Apparatus for forming pouch-type battery case, pouch-type battery case manufactured using same, and method for forming cup part of pouch-type battery case by using apparatus for forming pouch-type battery case

Abstract

The present invention relates to an apparatus for forming a pouch-type battery case, a pouch-type battery case manufactured using same, and a method for forming a cup part of a pouch-type battery case by using the apparatus for forming a pouch-type battery case, the apparatus comprising: punches, which apply pressure to a laminate sheet so as to form cup parts for pouch-type battery cases; dies having the laminate sheet disposed thereon and including grooves into which the punches are inserted; and strippers which fix the laminate sheet while positioned on the dies and which have through-holes through which the punches are to move, wherein the dies have a step composed of the upper end portion and the lower end portion of different heights, the upper end portion forms the inner side of the die, which has a planar rectangular frame shape, and the lower end portion forms the outer side of the die.

Description

A pouch-type battery case forming device, a pouch-type battery case manufactured using the same, and a method for forming a cup portion of a pouch-type battery case using the pouch-type battery case forming device

[0001] This application claims the benefit of priority to Korean Patent Application No. 2023-0107897, filed August 17, 2023, and Korean Patent Application No. 2024-0107422, filed August 12, 2024, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a pouch-type battery case forming device capable of preventing cracks from forming in a portion where the thickness has become thin due to stretching during forming of a cup portion of a pouch-type battery cell, a pouch-type battery case manufactured using the same, and a method for forming a cup portion of a pouch-type battery case using the pouch-type battery case forming device.

[0003]

[0004] Rechargeable lithium secondary batteries are widely used as energy sources for wireless mobile devices and wearable devices, and are also used as energy sources for electric vehicles and hybrid electric vehicles, which are presented as alternatives to existing gasoline and diesel vehicles that cause air pollution.

[0005] Lithium secondary batteries can be classified into cylindrical or square secondary batteries made of metal, depending on the material of the case, and pouch-type secondary batteries made of laminated sheets. The pouch-type secondary batteries are used in various devices due to their high energy density per weight due to their high degree of integration and stacking, low manufacturing costs, and ease of shape modification.

[0006] A pouch-type secondary battery uses a laminate sheet including an outer covering layer, a metal barrier layer, and an inner adhesive layer as a battery case, and an electrode assembly and an electrolyte are embedded together in a storage portion formed on the laminate sheet.

[0007] In order to form an electrode assembly receiving portion in a pouch-type battery case, a laminate sheet is placed on a die and fixed with a holder, and a method of pressing the laminate sheet with a punch is used. Due to the softness limitations of the laminate sheet and the frictional force between the punch and the laminate sheet, external defects such as pin-holes or cracks occur on the outer surface of the laminate sheet during the process of forming the electrode assembly receiving portion.

[0008] Fig. 1 is a front view of a conventional pouch-type battery case forming device, Fig. 2 is a step of forming a cup portion of a pouch-type battery case using the pouch-type battery case forming device of Fig. 1, and Fig. 3 is a vertical cross-sectional view of a portion of a pouch-type battery case manufactured using the pouch-type battery case forming device of Fig. 1.

[0009] Referring to FIGS. 1 to 3, a pouch-type battery case forming device (100) includes a die (120) for placing a laminate sheet (10) on top, a stripper (130) positioned on top of the die (120) for fixing the laminate sheet (10), and a punch (110) for pressing the laminate sheet (10) to form a cup portion.

[0010] The upper surface of the die (120) of the pouch-type battery case forming device (100) and the lower surface of the stripper (130) that is in close contact with the upper surface of the die (120) are configured in a flat shape.

[0011] Accordingly, as shown in FIG. 2, after placing the laminate sheet (10) between the die (120) and the stripper (130), and then pressing the laminate sheet (10) using the punch (110) while fixing the laminate sheet (10) with the die (120) and the stripper (130), a pouch-shaped battery case having the shape shown in FIG. 3 is manufactured.

