Pouch-type battery case and its forming device

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 in their entirety.

[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-metal hydride 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, as well as in power storage devices for storing surplus generated power and newly renewable energy and 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, an electrolyte is injected, and then sealed.

[0005] Secondary batteries are classified into pouch type, can type, etc. according to the material of the case that houses the electrode assembly. The pouch type houses the electrode assembly in a pouch made of a flexible polymer material. Also, the can type houses the electrode assembly in a case made of a material such as metal or plastic.

[0006] Referring to FIG. 1, generally, the pouch-type battery case 1 is manufactured by performing press working on a flexible pouch sheet to form the cup portion 2. Then, when the cup portion 2 is formed, the secondary battery is manufactured by housing the electrode assembly inside the cup portion 2 and sealing the terrace 4. In such press working, the drawing forming is performed by inserting the pouch sheet into a forming device such as a press equipment and applying pressure to the pouch sheet with a punch to stretch the pouch sheet.

[0007] During the forming process of the cup portion 3, undulations 5 may occur around the cup portion 3 in the pouch sheet. In particular, such undulations 5 are prominent near the corner 3 of the cup portion 2. Therefore, due to the undulations 5, there is a risk of seal failure in the pouch-type battery case 1.

Summary of the Invention

Problems to be Solved by the Invention

[0008] One problem to be solved by the present invention is to provide a pouch-type battery case in which the sealing quality is improved by a protruding portion formed around the cup portion, and a forming device for manufacturing the same.

Means for Solving the Problems

[0009] 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 in a direction opposite to the depth direction of the cup portion from the terrace. At least a part of the seal portion may be formed on the protruding portion.

[0010] Each of the pair of cases may include the cup portion, the terrace, and the protruding portion. The protruding portion of any one of the pair of cases and the protruding portion of the other one may be in contact and sealed.

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

[0012] At least a part of the protruding portion 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 seal portion.

[0014] Both side edges in the width direction of the seal portion may be located inside both side edges in the width direction of the protruding portion.

[0015] The protruding portion may include a first portion located outside the entire width direction of the cup portion and a second portion connected to the first portion and located outside the entire length direction of the cup portion.

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

[0017] According to an embodiment of the present invention, a forming device may include a die in which a forming recess is formed, a punch disposed to face the forming recess, a stripper positioned around the punch and facing the die, a sub-forming recess formed in the stripper, a sub-punch protruding from the die and facing the sub-forming recess, a pressing portion disposed in the sub-forming recess, and an elastic member that applies an elastic force toward the sub-punch to the pressing portion.

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

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

[0020] The sub-punch may include a first punch portion located outside the entire width direction of the forming recess and a second punch portion connected to the first punch portion and located outside the entire length direction of the forming recess.

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

[0022] The sub-punch may further include a third punch portion located outside the first punch portion and forming a predetermined interval 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] A mounting recess for mounting the sub-punch may be formed in the die.

Advantages of the Invention

[0025] According to a preferred embodiment of the present invention, it is possible to prevent the occurrence of undulations in the pouch sheet around the cup portion due to the protruding 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 the Drawings

[0028]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Embodiments for Carrying Out the Invention

[0029] Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in detail so that those having ordinary knowledge in the technical field to which the present invention pertains can easily implement it. However, the present invention can be realized in various different forms and is not limited or restricted to the following embodiments.

[0030] To clearly explain the present invention, detailed descriptions of parts not related to the explanation or related known technologies that may obscure the gist of the present invention are omitted. When attaching reference numerals to the components of each drawing in this specification, the same or similar reference numerals are attached to the same or similar components throughout the specification.

[0031] Note that the terms and words used in this specification and the claims should not be construed as being limited to their ordinary or dictionary meanings. Based on the principle that the inventor can appropriately define the concept of the terms in order to explain his invention in the best possible way, they should be construed as meanings and concepts consistent with the technical idea of the present invention.

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

[0033] The forming apparatus according to the first embodiment of the present invention can form a pouch sheet (not shown) to manufacture a pouch-type battery case 100 (see FIG. 4). The pouch sheet may be a sheet-like member formed by laminating multiple layers. For example, the pouch sheet may include a first resin layer (e.g., made of polypropylene) forming one side, a second resin layer (e.g., made of polyethylene terephthalate) forming the other side, and a metal layer (e.g., made of aluminum) located between the first and second resin layers. The pouch sheet may be flexible and formable. The pouch sheet may also be referred to as a pouch film.

