Pouch-type battery case and forming device thereof

Abstract

The pouch-type battery case according to an embodiment of the present invention may include a pair of cases. At least one of the pair of cases may include a recessed cup portion, a terrace located around the cup portion where a seal portion is formed, and a protruding portion protruding from the terrace in a direction opposite to the depth direction of the cup portion. At least a part of the seal portion may be formed on the protruding portion.

Description

Technical Field

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0101639 filed on August 12, 2022, and Korean Patent Application No. 10-2023-0094872 filed on July 20, 2023, and all the contents disclosed in the documents of the Korean patent applications are incorporated herein by reference.

[0002] The present invention relates to a pouch-type battery case and a forming device for manufacturing the same.

Background Art

[0003] Generally, types of secondary batteries include nickel cadmium batteries, nickel hydrogen batteries, lithium ion batteries, lithium ion polymer batteries, and the like. Such secondary batteries are used not only in small products such as digital cameras, P-DVDs, MP3Ps, mobile phones, PDAs (registered trademarks), portable game devices, power tools, e-bikes, etc., but also in large products that require high power such as electric vehicles and hybrid vehicles, and in power storage devices for storing surplus generated power and new renewable energy, as well as backup power storage devices.

[0004] To manufacture such secondary batteries, first, an electrode active material slurry is applied to a positive electrode current collector and a negative electrode current collector to manufacture a positive electrode and a negative electrode, and by laminating them on both sides of a separator, an electrode assembly of a predetermined shape is formed. Then, the electrode assembly is housed in a battery case, electrolyte is injected, and then sealed.

[0005] Rechargeable batteries are classified into pouch type and can type depending on the material of the case that houses the electrode assembly. Pouch type batteries house the electrode assembly in a pouch made of a flexible polymer material. Can type batteries house the electrode assembly in a case made of a material such as metal or plastic.

[0006] Referring to Figure 1, generally, a pouch-type battery case 1 is manufactured by press-forming a flexible pouch sheet to form a cup portion 2. Once the cup portion 2 is formed, the electrode assembly is housed inside the cup portion 2 and the terrace 4 is sealed to manufacture a secondary battery. In such press-forming, drawing molding is performed by inserting the pouch sheet into a forming device such as a press and applying pressure to the pouch sheet with a punch to stretch it.

[0007] During the molding process of the cup portion 3, undulations 5 may occur around the cup portion 3 in the pouch sheet. In particular, these undulations 5 are noticeable near the corners 3 of the cup portion 2. Therefore, these undulations 5 may cause sealing defects in the pouch-type battery case 1. [Overview of the project] [Problems that the invention aims to solve]

[0008] One problem that the present invention aims to solve is to provide a pouch-type battery case in which the sealing quality is improved by a protrusion formed around the cup portion, and a forming apparatus for manufacturing the same. [Means for solving the problem]

[0009] An embodiment of the present invention may include a pair of cases. At least one of the pair of cases may include a cup portion formed by a recess, a terrace located around the cup portion where a sealing portion is formed, and a projection formed protruding from the terrace in the direction opposite to the depth direction of the cup portion. At least a portion of the sealing portion may be formed on the projection.

[0010] Each of the pair of cases may include the cup portion, the terrace, and the protrusion. One protrusion of the pair of cases may be in contact with the other protrusion to seal.

[0011] The protruding portion may extend along the sealing portion.

[0012] At least a portion of the protrusion may be located outside the corner of the cup portion.

[0013] The width of the protruding portion may be wider than the width of the sealing portion.

[0014] The side edges in the width direction of the sealing portion may be located inward from the side edges in the width direction of the protruding portion.

[0015] The protruding portion may include a first portion located on the outer side in the overall width direction of the cup portion, and a second portion connected to the first portion and located on the outer side in the overall length direction of the cup portion.

[0016] The first part may extend parallel to the entire length of the cup portion, and the second part may extend parallel to the entire width of the cup portion.

[0017] A forming apparatus according to an embodiment of the present invention may include a die having a forming recess formed therein, a punch positioned opposite the forming recess, a stripper positioned around the punch and opposite the die, a sub-forming recess formed in the stripper, a sub-punch protruding from the die and opposite the sub-forming recess, a pressurizing portion positioned within the sub-forming recess, and an elastic member that applies an elastic force toward the sub-punch to the pressurizing portion.

[0018] The sub-punch may be located outside the molding recess.

[0019] At least a portion of the sub-punch may be located outside the corner of the molding recess.

[0020] The sub-punch may include a first punch portion located on the outer side in the overall width direction of the molding recess, and a second punch portion connected to the first punch portion and located on the outer side in the overall length direction of the molding recess.

[0021] The first punch portion may extend parallel to the entire length of the molding recess, and the second punch portion may extend parallel to the entire width of the molding recess.

[0022] The sub-punch may further include a third punch portion located outside the first punch portion and forming a predetermined distance from the first punch portion, and a fourth punch portion connecting the third punch portion and the first punch portion.

[0023] The third punch portion may extend parallel to the first punch portion, and the fourth punch portion may extend parallel to the second punch portion.

