Pouch-type battery cell and method for manufacturing same

Abstract

The present invention relates to a pouch-type battery cell, and a method for manufacturing same. In a pouch-type battery cell according to one example, an electrode assembly is accommodated between a first exterior material and a second exterior material each 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 resin layer and the second resin layer. The pouch-type battery cell includes: an accommodating part that is formed on the first exterior material and accommodates the electrode assembly; a folded part folded such that an end portion of the first exterior material covers an end portion of the second exterior material; and a sealing prevention film disposed between the first resin layer of the first exterior material and the first resin layer of the second exterior material in the folded part.

Description

Pouch-type battery cell and method of manufacturing the same

[0001] [Cross-reference with related applications]

[0002] This application claims the benefit of priority based on Korean patent application 10-2024-0196230 filed December 24, 2024, and all contents disclosed in the literature of said Korean patent applications are incorporated herein as part of this specification.

[0003] [Technology Field]

[0004] The present invention relates to a pouch-type battery cell and a method for manufacturing the same, and more specifically, to a pouch-type battery cell and a method for manufacturing the same that delays the time for insulating oil to penetrate into a first resin layer forming the innermost layer of the outer casing of a pouch battery.

[0005] Since heat generated during rapid charging of pouch-type batteries must be effectively dissipated, a method of injecting cooled insulating oil into the module may be used. The internal structure of the pouch, which must provide cooling and insulation simultaneously, must be designed for efficient heat dissipation and insulation maintenance, and in this case, the insulating oil may swell the resin layer of the pouch.

[0006] To address these issues, there is a need for pouches capable of blocking or delaying the penetration of insulating oil to ensure the chemical stability of the resin layer and battery durability.

[0007] The present invention has been devised to solve the above problems, and the objective of the present invention is to provide a pouch-type battery cell and a method for manufacturing the same that delays the time for insulating oil to penetrate into the first resin layer forming the innermost layer of the outer casing of a pouch battery.

[0008] The problems of the present invention are not limited to those mentioned above, and other unmentioned problems will be clearly understood by a person skilled in the art to which the present invention pertains from the description below.

[0009] In one example, a pouch-type battery cell comprises a first outer layer comprising a first resin layer forming the innermost layer, a second resin layer forming the outermost layer, and a metal layer laminated between the first resin layer and the second resin layer, wherein an electrode assembly is accommodated between the first outer layer and the second outer layer, a storage portion formed in the first outer layer and accommodating the electrode assembly, a fold portion folded such that the end of the first outer layer covers the end of the second outer layer, and a sealing prevention film disposed between the first resin layer of the first outer layer and the first resin layer of the second outer layer at the fold portion.

[0010] In another example, the first exterior material includes a first sealing portion located around the perimeter of the storage portion, and the second exterior material includes a second sealing portion that is in contact with and sealed by the first sealing portion, and in the fold portion, the end of the first sealing portion may cover the end of the second sealing portion.

[0011] In another example, the first sealing portion may include an overlapping portion that overlaps with the second sealing portion in the thickness direction of the second sealing portion, and an extension portion that extends from the overlapping portion and is folded to define the fold portion.

[0012] In another example, the extension may include a first folding portion that is folded in a direction in which the overlapping portion faces the second sealing portion, and a second folding portion that is connected to the first folding portion and is folded such that the end of the extension may come into contact with the end of the second sealing portion.

[0013] In another example, the sealing prevention film may be located on the side extending from the second sealing portion.

[0014] In another example, the sealing prevention film may include polytetrafluoroethylene (PTFE) material.

[0015] In another example, at the folded portion, the metal layers of the first exterior material and the second exterior material may come into contact with each other.

[0016] In another example, at the above-mentioned folding portion, the second resin layer of the first exterior material and the second exterior material can be sealed and joined to each other.

[0017] In one example, a method for manufacturing a pouch-type battery cell comprises the steps of: accommodating an electrode assembly between a first outer layer and a second outer layer, the first outer layer comprising a first resin layer forming the innermost layer, a second resin layer forming the outermost layer, and a metal layer laminated between the first resin layer and the second resin layer; and folding the edge portion of the first outer layer to form a fold portion so that the end of the first outer layer covers the end of the second outer layer, wherein, during the step of forming the fold portion, a sealing prevention film that prevents sealing between the first resin layers may be placed between the end of the first outer layer and the end of the second outer layer.