[0012] In the pouch-shaped battery case of Fig. 3, the depth (H) of the cup portion in which the electrode assembly is stored can be expressed as the sum of R1 of the curved surface of the upper portion of the cup portion, R2 of the curved surface of the lower portion of the cup portion, and L1, the length of the flat section of the side of the cup portion.

[0013] When forming a pouch-type battery case, the lower portion of the cup part is stretched first, so when forming is complete, the lower portion of the cup part becomes the most stretched portion. In Fig. 3, portion A is the area with the greatest stretch, resulting in a thin residual thickness. Therefore, there is a high risk of pinholes or cracks forming in portion A.

[0014] Therefore, a technology is needed that can form the cup portion deeper to increase the capacity of a pouch-type battery case while preventing pinholes or cracks from forming due to excessive stretching.

[0015]

[0016] The present invention is intended to solve the above problems, and provides a pouch-type battery case forming apparatus capable of improving the quality of a final product, a pouch-type battery cell, by preventing excessive stretching of a portion of a laminate sheet when forming a pouch-type battery case, a pouch-type battery case manufactured using the same, and a method for forming a cup portion of a pouch-type battery case using the pouch-type battery case forming apparatus.

[0017]

[0018] In order to achieve these objects, a pouch-type battery case forming device according to the present invention comprises: a punch for forming a cup portion for a pouch-type battery case by pressing a laminate sheet; a die having the laminate sheet disposed thereon and a groove into which the punch is inserted; and a stripper positioned on the upper portion of the die to fix the laminate sheet and having a through hole formed therein for movement of the punch; wherein the die is composed of an upper portion and a lower portion having different heights, the upper portion constituting the inner side of the die having a square frame shape in plan view, and the lower portion constituting the outer side of the die.

[0019] The above stripper has a form in which a step is formed that is in close contact with the upper and lower parts of the die, and the stripper may include an inner part that is in close contact with the upper part of the die and an outer part that is in close contact with the lower part of the die.

[0020] The above die may be formed in a form in which the upper part can move up and down independently from the lower part.

[0021] A groove may be formed on the inner side of the stripper, and an elastic member may be added so that at least a portion of the elastic member is received in the groove.

[0022] The above elastic member is a spring, the grooves are formed to be spaced apart at regular intervals, and the spring can be added so that at least a portion of it is received in the grooves.

[0023] The above grooves are formed so as to be spaced apart at regular intervals along a square line, and the square line may be configured in the form of two lines spaced apart from each other.

[0024] The above elastic member is elastic rubber, the groove is formed in a square ring shape, and the elastic rubber can be added so that at least a portion of it is received in the groove.

[0025] The above home may be configured in the form of two lines spaced apart from each other.

[0026] The above punch may have a curved boundary where the lower pressure surface and the side surface meet.

[0027] The above die may have a boundary where the upper portion and the inner surface of the upper portion meet in a curved shape.

[0028] A pouch-type battery case forming device that, when the inner side of the stripper and the upper side of the die are in close contact, the entire elastic member is accommodated in the groove, and the elastic member is compressed to the maximum extent to close the laminate sheet to the upper side of the die.

[0029] When the inner side of the stripper and the upper side of the die are brought into close contact, the laminate sheet can be stretched along the upper side surface of the die.

[0030] In the pouch-shaped battery case manufactured using the above pouch-shaped battery case forming device, the outer periphery of the cup portion includes an inner outer periphery and an outer outer periphery, and the height from the bottom of the cup portion to the inner outer periphery may be higher than the height from the bottom of the cup portion to the outer outer periphery.

[0031] The height from the bottom of the cup portion to the inner outer periphery may be configured to be a size equal to the height of the lower portion of the die of the pouch-type battery case forming device plus the height difference between the upper portion and the lower portion.