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

[0035] The die 10 may have a generally 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 onto a die back plate 10a.

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

[0038] In the die 10 according to the present embodiment, a pair of partitioned molding recesses 11 may be formed. 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 punch 20 described later is simultaneously inserted into the pair of molding recesses 11 to perform a drawing molding of the pouch sheet, 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 disposed between the die 10 and the stripper 30, the bottom surface of the stripper 30 may face the upper surface of the pouch sheet. The stripper 30 can fix the pouch sheet together with the die 10.

[0040] An opening may be formed in the stripper 30 that penetrates vertically and in which the punch 20 is disposed. That is, the stripper 30 can surround the punch 20.

[0041] The stripper 30 may be coupled to the lower side of the stripper back plate 30a. A sub-opening corresponding to the opening of the stripper 30 may be formed in the stripper back plate 30a. Therefore, the punch 20 can protrude above the stripper back plate 30a.

[0042] At least one of the stripper 30 and the die 10 may be configured to be movable up and down so that the distance between them can be changed. In a state where 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. In a state where the pouch sheet is located between the stripper 30 and the die 10, the stripper 30 can descend toward the die 10, or the die 10 can ascend toward the stripper 30. Therefore, the pouch sheet can be fixed between the upper surface of the die 10 and the bottom surface of the stripper 30.

[0043] The punch 20 may be disposed in the opening of the stripper 30. When the pouch sheet is disposed between the die 10 and the stripper 30, the punch 20 may face the forming recess 11 formed in the die 10 through the pouch sheet. When a pair of forming recesses 11 are formed in the die 10, correspondingly, a pair of punches 20 may also be provided. The pair of punches 20 may be connected or separated from each other.

[0044] When the die 10 and the stripper 30 rise with respect to the punch 20 while fixing the pouch sheet, the punch 20 is inserted into the forming recess 11 of the die 10 while pressing the pouch sheet. Alternatively, when the punch 20 descends with respect to the die 10 and the stripper 30 while fixing the pouch sheet, the punch 20 is inserted into the forming recess 11 while pressing the pouch sheet.

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

[0046] The sub-forming recess 40 may be formed in the stripper 30. More specifically, the sub-forming recess 40 may be formed to be recessed upward from the bottom surface of the stripper 30. The sub-forming recess 40 may be formed to have a predetermined depth and may be formed through 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 press the pouch sheet, whereby a protruding portion 140 (see FIG. 4) is formed in the pouch sheet.

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

[0049] The sub-punch 50 may be attached to the die 10. For example, the die 10 may be formed with a mounting recess 13 to which the sub-punch 50 is attached. However, it is not limited thereto, and the sub-punch 50 may be integrally formed with the die 10.

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

[0051] Referring to FIG. 3, the sub-punch 50 of the forming device according to the present embodiment may be located outside the corner of the forming recess 11. Each forming recess 11 may be substantially square-shaped, and the portion corresponding to the vertex of the square shape may be referred to as the corner of the forming recess 11. Those skilled in the art will easily understand that the corner of the forming recess 11 may be formed in a curved shape.

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

[0053] Similarly, a plurality of sub-forming recesses 40 may be provided. The first sub-punch 50A may be inserted into a part of the plurality of sub-forming recesses 40, and the second sub-punch 50B may be inserted into another part thereof.

[0054] The plurality of sub-punches 50 may be located on the opposite side of the partition wall 12 of the die 10. More specifically, among the four corners of each forming recess 11, a pair of inner corners may be defined by the partition wall 12, and a 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, a pair of the first sub-punches 50A and the second sub-punches 50B may be provided respectively.

[0055] Each sub-punch 50 may have a shape surrounding the corner of the forming 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 forming recess 11 with respect to the entire width direction of the forming recess 11. The first punch portion 51 may extend parallel to the entire length of the forming recess 11.