[0018] In another example, prior to the step of forming the fold portion, the method may further include the step of sealing the abutting area between the first sealing portion of the first exterior material and the second sealing portion of the second exterior material.

[0019] In another example, after the step of forming the fold portion, a step of sealing the fold portion may be further included.

[0020] In another example, during the step of sealing the fold portion, the sealing tool may press the boundary between the end of the first exterior material and the end of the second exterior material.

[0021] In another example, the first exterior material includes a first sealing portion located around the perimeter, and the second exterior material includes a second sealing portion that is in contact with and sealed by the first sealing portion; in the fold portion, the end of the first sealing portion covers the end of the second sealing portion, and the first sealing portion includes an overlapping portion that overlaps with the second sealing portion in the thickness direction of the second sealing portion, and an extension portion that extends from the overlapping portion and is folded to define the fold portion; in the step of forming the fold portion, the extension portion may be folded in a direction in which the first sealing portion faces the second sealing portion to form a first fold portion, and the end of the extension portion may be folded so as to be in contact with the end of the second sealing portion to form a second fold portion connected to the first fold portion.

[0022] According to one aspect of the present invention, insulating oil can be trapped by a sealing prevention material of a pouch-type battery cell.

[0023] 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 attached drawings.

[0024] FIG. 1 is a cross-sectional view of a pouch-type battery cell according to one embodiment of the present invention before the fold portion is formed.

[0025] FIG. 2 is an enlarged cross-sectional view of a pouch-type battery cell after the fold portion is formed according to one embodiment of the present invention.

[0026] FIG. 3 is a drawing to help understand the cross-sectional structure of a pouch-type battery cell before the formation of a fold portion according to one embodiment of the present invention.

[0027] FIG. 4 is a drawing to help understand the cross-sectional structure after the formation of a fold portion of a pouch-type battery cell according to one embodiment of the present invention.

[0028] FIG. 5 is a drawing to help understand the cross-sectional structure after the formation of a fold portion of a pouch-type battery cell according to one embodiment of the present invention.

[0029] FIG. 6 is a flowchart of a method for manufacturing a pouch-type battery cell according to one embodiment of the present invention.

[0030] Preferred embodiments of the present invention are described in detail so that those skilled in the knowledge can easily implement them. However, the present invention may be embodied in various different forms and is not limited or restricted by the following embodiments.

[0031] In order to clearly explain the present invention, detailed descriptions of related prior art that are irrelevant to the explanation or that may unnecessarily obscure the essence of the invention have been omitted. Furthermore, when assigning reference numerals to the components of each drawing in this specification, identical or similar reference numerals are assigned to identical or similar components throughout the entire specification.

[0032] Furthermore, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.

[0033] FIG. 1 is a cross-sectional view of a pouch-type battery cell according to an embodiment of the present invention before the folding portion is formed. FIG. 2 is an enlarged cross-sectional view of a pouch-type battery cell according to an embodiment of the present invention after the folding portion is formed. FIG. 3 is a diagram to aid in understanding the cross-sectional structure of a pouch-type battery cell according to an embodiment of the present invention before the folding portion is formed. FIG. 4 is a diagram to aid in understanding the cross-sectional structure of a pouch-type battery cell according to an embodiment of the present invention after the folding portion is formed. FIG. 5 is a diagram to aid in understanding the cross-sectional structure of a pouch-type battery cell according to an embodiment of the present invention after the folding portion is formed. FIG. 6 is a flowchart of a method for manufacturing a pouch-type battery cell according to an embodiment of the present invention.

[0034] As illustrated in FIG. 1, in this embodiment, the pouch-type battery cell (1) may include a first outer layer (100) and a second outer layer (200). The first outer layer (100) may include a first resin layer (110) forming the innermost layer, a second resin layer (130) forming the outermost layer, and a metal layer (120) laminated between the first resin layer (110) and the second resin layer (130). The second outer layer (200) may include a first resin layer (210) forming the innermost layer, a second resin layer (230) forming the outermost layer, and a metal layer (220) laminated between the first resin layer (210) and the second resin layer (230).