[0024] The die may have a mounting recess formed therein, into which the sub-punch is mounted. [Effects of the Invention]

[0025] According to a preferred embodiment of the present invention, the protruding portion can prevent the pouch sheet from becoming wavy around the cup portion.

[0026] In addition, since the protruding portion protruding in the direction opposite to the cup portion is sealed, compared with the conventional battery case in which undulations occur around the cup portion on the terrace, the sealing reliability of the battery case is improved, and the risk of electrolyte leakage can be minimized.

[0027] The effects according to the present invention are not limited to the contents exemplified above, and more various effects are incorporated in this specification.

Brief Description of Drawings

[0028] [Figure 1] It is a figure which expands and shows the periphery of the corner of the cup part in the conventional pouch type battery case. [Figure 2] It is a schematic cross-sectional view of the forming device according to the first embodiment of the present invention. [Figure 3] It is a plan view of the die included in the forming device according to the first embodiment of the present invention. [Figure 4] It is a schematic view of the pouch type battery case formed by the forming device according to the first embodiment of the present invention. [Figure 5] It is a cross-sectional view taken along the line A-A' of FIG. 4. [Figure 6] It is a side view showing the sealed state of the pouch type battery case shown in FIG. 4. [Figure 7] It is a modification example of the pouch type battery case shown in FIG. 4. [Figure 8] It is a side view showing the folded state of the pouch type battery case shown in FIG. 7. [Figure 9] It is a plan view of the die included in the forming device according to the second embodiment of the present invention. [Figure 10] It is a schematic view of the pouch type battery case formed by the forming device according to the second embodiment of the present invention. [Figure 11] It is a plan view showing the sealed state of the pouch type battery case shown in FIG. 10. [Figure 12]This is a plan view of a die included in a forming apparatus according to a third embodiment of the present invention. [Figure 13] This is a schematic diagram of a pouch-type battery case formed by a forming apparatus according to a third embodiment of the present invention. [Figure 14] Figure 13 is a plan view showing the sealed pouch-type battery case. [Modes for carrying out the invention]

[0029] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings, so that they can be easily implemented by a person with ordinary skill in the art to which the present invention pertains. However, the present invention can be realized in a variety of different forms and is not limited to or restricted to the following embodiments.

[0030] In order to clearly explain the present invention, detailed descriptions of parts unrelated to the description or related prior art that may obscure the gist of the invention have been omitted. In this specification, when assigning reference numerals to components in each drawing, the same or similar reference numerals are assigned to components that are the same or similar throughout the specification.

[0031] Furthermore, the terms and words used in this specification and the claims should not be interpreted in a manner limited to their ordinary or dictionary meanings. Rather, based on the principle that inventors can appropriately define the concepts of terms in order to best describe their invention, they should be interpreted in a way that is consistent with the technical idea of ​​the present invention.

[0032] Figure 2 is a schematic cross-sectional view of a forming apparatus according to the first embodiment of the present invention, and Figure 3 is a plan view of a die included in the forming apparatus according to the first embodiment of the present invention.

[0033] A forming apparatus according to the first embodiment of the present invention can manufacture a pouch-type battery case 100 (see Figure 4) by forming a pouch sheet (not shown). The pouch sheet may be a sheet-like member in which multiple layers are laminated. For example, the pouch sheet may include a first resin layer (e.g., made of polypropylene) forming one surface, a second resin layer (e.g., made of polyethylene terephthalate) forming the other surface, and a metal layer (e.g., made of aluminum) located between the first and second resin layers. The pouch sheet may have flexibility and moldability. The pouch sheet can also be called a pouch film.

[0034] The forming apparatus may include a die 10 having a forming recess 11, a punch 20 positioned opposite the forming recess 11, a stripper 30 positioned around the punch 20 and facing the die 10, a sub-forming recess 40 formed in the stripper 30, and a sub-punch 50 protruding from the die 10 and facing the sub-forming recess 40.

[0035] The die 10 may have a substantially horizontal plate shape. When the pouch sheet is placed between the die 10 and the stripper 30, the top surface of the die 10 may face the bottom surface of the pouch sheet.

[0036] The die 10 may be bonded to the die back plate 10a.

[0037] The die 10 may have at least one molding recess 11 that is recessed downward from the top surface. The molding recess 11 may, but is not limited to, be formed to penetrate to the bottom surface of the die 10. The punch 20, which will be described later, is inserted into the molding recess 11 to pressurize the pouch sheet, thereby forming a cup portion 110 (see Figure 4) in the pouch sheet.

[0038] In this embodiment, the die 10 may have a pair of partitioned molding recesses 11. The pair of molding recesses 11 may be formed adjacent to each other, and the die 10 may be provided with a partition wall 12 located between the pair of molding recesses 11. When the pouch sheet is drawn-molded by simultaneously inserting the punch 20 (described later) into the pair of molding recesses 11, a pair of cup portions 110 are formed corresponding to the pair of molding recesses 11, and a bridge 130 corresponding to the partition wall 12 of the die 10 may be formed between such a pair of cup portions 110.

[0039] The stripper 30 may have a substantially horizontal plate shape. When the pouch sheet is placed between the die 10 and the stripper 30, the bottom surface of the stripper 30 may face the top surface of the pouch sheet. The stripper 30 can fix the pouch sheet together with the die 10.

