Molding device

Abstract

A molding device according to an embodiment of the present invention is capable of molding a pouch sheet. The molding device may comprise: a die in which a pair of molding spaces recessed downward from an upper surface are formed, and a partition wall part is provided between the pair of molding spaces; and a punch inserted into a molding space and configured to press a pouch sheet. At least one of the punch and the partition wall part may be provided with: a contact part extending in one direction and configured to come into contact with the pouch sheet; and an elastic member for applying an elastic force to the contact part, in a direction towards the pouch sheet.

Description

Molding device

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority from Korean Patent Application No. 10-2023-0099104, filed July 28, 2023, the entire contents of which are incorporated herein by reference.

[0003] Technology field

[0004] The present invention relates to a molding device for molding a pouch sheet.

[0005] Common types of secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, lithium-ion batteries, and lithium-ion polymer batteries. These batteries are used in small products such as digital cameras, DVDs, MP3 players, mobile phones, PDAs, portable game devices, power tools, and e-bikes, as well as in larger products requiring high output, such as electric and hybrid vehicles, as well as power storage devices that store surplus generated power or renewable energy, and as backup power storage devices.

[0006] To manufacture these 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 these are laminated on both sides of a separator to form an electrode assembly of a predetermined shape. Then, the electrode assembly is housed in a battery case, filled with electrolyte, and sealed.

[0007] Secondary 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 materials such as metal or plastic.

[0008] Typically, pouch-type battery cases are manufactured by forming a cup portion by press-processing a flexible pouch sheet. Once the cup portion is formed, an electrode assembly is housed within the cup portion and the sides are sealed to manufacture a secondary battery.

[0009] Among these press processes, drawing forming is performed by inserting a pouch film into a forming device such as a press machine and applying pressure to the pouch film with a punch to stretch the pouch film.

[0010] To achieve high-energy density secondary batteries, it is desirable to mold the bridge between a pair of cups in a pouch-type battery case with a small width. However, the smaller the bridge width, the smaller the remaining thickness of the bridge, increasing the likelihood of cracks, which can compromise the performance and safety of the secondary battery.

[0011] The problem to be solved by the present invention is to provide a molding device capable of increasing the remaining thickness of a bridge of a pouch-type battery case.

[0012] A molding device according to an embodiment of the present invention can mold a pouch sheet. The molding device may include a die having a pair of molding spaces that are sunken downward from an upper surface and a partition wall portion provided between the pair of molding spaces; and a punch that is inserted into the molding spaces and configured to press the pouch sheet. At least one of the punch and the partition wall portion may be provided with a contact portion that extends in one direction and is configured to contact the pouch sheet; and an elastic member that applies an elastic force to the contact portion in a direction toward the pouch sheet.

[0013] The above contact portion may extend parallel to the bulkhead portion.

[0014] At least one of the punch and bulkhead portions may be provided with a mounting groove in which the elastic member is mounted.

[0015] The above elastic member may be provided in multiple numbers so as to be arranged at predetermined intervals in the longitudinal direction of the contact portion.

[0016] A molding device according to an embodiment of the present invention can mold a pouch sheet. The molding device may include a die having a pair of molding spaces that are sunken downward from an upper surface and a partition wall portion provided between the pair of molding spaces; and a punch that is inserted into the molding spaces and configured to press the pouch sheet. The partition wall portion may include a contact portion that extends in one direction and is configured to contact the pouch sheet; and an elastic member that applies an elastic force to the contact portion in a direction toward the pouch sheet.

[0017] The upper edges of the above contact portion may be formed to be rounded.

[0018] The above contact portion may be located on the upper portion of the bulkhead.

[0019] A vertically extending guide protrusion may be formed on one of the above-mentioned bulkhead portions and contact portions, and a guide hole into which the guide protrusion is inserted may be formed on the other.

