form the insulating sealing portion 140.

[0053] The insulating sealing portion 140 may be formed inside the folded portion 130 or may overlap with a part of the inside of the folded portion 130 .

[0054] The insulating sealing portion 140 may be formed long along the end portions 120 of the pair of cases 100. The insulating sealing portion 140 may be connected to the first resin layer 101 in the cup portion 110. Therefore, the electrode assembly 200 and the electrolyte in the cup portion 110 may be sealed in an insulating state by the insulating sealing portion 140.

[0055] The metal sealing portion 150 may be formed by sealing the metal layers 103 of the pair of cases 100 together. More specifically, the metal layers 103 of the end portions 120 of the pair of cases 100 may be welded together to form the metal sealing portion 150.

[0056] The metal sealing portion 150 may be formed long along the folded portion 130. The metal sealing portion 150 may be located outside the insulating sealing portion 140.

[0057] The metal sealing portion 150 is formed by welding the metal layers 103 together, and therefore has a higher sealing strength than the insulating sealing portion 140, which is formed by fusing the first resin layers 101 together. This can significantly increase the sealing strength of the pouch-type battery cell 10.

[0058] The metal sealing portion 150 may be formed on the folding portion 130. The metal sealing portion 150 may be formed by laser welding the metal layers 103 of the folding portion 130 together in a state where the folding portion 130 is formed. Thus, the metal sealing portion 150 may be double-sealed.

[0059] The laser beam for forming the metal sealing portion 150 may be irradiated to one side of the folding portion 130, and the irradiation direction is not limited. For example, the laser beam may be irradiated to the upper or lower side of the folding portion 130.

[0060] In further detail, the metal sealing portion 150 may include a first metal sealing portion 151 in which one side (e.g., the upper side) of the metal layer 103 of the other case 100B is sealed with the metal layer 103 of the one case 100A, and a second metal sealing portion 152 in which the other side (e.g., the lower side) of the metal layer 103 of the other case 100B is sealed with the metal layer 103 of the one case 100A.

[0061] The metal sealing portion 150 is formed twice on the folding portion 130 in this manner, which may further increase the sealing strength of the pouch-type battery cell 10. Also, compared to when the folding portion 130 is not formed, the ratio of the gap between the metal layers 103 to the thickness of the folding portion 130 is smaller, which may advantageously improve the quality of laser welding.

[0062] The metal sealing part 150 may be free of the first resin layer 101 and the second resin layer 102 .

[0063] More specifically, the end portions 120 of the pair of cases 100 forming the folded portion 130 may include exposed regions where the first resin layer 101 and the second resin layer 102 are removed and the metal layer 103 is exposed to the inside and outside. The folded portion 130 may be formed by folding the exposed region of one case 100A to cover the exposed region of the other case 100B. That is, the folded portion 130 may be formed by folding the metal layer 103 of one case 100A to cover the metal layer 103 of the other case 100B.

[0064] This makes it possible to prevent the sealing quality and strength of the metal sealing portion 150 from being reduced by the first resin layer 101 and the second resin layer 102.

[0065] FIG. 3 is a cross-sectional view of a pouch-type battery cell according to a second embodiment of the present invention.

[0066] Below, the content that overlaps with the first embodiment described above will be omitted, and the differences will be mainly explained.

[0067] In the pouch-type battery cell 10 according to the second embodiment of the present invention, one of the pair of cases 100 may not have a cup portion 110. For example, one case 100A may not have a cup portion, and the other case 100B may have a cup portion 110. In this case, the end portion 120 of one case 100A may be located around the portion of the other case 100B that faces the cup portion 110.

[0068] As described above, the foldable portion 130 can be formed by folding the terminal end 120 of one case 100A so that it covers the terminal end 120 of the other case 100B. However, this is not limited to this, and it is of course also possible to form the foldable portion 130 by folding the terminal end 120 of the other case 100B so that it covers the terminal end 120 of the one case 100A.

[0069] In addition, the first resin layers 101 of the end portions 120 of the pair of cases 100 may be heat-sealed to each other to form the insulating sealing portion 140, and the metal layers 103 of the folding portion 130 may be welded to each other to form the metal sealing portion 150. The above description of the sealing portions 140 and 150 is applicable.

[0070] FIG. 4 is an enlarged cross-sectional view of a folded portion of a pouch-type battery cell according to a third embodiment of the present invention.

[0071] The following description will focus on the differences from the first embodiment, omitting the overlapping parts.

