Battery cell comprising case and manufacturing device of case

Abstract

A battery cell is provided. The battery cell may include a case and an electrode assembly arranged in the case. The case may include a central portion having a first thickness, and an edge portion extending from the central portion and having a second thickness less than the first thickness.

Description

Battery cell including case and manufacturing device of the case

[0001] The present disclosure relates to a battery cell including a case and a device for manufacturing the case.

[0002] Unlike primary batteries, secondary batteries can be recharged and discharged, making them suitable for a wide range of applications, including digital cameras, mobile phones, laptops, hybrid and electric vehicles, and energy storage systems (ESS). Secondary batteries can be lithium-ion batteries, nickel-cadmium batteries, nickel-metal hydride batteries, or nickel-hydrogen batteries.

[0003] Secondary batteries are manufactured as flexible pouch-type battery cells or rigid square or cylindrical can-type battery cells. Multiple battery cells can be formed into a stacked cell assembly. The cell assembly can be arranged within a module housing to form a battery module, and multiple battery modules can be arranged within a pack housing to form a battery pack.

[0004] A square battery cell may include a case that accommodates an electrode assembly (e.g., a jelly-roll type electrode assembly). However, if the case is formed with a uniform thickness, the electrode assembly may be tightly adhered to the case. If the electrode assembly is tightly adhered to the case, the escape of gas generated from the electrode assembly to the outside may be impeded.

[0005] According to one aspect of the present disclosure, a battery cell and a method of manufacturing the case may be provided, the case including a case capable of providing a path for gas generated in an electrode assembly to be discharged to the outside of the battery cell.

[0006] The battery cell of the present disclosure can be widely applied in green technology fields such as electric vehicles, battery charging stations, and other battery-powered solar and wind power generation. Furthermore, the battery cell of the present disclosure can be used in eco-friendly electric vehicles and hybrid vehicles, which aim to prevent climate change by suppressing air pollution and greenhouse gas emissions.

[0007] A battery cell of the present disclosure includes a case and an electrode assembly disposed within the case. The case includes a central portion having a first thickness and a periphery extending from the central portion and having a second thickness thinner than the first thickness.

[0008] According to one embodiment, the case may include a first side region having a first width and a second side region having a second width greater than the first width. The central portion and the edge portion may form at least a portion of the second side region.

[0009] In one embodiment, the central portion may be configured to provide pressure to the electrode assembly.

[0010] In one embodiment, the first distance between the electrode assembly and the center portion may be shorter than the second distance between the electrode assembly and the edge portion.

[0011] According to one embodiment, the central portion and the edge portion can form a curved inner surface.

[0012] In one embodiment, the battery cell may further include an insulator covering at least a portion of the electrode assembly. The edge portion may be spaced apart from the insulator.

[0013] According to one embodiment, the electrode assembly may include a first electrode assembly including a first side facing the case and a second side opposite the first side, and a second electrode assembly including a third side facing the second side and a fourth side opposite the third side and facing the case.

[0014] According to one embodiment, the central portion may include a first central portion providing pressure to the first surface of the first electrode assembly and a second central portion providing pressure to the fourth surface of the second electrode assembly.

[0015] In one embodiment, the case may include an opening extending from a first end of the case to a second end opposite the first end. The battery cell may further include a first cap assembly covering the first end, and a second cap assembly covering a second end of the opening.

[0016] In one embodiment, the case can be manufactured using an extrusion process.

[0017] A device for manufacturing a battery cell case of the present disclosure may include a first extrusion mold including a base including at least one first through hole for accommodating a metal base material and a core portion protruding from the base, and a second extrusion mold including a receiving portion for accommodating the core portion. The core portion may include a first central core portion having a first length and an end portion extending from the central core portion and having a second length greater than the first length.

[0018] In one embodiment, the first extrusion mold may include a back surface configured to face a piston for pressurizing the metal base material and a front surface opposite the back surface. The second extrusion mold may be disposed on the front surface of the first extrusion mold.