[0020] When the contact portion is in the basic state, the upper end of the contact portion is positioned higher than the upper surface of the die, and when the contact portion is pressed downward by the pouch sheet, the upper end of the contact portion may be positioned lower than the upper surface of the die or on the same plane as the upper surface of the die.

[0021] A molding device according to an embodiment of the present invention can mold a pouch sheet. The molding device may include a die having a molding space formed downwardly from an upper surface; and a punch inserted into the molding space and configured to press the pouch sheet. The punch may be provided with a contact portion defining a lower edge of the punch and extending in one direction; and an elastic member applying an elastic force downward to the contact portion.

[0022] When the contact portion is in the basic state, the lower end of the contact portion is positioned lower than the bottom surface of the punch, and when the contact portion is pressed upward by the pouch sheet, the lower end of the contact portion can be positioned on the same plane as the bottom surface of the punch.

[0023] The lower edge connecting the bottom surface and the outer surface of the above contact portion can be formed to be rounded.

[0024] One of the punch and contact portion may be formed with a vertically extending guide protrusion, and the other may be formed with a guide hole into which the guide protrusion is inserted.

[0025] According to a preferred embodiment of the present invention, the width of the bridge of a pouch-type battery case can be formed sufficiently narrow while preventing the remaining thickness from becoming excessively thin. This makes it possible to increase the energy density of the pouch-type secondary battery while preventing cracks from occurring in the bridge.

[0026] In addition, the configurations according to preferred embodiments of the present invention may include effects that can be easily predicted by those skilled in the art.

[0027] The following drawings attached to this specification illustrate preferred embodiments of the present invention, and together with the detailed description of the invention described below, serve to further understand the technical idea of ​​the present invention, and therefore, the present invention should not be interpreted as being limited to matters described in such drawings.

[0028] Figure 1 is an exploded view of a pouch-type secondary battery.

[0029] FIG. 2 is a perspective view of a molding device for molding the pouch-type secondary battery illustrated in FIG. 1.

[0030] Figure 3 is a schematic cross-sectional view of a molding device according to one embodiment of the present invention.

[0031] Figure 4 is a perspective view of the die illustrated in Figure 3.

[0032] Figure 5 is a cross-sectional view taken along line A-A' of Figure 4.

[0033] Figure 6 is a schematic cross-sectional view of a molding device according to another embodiment of the present invention.

[0034] Figure 7 is a bottom view of the punch shown in Figure 6.

[0035] Figure 8 is a cross-sectional view taken along line B-B' of Figure 6.

[0036] Hereinafter, with reference to the attached drawings, preferred embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the invention. However, the present invention may be implemented in various different forms and is not limited or restricted by the following examples.

[0037] In order to clearly explain the present invention, a detailed description of a part that is irrelevant to the description or a related known technology that may unnecessarily obscure the gist of the present invention has been omitted, and when adding reference signs to components of each drawing in this specification, the same or similar reference signs are attached to the same or similar components throughout the specification.

[0038] In addition, terms and words used in this specification and claims should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted as meanings and concepts that conform to the technical idea of ​​the present invention based on the principle that the inventor can appropriately define the concept of the term to explain his or her own invention in the best way.

[0039] Figure 1 is an exploded view of a pouch-type secondary battery.

[0040] A pouch-type secondary battery (1) may include a pouch-type battery case (10) (hereinafter, “battery case”) and an electrode assembly (20).

[0041] The battery case (10) can be manufactured by molding a pouch sheet. The pouch sheet can be a laminate sheet including a first resin layer, a metal layer, and a second resin layer. The first resin layer can form the innermost layer of the battery case (10). The second resin layer can form the outermost layer of the battery case (10). The metal layer is positioned between the first resin layer and the second resin layer, and can have rigidity and moldability.

[0042] For example, the first resin layer may include a polypropylene (PP) material. The second resin layer may include a polyethylene terephthalate (PET) material. The metal layer may include an aluminum or stainless steel material. However, the materials of each layer are not limited thereto.

