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

Abstract

The present invention relates to a pouch-type battery case molding device including: a punch that presses a laminate sheet to form a cup portion for a pouch-type battery case; a die having a groove on which the laminate sheet is placed and into which the punch is inserted; and a stripper located above the die, fixing the laminate sheet, and having a through hole through which the punch moves, the die having an upper end and a lower end with different heights and a stepped shape, the upper end forming the inside of the die having a square frame shape in plan view, and the lower end forming the outside of the die; a pouch-type battery case manufactured using the pouch-type battery case molding device; and a method for molding a cup portion of a pouch-type battery case using the pouch-type battery case molding device.

Description

[Technical Field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0107897 filed on August 17, 2023, and Korean Patent Application No. 10-2024-0107422 filed on August 12, 2024, and all contents disclosed in the Korean patent applications are incorporated herein by reference.

[0002] The present invention relates to a pouch-type battery case molding device that can prevent cracks from occurring in the portion of a pouch-type battery cell that has become thin due to stretching when the cup portion of the pouch-type battery cell is molded, a pouch-type battery case manufactured using the same, and a method for molding the cup portion of a pouch-type battery case using the pouch-type battery case molding device. [Background technology]

[0003] Rechargeable lithium secondary batteries are widely used as energy sources for wireless mobile devices or wearable devices, as well as for electric vehicles and hybrid electric vehicles, which are presented as alternatives to existing gasoline and diesel vehicles that cause air pollution.

[0004] Depending on the case material, lithium secondary batteries can be classified into cylindrical or prismatic secondary batteries made of metal materials, pouch-type secondary batteries made of laminated sheets, etc. Pouch-type secondary batteries are used in a variety of devices due to their advantages of high energy density per weight, low manufacturing costs, and ease of shape modification, as they are stacked at a high density.

[0005] A pouch-type secondary battery uses a laminate sheet including an outer coating layer, a metal barrier layer, and an inner adhesive layer as a battery case, and an electrode assembly and an electrolyte are housed together in a receiving portion formed in the laminate sheet.

[0006] To form an electrode assembly receiving portion in a pouch-type battery case, a laminate sheet is placed on a die, fixed with a holder, and pressed with a punch.Due to the limited flexibility of the laminate sheet and the friction between the punch and the laminate sheet, external defects such as pinholes or cracks may occur on the outer surface of the laminate sheet during the process of forming the electrode assembly receiving portion.

[0007] FIG. 1 is a front view of a conventional pouch-type battery case molding apparatus, FIG. 2 is a diagram showing the stage of molding the cup portion of a pouch-type battery case using the pouch-type battery case molding apparatus 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 molding apparatus of FIG. 1.

[0008] Referring to Figures 1 to 3, pouch-type battery case molding apparatus 100 includes a die 120 on which laminate sheet 10 is placed, a stripper 130 located above die 120 and fixing laminate sheet 10, and a punch 110 that presses laminate sheet 10 to form a cup portion.

[0009] The upper surface of the die 120 of the pouch-type battery case molding apparatus 100 and the lower surface of the stripper 130 that comes into close contact with the upper surface of the die 120 are configured to be flat.

[0010] Therefore, as shown in Figure 2, after placing the laminate sheet 10 between the die 120 and the stripper 130, the laminate sheet 10 is fixed by the die 120 and the stripper 130, and then the laminate sheet 10 is pressed with the punch 110, thereby producing a pouch-type battery case in the form shown in Figure 3.

[0011] In the pouch-type battery case of FIG. 3, the depth H of the cup portion that houses the electrode assembly can be expressed as the sum of R1, the curved surface of the upper end of the cup portion, R2, the curved surface of the lower end of the cup portion, and L1, which is the length of the flat section of the side surface of the cup portion.

[0012] When molding a pouch-shaped battery case, the bottom of the cup is stretched first, so when molding is complete, the bottom of the cup is the most stretched part. In Figure 3, part A is the most stretched part, and the remaining part is thin. Therefore, there is a high risk of pinholes and cracks occurring in part A.