[0040] The stripper 30 may have an opening that penetrates vertically, into which the punch 20 is positioned. In other words, the stripper 30 can surround the punch 20.

[0041] The stripper 30 may be coupled to the underside of the stripper backplate 30a. The stripper backplate 30a may have a sub-opening corresponding to the open portion of the stripper 30. Thus, the punch 20 can protrude above the stripper backplate 30a.

[0042] At least one of the stripper 30 and the die 10 may be configured to be vertically movable so that the distance between them can be changed. When the space between the stripper 30 and the die 10 is widened, the pouch sheet can enter between the stripper 30 and the die 10. When the pouch sheet is positioned between the stripper 30 and the die 10, the stripper 30 can descend toward the die 10 or the die 10 can rise toward the stripper 30. Thus, the pouch sheet can be fixed between the top surface of the die 10 and the bottom surface of the stripper 30.

[0043] The punch 20 may be positioned in the open portion of the stripper 30. If the pouch sheet is positioned between the die 10 and the stripper 30, the punch 20 may face the molding recess 11 formed in the die 10 via the pouch sheet. If a pair of molding recesses 11 are formed in the die 10, a pair of punches 20 may be provided correspondingly. The pair of punches 20 may be connected to or separated from each other.

[0044] When the die 10 and stripper 30 rise relative to the punch 20 with the pouch sheet fixed in place, the punch 20 is inserted into the molding recess 11 of the die 10 while applying pressure to the pouch sheet. Alternatively, when the die 10 and stripper 30 lower the punch 20 relative to the die 10 and stripper 30 with the pouch sheet fixed in place, the punch 20 is inserted into the molding recess 11 while applying pressure to the pouch sheet.

[0045] Therefore, in the pouch sheet, the portion pressed by the punch 20 and a part of its surrounding area are stretched, and the cup portion 110 (see Figure 4) is formed.

[0046] The sub-molding recess 40 may be formed in the stripper 30. More specifically, the sub-molding recess 40 may be formed as a depression above the bottom surface of the stripper 30. The sub-molding recess 40 may be formed to a predetermined depth and may penetrate the stripper 30.

[0047] The sub-forming recess 40 may be located outside the punch 20. That is, the sub-forming recess 40 may be located outside the opening formed in the stripper 30. The sub-punch 50, described later, is inserted into the sub-forming recess 40 to pressurize the pouch sheet, thereby forming a protrusion 140 (see Figure 4) on the pouch sheet.

[0048] The sub-punch 50 may protrude upward from the die 10. The sub-punch 50 may face a sub-forming recess 40 formed in the stripper 30.

[0049] The sub-punch 50 may be mounted on the die 10. For example, the die 10 may have a mounting recess 13 for mounting the sub-punch 50. However, it is not limited to this, and the sub-punch 50 may also be formed integrally with the die 10.

[0050] The sub-punch 50 may be located outside the molding recess 11.

[0051] Referring to Figure 3, the sub-punch 50 of the forming apparatus according to this embodiment may be located outside the corners of the forming recesses 11. Each forming recess 11 may be substantially rectangular in shape, and the parts corresponding to the vertices of the rectangular shape can be called the corners of the forming recesses 11. Those skilled in the art will easily understand that the corners of the forming recesses 11 may also be formed in a curved shape.

[0052] Multiple sub-punches 50 may be provided. As shown in Figure 3, the multiple sub-punches 50 may include a first sub-punch 50A located outside the corner of one molding recess 11 and a second sub-punch 50B located outside the corner of another molding recess 11.

[0053] Similarly, there may be multiple sub-forming recesses 40. A first sub-punch 50A may be inserted into some of the multiple sub-forming recesses 40, and a second sub-punch 50B may be inserted into other parts.

[0054] Multiple sub-punches 50 may be located on the opposite side of the partition wall 12 of the die 10. More specifically, of the four corners of each forming recess 11, one pair of inner corners may be defined by the partition wall 12, and one pair of outer corners may be located on the opposite side of the partition wall 12. Each sub-punch 50 may be located outside the outer corner of the forming recess 11. More specifically, the first sub-punch 50A may be located outside the outer corner of one forming recess 11, and the second sub-punch 50B may be located outside the outer corner of another forming recess 11. That is, there may be one pair each of the first sub-punches 50A and the second sub-punches 50B.

[0055] Each sub-punch 50 may have a shape that surrounds the corner of the molded recess 11. More specifically, each sub-punch 50 may include a first punch portion 51 and a second punch portion 52.

[0056] The first punch portion 51 may be located outside the molding recess 11 with respect to the overall width direction of the molding recess 11. The first punch portion 51 may extend parallel to the entire length of the molding recess 11.

[0057] The second punch portion 52 may be located outside the molding recess 11 with respect to the overall length of the molding recess 11. The second punch portion 52 may extend parallel to the entire width of the molding recess 11.

[0058] The first punch portion 51 and the second punch portion 52 may be connected.