[0019] In one embodiment, the first through hole may be positioned adjacent to a corner of the core portion.

[0020] In one embodiment, the second extrusion mold may include an inner surface defining the receiving portion. A distance between the central core portion and the inner surface may be longer than a distance between an end of the core portion and the inner surface.

[0021] According to one embodiment of the present disclosure, gas generated from the electrode assembly can be released outside the battery cell. By discharging the gas generated from the electrode assembly, the lifespan of the electrode assembly can be improved.

[0022] FIG. 1 is a perspective view of a battery cell according to one embodiment.

[0023] Figure 2 is a cross-sectional view taken along line A-A' of Figure 1.

[0024] Figure 3 is a perspective view of a case according to one embodiment.

[0025] FIGS. 4A, 4B, and 4C are schematic diagrams of a manufacturing apparatus for a case according to one embodiment.

[0026] FIG. 5 is a perspective view of a battery cell according to one embodiment.

[0027] FIG. 6A is a perspective view of an electrode assembly according to one embodiment. FIG. 6B is a drawing for explaining the connection between the electrode assembly and the cap assembly according to one embodiment.

[0028] Figure 7 is a cross-sectional view taken along line B-B' of Figure 5.

[0029] Hereinafter, the present disclosure will be described in detail with reference to the attached drawings. However, these are merely exemplary and the present disclosure is not limited to the specific embodiments described as examples.

[0030] The terms and words used in this specification and claims described below are not to be construed as limited to their conventional or dictionary meanings. The inventor will interpret these terms and concepts in a way that is consistent with the technical spirit of the present disclosure, based on the principle that the inventor can appropriately define the concepts of the terms to best explain his or her invention.

[0031] Accordingly, it will be understood that the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present disclosure and do not represent all of the technical ideas of the present disclosure, and that there may be various equivalents and modified examples that can replace them at the time of filing this application.

[0032] Detailed descriptions of known functions and configurations that may obscure the gist of the present disclosure are omitted. In the attached drawings, some components are exaggerated, omitted, or schematically depicted, and the sizes of each component do not fully reflect the actual size.

[0033]

[0034] FIG. 1 is a perspective view of a battery cell according to one embodiment.

[0035] Referring to FIG. 1, the battery cell (100) may be a square secondary battery cell. For example, the battery cell (100) may be a lithium ion battery or a nickel metal hydride battery capable of being charged and discharged. The battery cell (100) may include a case (120) and / or a cap assembly (140, 150).

[0036] The battery cell (100) of FIG. 1 may be a secondary battery. For example, the battery cell (100) may be a lithium ion battery, but is not limited thereto. For example, the battery cell (100) may be a nickel-cadmium battery, a nickel-metal hydride battery, or a nickel-hydrogen battery capable of being recharged and discharged.

[0037] The case (120) forms at least a portion of the exterior of the battery cell (100) and can accommodate an electrode assembly (e.g., the electrode assembly (110) of FIG. 2). For example, the case (120) can provide a space in which the electrode assembly (110) and the electrolyte are accommodated. According to one embodiment, the case (120) can include aluminum. The case (120) can be referred to as a can or a housing. The case (120) can have a substantially rectangular parallelepiped shape with at least a portion being open. For example, the case (120) can include a first side region (120a) having a first width (w1) and a second side region (120b) having a second width (w2) greater than the first width (w1) of the first side region (120a). The first side area (120a) may be referred to as a narrow side, and the second side area (120b) may be referred to as a wide side.

[0038] According to one embodiment, the cap assemblies (140, 150) may be respectively coupled to both sides of the longitudinal direction (e.g., Y-axis direction) of the case (120). For example, the cap assemblies (140, 150) may accommodate the electrode assembly (110) and the electrolyte together with the case (120). The cap assemblies (140, 150) may include a first cap assembly (140) coupled to an end of the case (120) in a first direction (+Y direction) and a second cap assembly (150) coupled to an end of the case (120) in a second direction (-Y direction) opposite to the first direction (+Y direction). The first cap assembly (140) may cover a first end (128a) of the case (120). The second cap assembly (150) may cover a second end (128b) of the case (120).