[0013] Therefore, a technology is needed that can form a deeper cup portion to increase the capacity of a pouch-type battery case and prevent pinholes and cracks from occurring due to excessive stretching. Summary of the Invention [Problem to be solved by the invention]

[0014] The present invention has been made to solve the above problems, and aims to provide a pouch-type battery case molding device that can prevent excessive stretching of a portion of a laminate sheet when molding a pouch-type battery case, thereby improving the quality of the final product, a pouch-type battery cell, a pouch-type battery case manufactured using the same, and a method for molding the cup portion of a pouch-type battery case using the pouch-type battery case molding device. [Means for solving the problem]

[0015] To achieve this object, a pouch-type battery case molding apparatus according to the present invention includes a punch that presses a laminate sheet to form a cup portion for a pouch-type battery case; a die having a groove on which the laminate sheet is disposed and into which the punch is inserted; and a stripper that is disposed above the die, fixes the laminate sheet, and has a through hole through which the punch moves. The die may include upper and lower ends with different heights, and the upper end may form the inside of the die having a rectangular frame shape in plan view, and the lower end may form the outside of the die.

[0016] The stripper may have a step formed therein to contact the upper and lower ends of the die, and may include an inner portion that contacts the upper end of the die and an outer portion that contacts the lower end of the die.

[0017] The die may have a configuration in which the upper end and the lower end are movable up and down independently.

[0018] A groove may be formed on a lower surface of the inner portion of the stripper, and an elastic member may be provided so that at least a portion of the elastic member is received in the groove.

[0019] The elastic member may be a spring, the grooves may be spaced apart at regular intervals, and the spring may be at least partially received in the groove.

[0020] The grooves may be formed along a rectangular line at regular intervals, and the rectangular line may be configured as two lines spaced apart from each other.

[0021] The elastic member may be elastic rubber, the groove may be formed in a square ring shape, and at least a portion of the elastic rubber may be accommodated in the groove.

[0022] The groove may be configured in the form of two lines spaced apart from each other.

[0023] The punch may have a curved boundary where the pressing surface, which is the lower surface, meets the side surface.

[0024] The die may have a curved boundary where the upper end meets the inner surface of the upper end.

[0025] When the inner part of the stripper and the upper end of the die are in close contact with each other, the entire elastic member is accommodated in the groove, and the elastic member can tightly contact the laminate sheet with the upper end of the die in a maximally compressed state.

[0026] When the inner portion of the stripper and the upper end of the die are in close contact with each other, the laminate sheet may be stretched along the surface of the upper end of the die.

[0027] In the pouch-type battery case manufactured by the pouch-type battery case molding apparatus, the outer periphery of the cup portion may include 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 greater than the height from the bottom of the cup portion to the outer outer periphery.

[0028] The height from the bottom of the cup portion to the inner outer periphery may be configured to be the height of the lower end of the die of the pouch-type battery case molding device plus the height difference between the upper end and the lower end.

[0029] The method for forming the cup portion of a pouch-type battery case using the pouch-type battery case forming apparatus includes: a first step of placing a laminate sheet between a die and a stripper and placing a punch in the through hole of the stripper; a second step of sandwiching the laminate sheet between the lower end of the die and the outer part of the stripper while the upper surfaces of the upper and lower ends of the die are at the same height; a third step of primarily stretching the laminate sheet as the upper end of the die moves upward and the upper end and the inner part of the stripper sandwich the laminate sheet and come into close contact; and a fourth step of secondly stretching the laminate sheet by moving the punch downward in a state in which the laminate sheet has been primarily stretched, thereby forming the cup portion of a pouch-type battery cell. In the second step, the laminate sheet may be fixed in position by the close contact between the lower end of the die and the outer part of the stripper.

[0030] In the third step, the laminate sheet may be first stretched at a position where the upper end of the cup portion is to be formed.

[0031] In the fourth step, the laminate sheet may be fixed in position while being pressed toward the upper end of the die by the elastic force of an elastic member provided on the lower surface of the inner portion of the stripper.

[0032] Furthermore, the present invention can also be provided in the form of various combinations of means for solving the above problems. [Effects of the Invention]

[0033] As described above, the pouch-shaped battery case molding device according to the present invention has a structure in which steps are formed on the upper surface of the die and the lower surface of the stripper. The laminate sheet is stretched twice: when the die and the stripper come into close contact with each other and when pressed by the punch, thereby preventing excessive stretching of a portion of the laminate sheet.

