POUCH-SHAPED BATTERY HOUSING MOLDING APPARATUS, POUCH-SHAPED BATTERY HOUSING MANUFACTURED USING THE SAME, AND METHOD FOR MOLDING Cup POUCH OF POUCH-SHAPED BATTERY HOUSING USING THE

Abstract

The present invention discloses a pouch-shaped battery case forming apparatus, a pouch-shaped battery case manufactured using the pouch-shaped battery case forming apparatus, and a method of forming a cup portion of the pouch-shaped battery case using the pouch-shaped battery case forming apparatus, the pouch-shaped battery case forming apparatus comprising: a punch, a punch configured to press the laminated sheet to form a cup portion of the pouch-shaped battery case; a mold configured to have the laminated sheet disposed thereon, the mold including a recess into which the punch is inserted; and a stripper configured to fix the laminated sheet while being positioned above the mold, the stripper being formed with a through-hole through which the punch moves, in which the mold includes an upper end portion and a lower end portion having different heights, and the upper end portion constituting an inner side of the mold in the form of a quadrilateral frame on a plane, and the lower end portion constituting an outer side of the mold.

Description

Technical Field

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

[0002] The present invention relates to a pouch-shaped battery case forming device that can prevent the formation of cracks in a portion with reduced thickness due to stretching when forming the cup portion of a pouch-shaped battery cell, a pouch-shaped battery case manufactured using the pouch-shaped battery case forming device, and a method for forming the cup portion of a pouch-shaped battery case using the pouch-shaped battery case forming device. Background Art

[0003] Lithium secondary batteries capable of charging and discharging have been widely used as energy sources for wireless mobile devices or wearable devices worn on the body, and have also been used as energy sources for electric vehicles and hybrid electric vehicles proposed as alternatives to existing gasoline and diesel vehicles that cause air pollution.

[0004] Based on the material of its shell, lithium secondary batteries can be divided into cylindrical secondary batteries made of metal materials, prismatic secondary batteries made of metal materials, or pouch-shaped secondary batteries made of laminated sheets. The advantages of pouch-shaped secondary batteries are that pouch-shaped secondary batteries are stacked with high integration, thus having a high energy density per unit weight, are manufactured at low cost, and are easily deformed. Therefore, pouch-shaped secondary batteries are used in various devices.

[0005] The pouch-shaped 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 is configured to have a structure in which an electrode assembly is accommodated in a receiving part formed in the laminate sheet together with an electrolyte.

[0006] In order to form an electrode assembly receiving portion in a pouch-shaped battery case, a method of placing a laminate sheet on a mold, fixing the laminate sheet with a holder, and pressing the laminate sheet with a punch is used. In the process of forming the electrode assembly receiving portion, appearance defects such as pinholes or cracks are formed on the outer surface of the laminate sheet due to the limited softness of the laminate sheet and the friction between the punch and the laminate sheet.

[0007] Figure 1 It is a front view of a conventional pouch-shaped battery casing forming device. Figure 2 It is shown that the use Figure 1A view of the steps of forming the cup portion of the pouch-shaped battery case by the pouch-shaped battery case forming apparatus, Figure 3 is used Figure 1 A partial vertical cross-sectional view of a pouch-shaped battery case manufactured by a pouch-shaped battery case forming equipment.

[0008] Reference Figures 1 to 3 The pouch-shaped battery case forming apparatus 100 includes a mold 120 configured to set a laminate sheet 10 thereon; a demolding device 130 configured to fix the laminate sheet 10 while being located above the mold 120; and a punch 110 configured to press the laminate sheet 10 to form a cup portion.

[0009] An upper surface of the mold 120 of the pouch-shaped battery case forming apparatus 100 and a lower surface of the demolding device 130 configured to be in close contact with the upper surface of the mold 120 are flat.

[0010] Therefore, if Figure 2 As shown in FIG. 1 , after the laminate 10 is set between the mold 120 and the demolding device 130, when the laminate 10 is pressed by the punch 110 in a state where the laminate 10 is fixed by the mold 120 and the demolding device 130, a laminate having Figure 3 A pouch-shaped battery case of the shape shown in FIG.