[0043] The battery case (10) may include a pair of cup parts (11) and a bridge (13) located between the pair of cup parts (11).

[0044] A pair of cup portions (11) can be recessed to a predetermined depth. An electrode assembly (20) can be accommodated within one of the cup portions (11). More specifically, when the electrode assembly (20) is placed in one of the cup portions (11), the bridge (13) of the battery case (10) can be folded so that the other cup portion (11) can completely cover the electrode assembly (20). Thereafter, the periphery of the cup portion (11) can be sealed so that the electrode assembly (20) can be sealed within the cup portion (11).

[0045] The electrode assembly (20) may have a structure in which a plurality of positive electrodes and a plurality of negative electrodes are alternately stacked with a separator in between. The type of the electrode assembly (20) is not limited.

[0046] FIG. 2 is a perspective view of a molding device for molding the pouch-type secondary battery illustrated in FIG. 1.

[0047] Below, the drawing symbol of the pouch sheet is indicated as '10', which is the same as that of the pouch-type battery case.

[0048] A forming device (100) can form a pouch sheet (10). The forming device (100) can include a die (110) and a punch (120). The forming device (100) can further include a stripper (30).

[0049] The forming device (100) can form a pouch sheet (10) located between a die (110) and a punch (120).

[0050] The die (110) may be positioned on the lower side of the pouch sheet (10). A pair of molding spaces (111) that are sunken downward from the upper surface (110a) may be formed in the die (110), and a partition wall (112) may be provided between the pair of molding spaces (111).

[0051] The punch (120) may be positioned on the upper side of the pouch sheet (10). The punch (120) may be inserted into the forming space (111) of the die (110) and pressurize the pouch sheet (10). A pair of punches (120) may be provided to correspond to a pair of forming spaces (111). The pair of punches (120) may be integrally connected to each other, but is not limited thereto.

[0052] The stripper (130) may be positioned on the upper side of the pouch sheet (10). The pouch film (10) may be fixed between the die (110) and the stripper (130). A through-hole in which a punch (120) is positioned may be formed in the stripper (130).

[0053] With the pouch film (10) fixed between the die (110) and the stripper (130), the die (110) and the stripper (130) can be raised together or the punch (120) can be lowered so that the punch (120) can be inserted into the insertion space (111). As a result, the punch (120) can press downward the pouch film (10) fixed between the die (110) and the stripper (130). At this time, the partition wall (112) of the die (110) can press upward the pouch film (10).

[0054] In the pouch film (10), the portion pressed by the punch (120) can be formed into a cup portion (11), and the portion pressed by the partition wall portion (112) can be formed into a bridge (13).

[0055] In order to increase the energy density of a pouch-type secondary battery (1), it is advantageous to reduce the width of the bridge (13). However, as the width of the bridge (13) becomes narrower, the amount of pouch sheet (10) flowing into the bridge (13) decreases, which reduces the remaining thickness of the bridge (13), and thus there is a risk of cracks occurring. To prevent this, it is necessary to improve the amount of pouch sheet (10) flowing into the bridge (13).

[0056] To this end, the forming device (100) according to the present invention may be provided with a contact portion (113)(121) extending in one direction and configured to contact the pouch sheet (10) in at least one of the punch (120) and the partition wall portion (112), and an elastic member (114)(122) that applies an elastic force to the contact portion (113)(121) in a direction toward the pouch sheet (10).

[0057] When the punch (120) and the bulkhead (112) are provided with contact portions (113)(121) and elastic members (114)(122), respectively, the contact portion (113) and the elastic member (114) provided in the bulkhead (112) may be referred to as a first contact portion and a first elastic member, respectively, and the contact portion (121) and the elastic member (122) provided in the punch (120) may be referred to as a second contact portion and a second elastic member, respectively.

[0058] FIG. 3 is a schematic cross-sectional view of a molding device according to one embodiment of the present invention, FIG. 4 is a perspective view of the die illustrated in FIG. 3, and FIG. 5 is a cross-sectional view taken along line A-A' of FIG. 4.