[0057] The second punch portion 52 may be located outside the forming recess 11 with respect to the entire length direction of the forming recess 11. The second punch portion 52 may extend parallel to the entire width of the forming 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 substantially constant. More specifically, the distance in the entire 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 entire length direction of the forming recess 11 between the second punch portion 52 and the forming recess 11. However, it is not limited thereto.

[0060] The shape of the sub-forming recess 40 may correspond to the shape of the sub-punch 50. When the sub-punch 50 is inserted into the sub-forming recess 40, a predetermined interval may be formed between the inner circumference of the sub-forming 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-forming recess 40 and a part of the periphery thereof are stretched, and the protrusion 140 (see FIG. 4) is formed. The protrusion 140 can prevent the occurrence of undulation in the pouch sheet around the corner of the cup portion 110.

[0062] On the other hand, the forming device may further include a pressing portion 61 disposed in the sub-forming recess 40 and an elastic member 62 that applies an elastic force to the pressing portion 61.

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

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

[0065] Therefore, the pressing portion 61 can apply a predetermined surface pressure to the pouch sheet extended into the sub-insertion recess 40 by the sub-punch 50. Therefore, a uniform surface pressure can be applied to the pouch sheet extended in the sub-insertion recess 40, and it is possible to prevent the pouch sheet from being warped.

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

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

[0068] The pouch-type battery case 100 (hereinafter, "battery case") can accommodate an electrode assembly (not shown) therein and may be formed by molding a pouch sheet. More specifically, when a forming device according to an embodiment of the present invention performs a drawing molding on the pouch sheet, a part thereof is extended to form a cup portion 110 and a protruding portion 140, so that the battery case 100 may be manufactured.

[0069] The battery case 100 may include a recessed cup portion 110, a terrace 120 positioned around the cup portion 110, and a protruding portion 140 protruding from the terrace 120 in a direction opposite to the depth direction of the cup portion 110 and located outside the cup portion 110.

[0070] More specifically, the battery case 100 may include a pair of cases 101, 102, and more specifically, a first case 101 and a second case 102, and 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] Hereinafter, the case where one side of the first case 101 and the second case 102 are connected to each other as shown in FIG. 4 will be described as an example. However, it is needless to say that the present invention is not limited thereto, and the first case 101 and the second case 102 may be separated and manufactured separately.

[0072] In the case of the present 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] That is, the battery case 100 may include a pair of cup portions 110. The battery case 100 may further include a bridge 130 positioned between the pair of cup portions 110.

[0074] The cup portion 110 may be recessed from the terrace 120 by a predetermined depth to form a space for accommodating an electrode assembly (not shown). The electrode assembly may be accommodated in one of the cup portions 110, and then the bridge 130 may be folded so that the pair of cup portions 110 face each other. Then, the other cup portion 110 may cover the electrode assembly from above. By doing so, the electrode assembly can be accommodated within the pair of cup portions 110.

[0075] Each cup portion 110 may be substantially quadrilateral. The portion where the long side and the short side of each cup portion 110 are in contact can be referred to as the corner 111 of the cup portion 110. A person skilled in the art will easily understand that the corner 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. 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 protrude from the terrace 120 in a direction opposite to the cup portion 110. For example, the cup portion 110 may be recessed downward, and the protruding portion 140 may protrude upward.

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

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

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

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

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

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

[0084] The first part 141 and the second part 142 may be connected.

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

[0086] The plurality of protruding parts 140 may be located on the opposite side of the bridge 130. More specifically, among the four corners 111 of each cup part 110, a pair of inner corners may be defined by the bridge 130, and a pair of outer corners 111 may be located on the opposite side of the bridge 130. Each protruding part 140 may be located outside the outer corner of the cup part 110. More specifically, the first protruding part 140A may be located outside the outer corner of one cup part 110, and the second protruding part 140B may be located outside the outer corner of the other cup part 110. That is, a pair of the first protruding part 140A and the second protruding part 140B may be provided respectively.

[0087] On the other hand, although not shown in the drawings, a pair of the first protruding parts 140A may be formed to be connected to each other. More specifically, the first parts 141 of the pair of the first protruding parts 140A may extend long so as to be connected to each other. Also, a pair of the second protruding parts 140B may be formed to be connected to each other. More specifically, the first parts 141 of the pair of the second protruding parts 140B may extend long so as to be connected to each other.