[0011] exist Figure 3 In the pouch-shaped battery case, the depth H of the cup portion accommodating the electrode assembly can be expressed as the sum of the curved surface R1 at the upper end of the cup portion, the curved surface R2 at the lower end of the cup portion, and the length L1 of the flat portion of the side surface of the cup portion.

[0012] Since the lower end of the cup portion is stretched first when the pouch-shaped battery case is formed, the lower end of the cup portion is the most stretched portion when the forming is completed. Figure 3 Among them, part A is the part that is stretched the most, resulting in a smaller retained thickness. Therefore, the risk of pinholes or cracks occurring in part A is high.

[0013] Therefore, there is a need for a technology capable of forming the cup more deeply to increase the capacity of the pouch-shaped battery case while preventing pinholes or cracks from occurring due to excessive stretching. Summary of the invention

[0014] Technical issues

[0015] The present invention is made to address the above-mentioned problems, and its purpose is to provide a pouch-shaped battery case forming device that can prevent a part of a laminate sheet from being over-stretched when forming a pouch-shaped battery case, thereby improving the quality of the pouch-shaped battery unit as a final product, a pouch-shaped battery case manufactured using the pouch-shaped battery case forming device, and a method for forming the cup portion of a pouch-shaped battery case using the pouch-shaped battery case forming device.

[0016] Technical Solution

[0017] To achieve the above objectives, the pouch-shaped battery case forming equipment according to the present invention includes: a punch, which is configured to press a laminate to form a cup portion of a pouch-shaped battery case; a mold, which is configured to allow the laminate to be arranged above it, and the mold includes a recess into which the punch is inserted; and a demolder, which is configured to fix the laminate while being located above the mold, and the demolder is formed with a through hole for the punch to move through, wherein the mold includes an upper end and a lower end with different heights, and the upper end constitutes the inner side of the mold in the form of a quadrilateral frame on a plane, and the lower end constitutes the outer side of the mold.

[0018] The demolding tool may have steps configured to be in close contact with the upper end portion and the lower end portion of the mold, and the demolding tool may include an inner portion configured to be in close contact with the upper end portion of the mold and an outer portion configured to be in close contact with the lower end portion of the mold.

[0019] The mold may be configured such that the upper end portion and the lower end portion can individually and independently move up and down.

[0020] A recess may be formed in a lower surface of the inner portion of the ejector, and an elastic member may be added such that at least a portion of the elastic member is accommodated in the recess.

[0021] The elastic member may be a spring, the recesses may be formed to be spaced apart from each other by a predetermined distance, and the spring may be added such that at least a portion of the spring is accommodated in the recess.

[0022] The recessed portions may be formed to be spaced apart from each other by a predetermined distance along a quadrilateral line, and the quadrilateral line may be composed of two lines spaced apart from each other.

[0023] The elastic member may be an elastic rubber, the recess may be in the form of a quadrangular ring, and the elastic rubber may be added such that at least a portion of the elastic rubber is accommodated in the recess.

[0024] The recess may be formed by two lines which are spaced apart from each other.

[0025] The punch may have a curved surface at a boundary where a lower surface as a pressing surface and a side surface meet each other.

[0026] The mold may have a curved surface at a boundary where the upper end portion and an inner surface of the upper end portion meet each other.

[0027] When the inner portion of the demolding device and the upper end portion of the mold are in close contact with each other, the entire elastic member may be accommodated in the recess, and the elastic member may bring the laminate into close contact with the upper end portion of the mold in a maximum compression state.

[0028] When the inner portion of the demolding tool and the upper end portion of the mold are in close contact with each other, the laminated sheet may be stretched along the surface of the upper end portion of the mold.

[0029] A pouch-shaped battery case manufactured using the pouch-shaped battery case forming equipment is configured such that 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 is greater than the height from the bottom of the cup portion to the outer outer periphery.

[0030] The height from the bottom of the cup portion to the inner outer periphery may be the sum of a height difference between an upper end portion and a lower end portion of a mold of the pouch-shaped battery case forming apparatus and a height of the lower end portion of the mold.