[0035] As illustrated in FIG. 2, the pouch-type battery cell (1) may include a storage portion (300), a folding portion (400), and a sealing prevention film (500). The storage portion (300) is formed in the first outer material (100) and can accommodate an electrode assembly (10). The folding portion (400) can be folded so that the end of the first outer material (100) covers the end of the second outer material (200). The sealing prevention film (500) may be disposed in the folding portion (400) between the first resin layer (110) of the first outer material (100) and the first resin layer (210) of the second outer material (200).

[0036] The sealing prevention film (500) may be in the form of a film. However, the sealing prevention film (500) is not limited to the form of a film. When the sealing prevention film (500) is placed between the first resin layer (110) of the first exterior material (100) and the first resin layer (210) of the second exterior material (200) at the fold portion (400), each first resin layer (110, 210) may not be heat-fused to each other, and the space between them may be filled with the sealing prevention film (500) or the space between them may be opened to form a predetermined gap. Accordingly, insulating oil attempting to penetrate into each first resin layer (110, 210) may be trapped in the gap by the film (500).

[0037] The first resin layer (110, 210) may include polypropylene. The second resin layer (130, 230) may include polyethylene terephthalate. The metal layer (120, 220) may include aluminum. The pouch-type battery cell (1) may include a layer containing nylon between the metal layer (120, 220) and the second resin layer (130, 230).

[0038] In this embodiment, the first exterior material (100) may include a first sealing portion (140). The first sealing portion (140) may be located around the perimeter of the storage portion (300). The second exterior material (200) may include a second sealing portion (240). The second sealing portion (240) may be in contact with and sealed to the first sealing portion (140). In the second sealing portion (240), the end of the first sealing portion (140) may cover the end of the second sealing portion (240) at the fold portion (400).

[0039] As illustrated in FIGS. 3, 4 and 5, in this embodiment, the first sealing portion (140) may include an overlapping portion (141) and an extension portion (142). The overlapping portion (141) may overlap in the thickness direction of the second sealing portion (240). The extension portion (142) may extend from the overlapping portion (141) and be folded to define a fold portion (400).

[0040] In this embodiment, the extension portion (142) may include a first folding portion (142a) and a second folding portion (142b). The first folding portion (142a) may be folded in a direction in which the overlapping portion (141) faces the second sealing portion (240). The second folding portion (142b) is connected to the first folding portion (142a) and may be folded so that the end of the extension portion (142) touches the end of the second sealing portion (240). When the end of the extension portion (142) is folded so that it touches the end of the second sealing portion (240), a folding boundary (F) may be formed. The folding boundary (F) may be parallel to the extending direction of the second sealing portion (240).

[0041] As illustrated in FIGS. 4 and 5, in this embodiment, the sealing prevention film (500) may be located on the side of the extending direction of the second sealing portion (240). In this case, the sealing prevention film (500) may extend in the extending direction of the second sealing portion (240). Additionally, the sealing prevention film (500) may extend in the thickness direction of the second sealing portion (240). As illustrated in FIG. 5, when the sealing prevention film (500) extends in the extending direction of the second sealing portion (240), the sealing prevention film (500) may occupy a portion of the empty space that may occur at the fold boundary (F). Accordingly, insulating oil attempting to penetrate into each first resin layer (110, 210) may be trapped in the gap by the film (500). In this embodiment, the sealing prevention film (500) may include a polytetrafluoroethylene (PTFE) material. When the sealing prevention film (500) contains polytetrafluoroethylene material, since polytetrafluoroethylene has low reactivity, it can more stably prevent or delay the penetration of insulating oil.

[0042] The sealing prevention film (500) may include a polyimide (PI) material. When the sealing prevention film (500) includes a polyimide material, since the polyimide is a material with low reactivity, it can more stably prevent or delay the penetration of insulating oil.

[0043] As illustrated in FIGS. 4 and 5, in this embodiment, the metal layers (120, 220) of the first outer layer (100) and the second outer layer (200) of the pouch-type battery cell (1) may come into contact with each other at the folding portion (400). When the metal layers (120, 220) of the first outer layer (100) and the second outer layer (200) come into contact with each other, insulating oil attempting to penetrate in a direction other than the direction toward the first resin layer (110, 210) from the second resin layer (130, 230) may be trapped.