[0072] In the pouch-type battery cell 10 according to the third embodiment of the present invention, the second resin layer 102 may be omitted from one of the outer surfaces on either side of the folding portion 130. Preferably, the second resin layer 102 may be omitted from one of the outer surfaces on either side of the folding portion 130, including the end of one of the case 100A (the upper surface, as viewed in FIG. 4), and the second resin layer 102 may be included on the opposite upper surface (the lower surface, as viewed in FIG. 4). That is, while the second resin layer 102 was omitted from the outer surfaces on either side of the folding portion 130 in the first embodiment described above, the second resin layer 102 is included on one of the outer surfaces on either side of the folding portion 130 in this embodiment.

[0073] The laser beam for forming the metal sealing part 150 may be irradiated onto one of the outer surfaces on both sides of the folded part 130, excluding the second resin layer 102. Therefore, damage to the second resin layer 102 can be minimized during the process of welding the metal layers 103 of the folded part 130 together to form the metal sealing part 150.

[0074] FIG. 5 is a cross-sectional view of a pouch-type battery cell according to a comparative example.

[0075] The pouch-type battery cell 10' according to the comparative example includes an insulating sealing portion 140 in which the first resin layers 101 of the end portions 120 of a pair of cases 100 are heat-sealed together, but may not include a metal sealing portion 150 in which the metal layers 103 are welded together.

[0076] The insulating sealing portion 140 is formed by heat-sealing the first resin layers 101 together, and is therefore vulnerable to high heat. For example, if the first resin layer 101 contains polypropylene (PP), the insulating sealing portion 140 may melt at a temperature of approximately 150°C. Therefore, if the electrode assembly 200 exceeds the critical temperature due to abnormal heat generation, the temperature may rise rapidly to approximately 1000°C or more, which may damage the sealing of the pouch-type battery cell 10'.

[0077] Meanwhile, the pouch-type battery cell 10 according to the present invention includes the metal sealing part 150 that is doubly sealed at the folding part 130, so even if the insulating sealing part 140 is melted, the sealing of the pouch-type battery cell 10 can be maintained. In addition, the metal sealing part 150 can have higher sealing strength than the insulating sealing part 140.

[0078] In particular, when the metal layer 103 forming the metal sealing portion 150 includes a stainless steel material, the metal sealing portion 150 can maintain sealing without melting up to a temperature of approximately 1400° C. This can prevent or sufficiently delay thermal propagation (TP) from occurring in other battery cells around the pouch-type battery cell 10.

[0079] FIG. 6 is a flowchart of a method for manufacturing a pouch-type battery cell according to a fourth embodiment of the present invention.

[0080] The method for manufacturing the pouch-type battery cell according to the fourth embodiment of the present invention may be the method for manufacturing the pouch-type battery cell 10 described above.

[0081] The method for manufacturing the pouch-type battery cell includes step S10 (hereinafter referred to as the "accommodating step") of accommodating the electrode assembly 200 in the cup portion 110 formed in at least one of the pair of cases 100, step S20 (hereinafter referred to as the "insulating sealing step") of sealing the first resin layers 101 of the pair of cases 100 together, step S30 (hereinafter referred to as the "processing step") of folding the end portion 120 of one of the pair of cases 100, case 100A, to cover the end portion 120 of the other case 100B to form a folding portion 130, and step S40 (hereinafter referred to as the "metal sealing step") of sealing the metal layers 103 together at the folding portion 130.

[0082] During the receiving step S10, the end portions 120 of the pair of cases 100 may come into contact with each other while the electrode assembly 200 is received in the cup portion 110. Thus, the electrode assembly 200 may be received between the pair of cases 100.

[0083] In the insulating sealing step S20, the first resin layers 101 of the end portions 120 of the pair of cases 100 are heat-sealed to each other to form the insulating sealing portion 140.

[0084] In processing step S30, one case 100A may be folded so that the exposed region of the other case 100B covers the exposed region of the other case 100B. The exposed region may refer to a region where the first resin layer 101 is removed from the end portion 120 of each case 100, exposing the metal layer 103 to the inside. Also, the second resin layer 102 may be removed from at least a portion of the exposed region, exposing the metal layer 103 to the outside.

[0085] Furthermore, if the corners of the end portion 120 of one case 100A are folded twice, the processing step S30 may include a process of crimping the folded corners, thereby preventing the corners from becoming thicker than necessary.