[0034] In addition, a pouch-type battery case manufactured using this method has a relatively deep cup portion, so that a pouch-type battery cell with increased capacity can be provided. [Brief explanation of the drawings]

[0035] [Figure 1] FIG. 1 is a front view of a conventional pouch-type battery case molding device.

[0036] [Figure 2] 3A and 3B are diagrams showing the stage of forming the cup portion of the pouch-type battery case using the pouch-type battery case forming apparatus of FIG. 1.

[0037] [Figure 3] 2 is a vertical cross-sectional view of a portion of a pouch-shaped battery case manufactured by the pouch-shaped battery case molding apparatus of FIG. 1. FIG.

[0038] [Figure 4] FIG. 1 is a front view of a pouch-type battery case molding device according to a first embodiment.

[0039] [Figure 5]FIG. 2 is a perspective view of a die of the pouch-type battery case molding apparatus according to the first embodiment.

[0040] [Figure 6] FIG. 2 is a perspective view of a stripper of the pouch-type battery case molding apparatus according to the first embodiment.

[0041] [Figure 7] FIG. 10 is a perspective view of a stripper of a pouch-type battery case molding apparatus according to a second embodiment.

[0042] [Figure 8] 3A to 3C are diagrams showing the step of forming the cup portion of the pouch-type battery case using the pouch-type battery case forming apparatus according to the first embodiment.

[0043] [Figure 9] 1 is a vertical cross-sectional view of a portion of a pouch-type battery case manufactured by a pouch-type battery case molding apparatus according to the present invention.

[0044] [Figure 10] 1 is a photograph of a corner portion of a pouch-type battery case manufactured according to an example.

[0045] [Figure 11] 10 is a photograph of a corner portion of a pouch-type battery case manufactured according to a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0046] Hereinafter, with reference to the accompanying drawings, a detailed description will be given of an embodiment of the present invention that will enable a person skilled in the art to easily carry out the present invention. In describing the operation principle of the embodiment of the present invention in detail, detailed description of related well-known functions or configurations will be omitted if it is determined that such detailed description may unnecessarily obscure the gist of the present invention.

[0047] Throughout the drawings, the same reference numerals are used for parts having similar functions and actions. Throughout the specification, when a part is said to be connected to another part, this includes not only a direct connection but also an indirect connection via another element therebetween. Furthermore, unless otherwise specified, "including a certain element" does not mean that other elements are excluded, but that other elements may also be included.

[0048] Descriptions that limit or specify additional elements are applicable to all inventions and are not limited to a particular invention unless otherwise limited.

[0049] Throughout the description and claims of this invention, the singular includes the plural unless otherwise stated.

[0050] Throughout the description and claims, "or" includes "and" unless otherwise stated. Thus, "comprising A or B" means the three cases of including A, including B, or including both A and B.

[0051] The invention will now be explained with reference to the drawings and in conjunction with detailed embodiments.

[0052] FIG. 4 is a front view of the pouch-shaped battery case molding apparatus according to the first embodiment, FIG. 5 is a perspective view of a die of the pouch-shaped battery case molding apparatus according to the first embodiment, and FIG. 6 is a perspective view of a stripper of the pouch-shaped battery case molding apparatus according to the first embodiment.

[0053] 4 to 6, a pouch-type battery case forming apparatus 200 according to the present invention includes a punch 210 that presses a laminate sheet 10 to form a cup portion for a pouch-type battery case, a die 220 that includes a groove 223 into which the punch 210 is inserted, and a stripper 230 that is located above the die 220, fixes the laminate sheet 10, and has a through hole 233 formed therein for the punch 210 to move through.

[0054] 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 in place.

[0055] The die 220 includes an upper end 221 and a lower end 222 having different heights, and is configured so that when the die 220 and the stripper 230 are in close contact with each other, the upper surface of the upper end 221 protrudes higher than the upper surface of the lower end 222.

[0056] The upper end 221 forms the inside of the die 220 having a square frame shape on a plane, and the lower end 222 forms the outside of the die 220 .

[0057] That is, in the pouch-type battery case molding apparatus according to the present invention, the inside of die 220 adjacent to central groove 223 forms upper end 221 that protrudes relatively higher than the outside, and the outside of die 220 forms lower end 222 that is recessed relatively lower than the inside.