[0031] A method for forming a cup portion of a pouch-shaped battery case using the pouch-shaped battery case forming device, comprising: a first step of arranging a laminate sheet between the mold and the demolding device, and arranging the punch in a through hole of the demolding device; a second step of making the lower end of the mold and the outer portion of the demolding device closely contact each other with the laminate sheet sandwiched therebetween, in a state where the upper surfaces of the upper end and the lower end of the mold are at the same height; a third step of performing a primary stretching on the laminate sheet during the process of moving the upper end of the mold upward so that the upper end of the mold and the inner portion of the demolding device closely contact each other with the laminate sheet sandwiched therebetween; and a fourth step of moving the punch downward in a state where the laminate sheet is primarily stretched, thereby forming the cup portion of the pouch-shaped battery cell while performing a secondary stretching on the laminate sheet, wherein in the second step, the laminate sheet is fixed in position due to the close contact between the lower end of the mold and the outer portion of the demolding device.

[0032] In the third step, the laminated sheet may be primarily stretched at a position where the upper end of the cup portion is to be formed.

[0033] In the fourth step, the laminated sheet may be fixed in position in a state of being pressed toward the upper end portion of the mold due to an elastic force of an elastic member added to the lower surface of the inner portion of the demolding tool.

[0034] In addition, the present invention can provide various combinations of the above-mentioned solving means.

[0035] Beneficial Effects

[0036] As is obvious from the above description, the pouch-shaped battery case forming apparatus according to the present invention includes a structure in which steps are formed on the upper surface of the mold and the lower surface of the demolding device. Since the laminate is divided into two parts, namely, when the mold and the demolding device are in close contact with each other and when the laminate is pressed using a punch, it is possible to prevent a portion of the laminate from being over-stretched.

[0037] In addition, since the depth of the cup portion of the pouch-shaped battery case manufactured using the pouch-shaped battery case forming apparatus increases, a pouch-shaped battery cell having an increased capacity can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 is a front view of a conventional pouch-shaped battery case forming device.

[0039] Figure 2 It is shown that the use Figure 1 A view of the steps of forming the cup portion of a pouch-shaped battery case by a pouch-shaped battery case forming apparatus.

[0040] Figure 3 is used Figure 1 A partial vertical cross-sectional view of a pouch-shaped battery case manufactured by a pouch-shaped battery case forming equipment.

[0041] Figure 4 is a front view of the pouch-shaped battery case forming apparatus according to the first embodiment.

[0042] Figure 5 is a perspective view of a mold of a pouch-shaped battery case forming apparatus according to a first embodiment.

[0043] Figure 6 is a perspective view of a demolding device of a pouch-shaped battery case forming apparatus according to a first embodiment.

[0044] Figure 7 is a perspective view of a demolding device of a pouch-shaped battery case forming apparatus according to a second embodiment.

[0045] Figure 8 1 is a view showing a step of forming a cup portion of a pouch-shaped battery case using the pouch-shaped battery case forming apparatus according to the first embodiment.

[0046] Fig. 9 is a partial vertical cross-sectional view of a pouch-shaped battery case manufactured using the pouch-shaped battery case forming apparatus according to the present invention.

[0047] Fig.10 is a photograph of a corner of a pouch-shaped battery case manufactured in Example.

[0048] Fig.11This is a photograph of a corner portion of a pouch-shaped battery case manufactured in a comparative example. DETAILED DESCRIPTION

[0049] Now, the preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement the preferred embodiments of the present invention. However, in describing the working principle of the preferred embodiments of the present invention in detail, when the detailed description of the known functions and structures incorporated herein may obscure the subject matter of the present invention, the detailed description will be omitted.

[0050] The same reference numerals will be used throughout the drawings to denote components that perform similar functions or operations. Where a component is referred to as being connected to another component throughout the application, the component may not only be directly connected to the other component, but the component may also be indirectly connected to the other component via another component. In addition, the inclusion of a certain element does not mean the exclusion of other elements, but means that other elements may be further included unless otherwise specified.

[0051] Unless otherwise specifically limited, the description that specifies elements by limitation or addition can be applied to all inventions and does not limit the specific invention.

[0052] In the specification and claims describing the present application, unless otherwise mentioned, the singular form is intended to include the plural form.

[0053] In the specification and claims describing the present application, unless otherwise mentioned, "or" includes "and." Therefore, "including A or B" refers to three cases, namely, the case including A, the case including B, and the case including A and B.