[0032] A method for forming a cup portion of a pouch-type battery case using the above pouch-type battery case forming device comprises: a first step of arranging a laminate sheet between a die and a stripper, and arranging a punch within a through-hole of the stripper; a second step of bringing the lower portion of the die and the outer portion of the stripper into close contact with the laminate sheet interposed therebetween while the upper surface heights of the upper portion and the lower portion of the die are the same; a third step of first stretching the laminate sheet while the upper portion of the die moves upward and the upper portion and the inner portion of the stripper are brought into close contact with the laminate sheet interposed therebetween; and a fourth step of forming a cup portion of a pouch-type battery cell by secondarily stretching the laminate sheet while moving the punch downward in a state where the laminate sheet is first stretched. In the second step, the position of the laminate sheet can be fixed by the close contact between the lower portion of the die and the outer portion of the stripper.

[0033] In the third step, the laminate sheet can be first stretched at a position where the upper end of the cup portion is to be formed.

[0034] In the fourth step, the laminate sheet can be fixed in position while being pressed toward the upper end of the die by the elastic force of the elastic member added to the inner lower surface of the stripper.

[0035] The present invention can also be provided in a form in which various means for solving the above problem are combined.

[0036]

[0037] As described above, the pouch-type battery case forming device according to the present invention includes a structure in which a step is formed on the upper surface of the die and the lower surface of the stripper, and the laminate sheet is stretched twice, when the die and the stripper are in close contact and when pressurized with a punch, so that excessive stretching can be prevented from occurring in a part of the laminate sheet.

[0038] In addition, since the depth of the cup portion of the pouch-type battery case manufactured using this is relatively deep, a pouch-type battery cell with increased capacity can be provided.

[0039]

[0040] Figure 1 is a front view of a conventional pouch-type battery case forming device.

[0041] Fig. 2 is a step of forming a cup portion of a pouch-type battery case using the pouch-type battery case forming device of Fig. 1.

[0042] Fig. 3 is a vertical cross-sectional view of a portion of a pouch-shaped battery case manufactured using the pouch-shaped battery case forming device of Fig. 1.

[0043] Fig. 4 is a front view of a pouch-type battery case forming device according to the first embodiment.

[0044] Fig. 5 is a perspective view of a die of a pouch-type battery case forming device according to the first embodiment.

[0045] Fig. 6 is a perspective view of a stripper of a pouch-type battery case forming device according to the first embodiment.

[0046] Fig. 7 is a perspective view of a stripper of a pouch-type battery case forming device according to a second embodiment.

[0047] Fig. 8 is a step of forming a cup portion of a pouch-type battery case using a pouch-type battery case forming device according to the first embodiment.

[0048] Figure 9 is a vertical cross-sectional view of a portion of a pouch-type battery case manufactured using a pouch-type battery case forming device according to the present invention.

[0049] Figure 10 is a photo of a corner of a pouch-type battery case manufactured in an example.

[0050] Figure 11 is a photo of a corner of a pouch-type battery case manufactured in a comparative example.

[0051]

[0052] Hereinafter, with reference to the attached drawings, embodiments of the present invention will be described in detail, so that those skilled in the art can easily implement the present invention. When describing the operating principles of the embodiments of the present invention in detail, detailed descriptions of known functions or components will be omitted if they are deemed to unnecessarily obscure the gist of the present invention.

[0053] Parts with similar functions and actions are designated by the same drawing reference numerals throughout the drawings. Throughout the specification, when a part is said to be connected to another part, this includes not only direct connections but also indirect connections with other elements intervening. Furthermore, inclusion of a component does not exclude other components unless otherwise specifically stated, but rather implies the inclusion of additional components.

[0054] The description that concretizes or adds to the components may be applied to all inventions unless there is a special limitation, and is not limited to the description of a specific invention.

[0055] Throughout the description and claims of the invention herein, the singular includes the plural unless otherwise stated.

[0056] Throughout the description and claims of the present invention, the term "or" includes "and" unless otherwise stated. Therefore, "comprising A or B" means all three cases of including A, including B, or including A and B.