[0059] On the upper surface of the die 10, the distance between the forming recess 11 and the sub-punch 50 may be approximately constant. More specifically, the distance in the overall width direction of the forming recess 11 between the first punch portion 51 and the forming recess 11 may correspond to the distance in the overall length direction of the forming recess 11 between the second punch portion 52 and the forming recess 11. However, it is not limited to this.

[0060] The shape of the sub-molding recess 40 may correspond to the shape of the sub-punch 50. When the sub-punch 50 is inserted into the sub-molding recess 40, a predetermined gap may be formed between the inner circumference of the sub-molding recess 40 and the outer circumference of the sub-punch 50 so that the pouch sheet can be easily stretched.

[0061] Therefore, in the pouch sheet, the portion pressed by the sub-punch 50 inserted into the sub-molding recess 40 and a part of its surrounding area are stretched, and a protrusion 140 (see Figure 4) is formed. The protrusion 140 prevents the pouch sheet from becoming wavy around the corners of the cup portion 110.

[0062] On the other hand, the forming apparatus may further include a pressurizing section 61 positioned within the sub-molding recess 40 and an elastic member 62 that applies elastic force to the pressurizing section 61.

[0063] The pressurizing portion 61 may have a shape corresponding to the sub-molding recess 40 and the sub-punch 50. The pressurizing portion 61 may be slidably disposed within the sub-molding recess 40.

[0064] The elastic member 62 may be placed inside the sub-molding recess 40. The elastic member 62 can apply an elastic force toward the sub-punch 50 to the pressurizing portion 61. For example, the elastic member 62 may be a spring.

[0065] Therefore, the pressurizing section 61 can apply a predetermined surface pressure to the pouch sheet stretched into the sub-insertion recess 40 by the sub-punch 50. As a result, uniform surface pressure is applied to the pouch sheet stretched into the sub-insertion recess 40, preventing the pouch sheet from becoming wavy.

[0066] Figure 4 is a schematic diagram of a pouch-type battery case formed by a forming apparatus according to the first embodiment of the present invention, Figure 5 is a cross-sectional view taken along line A-A' in Figure 4, and Figure 6 is a side view showing the sealed pouch-type battery case shown in Figure 4.

[0067] Hereinafter, a pouch-type battery case 100 manufactured by the forming apparatus according to the first embodiment will be described as an embodiment of the present invention.

[0068] The pouch-type battery case 100 (hereinafter referred to as "battery case") can house an electrode assembly (not shown) inside and may be formed by molding a pouch sheet. More specifically, the battery case 100 may be manufactured by a forming apparatus according to one embodiment of the present invention, in which a part of the pouch sheet is stretched to form a cup portion 110 and a protruding portion 140.

[0069] The battery case 100 may include a cup portion 110 formed in a curved shape, a terrace 120 located around the cup portion 110, and a projection 140 that protrudes from the terrace 120 in the direction opposite to the depth direction of the cup portion 110 and is located outside the cup portion 110.

[0070] More specifically, the battery case 100 may include a pair of cases 101 and 102, more specifically, a first case 101 and a second case 102, where at least one of the first case 101 and the second case 102 may include a cup portion 110, a terrace 120, and a protruding portion 140.

[0071] In the following description, the first case 101 and the second case 102 will be explained using the example of a case where one side is connected to the other, as shown in Figure 4. However, it goes without saying that the explanation is not limited to this, and it is also possible for the first case 101 and the second case 102 to be manufactured separately.

[0072] In this embodiment, each of the first case 101 and the second case 102 may include a cup portion 110, a terrace 120, and a protruding portion 140.

[0073] In other words, the battery case 100 may include a pair of cup portions 110. The battery case 100 may further include a bridge 130 located between the pair of cup portions 110.

[0074] The cup portion 110 can indent from the terrace 120 by a predetermined depth, forming a space in which an electrode assembly (not shown) can be housed. The electrode assembly can be housed in one of the cup portions 110, and then the bridge 130 can be folded so that a pair of cup portions 110 face each other. In this way, the other cup portion 110 can cover the electrode assembly from above. In this manner, the electrode assembly can be housed within a pair of cup portions 110.

[0075] Each cup portion 110 may be approximately rectangular in shape. The portion where the long side and short side of each cup portion 110 meet can be called the corner 111 of the cup portion 110. Those skilled in the art will easily understand that the corners 111 of the cup portion 110 may be formed in a curved shape.

[0076] The terrace 120 of the first case 101 and the terrace 120 of the second case 102 may be connected to each other on both sides of the bridge 130. When the bridge 130 is folded, the terraces 120 may also be folded together with it. More specifically, the portion where the terrace 120 of the first case 101 and the terrace 120 of the second case 102 are connected may be folded together with the bridge 130.

[0077] The protruding portion 140 may project from the terrace 120 in the opposite direction to the cup portion 110. For example, the cup portion 110 may curve downwards, and the protruding portion 140 may project upwards.

[0078] The protrusion 140 may be formed outside the cup portion 110. At least a portion of the protrusion 140 may be located outside the corner 111 of the cup portion 110.

[0079] In this embodiment, the protrusion 140 may be formed on the terrace 120 on the outside of the corner 111 of the cup portion 110.