[0054] Embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0055] Figure 4 is a front view of a pouch-shaped battery case forming apparatus according to a first embodiment, Figure 5 is a perspective view of a mold of a pouch-shaped battery case forming apparatus according to a first embodiment, Figure 6 is a perspective view of a demolding device of a pouch-shaped battery case forming apparatus according to a first embodiment.

[0056] Reference Figures 4 to 6 According to the present invention, the pouch-shaped battery case forming device 200 includes: a punch 210, which is configured to press the laminate sheet 10 to form the cup portion of the pouch-shaped battery case; a mold 220, which includes a recess 223 for the punch 210 to be inserted therein; and a demolder 230, which is configured to fix the laminate sheet 10 while being located above the mold 220, and the demolder is formed with a through hole 233 for the punch 210 to move through.

[0057] The laminated sheet 10 is disposed between the top of the mold 220 and the bottom of the demolder 230 , and the mold 220 and the demolder 230 are in close contact with each other to fix the laminated sheet 10 .

[0058] The mold 220 includes an upper end portion 221 and a lower end portion 222 having different heights, and is configured such that an upper surface of the upper end portion 221 protrudes upward than an upper surface of the lower end portion 222 when the mold 220 and the demolder 230 are in close contact with each other.

[0059] The upper end portion 221 constitutes the inner side of the mold 220 in the form of a quadrilateral frame on a plane, and the lower end portion 222 constitutes the outer side of the mold 220 .

[0060] That is, in the bag-shaped battery case forming equipment according to the present invention, the inner side of the mold 220 adjacent to the recess 223 located in the center of the mold constitutes an upper end 221 that protrudes upward than the outer side of the mold, and the outer side of the mold 220 constitutes a lower end 222 that is recessed downward than the inner side of the mold.

[0061] In the pouch-shaped battery case forming apparatus according to the first embodiment, the upper end portion 221 and the lower end portion 222 constituting the mold 220 are configured to be individually and independently movable up and down.

[0062] The mold 220 has a curved surface at the boundary where the upper end portion 221 and the inner surface 224 of the upper end portion 221 intersect each other, so that when the cup portion is formed on the laminated sheet 10 using the punch 210, the laminated sheet 10 can be prevented from being damaged due to friction between the punch 210 and the mold 220.

[0063] The punch 210 has a curved surface at the boundary where the lower surface and the side surface as the pressing surface intersect each other, so that when the laminate 10 is stretched using the punch 210, the laminate 10 can be prevented from being damaged at the curved surface of the punch 210 where the laminate 10 contacts the punch 210.

[0064] The lower surface of the demolding device 230 is configured to have a step structure so as to be in close contact with the upper end portion 221 and the lower end portion 222 of the mold 220 forming the step, and the demolding device 230 includes an inner portion 231 configured to contact the upper surface of the upper end portion 221 of the mold 220 and an outer portion 232 configured to contact the upper surface of the lower end portion 222 of the mold 230.

[0065] That is, in the bag-shaped battery case forming equipment according to the present invention, the demolding device is configured so that the inner part 231 adjacent to the through hole 233 located in the center of the demolding device is recessed upward than the outer part 232, so that the height of the inner part 231 is smaller than the height of the outer part 232.

[0066] The demolding tool 230 has a curved surface at the boundary where the lower surface of the inner portion 231 and the inner surface 234 meet each other, so that when the laminated sheet 10 is pressed using the punch 210 to form the cup portion, the laminated sheet 10 can be prevented from being damaged due to friction between the demolding tool 230 and the punch 210.

[0067] In order to prevent the laminate sheet 10 from wrinkling during the process of stretching the laminate sheet 10 to form the cup portion, a structure capable of reliably fixing the laminate sheet 10 may be provided.

[0068] In this regard, a recess is formed in the lower surface of the inner portion 231 of the demolding device 230, and an elastic member is added so that the elastic member is accommodated in the recess. The elastic member is configured so that a portion of the upper portion is accommodated and fixed in the recess, and the remaining portion protrudes outward from the lower surface of the inner portion 231. Since the elastic member contracts and becomes more elastic as the demolding device 230 and the mold 220 approach each other, the elastic member can strongly press the laminated sheet 10 in the direction toward the mold 220, so that the laminated sheet 10 can be reliably fixed.