[0059] According to one embodiment of the present invention, a molding device (100) may be provided with a contact portion (113) and an elastic member (114) in a partition wall portion (112) of a die (110), as shown in FIG. 3.

[0060] The contact portion (113) can be in contact with the bottom surface of the pouch sheet (10). The contact portion (113) can be pressed downward by the pouch sheet (10). The contact portion (113) can be moved in the vertical direction by an external force.

[0061] The upper edges of both contact portions (113) can be formed to be rounded. Accordingly, the pouch sheet (10) can be prevented from being cracked by the upper edges of the contact portions (113).

[0062] The contact portion (113) may extend parallel to the bulkhead portion (112). The contact portion (113) may be bar-shaped. The contact portion (113) may be positioned above the bulkhead portion (112). The bulkhead portion (112) may limit the height to which the contact portion (113) descends. In other words, the bulkhead portion (112) may function as a limiter.

[0063] A vertically extending guide protrusion (117) may be formed on one of the bulkhead portion (112) and the contact portion (113), and a guide hole (118) into which the guide protrusion (117) is inserted may be formed on the other. As a result, the contact portion (113) can move in the vertical direction with respect to the bulkhead portion (112).

[0064] For example, as illustrated in FIG. 5, the guide protrusion (117) may protrude upward from the partition wall portion (112), and the guide hole (118) may be formed by being recessed or penetrating into the contact portion (113). As another example, the guide protrusion (117) may protrude downward from the contact portion (113), and the guide hole (118) may be formed by being recessed or penetrating into the partition wall portion (112).

[0065] The elastic member (114) can apply an elastic force upward to the contact portion (113). For example, the elastic member (114) can be a coil spring. A plurality of elastic members (114) can be provided so as to be arranged at predetermined intervals in the longitudinal direction of the contact portion (113). The plurality of elastic members (114) can apply an elastic force upward to the contact portion (113) evenly.

[0066] The bulkhead (112) may be provided with a mounting groove (112a) into which an elastic member (114) is mounted. The lower end of the elastic member (114) may be fixed within the mounting groove (112a). A plurality of mounting grooves (112a) may be provided at predetermined intervals in the longitudinal direction of the bulkhead (112) so as to enable mounting of a plurality of elastic members (114).

[0067] When the punch (120) presses the pouch sheet (10) downward, the force with which the pouch sheet (10) presses the contact portion (113) downward and the force with which the elastic member (114) presses the contact portion (113) upward can be appropriately balanced. Accordingly, a portion of the pouch sheet (10) corresponding to the contact portion (113) can be formed into a bridge (13) (see FIG. 1), but the amount of pouch sheet (10) flowing into the bridge (13) can be sufficient. This makes it possible to form the width of the bridge (13) sufficiently narrow while preventing the remaining thickness from becoming excessively thin.

[0068] As illustrated in FIG. 5, when the contact portion (113) is in the basic state, the upper end of the contact portion (113) may be positioned (P1) higher than the upper surface (110a) of the die (110). The basic state may refer to a state before the punch (120) presses the pouch sheet (10). When the contact portion (113) is pressed downward by the pouch sheet (10), the upper end of the contact portion (113) may be positioned (P2) lower than the upper surface (110a) of the die (110) or on the same plane as the upper surface (110a) of the die (110).

[0069] This can prevent the height of the bridge (113) from being formed excessively high. In addition, since the deformation amount of the elastic member (114) increases, the elastic force applied by the elastic member (114) to the contact portion (113) can be sufficiently increased. This can prevent the remaining thickness of the bridge (13) from becoming excessively thin.

[0070] FIG. 6 is a schematic cross-sectional view of a molding device according to another embodiment of the present invention, FIG. 7 is a bottom view of the punch illustrated in FIG. 6, and FIG. 8 is a cross-sectional view taken along line B-B' of FIG. 6.