[0039] The cap assembly (140, 150) may include a plurality of components. For example, the cap assembly (140) may include a cap plate that is coupled to the case (120) to seal the case (120), and a terminal plate (141) that is electrically connected to the electrode assembly (110).

[0040] The terminal plate (141) may have a positive or negative polarity. For example, based on the drawing, the first terminal plate (141) disposed in the first direction (+Y direction) of the case (120) may have a negative polarity, and the second terminal plate (not shown) disposed in the second direction (-Y direction) of the case (120) may have a positive polarity.

[0041] The components of the cap assembly (140, 150) described above are only examples, and thus some of the components of the cap assembly (140, 150) may be omitted or other configurations not described may be added. For example, the cap assembly (140, 150) may include a current collector, an insulating plate, a rivet terminal, and / or a gasket.

[0042] According to one embodiment, the battery cell (100) may include a venting portion (not shown) that provides a path for releasing gas generated in the electrode assembly (110) to the outside of the case (120). The venting portion may include a notch portion configured to rupture when a specified pressure is exceeded. The venting portion may be formed in the cap assembly (140, 150) or the case (120).

[0043]

[0044] Fig. 2 is a cross-sectional view taken along line A-A' of Fig. 1. Fig. 3 is a perspective view of a case according to one embodiment.

[0045] Referring to FIGS. 2 and 3, the battery cell (100) may include an electrode assembly (110), a case (120), and / or an insulator (160). The description of the battery cell (100) and the case (120) of FIG. 1 may be applied to the battery cell (100) and the case (120) of FIGS. 2 and / or 3.

[0046] The electrode assembly (110) may include a positive electrode plate, a negative electrode plate, and at least one separator to prevent contact between the positive electrode plate and the negative electrode plate.

[0047] According to one embodiment, the electrode assembly (110) may be a jelly roll type electrode assembly in which a positive electrode plate, a negative electrode plate, and at least one separator are wound together.

[0048] However, the structure of the electrode assembly (110) may be designed selectively. For example, the electrode assembly (110) may be a Z-folding type electrode assembly including a plurality of folded separators, or a stacked electrode assembly in which one positive electrode plate among a plurality of positive electrode plates, one separator among a plurality of separators, one negative electrode plate among a plurality of separators, and another separator among a plurality of separators are alternately stacked.

[0049] According to one embodiment, the case (120) may include an opening (128) extending from one side (+Y direction) to the other side (-Y direction) in the longitudinal direction (Y-axis direction) of the battery cell (100). The opening (128) may extend from a first end (128a) located at one side of the battery cell (100) to a second end (128b) located at the other side of the battery cell (100). The opening (128) may be an empty space connected to an internal space. For example, the case (120) may be a hollow body. The cross-section of the case (120) may be formed in a closed curve shape.

[0050] The case (120) may be formed to have different thicknesses for each section. According to one embodiment, the second side region (120b) of the case (120) may have different thicknesses for each section. For example, the thickness of the central portion (121) of the second side region (120b) may be thinner than the thickness of the edge portion (122).

[0051] According to one embodiment, the case (120) may include a central portion (121) having a first thickness (t1) and a border portion (122) having a second thickness (t2) thinner than the first thickness (t1). The border portion (122) may extend from the central portion (121). For example, the border portion (122) may be a portion of the case (120) extending from an edge of the central portion (121).

[0052] In one embodiment, the central portion (121) can provide pressure to the electrode assembly (110). For example, the central portion (121) can be in contact with the electrode assembly (110) or the insulator (160). The edge portion (122) can be spaced apart from the electrode assembly (110) or the insulator (160). In one embodiment, a first distance (d1) between the central portion (121) and the electrode assembly (110) can be shorter than a second distance (d2) between the edge portion (122) and the electrode assembly (110). In one embodiment, the sum of the first distance (d1) and the first thickness (t1) can be substantially equal to the second distance (d2) and the second thickness (t2).