[0080] The protrusions 140 may be multiple. The multiple protrusions 140 may include a first protrusion 140A located outside the corner 111 of one cup portion 110 and a second protrusion 140B located outside the corner 111 of another cup portion 110. That is, either the first protrusion 140A or the second protrusion 140B may be included in the first case 101, and the other may be included in the second case 102.

[0081] Each projection 140 may have a shape that surrounds the corner 111 of the cup portion 110. More specifically, each projection 140 may include a first portion 141 and a second portion 142.

[0082] The first part 141 may be located outside the cup portion 110 with respect to the overall width direction of the cup portion 110. The first part 141 may extend parallel to the entire length of the cup portion 110.

[0083] The second part 142 may be located outside the cup portion 110 with respect to the overall length of the cup portion 110. The second part 142 may extend parallel to the overall width of the cup portion 110.

[0084] Section 141 of Part 1 and Section 142 of Part 2 may be linked together.

[0085] On the terrace 120, the distance between the cup portion 110 and the protruding portion 140 may be substantially constant. More specifically, the distance in the width direction of the cup portion 110 between the first portion 141 and the cup portion 110 may correspond to the distance in the length direction of the cup portion 110 between the second portion 142 and the cup portion 110. However, it is not limited to this.

[0086] Multiple protrusions 140 may be located on the opposite side of the bridge 130. More specifically, of the four corners 111 of each cup portion 110, one pair of inner corners may be defined by the bridge 130, and one pair of outer corners 111 may be located on the opposite side of the bridge 130. Each protrusion 140 may be located outside the outer corner of the cup portion 110. More specifically, the first protrusion 140A may be located outside the outer corner of one cup portion 110, and the second protrusion 140B may be located outside the outer corner of another cup portion 110. That is, there may be one pair each of the first protrusion 140A and the second protrusion 140B.

[0087] On the other hand, although not shown in the drawings, a pair of first projections 140A may be formed to connect with each other. More specifically, the first portion 141 of the pair of first projections 140A may extend to connect with each other. Also, a pair of second projections 140B may be formed to connect with each other. More specifically, the first portion 141 of the pair of second projections 140B may extend to connect with each other.

[0088] Since the pouch sheet extends in opposite directions from the protruding portion 140 and the cup portion 110, it is possible to prevent undulation from occurring on the terrace 120 around the corner 111 of the cup portion 110.

[0089] When the bridge 130 is folded, the terraces 120 of the first case 101 and the terraces 120 of the second case 102 face each other and are sealed. The area where the terraces 120 of the first case 101 and the terraces 120 of the second case 102 are sealed can be defined as the seal portion 150. Such a seal portion 150 may extend along the perimeter of the cup portion 110. In this embodiment, when the first case 101 and the second case 102 are connected by the bridge 130, the seal portion 150 may be formed along three sides of the battery case 10. In contrast, when the first case 101 and the second case 102 are separated, the seal portion 150 may be formed along all four sides of the battery case 100.

[0090] At least a portion of the sealing portion 150 may be formed as a protruding portion 140.

[0091] In other words, the protrusion 140 may be sealed. In this embodiment, if each of a pair of cases 101 and 102 includes a protrusion 140, the protrusion 140A of one of the cases 101 and 102 and the other protrusion 140B may be in contact and sealed. In other words, the first protrusion 140A and the second protrusion 140B may be in contact and sealed. More specifically, the sealing portion 150 of the battery case 100 may be formed to pass through the portion where the first protrusion 140A and the second protrusion 140B are in contact.

[0092] The width W1 of the protrusion 140 may be wider than the width W2 of the sealing portion 150. More specifically, the side edges in the width direction of the sealing portion 150 may be located inward from the side edges in the width direction of the protrusion 140. That is, the sealing tool for sealing the battery case 100 may press on the inside of the protrusion 140 rather than on both sides in the width direction of the protrusion 140. This allows for the maintenance of high sealing quality.

[0093] A sealing tool (not shown) for sealing the battery case 100 may press both the protrusion 140 and the portion of the terrace 120 where the protrusion 140 is not formed (in this embodiment, the portion around the cup portion excluding the area around the corner of the cup portion) to form the sealing portion 150. The protrusion 140 may protrude from the terrace 120 to a height that does not hinder the formation of the sealing portion 150. Therefore, when the first protrusion 140A and the second protrusion 140B come into contact, the terrace 120 of the first case 101 and the terrace 120 of the second case 102 will also come into contact with or be adjacent to each other, and the sealing portion 150 can be easily formed.

[0094] Since the protrusion 140 is sealed in this way, the sealing reliability of the battery case 100 is improved compared to conventional battery cases where undulation occurs around the cup portion on the terrace, and the risk of electrolyte leakage can be minimized.

[0095] In particular, as in this embodiment, when the protrusions 140 are formed only around the corners 111 of the cup portion 110, there is an advantage in that the amount of stretching of the pouch sheet that is stretched into the molding recess 11 of the die 10 during the molding of the cup portion 110 becomes uniform. Also, if there are no protrusions 140 on the terrace 120, undulations will occur concentrated around the corners of the cup portion 110, so such undulations can be effectively removed.