[0071] According to another embodiment of the present invention, a molding device (100) may be provided with a contact portion (121) and an elastic member (122) on a punch (120), as shown in FIG. 6.

[0072] Each of a pair of punches (120) may be provided with a contact portion (121). The contact portion (121) may define a lower edge of the punch (120). More specifically, the contact portion (121) may form a lower edge adjacent to a partition wall (112) of the die (110) among the lower edges of the punch (120). The contact portion (121) may define a lower edge of a portion of the pair of punches (120) that faces each other. The contact portion (121) may be provided at a portion where the bottom surface (120a) and the outer surface (120b) of the punch (120) meet.

[0073] The contact portion (121) can be in contact with the upper surface of the pouch sheet (10). The contact portion (121) can be pressed upward by the pouch sheet (10). The contact portion (121) can be moved in the vertical direction by an external force.

[0074] The lower edge connecting the bottom surface and the outer surface of the contact portion (121) may be formed to be rounded. The outer surface may refer to a surface where a pair of contact portions (121) face each other. This prevents the pouch sheet (10) from being cracked by the lower edge of the contact portion (121).

[0075] The contact portion (121) may extend parallel to the partition wall portion (112) of the die (110). The contact portion (121) may be bar-shaped. The contact portion (121) may be located at the bottom of the punch (120). The punch (120) may limit the height to which the contact portion (121) rises. That is, the punch (120) may function as a limiter.

[0076] A vertically extending guide protrusion (127) may be formed on one of the punch (120) and the contact portion (121), and a guide hole (128) into which the guide protrusion (127) is inserted may be formed on the other. As a result, the contact portion (121) can move in the vertical direction relative to the punch (120).

[0077] For example, as illustrated in FIG. 8, the guide protrusion (127) may protrude downward from the punch (120), and the guide hole (128) may be formed by being recessed or penetrating into the contact portion (121). As another example, the guide protrusion (127) may protrude upward from the contact portion (121), and the guide hole (128) may be formed by being recessed or penetrating into the punch (120).

[0078] The elastic member (122) can apply an elastic force downward to the contact portion (121). For example, the elastic member (122) can be a coil spring. A plurality of elastic members (122) can be provided so as to be arranged at predetermined intervals in the longitudinal direction of the contact portion (121). The plurality of elastic members (122) can apply an elastic force downward to the contact portion (121) evenly.

[0079] The punch (120) may be provided with a mounting groove (120c) into which an elastic member (122) is mounted. The upper end of the elastic member (122) may be fixed within the mounting groove (120c). A plurality of mounting grooves (120c) may be provided at predetermined intervals in the longitudinal direction of the punch (120) so as to enable mounting of a plurality of elastic members (122).

[0080] When the punch (120) presses the pouch sheet (10) downward, the force with which the pouch sheet (10) presses the contact portion (121) upward and the force with which the elastic member (122) presses the contact portion (121) downward can be appropriately balanced. Accordingly, the portion corresponding to the contact portion (121) in the pouch sheet (10) can be formed as a portion adjacent to the bridge (13) among the lower edges of the cup portion (11) (see FIG. 1). In addition, the amount of pouch sheet (10) flowing into the bridge (13) in the pouch sheet (10) can be sufficient. As a result, the width of the bridge (13) can be formed sufficiently narrow while preventing the remaining thickness from becoming excessively thin.

[0081] As illustrated in Fig. 6, when the contact portion (121) is in the basic state, the lower end of the contact portion (121) may be positioned (P1') lower than the bottom surface (120a) of the punch (120). The basic state may refer to a state before the punch (120) presses the pouch sheet (10). When the contact portion (121) is pressed upward by the pouch sheet (10), the lower end of the contact portion (121) may be positioned on the same plane as the bottom surface (120a) of the punch (120).