[0058] In the pouch-type battery case molding apparatus according to the first embodiment, the upper end 221 and the lower end 222 constituting the die 220 are configured to be able to move up and down independently.

[0059] The boundary where the upper end 221 of the die 220 meets the inner surface 224 of the upper end 221 has a curved shape, so when a cup portion is formed in the laminate sheet 10 using the punch 210, damage to the laminate sheet 10 due to friction between the punch 210 and the die 220 can be prevented.

[0060] The punch 210 has a curved boundary where the pressing surface (bottom surface) meets the side surface, so when the laminate sheet 10 is stretched 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.

[0061] The lower surface of the stripper 230 is configured with a stepped structure so as to be in close contact with the upper end 221 and lower end 222 of the die 220, which have steps formed thereon, so that the stripper 230 includes an inner portion 231 that is in close contact with the upper surface of the upper end 221 of the die 220, and an outer portion 232 that is in close contact with the upper surface of the lower end 222 of the die 220.

[0062] That is, in the pouch-type battery case molding device according to the present invention, the stripper is configured such that the inner part 231 adjacent to the central through-hole 233 is recessed relatively upward compared to the outer part 232, and the height of the inner part 231 is lower than the height of the outer part 232.

[0063] The boundary where the lower surface of the inner portion 231 meets the inner surface 234 of the stripper 230 has a curved shape, so that when the punch 210 presses the laminate sheet 10 to form the cup portion, damage to the laminate sheet 10 due to friction caused by contact between the stripper 230 and the punch 210 can be prevented.

[0064] In order to prevent wrinkles from occurring in the laminate sheet 10 during the process of stretching the laminate sheet 10 to form the cup portion, the laminate sheet 10 may have a structure that can stably fix the laminate sheet 10.

[0065] In this regard, a groove is formed on the lower surface of the inner part 231 of the stripper 230, and an elastic member is accommodated within the groove. An upper portion of the elastic member is accommodated and fixed within the groove, and the remaining portion is configured to protrude outward from the lower surface of the inner part 231. The elastic member contracts and its elastic force increases as the stripper 230 and the die 220 approach each other, so that the laminate sheet 10 can be strongly pressed toward the die 220 and stably fixed.

[0066] In one specific example, the elastic member may be a spring 240. Here, the grooves may be formed to be spaced apart at regular intervals along a rectangular line on the lower surface of the inner part 231 having a rectangular frame shape, and the rectangular line is configured as two lines spaced apart from each other.

[0067] Alternatively, unlike the configuration shown in FIG. 6, the grooves may be formed continuously along the rectangular line rather than being spaced apart at regular intervals, and the springs may be accommodated in close contact along the rectangular line of the groove.

[0068] The upper portion of the spring 240 is received in the groove, and the remaining portion can protrude above the lower surface of the outer portion 232 when the spring 240 is in an uncompressed state.

[0069] Meanwhile, the sealing portion of the pouch-type battery case manufactured by the pouch-type battery case forming apparatus according to the present invention may be formed in a portion of the laminate sheet 10 that is interposed between the upper end 221 of the die 220 and the inner portion 231 of the stripper 230 at a surface where the upper end 221 of the die 220 and the inner portion 231 of the stripper 230 are in close contact with each other. Therefore, in order to ensure the sealing force of the sealing portion, the width w of the upper end 221 of the die 220 may be configured to be equal to or larger than the width of the sealing portion.

[0070] FIG. 7 is a perspective view of a stripper of a pouch-type battery case molding apparatus according to the second embodiment.

[0071] Referring to FIG. 7, when comparing the stripper of the pouch-type battery case forming apparatus according to the second embodiment with the stripper of the pouch-type battery case forming apparatus according to the first embodiment, the difference is that the groove formed on the underside of the inner part 231 is in the shape of a square ring, the elastic member is elastic rubber 250, and at least a portion of the elastic rubber 250 is configured to be accommodated in the groove.

[0072] The groove may be formed by one square ring-shaped line, or may be formed by two square ring-shaped lines spaced apart from each other.

[0073] Since the elastic rubber 250 is accommodated in the grooves, the greater the number of grooves, the greater the force with which the elastic rubber 250 adheres the laminate sheet 10 to the upper end 221 of the die 220, thereby stably fixing the laminate sheet 10. This prevents wrinkles from forming in the laminate sheet 10 during the process of stretching the laminate sheet 10.