[0057] The present invention is described in detail with examples according to the drawings.

[0058] FIG. 4 is a front view of a pouch-type battery case forming device according to the first embodiment, FIG. 5 is a perspective view of a die of a pouch-type battery case forming device according to the first embodiment, and FIG. 6 is a perspective view of a stripper of a pouch-type battery case forming device according to the first embodiment.

[0059] Referring to FIGS. 4 to 6, a pouch-type battery case forming device (200) according to the present invention includes a punch (210) that pressurizes a laminate sheet (10) to form a cup portion for a pouch-type battery case, a die (220) including a groove (223) into which the punch (210) is inserted, and a stripper (230) positioned on the upper portion of the die (220) to fix the laminate sheet (10) and have a through hole (233) formed therein for movement of the punch (210).

[0060] The laminate sheet (10) is placed between the upper part of the die (220) and the lower part of the stripper (230), and the die (220) and the stripper (230) are in close contact with each other to fix the laminate sheet (10).

[0061] The die (220) includes an upper part (221) and a lower part (222) with different heights, and when the die (220) and the stripper (230) are in close contact with each other, the upper surface of the upper part (221) is configured to protrude upwards more than the upper surface of the lower part (222).

[0062] The upper part (221) constitutes the inner side of the die (220), which is a square frame shape on a plane, and the lower part (222) constitutes the outer side of the die (220).

[0063] That is, in the pouch-type battery case forming device according to the present invention, the die (220) has an upper portion (221) in which the inner side adjacent to the groove (223) in the center protrudes upward relatively more than the outer side, and the outer side of the die (220) has a lower portion (222) in which the outer side is concave downward relatively more than the inner side.

[0064] In the pouch-type battery case forming device according to the first embodiment, the upper part (221) and the lower part (222) constituting the die (220) are formed in a form that can move up and down independently.

[0065] The die (220) has a curved boundary where the upper part (221) and the inner surface (224) of the upper part (221) meet, so that when forming a cup part on the laminate sheet (10) using the punch (210), the laminate sheet (10) can be prevented from being damaged by friction between the punch (210) and the die (220).

[0066] The punch (210) has a curved boundary where the lower pressure surface and the side surface meet, so that when stretching the laminate sheet (10) using the punch (210), the laminate sheet (10) can be prevented from being damaged at the curved portion of the punch (210) where the laminate sheet (10) and the punch (210) come into contact.

[0067] The lower surface of the stripper (230) is configured with a stepped structure so that it is in close contact with the upper part (221) and the lower part (222) of the die (220) in which the steps are formed. The stripper (230) includes an inner part (231) that is in close contact with the upper surface of the upper part (221) of the die (220) and an outer part (232) that is in close contact with the upper surface of the lower part (222) of the die (230).

[0068] That is, in the pouch-type battery case forming device according to the present invention, the stripper is configured such that the inner part (231) adjacent to the central through hole (233) is relatively upwardly concave compared to the outer part (232), so that the height of the inner part (231) is lower than the height of the outer part (232).

[0069] The stripper (230) has a curved boundary where the lower surface of the inner part (231) and the inner side (234) meet, so that when the cup part is formed by pressing the laminate sheet (10) using the punch (210), the laminate sheet (10) can be prevented from being damaged due to friction caused by the contact between the stripper (230) and the punch (210).

[0070] In order to prevent wrinkles from forming in the laminate sheet (10) during the process of forming a cup portion by stretching the laminate sheet (10), a structure that allows the laminate sheet (10) to be stably fixed may be provided.

[0071] In this regard, a groove is formed on the lower surface of the inner portion (231) of the stripper (230), and an elastic member is added to be accommodated within the groove. The upper portion of the elastic member is configured to be accommodated and fixed within the groove, and the remaining portion is configured to protrude outward from the lower surface of the inner portion (231). Since the elastic member can contract and have stronger elasticity as the stripper (230) and the die (220) get closer, the laminate sheet (10) can be strongly pressed toward the die (220), so that the laminate sheet (10) can be stably fixed.