[0082] As a result, the bottom surface of the cup portion (11) can be formed flat. In addition, since the deformation amount of the elastic member (122) increases, the elastic force applied by the elastic member (122) to the contact portion (121) can be sufficiently increased. As a result, the remaining thickness of the bridge (13) can be prevented from becoming excessively thin.

[0083] The above description is merely an example of the technical idea of ​​the present invention, and those skilled in the art will appreciate that various modifications and variations can be made without departing from the essential characteristics of the present invention.

[0084] Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of ​​the present invention but to explain it, and the scope of the technical idea of ​​the present invention is not limited by these embodiments.

[0085] The scope of protection of the present invention should be interpreted by the claims below, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the rights of the present invention.

[0086] [Explanation of symbols]

[0087] 10: Pouch sheet, pouch-type battery case

[0088] 11: Cup 13: Bridge

[0089] 100: Molding device 110: Die

[0090] 111: Forming space 112: Bulkhead

[0091] 113: Contact part 114: Elastic member

[0092] 117: Guide protrusion 118: Guide hole

[0093] 120: Punch 121: Contact

[0094] 122: Elastic member 127: Guide protrusion

[0095] 128: Guide Hall

Claims

1. In a forming device for forming a pouch sheet, A die having a pair of molding spaces sunken downward from the upper surface and a partition wall provided between the pair of molding spaces; and A punch is included that is inserted into the above forming space and is configured to press the pouch sheet, At least one of the above punches and bulkheads, a contact portion extending in one direction and configured to contact the pouch sheet; and A molding device having an elastic member that applies elastic force to the contact portion in a direction toward the pouch sheet.

2. In paragraph 1, The above contact portion is a molding device extending parallel to the bulkhead portion.

3. In paragraph 1, A molding device having a mounting groove in which the elastic member is mounted, at least one of the punch and the bulkhead.

4. In paragraph 1, A molding device in which the above elastic member is provided in multiple numbers so as to be arranged at predetermined intervals in the longitudinal direction of the contact portion.

5. In a forming device for forming a pouch sheet, A die having a pair of molding spaces sunken downward from the upper surface and a partition wall provided between the pair of molding spaces; and A punch is included that is inserted into the above forming space and is configured to press the pouch sheet, In the above bulkhead, a contact portion extending in one direction and configured to contact the pouch sheet; and A molding device having an elastic member that applies elastic force in a direction toward the pouch sheet to the contact portion.

6. In paragraph 5, A molding device in which the upper edges of the above contact portion are formed to be rounded.

7. In paragraph 5, The above contact part is a forming device located on the upper part of the bulkhead.

8. In paragraph 5, A molding device in which a vertically extending guide protrusion is formed on one of the above-mentioned bulkhead portions and contact portions, and a guide hole into which the guide protrusion is inserted is formed on the other.

9. In paragraph 5, When the above contact portion is in the basic state, the upper end of the contact portion is located higher than the upper surface of the die, A molding device in which, when the contact portion is pressed downward by the pouch sheet, the upper end of the contact portion is lower than the upper surface of the die or is positioned on the same plane as the upper surface of the die.

10. In a forming device for forming a pouch sheet, A die having a molding space formed downwardly from the upper surface; and A punch is included that is inserted into the above forming space and is configured to press the pouch sheet, In the above punch, A contact portion extending in one direction, defining a lower edge of the punch; and A molding device having an elastic member that applies an elastic force downward to the above contact portion.

11. In paragraph 10, When the above contact portion is in the basic state, the lower end of the above contact portion is positioned lower than the bottom surface of the punch, A molding device in which, when the contact portion is pressed upward by the pouch sheet, the lower end of the contact portion is positioned on the same plane as the bottom surface of the punch.

12. In paragraph 10, A molding device in which the lower edge connecting the bottom surface and the outer surface of the above contact portion is formed to be round.

13. In paragraph 10, A molding device in which a vertically extending guide projection is formed on one of the punch and contact portions, and a guide hole into which the guide projection is inserted is formed on the other.

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