[0044] As illustrated in FIGS. 4 and 5, in this embodiment, the pouch-type battery cell (1) can have the second resin layers (130, 230) of the first outer material (100) and the second outer material (200) sealed and joined together at the folding portion (400). When the second resin layers (130, 230) of the first outer material (100) and the second outer material (200) are sealed and joined together, insulating oil attempting to penetrate in a direction other than the direction toward the first resin layer (110, 210) from the second resin layer (130, 230) can be trapped.

[0045] The following describes a method for manufacturing a pouch-type battery cell. In the method for manufacturing a pouch-type battery cell, redundant details regarding the pouch-type battery cell may be omitted. The composition and effects of the pouch-type battery cell can also be realized in the method for manufacturing a pouch-type battery cell.

[0046] As illustrated in FIG. 6, in this embodiment, a method for manufacturing a pouch-type battery cell may include a step of receiving an electrode assembly (S10) and a step of forming a fold (S30). In the step of receiving an electrode assembly (S10), an electrode assembly (10) may be received between a first outer material (100) and a second outer material (200), the first outer material (100) comprising a first resin layer (110, 210) forming the innermost layer, a second resin layer (130, 230) forming the outermost layer, and a metal layer (120) laminated between the first resin layer (110, 210) and the second resin layer (130, 230). In the step of forming a fold (S30), an edge portion of the first outer material (100) may be folded to form a fold (400) so that the end of the first outer material (100) covers the end of the second outer material (200). In the step (S30) of forming the fold portion, a sealing prevention film (500) may be placed between the end of the first exterior material (100) and the end of the second exterior material (200) to prevent sealing between the first resin layers (110, 210).

[0047] In this embodiment, the method for manufacturing a pouch-type battery cell may further include a step (S20) of sealing the contact area. In the step (S20) of sealing the contact area, the contact area between the first sealing portion (140) of the first outer material (100) and the second sealing portion (240) of the second outer material (200) may be sealed prior to the step (S30) of forming the fold portion.

[0048] In this embodiment, the method for manufacturing a pouch-type battery cell may further include a step (S40) of sealing the fold portion. The step (S40) of sealing the fold portion may be after the step (S30) of forming the fold portion.

[0049] In this embodiment, the method for manufacturing a pouch-type battery cell may, in the step (S40) of sealing the fold portion, have a sealing tool (600) press the boundary between the end of the first outer material (100) and the end of the second outer material (200).

[0050] In this embodiment, the method for manufacturing a pouch-type battery cell may, in the step of forming the folding portion, fold the extension portion (142) in a direction such that the first sealing portion (140) faces the second sealing portion (240) to form a first folding portion (142a), and fold the extension portion (142) so that the end of the extension portion (142) comes into contact with the end of the second sealing portion (240) to form a second folding portion (142b) connected to the first folding portion (142a).

[0051] In this embodiment, the method for manufacturing a pouch-type battery cell may, in the step (S30) of forming a folding portion, fold the extension portion (142) in a direction such that the first sealing portion (140) faces the second sealing portion (240) to form a first folding portion (142a), and fold the extension portion (142) so that the end of the extension portion (142) touches the end of the second sealing portion (240) to form a second folding portion (142b) connected to the first folding portion (142a).

[0052] Although the present invention has been described above by limited embodiments and drawings, the present invention is not limited thereto, and various implementations are possible within the scope of the technical spirit of the present invention and the equivalent scope of the claims described below by those skilled in the art to which the present invention belongs.

[0053] [Explanation of the symbol]