[0072] In one specific example, the elastic member may be a spring (240), and in this case, the grooves may be formed to be spaced apart at regular intervals. The grooves are formed to be spaced apart at regular intervals along a square line on the lower surface of the inner portion (231) formed in the shape of a square frame, and the square line is formed in the shape of two lines spaced apart from each other.

[0073] Alternatively, unlike as shown in Fig. 6, the grooves may be formed continuously along the rectangular line rather than being spaced apart at regular intervals, and the spring may be accommodated in such a way that it is in close contact with the rectangular line of the groove.

[0074] The upper part of the spring (240) is received in the groove, and the remaining part can protrude further than the lower surface of the outer circumference (232) when the spring (240) is not compressed.

[0075] Meanwhile, in a pouch-type battery case manufactured using a pouch-type battery case forming device according to the present invention, a sealing portion may be formed in a portion interposed between the upper portion (221) of the die (220) and the inner portion (231) of the stripper (230) among the laminate sheets (10) and in a surface where they are in close contact. In order to secure the sealing force of the sealing portion, the width (w) of the upper portion (221) of the die (220) may be configured to be the same size as or wider than the width of the sealing portion.

[0076] Fig. 7 is a perspective view of a stripper of a pouch-type battery case forming device according to a second embodiment.

[0077] Referring to FIG. 7, when comparing the stripper of the pouch-type battery case forming device according to the second embodiment with the stripper of the pouch-type battery case forming device according to the first embodiment, there is a difference in that the groove formed on the lower surface of the inner portion (231) is in the shape of a square ring, the elastic member is elastic rubber (250), and the elastic rubber (250) is added so that at least a portion is accommodated in the groove.

[0078] The above home may be formed by a single line in the shape of a square ring, or may be formed by two lines in the shape of square rings spaced apart from each other.

[0079] Since the elastic rubber (250) is accommodated in the above groove, as the number of grooves increases, the force with which the elastic rubber (250) adheres the laminate sheet (10) to the upper part (221) of the die (220) can increase, thereby stably fixing the laminate sheet (10). Accordingly, it is possible to prevent wrinkles from forming on the laminate sheet (10) during the process of stretching the laminate sheet (10).

[0080] Fig. 8 is a step of forming a cup portion of a pouch-type battery case using a pouch-type battery case forming device according to the first embodiment.

[0081] Referring to FIG. 8 together with FIG. 5 and FIG. 6, the method for forming a cup portion of a pouch-type battery case according to the present invention comprises the following steps: a first step of placing a laminate sheet (10) between a die (220) and a stripper (230), and placing a punch (210) in a through hole (233) of the stripper (230); a second step of closely contacting the lower portion (222) of the die (220) and the outer portion (232) of the stripper (230) with the laminate sheet (10) interposed therebetween while the upper portion (221) of the die (220) moves upwards and the upper portion (221) and the inner portion (231) of the stripper (230) are closely contacted with the laminate sheet (10) interposed therebetween; and a second step of closely contacting the upper portion (221) of the die (220) with the upper portion (221) and the inner portion (231) of the stripper (230) with the laminate sheet (10) interposed therebetween while the laminate sheet (10) is pressed against the upper portion (221) of the die (220). The third step of first stretching includes a fourth step of moving the punch (210) downwards while the laminate sheet (10) is first stretched to second stretch the laminate sheet (10) and form a cup portion of a pouch-type battery cell.

[0082] In the above second step, the laminate sheet (10) is fixed in position by the close contact between the lower part (222) of the die (220) and the outer part (232) of the stripper (230).

[0083] In addition, a spring (240) added to the inner side (231) of the stripper (230) can come into contact with the laminate sheet (10), and when the spring (240) is compressed by the laminate sheet (10), the laminate sheet (10) can be pressed toward the upper side (221) of the die (220) by elastic force. Therefore, the laminate sheet (10) can be fixed more firmly.