[0053] The lifespan of the electrode assembly (110) can be improved by the electrode assembly (110) being pressurized by the center portion (121) of the case (120). For example, when gas is generated in the electrode assembly (110), the gas can be released to the outside of the case (120) through the empty space between the edge portion (122) of the case (120) and the electrode assembly (110) and the venting portion (not shown).

[0054] According to one embodiment, the thickness of the case (120) may be changed gradually or continuously. For example, the central portion (121) and the edge portion (122) of the case (120) may form a curved inner surface (123).

[0055] The case (120) can be manufactured using an extrusion process. The case (120) can be formed in a shape extending along the longitudinal direction (e.g., Y-axis direction). For example, the central portion (121) of the case (120) can protrude toward the electrode assembly (110) and extend along the longitudinal direction (Y-axis direction).

[0056] An insulator (160) may be used to insulate the case (120) of the battery cell (100). For example, the insulator (160) may be referred to as a protective member, a protective tape, an insulating film, an insulating member, and / or an insulating tape. According to one embodiment, the insulator (160) may include an adhesive material for bonding with the case (120).

[0057] The insulator (160) may cover at least a portion of the electrode assembly (110). For example, the insulator (160) may be positioned between the electrode assembly (110) and the case (120). The insulator (160) is illustrated as covering the entire case (120), but the position at which the insulator (160) covers the electrode assembly (110) may vary depending on the design.

[0058]

[0059] FIGS. 4A, 4B, and 4C are schematic diagrams of a case manufacturing device according to one embodiment. For example, FIG. 4A is a schematic diagram of a first extrusion mold (210). FIG. 4B is a schematic diagram of a second extrusion mold (220). FIG. 4C is a schematic diagram of a case manufacturing device (200) in which a first extrusion mold (210) and a second extrusion mold (220) are combined.

[0060] Referring to FIGS. 4A, 4B, and / or 4C, the case manufacturing device (200) may include a first extrusion mold (210) and a second extrusion mold (220). The case manufacturing device (200) may be used to manufacture the case (120) of FIGS. 1 to 3. The case manufacturing device (200) may be referred to as a battery cell case manufacturing device.

[0061] In one embodiment, the case (120) may be manufactured using an extrusion process. For example, the case (120) may be manufactured using a first extrusion mold (210) and a second extrusion mold (220).

[0062] The first extrusion mold (210) may include a base (212) having at least one through hole (211) formed therein.

[0063] According to one embodiment, the base (212) may include a front surface (212a) facing a third direction (+X' direction) and a back surface (212b) facing a fourth direction (-X' direction) opposite to the third direction.

[0064] The through hole (211) may be an empty space formed by penetrating from the front surface (210a) to the back surface (210b) of the base (212). In one embodiment, the through hole (211) may be referred to as a first through hole.

[0065] The through hole (211) can accommodate a metal base material (not shown). For example, the metal base material can be inserted into the through hole (211) of the first extrusion mold (210). The metal base material located in the through hole (211) can be pressurized using a pressurizing device (e.g., a piston) not shown. The metal base material that has been pressurized by the pressurizing device can pass through the through hole (211) to the second extrusion mold (220). The metal base material can be a molten metal. According to one embodiment, the through hole (211) can be formed in multiple numbers. For example, the through hole (211) can be formed to correspond to at least a portion of a corner portion of the receiving portion (221).

[0066] According to one embodiment, the first extrusion mold (210) may include a core portion (213) protruding from a base (212). The core portion (213) may protrude from the front surface (212a) of the base (212) in a third direction (+X' direction).

[0067] According to one embodiment, the shape of the core portion (213) may be designed to correspond to the internal space of a case (e.g., case (120) of FIG. 2). For example, the case (120) may be manufactured by solidifying a metal base material positioned between the surface of the core portion (213) and the inner surface (220a) of the receiving portion (221). According to one embodiment, the through hole (211) may be positioned adjacent to a corner (216) of the core portion (213).