[0096] Furthermore, since the bridge 130 is foldable, it does not require a separate seal. If a protrusion 140 were formed on the inner corner 111 side of the cup portion 110 adjacent to the bridge 130, the bridge 130 would become thicker, which could reduce the energy density and appearance quality of the battery case 100. In other words, by having multiple protrusions 140 located on the opposite side of the bridge 130, it is possible to improve seal reliability while maintaining high energy density and appearance quality of the battery case 100.

[0097] Figure 7 shows a modified version of the pouch-type battery case shown in Figure 4, and Figure 8 is a side view showing the pouch-type battery case shown in Figure 7 in a folded state.

[0098] The following explanation will omit any content that overlaps with what was mentioned above and will focus on the differences.

[0099] The pouch-type battery case may include the cup portion 110, terrace 120, and protrusion 140 in only one of the first case 101 and the second case 102. That is, the battery case 100 may include a single cup portion 110.

[0100] Multiple protrusions 140 may be formed at the four corners 111 of the cup portion 110. That is, the first case 101 or the second case 102 may include four protrusions 140. On the other hand, although not shown in the drawings, at least a portion of the four protrusions 140 may be formed to connect with each other. More specifically, at least a portion of the four protrusions 140, the first portion 141 and / or the second portion 142, may extend to connect with each other.

[0101] When the first case 101 and the second case 102 are connected, the first case 101 and the second case 102 may be separated by a folding line 130'. The following explanation will be given using the case where the second case 102 includes a cup portion 110, a terrace 120, and a protruding portion 140 as an example.

[0102] An electrode assembly (not shown) is housed in the cup portion 110 formed in the second case 102, and then the folding line 130' can be folded so that the first case 101 covers the cup portion 110.

[0103] When the folding line 130' is folded, the terrace 120 of the second case 102 and the first case 101 face each other and are sealed. The area where the terrace 120 of the second case 102 and the first case 102 are sealed can be defined as the sealed portion 150.

[0104] The protrusion 140 of the second case 102 may abut against the first case 101 and be sealed. More specifically, the sealing portion 150 may be formed to pass through the portion where the protrusion 140 of the second case 102 and the first case 101 abut.

[0105] On the other hand, since the folding line 130' is folded, it does not require a separate seal. Therefore, in order to form the folding line 130' as close as possible to the cup portion 110, an embodiment is also possible in which the protrusion 140 is formed on the opposite side of the folding line 130'.

[0106] In other words, unlike the illustration in Figure 7, the first case 101 or the second case 102 may include a pair of protrusions 140 located on the outer corner side of the cup portion 110, but may not include a pair of protrusions located on the inner corner side of the cup portion 110.

[0107] Figure 9 is a plan view of a die included in a forming apparatus according to a second embodiment of the present invention.

[0108] The sub-punch 50 protruding from the die 10 of the forming apparatus in this embodiment may be located outside the forming recess 11. More specifically, the sub-punch 50 may extend along the periphery of the forming recess 11.

[0109] At least a portion of the sub-punch 50 may be located outside the corner of the molding recess 11.

[0110] The sub-punch 50 may include a first punch portion 51 extending parallel to the entire length of the molding recess 11 and a second punch portion 52 extending parallel to the entire width of the molding recess 11.

[0111] The sub-punch 50 may form a single closed loop surrounding a pair of forming recesses 11. More specifically, the first punch portion 51 and the second punch portion 52 may form a single closed loop.

[0112] If a single molding recess 11 is formed in the die 10, the sub-punch 50 may form a single closed loop surrounding the single molding recess 11.

[0113] However, it is not limited to this; the sub-punch 50 can also be formed to extend along the closed loop, but with some sections being cut off.

[0114] On the other hand, those skilled in the art will easily understand that the stripper 30 of the forming apparatus according to this embodiment has a sub-forming recess 40 that corresponds to the sub-punch 50.

[0115] Figure 10 is a schematic diagram of a pouch-type battery case formed by a forming apparatus according to a second embodiment of the present invention, and Figure 11 is a plan view showing the pouch-type battery case shown in Figure 10 in a sealed state.

[0116] In the following description, a pouch-type battery case 100 manufactured by the forming apparatus according to the second embodiment will be described as an embodiment of the present invention. While some information overlaps with what has been described above, the explanation will focus primarily on the differences.

[0117] The protrusion 140 may be formed by the sub-punch 50 of the die 10. The protrusion 140 may have a shape corresponding to the sub-punch 50 of the die 10.

[0118] The protrusion 140 may be formed outside the cup portion 110. The protrusion 140 may extend along the seal portion 150. That is, the protrusion 140 may be formed in an area that is to be later sealed to the terrace 120.

[0119] The protrusion 140 may have a shape that surrounds the cup portion 110. More specifically, the protrusion 140 may include a first portion 141 extending parallel to the entire length of the cup portion 110 and a second portion 142 extending parallel to the entire width of the cup portion 110.

[0120] With the pouch-type battery case 100 open, the protrusion 140 may form a single closed loop surrounding a pair of cup portions 110. If a single cup portion 110 is formed on the die 10, the sub-punch 50 may form a single closed loop surrounding the single cup portion 110. However, it is not limited to this, and the protrusion 140 may be formed to extend along the closed loop, but with some sections being cut off.