[0084] In the above second step, while the laminate sheet (10) is maintained in a taut state, in the third step, the laminate sheet (10) can be first stretched.

[0085] Specifically, the laminate sheet (10) has a step difference between the upper part (221) and the lower part (222) of the die (220), and a step difference between the inner part (231) and the outer part (232) of the stripper (230). When the inner part (231) of the stripper (230) and the upper part (221) of the die (220) are in close contact, the laminate sheet is stretched by the height of the step difference in the portion interposed between the die (220) and the stripper (230).

[0086] That is, simply by joining the inner part (231) of the stripper (230) and the upper part (221) of the die (220) so that they are in close contact with each other, primary stretching can be performed at the upper part of the cup part of the laminate sheet (10). Therefore, when using the pouch-type battery case forming device according to the present invention, the laminate sheet can be stretched more by the height of the step between the die and the stripper than when using a conventional die and stripper without a step.

[0087] In this way, since the pouch-type battery case forming device (200) according to the present invention includes a primary stretching process of stretching the laminate sheet (10) by the step height of the die (220) and the stripper (230), damage to the laminate sheet (10) due to excessive stretching can be mitigated compared to a case where a pouch-type battery case forming device without the step height is used.

[0088] In one specific example, the height of the step formed by the upper portion (221) and the lower portion (222) can be formed within a range of 6 mm. If the height of the step is 6 mm or more, cracks may occur at the corners when the laminate sheet is first stretched during the process of the die (220) and the stripper (230) being brought into close contact, which is not preferable. Considering the range in which the residual thickness of the metal layer of the pouch-type battery case satisfies 60% of the standard before stretching, the height of the step can be formed to be 6 mm or less.

[0089] In the fourth step above, the laminate sheet (10) can be fixed in position while being pressed toward the upper end (221) of the die (220) by the elastic force of the elastic member added to the lower surface (231) of the inner side of the stripper (230).

[0090] In this way, in the fourth step, not only can the laminate sheet (10) be fixed by the inner part (231) of the stripper (230) and the upper part (221) of the die (220) being in close contact, but also, since the elastic force of the spring (240) adds a force that presses the laminate sheet (10), it is possible to prevent wrinkles from forming on the laminate sheet (10) during the process of pressing the laminate sheet (10) with the punch (210).

[0091] Meanwhile, when the inner part (231) of the stripper (230) and the upper part (221) of the die (220) are brought into close contact, the entire spring (240) is received in the groove formed on the lower surface of the inner part (9231) of the stripper (230) and becomes in a state of maximum compression, so that the laminate sheet (10) can be brought into close contact with the upper part (221) of the die (220).

[0092] When using the stripper of the pouch-type battery case forming device according to the second embodiment, when the inner part (231) of the stripper (230) and the upper part (221) of the die (220) are in close contact, the entire elastic rubber (250) is received in the groove formed on the lower surface of the inner part (231) of the stripper (230) and becomes in a state of maximum compression, so that the laminate sheet (10) can be pressed against the upper part (221) of the die (220).

[0093] The third step is performed before the fourth step. That is, the present invention stretches the laminate sheet in two steps, first stretching the laminate sheet in the third step, and then stretching the laminate sheet a second time in the fourth step.

[0094] In addition, in the first elongation, elongation is mainly performed at the corner that becomes the upper part of the cup part when the cup part is completed, and in the second elongation, elongation is mainly performed at the corner that becomes the lower part of the cup part when the cup part is completed.

[0095] In this way, since the areas where stretching mainly occurs in the laminate sheet during the first and second stretching processes are different, not only can the depth of the cup portion be formed deeper, but the problem of excessive stretching occurring only in a specific area of ​​the laminate sheet can be solved.

[0096] Figure 9 is a vertical cross-sectional view of a portion of a pouch-type battery case manufactured using a pouch-type battery case forming device according to the present invention.