[0069] In a specific example, the elastic member may be a spring 240, in which case the recesses may be formed to be spaced a predetermined distance from each other. The recesses may be formed in the lower surface of the inner portion 231 in the form of a quadrilateral frame to be spaced a predetermined distance from each other along a quadrilateral line, wherein the quadrilateral line is composed of two lines spaced apart from each other.

[0070] Or, with Figure 6 Unlike that shown in , the recesses may not be spaced apart from each other by a predetermined distance, but may be continuously formed along a quadrilateral line, and the spring may be accommodated in close contact with the recesses along the quadrilateral line.

[0071] An upper portion of the spring 240 may be accommodated in the recess, and the remaining portion may protrude more than a lower surface of the outer peripheral side portion 232 in a state in which the spring 240 is not compressed.

[0072] In addition, in the pouch-shaped battery case manufactured using the pouch-shaped battery case forming equipment according to the present invention, a sealing portion can be formed in the portion of the laminate sheet 10 sandwiched between the upper end portion 221 of the mold 220 and the inner portion 231 of the demolding device 230 which are in close contact with each other, and in order to ensure the sealing force of the sealing portion, the width W of the upper end portion 221 of the mold 220 can be equal to or greater than the width of the sealing portion.

[0073] Figure 7 is a perspective view of a demolding device of a pouch-shaped battery case forming apparatus according to a second embodiment.

[0074] Reference Figure 7The demolding device of the pouch-shaped battery case forming apparatus according to the second embodiment differs from the demolding device of the pouch-shaped battery case forming apparatus according to the first embodiment in that the recess formed in the lower surface of the inner portion 231 is in the form of a quadrilateral ring, the elastic member is an elastic rubber 250, and the elastic rubber 250 is added so that at least a portion of the elastic rubber is accommodated in the recess.

[0075] The recessed portion may be constituted by a single quadrilateral loop line, or may be constituted by two quadrilateral loop lines spaced apart from each other.

[0076] Since the elastic rubber 250 is accommodated in the recesses, the greater the number of recesses, the greater the force with which the elastic rubber 250 presses the laminate 10 toward the upper end 221 of the mold 220, thereby reliably fixing the laminate 10. Therefore, during the process of stretching the laminate 10, the laminate 10 can be prevented from wrinkling.

[0077] Figure 8 1 is a view showing a step of forming a cup portion of a pouch-shaped battery case using the pouch-shaped battery case forming apparatus according to the first embodiment.

[0078] Reference Figure 8 as well as Figure 5 and Figure 6 , the method for forming the cup portion of the pouch-shaped battery case according to the present invention includes: a first step of setting the laminate sheet 10 between the mold 220 and the demolding device 230, and setting the punch 210 in the through hole 233 of the demolding device 230; a second step of making the lower end portion 222 of the mold 220 and the outer portion 232 of the demolding device 230 closely contact each other with the laminate sheet 10 sandwiched therebetween, in a state where the upper end portion 221 of the mold 220 and the upper surface of the lower end portion 222 are at the same height; a third step of performing primary stretching on the laminate sheet 10 during the process of moving the upper end portion 221 of the mold 220 upward so that the upper end portion 221 of the mold 220 and the inner portion 231 of the demolding device 230 closely contact each other with the laminate sheet 10 sandwiched therebetween; a fourth step of moving the punch 210 downward in a state where the laminate sheet 10 is primarily stretched, thereby forming the cup portion of the pouch-shaped battery cell while performing secondary stretching on the laminate sheet 10.

[0079] In the second step, the laminated sheet 10 is fixed in position due to close contact between the lower end portion 222 of the mold 220 and the outer side portion 232 of the demolding device 230 .

[0080] In addition, the spring 240 added to the inner portion 231 of the demolding device 230 may contact the laminated sheet 10, and when the spring 240 is compressed by the laminated sheet 10, the spring may press the laminated sheet 10 toward the upper end portion 221 of the mold 220 with elastic force. Therefore, the laminated sheet 10 may be more firmly fixed.

[0081] While the laminated sheet 10 is maintained in a taut state in the second step, the laminated sheet 10 may be primarily stretched in the third step.