[0088] Since the pouch sheet extends from the protrusion 140 and the cup portion 110 in opposite directions from each other, it is possible to prevent a bulge from occurring in the terrace 120 around the corner 111 of the cup portion 110.

[0089] When the bridge 130 is folded, the terrace 120 of the first case 101 and the terrace 120 of the second case 102 face each other and are sealed. The region where the terrace 120 of the first case 101 and the terrace 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 periphery of the cup portion 110. As 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. On the other hand, when the first case 101 and the second case 102 are separated, the seal portion 150 may be formed along four sides of the battery case 100.

[0090] At least a part of the seal portion 150 may be formed on the protrusion 140.

[0091] That is, the protrusion 140 may be sealed. As in this embodiment, when each of the pair of cases 101 and 102 includes the protrusion 140, the protrusion 140A of one of the pair of cases 101 and 102 and the other protrusion 140B may be sealed in contact with each other. That is, the first protrusion 140A and the second protrusion 140B may be sealed in contact with each other. More specifically, the seal portion 150 of the battery case 100 may be formed so as to pass through the portion where the first protrusion 140A and the second protrusion 140B are in contact with each other.

[0092] The width W1 of the protruding portion 140 may be wider than the width W2 of the sealing portion 150. More specifically, both side edges in the width direction of the sealing portion 150 may be located inside both side edges in the width direction of the protruding portion 140. That is, instead of pressing both sides in the width direction of the protruding portion 140, the inside of the protruding portion 140 may be pressed for sealing. Thereby, high sealing quality can be maintained.

[0093] A sealing tool (not shown) for sealing the battery case 100 may form the sealing portion 150 by pressing both the protruding portion 140 and a portion where the protruding portion 140 is not formed on the terrace 120 (in the case of this embodiment, a portion excluding the periphery of the corner of the cup portion around the cup portion). The protruding portion 140 may protrude from the terrace 120 at a height that does not inhibit the formation of the sealing portion 150. Therefore, when the first protruding portion 140A and the second protruding portion 140B are in contact, the terraces 120 of the first case 101 and the second case 102 will also be in contact or adjacent to each other, and the sealing portion 150 can be easily formed.

[0094] Since the protruding portion 140 is sealed in this way, compared with the conventional battery case in which undulations occur around the cup portion on the terrace, the sealing reliability of the battery case 100 is improved, and the risk of electrolyte leakage can be minimized.

[0095] In particular, when the protruding portion 140 is formed only around the corner 111 of the cup portion 110 as in this embodiment, there is an advantage that the stretching amount of the pouch sheet extending into the forming recess 11 of the die 10 becomes uniform when the cup portion 110 is formed. Also, when there is no protruding portion 140 on the terrace 120, undulations occur intensively around the corner of the cup portion 110, so such undulations can be effectively removed.

[0096] In addition, since the bridge 130 is folded, it does not require another seal. If a protrusion 140 is formed on the inner corner 111 side of the cup part 110 adjacent to the bridge 130, the bridge 130 becomes thick, which may reduce the energy density and appearance quality of the battery case 100. That is, by positioning a plurality of protrusions 140 on the opposite side of the bridge 130, the seal reliability can be improved while maintaining the high energy density and appearance quality of the battery case 100.

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

[0098] Hereinafter, the content overlapping with the above-described content will be omitted, and the description will focus on the differences.

[0099] The pouch-type battery case may include the cup part 110, the terrace 120, and the 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 part 110.

[0100] The plurality of protrusions 140 may be formed at the four corners 111 of the cup part 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 part of the four protrusions 140 may be formed to be connected to each other. More specifically, the first part 141 and / or the second part 142 of at least a part of the four protrusions 140 may extend long so as to be connected to 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 partitioned by a folding line 130'. Hereinafter, a case where the second case 102 includes the cup part 110, the terrace 120, and the protrusion 140 will be described 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 will face each other and be sealed. The region where the terrace 120 of the second case 102 and the first case 102 are sealed can be defined as the seal portion 150.

[0104] The protrusion 140 of the second case 102 may be in contact with and sealed to the first case 101. More specifically, the seal portion 150 may be formed to pass through the portion where the protrusion 140 of the second case 102 and the first case 101 are in contact.