[0121] Any part of the protrusion 140 may be located outside one cup portion 110, and any other part may be located outside another cup portion 110. That is, any part of the protrusion 140 may be included in the first case 101, and any other part may be included in the second case 102. The protrusion 140 included in the first case 101 and the protrusion 140 included in the second case 102 may be symmetrical in shape.

[0122] As shown in Figure 11, when the bridge 130 is folded, the protrusions 140 of the first case 101 and the protrusions 140 of the second case 102 face each other and are sealed to form a seal portion 150. Such a seal portion 150 may extend along the periphery of the cup portion 110. In this embodiment, when the first case 101 and the second case 102 are connected by the bridge 130, the seal portion 150 may be formed along three sides of the battery case 10. In contrast, when the first case 101 and the second case 102 are separated, the seal portion 150 may be formed along all four sides of the battery case 100.

[0123] At least a portion of the sealing portion 150 may be formed on the protruding portion 140. In this embodiment, the sealing portion 150 may be formed on the protruding portion 140. A sealing tool (not shown) for sealing the battery case 100 can pressurize the protruding portion 140 to form the sealing portion 150.

[0124] More specifically, the seal portion 150 may include a first seal portion 151 formed along the second portion 142 and a second seal portion 152 formed along the first portion 141. The first seal portion 151 may be formed on the second portion 142, and the second seal portion 152 may be formed on the first portion 141.

[0125] Because the protrusion 140 is sealed in this way, the sealing reliability of the battery case 100 is improved compared to conventional battery cases where undulation occurs around the corners of the cup portion, and the risk of electrolyte leakage can be minimized.

[0126] In particular, when the protrusion 140 extends along the sealing portion 150, as in this embodiment, there is the advantage that the overall sealing quality of the sealing portion 150 is further improved.

[0127] Figure 12 is a plan view of a die included in a forming apparatus according to a third embodiment of the present invention.

[0128] The sub-punch 50 protruding from the die 10 of the forming apparatus according to this embodiment may further include a third punch portion 53 located outside the first punch portion 51, and a fourth punch portion 54 connecting the third punch portion 53 and the first punch portion 51.

[0129] The third punch portion 53 may form a predetermined distance from the first punch portion 51. In the pouch-type battery case 100, the portion corresponding to the aforementioned distance can function as a gas pocket.

[0130] The third punch portion 53 may extend parallel to the first punch portion 51. That is, the third punch portion 53 may be parallel to the entire length of the molded recess 11.

[0131] The fourth punch portion 54 may extend from the second punch portion 52. That is, the fourth punch portion 54 may be located on the same line as the second punch portion 52.

[0132] The first punch portion 51 and the second punch portion 52 may form a closed loop surrounding the molded recess 11. The first punch portion 51, the third punch portion 53, and the fourth punch portion 54 may form other closed loops.

[0133] On the other hand, those skilled in the art will easily understand that the stripper 30 of the forming apparatus according to this embodiment has a sub-forming recess 40 that corresponds to the sub-punch 50.

[0134] Figure 13 is a schematic diagram of a pouch-type battery case formed by a forming apparatus according to the third embodiment of the present invention, and Figure 14 is a plan view showing the sealed pouch-type battery case shown in Figure 13.

[0135] In the following description, a pouch-type battery case 100 manufactured by the forming apparatus according to the third embodiment will be described as an embodiment of the present invention. While some information overlaps with what has been described above, the explanation will focus primarily on the differences.

[0136] The protrusion 140 may be formed by the sub-punch 50 of the die 10. The protrusion 140 may have a shape corresponding to the sub-punch 50 of the die 10.

[0137] The protrusion 140 may be formed outside the cup portion 110. The protrusion 140 may extend along the seal portion 150. That is, the protrusion 140 may be formed in an area that is to be later sealed to the terrace 120.

[0138] The protrusion 140 may have a shape that surrounds the cup portion 110. More specifically, the protrusion 140 may include a first portion 141 extending parallel to the entire length of the cup portion 110 and a second portion 142 extending parallel to the entire width of the cup portion 110. The protrusion 140 may further include a third portion 143 parallel to the first portion 141 and a fourth portion 144 connecting the first portion 141 and the third portion 143.

[0139] Part 1 141 and Part 3 143 may be formed at predetermined intervals. Part 4 144 may extend from Part 2 142.

[0140] With the pouch-type battery case 100 open, the first part 141 and the second part 142 may form a closed loop surrounding the cup part 110, and the first part 141, the third part 143, and the fourth part 144 may form other closed loops.

[0141] As shown in Figure 14, when the bridge 130 is folded, the protrusion 140 of the first case 101 and the protrusion 140 of the second case 102 face each other and are sealed to form a seal portion 150.

[0142] In this embodiment, the sealing portion 150 may be formed on the protruding portion 140. A sealing tool (not shown) for sealing the battery case 100 can pressurize the protruding portion 140 to form the sealing portion 150.

[0143] More specifically, the seal portion 150 may include a first seal portion 151 formed along the second portion 142 and the fourth portion 144, a second seal portion 152 formed along the first portion 141, and a third seal portion 153 formed along the third portion 143. The first seal portion 151 may be formed on the second portion 142 and the fourth portion 144, the second seal portion 152 may be formed on the first portion 141, and the third seal portion 153 may be formed on the third portion 143.