[0082] Specifically, a step is formed between the upper end 221 and the lower end 222 of the mold 220, and a step is formed between the inner portion 231 and the outer portion 232 of the demolding device 230, so that when the inner portion 231 of the demolding device 230 and the upper end 221 of the mold 220 are in close contact with each other, the portion of the laminate inserted between the mold 220 and the demolding device 230 is stretched by the height of the step.

[0083] That is, the portion of the upper end of the laminated sheet 10 that becomes the cup portion can be primarily stretched only by the inner portion 231 of the demolding device 230 and the upper end portion 221 of the mold 220 being closely contacted with each other. Therefore, when the pouch-shaped battery case forming apparatus according to the present invention is used, the effect that the laminated sheet is further stretched by the height of the step of the mold and the demolding device can be obtained compared to when a conventional mold and demolding device without a step is used.

[0084] Therefore, since the pouch-shaped battery case forming equipment 200 according to the present invention performs the initial stretching process of stretching the laminate sheet 10 to the height of the steps of the mold 220 and the demolding device 230, the damage to the laminate sheet 10 caused by excessive stretching can be reduced compared to when using a pouch-shaped battery case forming equipment without steps.

[0085] In a specific example, the height of the step formed by the upper end portion 221 and the lower end portion 222 may be within 6 mm. A step height of 6 mm or more is not ideal because cracks may be formed at the corners of the laminate when the laminate is initially stretched while the mold 220 and the demolding device 230 are in close contact with each other. Considering that the retained thickness of the metal layer of the pouch-shaped battery case satisfies the range of 60% of the thickness before stretching, the height of the step may be 6 mm or less.

[0086] In the fourth step, the laminate sheet 10 may be fixed in position in a state of being pressed toward the upper end portion 221 of the mold 220 due to the elastic force of the elastic member added to the lower surface of the inner portion 231 of the demolding device 230 .

[0087] Therefore, in the fourth step, as the inner part 231 of the demolding device 230 and the upper end part 221 of the mold 220 are in close contact with each other, not only can the laminate 10 be fixed, but also the elastic force of the spring 240 adds a force to press the laminate 10, so that the laminate 10 can be prevented from wrinkling during the process of pressing the laminate 10 using the punch 210.

[0088] In addition, when the inner portion 231 of the demolding device 230 and the upper end portion 221 of the mold 220 are in close contact with each other, the entire spring 240 can be accommodated in a recess formed in the lower surface of the inner portion 9231 of the demolding device 230 so as to be in a state of maximum compression, thereby allowing the laminate 10 to be in close contact with the upper end portion 221 of the mold 220.

[0089] When using the demolding device of the pouch-shaped battery case forming device according to the second embodiment, when the inner portion 231 of the demolding device 230 and the upper end portion 221 of the mold 220 are in close contact with each other, the entire elastic rubber 250 can be accommodated in the recess formed in the lower surface of the inner portion 231 of the demolding device 230 so as to be in a state of maximum compression, thereby allowing the laminate sheet 10 to be in close contact with the upper end portion 221 of the mold 220.

[0090] The third step is performed before the fourth step. That is, in the present invention, the laminate is stretched twice, such as the primary stretching of the laminate in the third step, and the secondary stretching of the laminate in the fourth step.

[0091] Furthermore, in the primary stretching, stretching is performed mainly at the corner that becomes the upper end of the cup portion when the cup portion is completed, while in the secondary stretching, stretching is performed mainly at the corner that becomes the lower end of the cup portion when the cup portion is completed.

[0092] Therefore, since the portions of the laminate that are mainly stretched during the primary stretching and the secondary stretching are different, the cup portion can be formed more deeply, and the problem of excessive stretching only in a certain portion of the laminate can be solved.

[0093] Fig. 9 is a partial vertical cross-sectional view of a pouch-shaped battery case manufactured using the pouch-shaped battery case forming apparatus according to the present invention.

[0094] Reference Fig.10 The outer periphery 20 of the cup portion 30 includes an inner outer periphery 21 and an outer outer periphery 22 , and a height H from the bottom of the cup portion 30 to the inner outer periphery 21 is greater than a height H2 from the bottom of the cup portion 30 to the outer outer periphery 22 .