[0054] 1: Pouch-type battery cell

[0055] 10: Electrode assembly

[0056] 100: 1st exterior material

[0057] 110, 210: First resin layer

[0058] 120, 220: Metal layer

[0059] 130, 230: Second resin layer

[0060] 140: First sealing part

[0061] 141: Overlapping section

[0062] 142: Extension part

[0063] 142a: 1st folding section

[0064] 142b: Second folding section

[0065] 200: Second exterior material

[0066] 240: Second sealing section

[0067] 300: Storage compartment

[0068] 400: Fold

[0069] 500: Anti-sealing film

[0070] 600: Sealing Tool

[0071] F: Fold boundary

[0072] S10: Step of accommodating the electrode assembly

[0073] S20: Step of sealing the contact area

[0074] S30: Step of forming a fold

[0075] S40: Step of sealing the fold

Claims

1. A pouch-type battery cell comprising a first outer layer and a second outer layer, wherein the first outer layer comprises a first resin layer forming the innermost layer, a second resin layer forming the outermost layer, and a metal layer laminated between the first resin layer and the second resin layer, and an electrode assembly is accommodated between the first outer layer and the second outer layer, A storage portion formed in the first exterior material and accommodating the electrode assembly; A folded portion in which the end of the first exterior material is folded to cover the end of the second exterior material; and A pouch-type battery cell comprising a sealing prevention film disposed between the first resin layer of the first outer material and the first resin layer of the second outer material at the above-mentioned fold portion.

2. In Paragraph 1, The above-mentioned first exterior material is, It includes a first sealing portion located around the perimeter of the storage portion, and The above second exterior material is, A pouch-type battery cell comprising a second sealing portion that contacts and seals the first sealing portion, wherein, in the fold portion, the end of the first sealing portion covers the end of the second sealing portion.

3. In Paragraph 2, The above first sealing part is, An overlapping portion that overlaps with the second sealing portion in the thickness direction of the second sealing portion; and A pouch-type battery cell comprising an extension portion that extends from the overlapping portion and is folded to define the fold portion.

4. In Paragraph 3, The above extension part is, A first folding portion in which the above-mentioned overlapping portion is folded in a direction facing the second sealing portion; and A pouch-type battery cell comprising a second folding portion connected to the first folding portion and folded such that the end of the extension portion contacts the end of the second sealing portion.

5. In Paragraph 2, The above-mentioned sealing prevention film is, A pouch-type battery cell located on the side extending from the second sealing portion.

6. In Paragraph 1, The above-mentioned sealing prevention film is, A pouch-type battery cell comprising polytetrafluoroethylene (PTFE) material.

7. In Paragraph 1, A pouch-type battery cell in which the metal layers of the first outer material and the second outer material come into contact with each other at the above-mentioned fold portion.

8. In Paragraph 1, A pouch-type battery cell in which, at the above-mentioned folding portion, the second resin layer of the first outer material and the second outer material are sealed and bonded to each other.

9. A step of accommodating an electrode assembly between a first exterior material and a second exterior material, the first resin layer forming the innermost layer, the second resin layer forming the outermost layer, and a metal layer laminated between the first resin layer and the second resin layer; and The method includes the step of folding the edge portion of the first exterior material to form a fold portion so that the end of the first exterior material covers the end of the second exterior material. During the step of forming the above-mentioned fold portion, A method for manufacturing a pouch-type battery cell, wherein a sealing prevention film that prevents sealing between the first resin layers is placed between the end of the first outer material and the end of the second outer material.

10. In Paragraph 9, Prior to the step of forming the above-mentioned fold, A method for manufacturing a pouch-type battery cell, further comprising the step of sealing the contact area between the first sealing portion of the first outer material and the second sealing portion of the second outer material.

11. In Paragraph 9, After the step of forming the above-mentioned fold, A method for manufacturing a pouch-type battery cell, further comprising the step of sealing the above-mentioned fold portion.

12. In Paragraph 9, During the step of sealing the above-mentioned folded portion, The sealing tool is, A method for manufacturing a pouch-type battery cell, wherein the boundary between the end of the first outer material and the end of the second outer material is pressed.

13. In Paragraph 9, The above-mentioned first exterior material is, It includes a first sealing portion located around the perimeter, and The above second exterior material is, It includes a second sealing portion that contacts and seals the first sealing portion, and in the folded portion, the end of the first sealing portion covers the end of the second sealing portion. The above first sealing part is, An overlapping portion that overlaps with the second sealing portion in the thickness direction of the second sealing portion; and It includes an extension portion that extends from the above-mentioned overlapping portion and is folded to define the above-mentioned fold portion, and During the step of forming the above-mentioned fold portion, The above extension is folded in a direction in which the first sealing part faces the second sealing part to form a first folding part, and A method for manufacturing a pouch-type battery cell, wherein the end of the extension portion is folded to meet the end of the second sealing portion to form a second folding portion connected to the first folding portion.

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