[0068] The distance (e.g., third distance (d3)) between the central core portion (214) and the inner surface (220a) of the second extrusion mold (220) may be longer than the distance (e.g., fourth distance (d4)) between the end portion (215) of the core portion (213) and the inner surface (220a). In one embodiment, the third distance (d3) may be substantially equal to the first thickness (t1) of the central portion (e.g., the central portion (121) of FIG. 2), and the fourth distance (d4) may be substantially equal to the second thickness (t2) of the edge portion (e.g., the edge portion (122) of FIG. 2).

[0069] According to one embodiment, the core portion (213) may be formed to become thicker from the center to the ends. According to one embodiment, the core portion (213) may include a central core portion (214) having a first length (L1) and an end portion (215) having a second length (L2) greater than the first length (L1). For example, the outer surface (213a) of the core portion (213) may be formed as an arch-shaped curved surface.

[0070] The second extrusion mold (220) may include a receiving portion (221). The receiving portion (221) may receive the core portion (213). The second extrusion mold (220) may include an inner surface (220a) defining the receiving portion (221). The inner surface (220a) of the second extrusion mold (220) may be spaced apart from an outer surface (213a) of the core portion (223). A case (e.g., the case (120) of FIG. 2) may be formed by a hollow space (S) that is at least partially surrounded by the inner surface (220a) of the second extrusion mold (220) and the outer surface (213a) of the core portion (223). In one embodiment, the receiving portion (221) may be formed in a substantially rectangular parallelepiped shape. In one embodiment, the receiving portion (221) may be referred to as a second through hole. The above empty space (S) may be a space for accommodating a metal base material.

[0071] In one embodiment, the first extrusion mold (210) can be detachably coupled to the second extrusion mold (220). For example, the second extrusion mold (220) can be disposed on the front surface (212a) of the base (212). The rear surface (222) of the second extrusion mold (220) can face the front surface (212a) of the base (212). For example, the second extrusion mold (220) can be coupled to the first extrusion mold (210) while the core portion (213) is inserted into the receiving portion (221) of the second extrusion mold (220). In another embodiment, the first extrusion mold (210) can be formed integrally with the second extrusion mold (220).

[0072]

[0073] FIG. 5 is a perspective view of a battery cell according to one embodiment.

[0074] Referring to FIG. 5, the battery cell (400) may include an electrode assembly (not shown), a case (420), and a cap assembly (450). The configuration of the battery cell (100), the case (120), and the cap assembly (140, 150) of FIGS. 1, 2, and / or 3 may be all or part of the same as the configuration of the battery cell (400), the case (420), and the cap assembly (450) of FIG. 5. For example, at least part of the description of the battery cell (100), the case (120), and the cap assembly (140, 150) of FIGS. 1, 2, and / or 3 may be applied to the battery cell (400), the case (420), and the cap assembly (450) of FIG. 5.

[0075] In one embodiment, the battery cell (400) may include a cap assembly (450). For example, the cap assembly (450) may include a first terminal plate (451) and a second terminal plate (452) having a different polarity than the first terminal plate (451). In one embodiment, the cap assembly (450) may be referred to as an upper cap assembly.

[0076] The shape of the case (420) can be designed selectively. For example, if the thickness of the second side area (420b) of the case (120) is partially different, the device for manufacturing the case (120) can be designed selectively.

[0077] In one embodiment, the case (420) can be manufactured by connecting (e.g., welding) multiple parts. In one embodiment, the case (420) can include a first side region (420a) and a second side region (420b) having a width greater than the width of the first side region (420a). The first side region (420a) can be joined to the second side region (420b) by welding. For example, the case (420) of FIG. 5 can be manufactured by joining the first side region (420a) to a case (e.g., case 120 of FIG. 1) manufactured using the manufacturing apparatus (200) of the case of FIGS. 4a, 4b, and / or 4c.