[0097] Referring to FIG. 10, the outer periphery (20) of the cup portion (30) includes an inner outer periphery (21) and an outer outer periphery (22), and the height (H) from the bottom of the cup portion (30) to the inner outer periphery (21) is higher than the height (H2) from the bottom of the cup portion (30) to the outer outer periphery (22).

[0098] That is, the height (H) from the bottom of the cup portion (30) to the inner outer periphery (21) is configured as the size obtained by adding the height difference (H1) between the upper portion (221) and the lower portion (222) of the die (220) of the pouch-type battery case forming device (200) to the height (H2).

[0099] In this way, since the present invention forms the cup portion (30) by extending the depth by H1, it is possible to prevent cracks from occurring by alleviating excessive stretching in a portion of the laminate sheet (10) for the pouch-type battery case, and to provide a pouch-type battery cell with increased capacity.

[0100]

[0101] Hereinafter, the present invention will be described with reference to embodiments, but this is for easier understanding of the present invention, and the scope of the present invention is not limited thereto.

[0102]

[0103] <Example>

[0104] A pouch-type battery case forming device is prepared, which comprises a die having an upper portion with an inner protrusion and an outer concave lower portion formed on the upper surface as shown in Fig. 4, a stripper having an inner portion formed on the lower surface that is in close contact with the upper portion of the die and an outer portion formed on the lower surface that is in close contact with the lower portion of the die, and a punch for pressing a laminate sheet.

[0105] A pouch-type battery case was manufactured by pressing a laminate sheet using the above pouch-type battery case forming device and performing a first stretching and a second stretching process.

[0106] Figure 10 is a photo of a corner of a pouch-type battery case manufactured in an example.

[0107] Referring to Figure 10, the corners of the pouch-type battery case have a smooth appearance, so it was determined to be a good product.

[0108]

[0109] <Comparative Example>

[0110] As illustrated in Fig. 1, a pouch-type battery case forming device is prepared, which is configured as a flat surface without a step between the upper surface of the die and the lower surface of the scraper.

[0111] A pouch-type battery case was manufactured by pressing a laminate sheet using the above pouch-type battery case forming device.

[0112] Figure 11 is a photo of a corner of a pouch-type battery case manufactured in a comparative example.

[0113] Referring to Fig. 11, the corners of the pouch-shaped battery case are cracked and split, and wrinkles are also observed at the side corners of the cup portion. Therefore, the pouch-shaped battery case manufactured in the comparative example was determined to be defective.

[0114]

[0115] Anyone with ordinary knowledge in the field to which the present invention pertains will be able to perform various applications and modifications within the scope of the present invention based on the above contents.

[0116]

[0117] (Explanation of symbols)

[0118] 10: Laminate sheet

[0119] 20: Outer perimeter of the cup

[0120] 21: Inner outer periphery

[0121] 22: Outer periphery

[0122] 30: Cup

[0123] 100, 200: Pouch-type battery case forming device

[0124] 110, 210: Punch

[0125] 120, 220: Die

[0126] 130, 230: Stripper

[0127] 221: Top

[0128] 222: Lower part

[0129] 223: Home

[0130] 224, 234: Medial side

[0131] 231: Medial

[0132] 232: Outer part

[0133] 233: Penetration

[0134] 240: Spring

[0135] 250: Elastic rubber

[0136] H: Height from the bottom of the cup to the inner outer perimeter

[0137] H1: Height difference between the top and bottom of the die

[0138] H2: Height of the bottom of the die

Claims

1. A punch for forming a cup portion for a pouch-type battery case by pressing a laminate sheet; A die having a groove into which the punch is inserted, the laminate sheet being placed on the upper side; and A stripper positioned on the upper part of the die to fix the laminate sheet and having a through hole formed therein for the punch to move; Including, The above die is composed of upper and lower parts with different heights, A pouch-type battery case forming device in which the upper part constitutes the inner side of the die in the shape of a square frame on a plane, and the lower part constitutes the outer side of the die.