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

[0106] That is, different from the illustration in FIG. 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 and not include a pair of protrusions located on the inner corner side of the cup portion 110.

[0107] FIG. 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 according to the present 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 part of the sub-punch 50 may be located outside the corner of the forming recess 11.

[0110] The sub-punch 50 may include a first punch portion 51 extending parallel to the entire length of the forming recess 11 and a second punch portion 52 extending parallel to the entire width of the forming 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 forming recess 11 is formed in the die 10, the sub-punch 50 may form a single closed loop surrounding the single forming recess 11.

[0113] However, without being limited thereto, the sub-punch 50 may extend along a closed loop, but a part of the section may be formed to be cut.

[0114] On the other hand, those skilled in the art will easily understand that a sub-forming recess 40 corresponding to the sub-punch 50 is formed in the stripper 30 of the forming device according to the present embodiment.

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

[0116] Hereinafter, a pouch-type battery case 100 manufactured by a forming device according to a second embodiment will be described as an embodiment of the present invention. However, the contents overlapping with those described above are incorporated by reference, and the description will be centered on the differences.

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

[0118] The protruding portion 140 may be formed outside the cup portion 110. The protruding portion 140 may extend along the sealing portion 150. That is, the protruding portion 140 may be formed in a region that is to be sealed to the terrace 120 later.

[0119] The protruding portion 140 may have a shape surrounding the cup portion 110. More specifically, the protruding portion 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] In a state where the pouch-type battery case 100 is open, the protruding portion 140 may form a single closed loop surrounding the pair of cup portions 110. If a single cup portion 110 is formed in the die 10, the sub-punch 50 may form a single closed loop surrounding the single cup portion 110. However, it is not limited thereto, and although the protruding portion 140 extends along the closed loop, it is also possible to be formed such that some sections are cut.

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

[0122] As shown in FIG. 11, when the bridge 130 is folded, the protruding portion 140 of the first case 101 and the protruding portion 140 of the second case 102 face each other and are sealed to form the sealing portion 150. Such a sealing portion 150 may extend along the circumference of the cup portion 110. When the first case 101 and the second case 102 are connected by the bridge 130 as in the present embodiment, the sealing portion 150 may be formed along three sides of the battery case 10. On the other hand, when the first case 101 and the second case 102 are separated, the sealing portion 150 may be formed along four sides of the battery case 100.

[0123] At least a part of the sealing portion 150 may be formed on the protruding portion 140. In the case of 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 form the sealing portion 150 by pressing the protruding portion 140.

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

[0125] Since the protruding portion 140 is sealed in this way, compared with a conventional battery case in which a bulge occurs around the corner of the cup portion, the sealing reliability of the battery case 100 is improved, and the risk of electrolyte leakage can be minimized.

[0126] In particular, when the protruding portion 140 extends along the sealing portion 150 as in this embodiment, there is an advantage that the overall sealing quality of the sealing portion 150 becomes higher.

[0127] FIG. 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 interval from the first punch portion 51. In the pouch-type battery case 100, the portion corresponding to the interval can function as a gas pocket portion.

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

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

[0132] The first punch part 51 and the second punch part 52 may form one closed loop surrounding the forming recess 11. The first punch part 51, the third punch part 53, and the fourth punch part 54 may form another closed loop.

[0133] On the other hand, those skilled in the art will easily understand that a sub-forming recess 40 corresponding to the sub-punch 50 is formed in the stripper 30 of the forming device according to the present embodiment.

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

[0135] Hereinafter, the pouch-type battery case 100 manufactured by the forming device according to the third embodiment will be described as an embodiment of the present invention. The contents overlapping with those described above are incorporated by reference, and the description will focus on the differences.

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

[0137] The protruding part 140 may be formed outside the cup part 110. The protruding part 140 may extend along the sealing part 150. That is, the protruding part 140 may be formed in a region that is planned to be sealed to the terrace 120 later.

[0138] The protruding portion 140 may have a shape surrounding the cup portion 110. More specifically, the protruding portion 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 protruding portion 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] The first portion 141 and the third portion 143 may be formed at a predetermined interval. Also, the fourth portion 144 may extend from the second portion 142.