[0086] During the metal sealing step S40, the metal layers 103 of the folding unit 130 may be laser welded to each other to form the metal sealing unit 150. More specifically, the laser may be irradiated onto one side of the outer surfaces of both sides of the folding unit 130 from which the second resin layer 102 is removed.

[0087] The metal sealing portion 150 may be formed to include a first metal sealing portion 151 in which one side (e.g., the upper side) of the metal layer 103 of the other case 100B is sealed with the metal layer 103 of the one case 100A, and a second metal sealing portion 152 in which the other side (e.g., the lower side) of the metal layer 103 of the other case 100B is sealed with the metal layer 103 of the one case 100A.

[0088] Meanwhile, the processing step S30 and the metal sealing step S40 may be performed sequentially, but the order in which the insulating sealing step S20 is performed may be changed as necessary.

[0089] For example, as shown in FIG. 6, the insulating sealing step S20, the processing step S30, and the metal sealing step S40 may be performed in sequence.

[0090] As another example, the insulating sealing step S20 may be performed after the processing step S30 and the metal sealing step S40.

[0091] As another example, the insulating sealing step S20 may be performed between the processing step S30 and the metal sealing step S40.

[0092] The above description is merely an illustrative example of the technical concept of the present invention, and various modifications and variations may be made by those skilled in the art without departing from the essential characteristics of the present invention.

[0093] Therefore, the embodiments disclosed herein are intended to illustrate, not limit, the technical idea of the present invention, and the scope of the technical idea of the present invention is not limited by such embodiments.

[0094] The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the present invention. [Explanation of symbols]

[0095] 10: Pouch-type battery cell 100: Case 101: 1st resin layer 102: Second resin layer 103: Metal layer 110: Cup section 120: Termination 130: Folding section 140: Insulation sealing part 150: Metal sealing part 151: First metal sealing part 152: Second metal sealing part 200: Electrode assembly

Claims

1. A pouch-type battery cell in which an electrode assembly is housed between a pair of cases including a first resin layer forming an innermost layer, a second resin layer forming an outermost layer, and a metal layer laminated between the first and second resin layers, a cup portion formed in at least one of the pair of cases and configured to accommodate the electrode assembly; an insulating sealing portion formed by sealing the first resin layers of the pair of cases together; a folding portion in which an end portion of one of the pair of cases is folded over to cover an end portion of the other case; and The pouch-type battery cell includes a metal sealing portion formed in the folded portion and sealing the metal layers of the pair of cases together.

2. The pouch-type battery cell according to claim 1 , wherein the metal sealing portion is located outside the insulating sealing portion.

3. The metal sealing portion is a first metal sealing portion in which one surface of the metal layer of the other case is sealed to the metal layer of the one case; and The pouch-type battery cell according to claim 1 , wherein the other surface of the metal layer of the other case includes a second metal sealing portion sealed to the metal layer of the first case.

4. The pouch-type battery cell according to claim 1 , wherein the first resin layer and the second resin layer are excluded from the metal sealing portion.

5. the first resin layer is removed from the metal sealing portion; The pouch-type battery cell according to claim 1 , wherein the second resin layer is excluded from one of the outer surfaces on both sides of the folded portion.

6. The pouch-type battery cell of claim 1 , wherein the metal layer comprises a stainless steel material.

7. A method for manufacturing a pouch-type battery cell in which an electrode assembly is housed between a pair of cases including an innermost first resin layer, an outermost second resin layer, and a metal layer laminated between the first and second resin layers, receiving the electrode assembly in a cup portion formed in at least one of the pair of cases; sealing the first resin layers of the pair of cases together; forming a folded portion by folding an end portion of one of the pair of cases so as to cover an end portion of the other case; and A method for manufacturing a pouch-type battery cell, comprising sealing the metal layers together at the folded portion.

8. When sealing the first resin layers together, the first resin layers are thermally fused to each other; The method of claim 7 , wherein the metal layers are laser welded to each other during the sealing step.

9. the pair of end portions of the case include exposed regions in which the first resin layer is removed and the metal layer is exposed to the inside, The method for manufacturing a pouch-shaped battery cell according to claim 7 or 8, wherein the exposed area of the one case covers the exposed area of the other case during the forming of the folding portion.

10. 8. The method of claim 7, wherein, during the sealing of the metal layers, a laser is irradiated onto one side of the outer surfaces of both sides of the folded portion from which the second resin layer is removed.

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