[0078] According to one embodiment, the case (120) may be formed as an integral body. For example, a manufacturing device for the case (e.g., a manufacturing device for the case (200) of FIG. 4c) may include a mold (not shown) located in front of the second extrusion mold (220). As another example, the second extrusion mold (220) of FIG. 4b may include a groove for accommodating the core portion (213) of FIG. 4a. According to one embodiment, the second extrusion mold (220) is referred to as a deep drawing mold, and the receiving portion (221) may be formed in a groove shape.

[0079]

[0080] FIG. 6A is a perspective view of an electrode assembly according to one embodiment. FIG. 6B is a drawing for explaining the connection between the electrode assembly and the cap assembly according to one embodiment. FIG. 7 is a cross-sectional view taken along line B-B' of FIG. 5.

[0081] Referring to FIG. 6a, FIG. 6b and / or FIG. 7, a battery cell (400) may include an electrode assembly (410), a case (420), a cap assembly (450), and an insulator (460).

[0082] The configuration of the battery cell (100, 400), electrode assembly (110), case (120, 420), cap assembly (140, 150, 450) and insulator (160) of FIG. 1, FIG. 2, FIG. 3 and / or FIG. 5 may be all or part of the same as the configuration of the battery cell (400), case (420), cap assembly (450) and insulator (460) of FIG. 6a, FIG. 6b and / or FIG. 7. For example, at least part of the description of the battery cell (100, 400), electrode assembly (110), case (120, 420), cap assembly (140, 150, 450), and insulator (160) of FIGS. 1, 2, and 3 may be applied to the battery cell (400), electrode assembly (410), case (420), cap assembly (450), and insulator (460) of FIGS. 6A, 6B, and / or 7.

[0083] According to one embodiment, the electrode assembly (410) may be provided in multiple pieces. For example, the electrode assembly (410) may include a first electrode assembly (411) and a second electrode assembly (412). According to one embodiment, two electrode assemblies (411, 412) may be arranged within one case (420). The first electrode assembly (411) and the second electrode assembly (412) may be arranged within the case (420).

[0084] According to one embodiment, the insulator (460) may include a first insulator (461) surrounding at least a portion of the first electrode assembly (411) and a second insulator (462) surrounding at least a portion of the second electrode assembly (412). According to one embodiment (not shown), one insulator (460) may cover at least a portion of the first insulator (461) and at least a portion of the second insulator (462). According to one embodiment (not shown), the insulator (460) may be attached to a surface of the electrode assembly (410) except for a portion of the electrode assembly (410) where the foil (430) is positioned. According to one embodiment (not shown), the insulator (460) may be attached to five surfaces of the electrode assembly (410) except for one surface facing the cap assembly (450).

[0085] According to one embodiment, the battery cell (100) may include a foil (430) that electrically connects the electrode assembly (410) and terminal plates (451, 452). For example, the foil (430) may include a first foil (431) that connects a positive plate (not shown) of the electrode assembly (410) to a first terminal plate (451) and a second foil (432) that connects a negative plate (not shown) of the electrode assembly (410) to a second terminal plate (452). For example, the first foil (431) may be connected to a conductive rear portion (451a) of the first terminal plate (451), and the second foil (432) may be connected to a conductive rear portion (452a) of the second terminal plate (452).

[0086] According to one embodiment, the case (420) may include a central portion (421) having a third thickness (t3) and a border portion (422) having a fourth thickness (t4) thinner than the third thickness (t3). The border portion (422) may extend from the central portion (421). For example, the border portion (422) may be a portion of the case (420) extending from an edge of the central portion (421). The central portion (421) and the border portion (422) may be formed to have a curved inner surface (423).

[0087] In one embodiment, the rim portion (422) can be connected to the cap assembly (450). In one embodiment, the description of the first thickness (t1) of the central portion (121) and the second thickness (t2) of the rim portion (122) in FIG. 2 can be applied to the third thickness (t3) of the central portion (421) and the fourth thickness (t4) of the rim portion (422) in FIG. 7.