[0140] In the state where the pouch-type battery case 100 is open, the first portion 141 and the second portion 142 may form one closed loop surrounding the cup portion 110, and the first portion 141, the third portion 143, and the fourth portion 144 may form another closed loop.

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

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

[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] Hereinafter, each seal portion will be briefly described.

[0145] The first seal portion 151 may be formed first while the bridge 130 is folded. In this case, the first case 101 and the second case 102 may form an envelope shape with one end open. The electrolyte may be poured into the cup portion 110 through the open end.

[0146] The open end may then be sealed to form a third seal portion 153. The area between the cup portion 110 and the third seal portion 153 may be defined as a gas pocket portion 160. Gas generated by activation of the electrode assembly in the pouch-type battery case 100 may be collected in the gas pocket portion 160. A degassing process may then be performed in which the gas pocket portion 160 is perforated to discharge the gas.

[0147] Thereafter, the 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 the seal portions 150 involved in the manufacturing process are formed on the protrusion portion 140, there is an advantage that the sealing quality of the seal portions 150 is further improved overall.

[0148] The above description merely exemplifies the technical concept of the present invention, and various modifications and variations may be made by a person having ordinary knowledge in the technical field to which the present invention pertains without departing from the essential characteristics of the present invention.

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

[0150] The protection scope of the present invention should be interpreted by the appended patent claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of rights of the present invention.

Explanation of Reference Numerals

[0151] 10 Die 11 Forming Recess 13 Mounting Recess 20 Punch 30 Stripper 40 Sub-Forming Recess 50 Sub-Punch 61 Pressing Portion 62 Elastic Member 100 Pouch-Type Battery Case 110 Cup Portion 111 (Corner of the Cup Portion) 120 Terrace 130 Bridge 140 Protrusion 141 First Portion 142 Second Portion 143 Third Portion 144 Fourth Portion 150 Seal Portion 160 Gas Pocket Portion

Claims

1. In a pouch-type battery case including a pair of cases, at least one of the pair of cases includes 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, where at least a part of the seal portion is formed on the protruding portion, the pouch-type battery case.

2. Each of the pair of cases includes the cup portion, the terrace, and the protruding portion, where the protruding portion of any one of the pair of cases and the protruding portion of the other one are in contact and sealed, the pouch-type battery case according to Claim 1.

3. The protruding portion extends along the seal portion, the pouch-type battery case according to Claim 1.

4. At least a part of the protruding portion is located outside the corner of the cup portion, the pouch-type battery case according to Claim 1.

5. The width of the protruding portion is wider than the width of the seal portion, the pouch-type battery case according to Claim 1.

6. Both side edges in the width direction of the seal portion are located inside both side edges in the width direction of the protruding portion, the pouch-type battery case according to Claim 5.

7. The protruding portion includes a first portion located outside the entire width direction of the cup portion, and a second portion connected to the first portion and located outside the entire length direction of the cup portion, the pouch-type battery case according to any one of Claims 1 to 6.

8. The first portion extends parallel to the entire length of the cup portion, and the second portion extends parallel to the entire width of the cup portion, the pouch-type battery case according to Claim 7.

9. A die with a formed recessed portion, a punch disposed opposite to the formed recessed portion, a stripper located around the punch and facing the die, a sub-formed recessed portion formed in the stripper, a sub-punch protruding from the die and facing the sub-formed recessed portion, a pressing portion disposed in the sub-formed recessed portion, and an elastic member applying an elastic force toward the sub-punch to the pressing portion, the forming device.

10. The sub-punch is located outside the formed recessed portion, the forming device according to Claim 9.

11. At least a part of the sub-punch is located outside the corner of the formed recessed portion, the forming device according to Claim 10.

12. The sub-punch includes a first punch portion located outside the entire width direction of the formed recessed portion, The forming device according to claim 9, comprising a second punch portion connected to the first punch portion and located outside the entire length direction of the forming recess.

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

14. The sub-punch comprises a third punch portion located outside the first punch portion and forming a predetermined interval from the first punch portion, and a fourth punch portion connecting the third punch portion and the first punch portion. The forming device according to claim 12.

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

16. The forming device according to any one of claims 9 to 15, wherein a mounting recess for mounting the sub-punch is formed in the die.

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