[0074] FIG. 8 is a diagram showing the step of forming the cup portion of the pouch-type battery case using the pouch-type battery case forming apparatus according to the first embodiment.

[0075] 8 together with FIGS. 5 and 6, the method for forming the cup portion of the pouch-type battery case according to the present invention includes a first step of placing the laminate sheet 10 between the die 220 and the stripper 230, and placing the punch 210 in the through-hole 233 of the stripper 230, and a second step of placing the punch 210 in the through-hole 233 of the stripper 230, and a second step of placing the punch 210 in the through-hole 233 of the die 220, with the upper end 221 and the lower end 222 of the die 220 being flush with each other. a third step in which the upper end 221 of the die 220 moves upward and the upper end 221 and the inner portion 231 of the stripper 230 sandwich the laminate sheet 10 to form a first stretch on the laminate sheet 10 while the upper end 221 and the inner portion 231 of the stripper 230 are in close contact with each other while sandwiching the laminate sheet 10; and a fourth step in which the punch 210 is moved downward with the laminate sheet 10 having been first stretched, to form the cup portion of the pouch-type battery cell.

[0076] In the second step, the laminate sheet 10 is fixed in position by the tight contact between the lower end 222 of the die 220 and the outer portion 232 of the stripper 230 .

[0077] In addition, the spring 240 provided on the inner portion 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 elastic force can press the laminate sheet 10 toward the upper end 221 of the die 220. Therefore, the laminate sheet 10 can be more firmly fixed.

[0078] In the second step, the laminate sheet 10 is maintained in a taut state, and in the third step, the laminate sheet 10 can be stretched a first time.

[0079] Specifically, there is a step between the upper end 221 and the lower end 222 of the die 220, and a step between the inner part 231 and the outer part 232 of the stripper 230, so when the inner part 231 of the stripper 230 and the upper end 221 of the die 220 come into close contact, the part of the laminate sheet interposed between the die 220 and the stripper 230 is stretched by the height of the step.

[0080] That is, simply by tightly joining the inner portion 231 of the stripper 230 and the upper end 221 of the die 220 together, the laminate sheet 10 can be first stretched at the portion that will become the upper end of the cup portion. Therefore, when using the pouch-type battery case molding device according to the present invention, the laminate sheet can be stretched further by the height of the step between the die and the stripper, compared to when using a conventional die and stripper without a step.

[0081] As described above, the pouch-type battery case forming apparatus 200 according to the present invention includes a first stretching process that stretches the laminate sheet 10 by the height of the step between the die 220 and the stripper 230, and therefore, damage to the laminate sheet 10 due to excessive stretching can be reduced compared to when using a pouch-type battery case forming apparatus that does not have the step.

[0082] As a specific example, the height of the step formed between the upper end 221 and the lower end 222 may be within 6 mm. If the height of the step is 6 mm or more, it is undesirable because cracks may occur at the corners when the laminate sheet is first stretched while the die 220 and the stripper 230 are in close contact with each other. Considering that the remaining thickness of the metal layer of the pouch-type battery case should be 60% of the thickness before stretching, the height of the step may be 6 mm or less.

[0083] In the fourth step, the laminate sheet 10 may be fixed in position while being pressed toward the upper end 221 of the die 220 by the elastic force of the elastic member provided on the lower surface of the inner part 231 of the stripper 230.

[0084] In this way, in the fourth step, not only can the laminate sheet 10 be fixed by the inner portion 231 of the stripper 230 and the upper end portion 221 of the die 220 coming into close contact with each other, but also the elastic force of the spring 240 adds a force pressing against the laminate sheet 10, thereby preventing wrinkles from occurring in the laminate sheet 10 during the process of pressing the laminate sheet 10 with the punch 210.

[0085] On the other hand, when the inner portion 231 of the stripper 230 and the upper end portion 221 of the die 220 come into close contact with each other, the entire spring 240 is housed in a groove formed on the underside of the inner portion 231 of the stripper 230 and is placed in a maximally compressed state, allowing the laminate sheet 10 to be tightly contacted with the upper end portion 221 of the die 220.