[0144] The following is a brief explanation of each seal section.

[0145] The first seal portion 151 may be formed first with the bridge 130 folded. In that case, the first case 101 and the second case 102 can form an envelope shape with one end open. The electrolyte can be injected into the cup portion 110 from the open end.

[0146] Subsequently, the open end may be sealed to form a third seal portion 153. The portion between the cup portion 110 and the third seal portion 153 can be defined as a gas pocket portion 160. Gas generated when the electrode assembly inside the pouch-type battery case 100 is activated can be collected in the gas pocket portion 160. Then, a degassing process may be performed to discharge the gas by punching holes in the gas pocket portion 160.

[0147] Subsequently, a second seal portion 152 may be formed. The second seal portion 152 may be formed adjacent to the cup portion 110. The terrace 120 may be cut along a cut line CL located outside the second seal portion 152. That is, the portion located outside the cut line CL may be removed. In this way, when all seal portions 150 involved in the manufacturing process are formed on the protrusion 140, there is the advantage that the overall seal quality of the seal portions 150 is further improved.

[0148] The above description is merely illustrative of the technical concept of the present invention, and any person with ordinary skill in the art to which the present invention belongs could make various modifications and alterations without departing from the essential characteristics of the present invention.

[0149] Therefore, the embodiments disclosed in this invention are for illustrative purposes only, and not to limit the technical concept of the invention, and the scope of the technical concept of the invention is not limited by such embodiments.

[0150] The scope of protection of this invention should be interpreted in accordance with the appended claims, and all technical ideas equivalent thereto should be interpreted as being included within the scope of the rights of this invention. [Explanation of Symbols]

[0151] 10 Dies 11 Molded recess 13 Mounting recess 20 punches 30 Strippers 40 Sub-molding recess 50 Subpunch 61 Pressurized section 62 Elastic members 100 pouch-type battery cases 110 cup section 111 (Cup section) corner 120 Terrace 130 Bridge 140 Protrusion 141 Part 1 142 Part 2 143 Part 3 144 Part 4 150 sealing part 160 Gas pocket section

Claims

1. In a pouch-type battery case including a pair of cases, At least one of the aforementioned pair of cases is The cup portion formed by the indentation, A terrace located around the cup portion, where a sealing portion is formed, It includes a projection formed by projecting from the terrace in the direction opposite to the depth direction of the cup portion, At least a portion of the sealing portion is formed on the protruding portion, A pouch-type battery case in which the width of the protruding portion is wider than the width of the sealing portion.

2. Each of the pair of cases includes the cup portion, the terrace, and the protruding portion, The pouch-type battery case according to claim 1, wherein one of the protruding parts of the pair of cases and the other protruding part are in contact and sealed.

3. The pouch-type battery case according to claim 1, wherein the protruding portion extends along the sealing portion.

4. The pouch-type battery case according to claim 1, wherein at least a portion of the protrusion is located outside the corner of the cup portion.

5. The pouch-type battery case according to claim 1, wherein both side edges in the width direction of the sealing portion are located inward from both side edges in the width direction of the protruding portion.

6. The aforementioned protrusion is The first part located on the outer side in the overall width direction of the cup portion, A pouch-type battery case according to any one of claims 1 to 5, comprising a second part connected to the first part and located on the outer side in the overall length direction of the cup part.

7. The pouch-type battery case according to claim 6, wherein the first part extends parallel to the total length of the cup portion, and the second part extends parallel to the total width of the cup portion.

8. A die in which a molding recess is formed, A punch positioned opposite the aforementioned molding recess, A stripper positioned around the punch and facing the die, The stripper has a sub-molding recess formed therein, A sub-punch protruding from the die and facing the sub-forming recess, A pressurizing portion disposed within the sub-molding recess, The system includes an elastic member that applies an elastic force toward the sub-punch to the pressurizing portion, A forming apparatus for manufacturing a pouch-type battery case as described in claim 1.

9. The forming apparatus according to claim 8, wherein the sub-punch is located outside the forming recess.

10. The forming apparatus according to claim 9, wherein at least a portion of the sub-punch is located outside the corner of the forming recess.

11. The aforementioned subpunch is A first punch portion located on the outer side in the overall width direction of the molded recess, The forming apparatus according to claim 8, further comprising a second punch portion connected to the first punch portion and located on the outer side in the overall length direction of the forming recess.

12. The first punch portion extends parallel to the entire length of the molding recess, The forming apparatus according to claim 11, wherein the second punch portion extends parallel to the entire width of the forming recess.

13. The aforementioned subpunch is A third punch portion is located outside the first punch portion and forms a predetermined distance from the first punch portion, The forming apparatus according to claim 11, further comprising a fourth punch portion connecting the third punch portion and the first punch portion.

14. The forming apparatus according to claim 13, wherein the third punch portion extends parallel to the first punch portion, and the fourth punch portion extends parallel to the second punch portion.

15. The forming apparatus according to any one of claims 8 to 14, wherein the die has a mounting recess formed therein for mounting the sub-punch.

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