[0088] In one embodiment, the case (420) can provide pressure to the electrode assembly (410). For example, the case (420) can provide pressure to cause the first electrode assembly (411) and the second electrode assembly (412) to be in close contact with each other. The first electrode assembly (411) can include a first side (411a) facing the case (420) and a second side (411b) opposite the first side (411a). The second electrode assembly (412) can include a third side (412a) facing the second side (411b) and a fourth side (412b) opposite the third side (412a) and facing the case (420).

[0089] The central portion (421) may include a first central portion (421a) capable of providing pressure to a first surface (411a) of the first electrode assembly (411) and a second central portion (421b) capable of providing pressure to a fourth surface (412b) of the second electrode assembly (412). For example, the first central portion (421a) may contact the first insulator (461) and / or the first electrode assembly (411). The second central portion (421b) may contact the second insulator (462) and / or the second electrode assembly (412). As the electrode assembly (410) receives pressure from the first central portion (421a) and the second central portion (421b), the stability of the electrode assembly (410) may be increased.

[0090]

[0091] The above description is merely an example of applying the principles of the present disclosure, and other configurations may be further included without departing from the scope of the present disclosure.

[0092] While the embodiments of the present disclosure have been described above, the scope of the present disclosure is not limited thereto, and it will be apparent to those skilled in the art that various modifications and variations are possible without departing from the technical spirit of the present disclosure as set forth in the claims. For example, the present disclosure may be implemented by deleting some of the components in the above-described embodiments, and the embodiments may be implemented in combination with each other.

Claims

1. Case; and comprising an electrode assembly disposed within the case; The above case has a central portion having a first thickness, and A battery cell including a border portion extending from the center portion and having a second thickness thinner than the first thickness.

2. In paragraph 1, The above case is It comprises a first side region having a first width and a second side region having a second width greater than the first width, A battery cell wherein the central portion and the edge portion form at least a portion of the second side region.

3. In paragraph 1, A battery cell wherein the central portion is configured to provide pressure to the electrode assembly.

4. In paragraph 1, A battery cell wherein the first distance between the electrode assembly and the center is shorter than the second distance between the electrode assembly and the edge.

5. In paragraph 1, A battery cell in which the central portion and the edge portion form a curved inner surface.

6. In paragraph 1, Further comprising an insulator covering at least a portion of the electrode assembly; The above-mentioned border is a battery cell separated from the above-mentioned insulator.

7. In paragraph 1, A battery cell comprising a first electrode assembly including a first side facing the case and a second side opposite the first side, and a second electrode assembly including a third side facing the second side and a fourth side opposite the third side and facing the case.

8. In paragraph 7, A battery cell comprising a first center portion providing pressure to the first surface of the first electrode assembly and a second center portion providing pressure to the fourth surface of the second electrode assembly.

9. In paragraph 1, The case includes an opening extending from a first end of the case to a second end opposite the first end, A battery cell further comprising a first cap assembly covering the first end, and a second cap assembly covering the second end of the opening.

10. In paragraph 1, The above case is a battery cell manufactured using an extrusion process.

11. A first extrusion mold including a base including at least one through hole for accommodating a metal substrate and a core portion protruding from the base; and A second extrusion mold including a receiving portion that receives the core portion, The above core part A manufacturing device for a case including a first central core portion having a first length and an end portion extending from the central core portion and having a second length greater than the first length.

12. In paragraph 11, The first extrusion mold includes a back surface configured to face a piston for pressurizing the metal base material and a front surface opposite the back surface, The above second extrusion mold is a manufacturing device for a case arranged on the front surface of the above first extrusion mold.

13. In paragraph 11, A manufacturing device for a case, wherein at least one through hole is located adjacent to a corner of the core portion.

14. In paragraph 11, The second extrusion mold includes an inner surface defining the receiving portion, A device for manufacturing a case in which the distance between the central core portion and the inner surface is longer than the distance between the end portion of the core portion and the inner surface.

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