[0086] When using the stripper of the pouch-type battery case molding device according to the second embodiment, when the inner part 231 of the stripper 230 and the upper end 221 of the die 220 come into close contact with each other, the entire elastic rubber 250 is accommodated in the groove formed on the underside of the inner part 231 of the stripper 230 and is in a maximally compressed state, so that the laminate sheet 10 can be tightly attached to the upper end 221 of the die 220.

[0087] The third step is carried out prior to the fourth step. That is, in the present invention, the laminate sheet is stretched in two steps, i.e., the laminate sheet is stretched for the first time in the third step and then for the second time in the fourth step.

[0088] In addition, in the first stretching, the corners that will become the upper end of the cup when the cup is completed are mainly stretched, and in the second stretching, the corners that will become the lower end of the cup when the cup is completed are mainly stretched.

[0089] In this way, since the parts of the laminate sheet that are primarily stretched during the first and second stretching processes are different from each other, it is possible to form a deeper cup portion and also to solve the problem of excessive stretching only in certain parts of the laminate sheet.

[0090] FIG. 9 is a vertical cross-sectional view of a portion of a pouch-type battery case manufactured by the pouch-type battery case molding apparatus according to the present invention.

[0091] Referring to Figure 9, 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 greater than the height H2 from the bottom of the cup portion 30 to the outer outer periphery 22.

[0092] That is, the height H from the bottom of the cup portion 30 to the inner outer periphery 21 is the height H2 of the lower end 222 of the die 220 of the pouch-type battery case molding device 200 plus the height difference H1 between the upper end 221 and the lower end 222 of the die.

[0093] In this way, the present invention extends the depth of the cup portion 30 by H1, thereby mitigating excessive stretching of a portion of the laminate sheet 10 for pouch-type battery cases, preventing the occurrence of cracks, and providing a pouch-type battery cell with increased capacity.

[0094] Hereinafter, the present invention will be described with reference to examples, but these are for easier understanding of the present invention and are not intended to limit the scope of the present invention.

[0095] <Example>

[0096] As shown in FIG. 4, a pouch-shaped battery case molding device is prepared, which includes a die having an upper end that protrudes inward and a lower end that is recessed outward on its upper surface, a stripper having an inner portion that contacts the upper end of the die and an outer portion that contacts the lower end of the die on its lower surface, and a punch for pressing the laminate sheet.

[0097] The laminate sheet was pressed using the pouch-type battery case molding device and subjected to a first stretching process and a second stretching process to manufacture a pouch-type battery case.

[0098] FIG. 10 is a photograph of a corner of a pouch-type battery case manufactured in the example.

[0099] Referring to FIG. 10, the corners of the pouch-type battery case had a smooth appearance, and was therefore judged to be a non-defective product.

[0100] <Comparative Example>

[0101] As shown in FIG. 1, a pouch-type battery case molding device is prepared, which is configured in a flat shape with no step between the upper surface of the die and the lower surface of the stripper.

[0102] The laminate sheet was pressed using the pouch-type battery case molding device to produce a pouch-type battery case.

[0103] FIG. 11 is a photograph of a corner of a pouch-type battery case manufactured according to the comparative example.

[0104] 11, it can be seen that the corners of the pouch-type battery case were cracked and the corners of the cup portion were wrinkled. Therefore, the pouch-type battery case manufactured according to the comparative example was determined to be defective.

[0105] Those skilled in the art will be able to make various applications and modifications within the scope of the present invention based on the above content. [Explanation of symbols]

[0106] 10 Laminated Sheet

[0107] 20 Outer circumference of cup

[0108] 21 Inner and outer periphery

[0109] 22 Outer periphery

[0110] 30 Cup section

[0111] 100 Pouch-type battery case molding device 200 Pouch-type battery case molding equipment

[0112] 110 Punch 210 Punch

[0113] 120 Die 220 Die

[0114] 130 Stripper 230 Stripper

[0115] 221 Upper end

[0116] 222 Lower end

[0117] 223 Groove

[0118] 224 Inner surface 234 Inner surface

[0119] 231 Inner part

[0120] 232 Outer part

[0121] 233 Through hole

[0122] 240 Spring

[0123] 250 Elastic Rubber

[0124] H Height from the bottom of the cup to the inside periphery

[0125] H1 Height difference between the top and bottom of the die

[0126] H2 Height of the bottom edge of the die

Claims

1. a punch that presses the laminate sheet to form a cup portion for the pouch-type battery case; a die having a groove on which the laminate sheet is placed and into which the punch is inserted; a stripper located above the die, fixing the laminate sheet, and having a through hole through which the punch moves; Including, the die includes upper and lower ends having different heights; The upper end portion forms an inner side of the die having a square frame shape in plan view, and the lower end portion forms an outer side of the die.