2. In paragraph 1, The above stripper is formed with a step that is in close contact with the upper and lower parts of the die. The above stripper is a pouch-type battery case forming device including an inner part that is in close contact with the upper part of the die and an outer part that is in close contact with the lower part of the die.

3. In paragraph 1, The above die is a pouch-type battery case forming device in which the upper part is formed in a form that can move up and down independently from the lower part.

4. In paragraph 2, A groove is formed on the inner side of the above stripper, A pouch-shaped battery case forming device in which an elastic member is added so that at least a portion thereof is accommodated in the groove.

5. In paragraph 4, The above elastic member is a spring, The above grooves are formed to be spaced at regular intervals, A pouch-type battery case forming device in which at least a portion of the spring is added to be received in the groove.

6. In paragraph 5, A pouch-type battery case forming device in which the above-mentioned grooves are formed at regular intervals along a square line, and the square line is formed in the form of two lines spaced apart from each other.

7. In paragraph 4, The above elastic member is elastic rubber, The above home is formed in a square ring shape, A pouch-type battery case forming device in which at least a portion of the above elastic rubber is added so as to be accommodated in the above groove.

8. In paragraph 7, The above home is a pouch-type battery case forming device configured in the form of two lines spaced apart from each other.

9. In paragraph 1, The above punch is a pouch-type battery case forming device in which the boundary between the lower pressure surface and the side surface is formed into a curved shape.

10. In paragraph 1, The above die is a pouch-type battery case forming device in which the boundary between the upper part and the inner surface of the upper part is formed in a curved shape.

11. In paragraph 4, When the inner side of the stripper and the upper side of the die are in close contact, the entire elastic member is accommodated in the groove, A pouch-type battery case forming device that presses the laminate sheet against the upper part of the die while the elastic member is compressed to the maximum.

12. In paragraph 11, A pouch-shaped battery case forming device in which the laminate sheet is stretched along the upper surface of the die when the inner side of the stripper and the upper side of the die are brought into close contact.

13. In a pouch-type battery case manufactured using a pouch-type battery case forming device according to Articles 1 to 12, The outer periphery of the cup includes the inner outer periphery and the outer outer periphery, A pouch-type battery case in which the height from the bottom of the cup portion to the inner outer periphery is higher than the height from the bottom of the cup portion to the outer outer periphery.

14. In paragraph 13, A pouch-type battery case in which the height from the bottom of the cup portion to the inner outer periphery is a size equal to the height of the lower end of the die of the pouch-type battery case forming device plus the height difference between the upper end and the lower end.

15. A method for forming a cup portion of a pouch-type battery case using a pouch-type battery case forming device according to Articles 1 to 12, A first step is to place a laminate sheet between a die and a stripper and place a punch within a through hole of the stripper; A second step in which the upper surface heights of the upper and lower surfaces of the die are the same and the lower surface of the die and the outer surface of the stripper are pressed against each other with the laminate sheet interposed therebetween; A third step of first elongating the laminate sheet in a process in which the upper part of the die moves upward and the inner part of the stripper is brought into close contact with the laminate sheet while interposing the upper part therebetween; A fourth step of forming a cup portion of a pouch-type battery cell by moving the punch downward while the laminate sheet is first stretched and secondly stretching the laminate sheet; Including, A method for forming a cup portion of a pouch-shaped battery case, wherein the laminate sheet is fixed in position by close contact between the lower portion of the die and the outer portion of the stripper in the second step.

16. In paragraph 15, A method for forming a cup portion of a pouch-shaped battery case, wherein in the third step, the laminate sheet is first stretched at a position where the upper end of the cup portion is to be formed.

17. In paragraph 15, A method for forming a cup portion of a pouch-shaped battery case, wherein in the fourth step, the laminate sheet is fixed in position while being pressed toward the upper end of the die by the elastic force of an elastic member added to the lower surface of the inner side of the stripper.

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