[0095] That is, the height H from the bottom of the cup portion 30 to the inner outer periphery 21 is the sum of the height difference H1 between the upper end 221 and the lower end 222 of the mold 220 of the pouch-shaped battery case forming apparatus 200 and the height H2 of the lower end 222 of the mold.

[0096] Therefore, in the present invention, since the cup portion 30 is formed while its depth is increased by H1, excessive stretching of a portion of the laminate sheet 10 for a pouch-shaped battery case can be reduced to prevent cracks from occurring, and a pouch-shaped battery cell with increased capacity can be provided.

[0097] Hereinafter, the present invention will be described with reference to the following examples, which are only used for easier understanding of the present invention and should not be construed as limiting the scope of the present invention.

[0098] <Example>

[0099] like Figure 4 As shown in , a pouch-shaped battery case forming device is prepared, including: a mold, the mold having a protruding upper end formed on the inner side of the upper surface of the mold, and a recessed lower end formed on the outer side of the upper surface of the mold; a demolding tool, the demolding tool having an inner portion formed on the lower surface of the demolding tool so as to be in close contact with the upper end of the mold, and an outer portion formed on the lower surface of the demolding tool so as to be in close contact with the lower end of the mold; and a punch, the punch being configured to press a laminated sheet.

[0100] The pouch-shaped battery case forming apparatus is used to press a laminate sheet so that the laminate sheet is primarily stretched and secondarily stretched to manufacture a pouch-shaped battery case.

[0101] Fig.10 is a photograph of a corner of a pouch-shaped battery case manufactured in Example.

[0102] Reference Fig.10 , the corners of the pouch-shaped battery case had a smooth appearance, and thus the pouch-shaped battery case was determined to be a good product.

[0103] <Comparative Example>

[0104] like Figure 1 As shown in , a pouch-shaped battery case forming apparatus having a flat form without steps on an upper surface of a mold and a lower surface of a demolding device is prepared.

[0105] The pouch-shaped battery case forming apparatus is used to press a laminated sheet to manufacture a pouch-shaped battery case.

[0106] Fig.11 This is a photograph of a corner portion of a pouch-shaped battery case manufactured in a comparative example.

[0107] Reference Fig.11It can be seen that cracks appear at the corners of the pouch-shaped battery case, thereby forming a cracked shape, and wrinkles appear at the side corners of the cup. Therefore, the pouch-shaped battery case manufactured in the comparative example is determined to be defective.

[0108] Those skilled in the art to which the present invention pertains will appreciate that various applications and modifications can be made within the scope of the present invention based on the above description.

[0109] (Explanation of reference numbers)

[0110] 10: Laminated Sheet

[0111] 20: The outer perimeter of the cup

[0112] 21: Inside outer perimeter

[0113] 22: Outer perimeter

[0114] 30: Cup

[0115] 100, 200: Pouch-shaped battery case forming equipment

[0116] 110, 210: Punch

[0117] 120, 220: Mould

[0118] 130, 230: demoulding device

[0119] 221: Upper end

[0120] 222: Lower end

[0121] 223: concave part

[0122] 224, 234: Inner surface

[0123] 231: Inner part

[0124] 232: Outer part

[0125] 233: Through hole

[0126] 240: Spring

[0127] 250: Elastic rubber

[0128] H: The height from the bottom of the cup to the inner outer circumference

[0129] H1: The height difference between the upper and lower ends of the mold

[0130] H2: The height of the lower end of the mold.

Claims

1. A pouch-shaped battery case forming device, comprising: a punch configured to press the laminate to form a cup portion of a pouch-shaped battery case; a die configured to have the laminate disposed thereon, the die comprising a recess into which a punch is inserted; as well as a demolding device configured to fix the laminate while being located above the die, the demolding device being formed with a through hole through which the punch moves, wherein The mold includes an upper end and a lower end having different heights, and The upper end portion constitutes the inner side of the mold in the form of a quadrilateral frame on a plane, and the lower end portion constitutes the outer side of the mold.