2. the stripper has a step formed thereon to be in close contact with the upper end and the lower end of the die, The pouch-type battery case molding apparatus according to claim 1 , wherein the stripper includes an inner portion that comes into close contact with the upper end of the die, and an outer portion that comes into close contact with the lower end of the die.

3. The pouch-type battery case molding apparatus according to claim 1 , wherein the die has a shape in which the upper end portion can move up and down independently of the lower end portion.

4. The groove is formed on the lower surface of the inner portion of the stripper, The pouch-type battery case molding device according to claim 2 , wherein an elastic member is provided so that at least a portion of the elastic member is accommodated in the groove.

5. the elastic member is a spring, The grooves are formed to be spaced apart at regular intervals, The pouch-type battery case molding device according to claim 4 , wherein the spring is provided so that at least a portion of the spring is housed in the groove.

6. The pouch-type battery case molding apparatus according to claim 5, wherein the grooves are formed along a rectangular line at regular intervals, and the rectangular line is configured as two lines spaced apart from each other.

7. the elastic member is elastic rubber, The groove is formed in a square ring shape, The pouch-type battery case molding device according to claim 4 , wherein the elastic rubber is provided so that at least a portion of the elastic rubber is accommodated in the groove.

8. The pouch-type battery case molding apparatus according to claim 7 , wherein the groove is configured in the form of two lines spaced apart from each other.

9. The pouch-type battery case molding device according to claim 1 , wherein the punch has a curved boundary where a pressing surface, which is a lower surface, meets a side surface.

10. The pouch-type battery case molding apparatus according to claim 1 , wherein the die has a curved boundary where the upper end meets an inner surface of the upper end.

11. When the inner portion of the stripper and the upper end portion of the die are brought into close contact with each other, the entire elastic member is accommodated in the groove, The pouch-type battery case molding apparatus according to claim 4 , wherein the elastic member tightly contacts the laminate sheet with the upper end of the die in a maximally compressed state.

12. The pouch-type battery case molding apparatus according to claim 11 , wherein the laminate sheet is stretched along the surface of the upper end of the die when the inner part of the stripper and the upper end of the die are in close contact with each other.

13. A pouch-type battery case manufactured by the pouch-type battery case molding apparatus according to any one of claims 1 to 12, the outer periphery of the cup portion includes an inner periphery and an outer periphery; The pouch-type battery case has a height from the bottom of the cup portion to the inner outer periphery that is greater than a height from the bottom of the cup portion to the outer outer periphery.

14. 14. The pouch-type battery case according to claim 13, wherein the height from the bottom of the cup portion to the inner outer periphery is configured to be equal to the height of the lower end of the die of the pouch-type battery case molding 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 the pouch-type battery case forming apparatus according to any one of claims 1 to 12, comprising: a first step of disposing the laminate sheet between the die and the stripper and disposing the punch within a through hole of the stripper; a second stage in which the lower end of the die and the outer portion of the stripper are brought into close contact with each other, sandwiching the laminate sheet, while the heights of the upper surfaces of the upper end and lower end of the die are the same; a third step of primarily stretching the laminate sheet as the upper end of the die moves upward and the upper end and an inner portion of the stripper come into close contact with the laminate sheet; a fourth step of forming the cup portion of the pouch-type battery cell by moving the punch downward in a state where the laminate sheet is primarily stretched, thereby secondarily stretching the laminate sheet; Including, In the second step, the position of the laminate sheet is fixed by tight contact between the lower end of the die and the outer portion of the stripper.

16. 16. The method of claim 15, wherein in the third step, the laminate sheet is first stretched at a position where an upper end of the cup portion is to be formed.

17. 16. The method of claim 15, wherein in the fourth step, the laminate sheet is fixed in position while being pressed toward the upper end of the die by an elastic force of an elastic member provided on a lower surface of the inner portion of the stripper.

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