2. The pouch-shaped battery case forming apparatus according to claim 1, wherein The demolding device has steps configured to be in close contact with the upper end portion and the lower end portion of the mold, and The demolding device includes an inner portion configured to be in close contact with the upper end portion of the mold and an outer portion configured to be in close contact with the lower end portion of the mold. 3 . The pouch-shaped battery case forming apparatus according to claim 1 , wherein the mold is configured so that the upper end portion and the lower end portion can individually and independently move up and down.

4. The pouch-shaped battery case forming apparatus according to claim 2, wherein forming a recess in a lower surface of the inner portion of the stripper, and The elastic member is added such that at least a portion of the elastic member is accommodated in the recess.

5. The pouch-shaped battery case forming apparatus according to claim 4, wherein The elastic member is a spring, The recesses are formed to be spaced apart from each other by a predetermined distance, and The spring is added such that at least a portion of the spring is accommodated in the recess.

6. The pouch-shaped battery case forming apparatus according to claim 5, wherein The recesses are formed to be spaced apart from each other by a predetermined distance along a quadrilateral line, and The quadrilateral line is composed of two lines that are spaced apart from each other.

7. The pouch-shaped battery case forming apparatus according to claim 4, wherein The elastic member is elastic rubber, The recess is in the form of a quadrilateral ring, and The elastic rubber is added so that at least a portion of the elastic rubber is accommodated in the recessed portion. 8 . The pouch-shaped battery case forming apparatus according to claim 7 , wherein the recessed portion is composed of two lines spaced apart from each other. 9 . The pouch-shaped battery case forming apparatus according to claim 1 , wherein the punch has a curved surface at a boundary where a lower surface as a pressing surface and a side surface meet each other. 10 . The pouch-shaped battery case forming apparatus of claim 1 , wherein the mold has a curved surface at a boundary where the upper end portion and an inner surface of the upper end portion meet each other.

11. The pouch-shaped battery case forming apparatus according to claim 4, wherein When the inner portion of the demolding device and the upper end portion of the mold are in close contact with each other, the entire elastic member is accommodated in the recess, and The elastic member brings the laminate into close contact with the upper end portion of the mold in a maximum compression state.

12. The pouch-shaped battery case forming apparatus according to claim 11, wherein: When the inner portion of the demolding tool and the upper end portion of the mold are in close contact with each other, the laminated sheet is stretched along the surface of the upper end portion of the mold.

13. A pouch-shaped battery case manufactured using the pouch-shaped battery case forming apparatus according to any one of claims 1 to 12, wherein The outer periphery of the cup portion includes an inner outer periphery and an outer outer periphery, and A height from the bottom of the cup portion to the inner outer periphery is greater than a height from the bottom of the cup portion to the outer outer periphery.

14. The pouch-shaped battery case according to claim 13, wherein the height from the bottom of the cup portion to the inner outer periphery is the sum of the height difference between the upper and lower ends of the mold of the pouch-shaped battery case forming equipment and the height of the lower end of the mold.

15. A method for forming a cup portion of a pouch-shaped battery case using the pouch-shaped battery case forming apparatus according to any one of claims 1 to 12, the method comprising: In the first step, the laminate is arranged between the mold and the demoulder, and the punch is arranged in the through hole of the demoulder; a second step of bringing the lower end portion of the mold and the outer portion of the demolding device into close contact with each other with the laminated sheet sandwiched therebetween, in a state in which the upper surfaces of the upper end portion and the lower end portion of the mold are at the same height; a third step of performing primary stretching on the laminated sheet during the process in which the upper end portion of the mold is moved upward so that the upper end portion of the mold and the inner portion of the demolding device are in close contact with each other with the laminated sheet sandwiched therebetween; as well as In the fourth step, the punch is moved downward while the laminate is initially stretched, so as to form the cup portion of the pouch-shaped battery cell while performing secondary stretching on the laminate. In the second step, the laminated sheet is fixed in position due to close contact between the lower end portion of the mold and the outer side portion of the demolding tool.

16. The method according to claim 15, wherein: In the third step, the laminated sheet is primarily stretched at a position where the upper end of the cup portion is to be formed.

17. The method according to claim 15, wherein: In the fourth step, the laminated sheet is fixed in position in a state where it is pressed toward the upper end portion of the mold due to the elastic force of the elastic member added to the lower surface of the inner portion of the demolding tool.

Images