Secondary battery manufacturing device and secondary battery manufacturing method

Abstract

A secondary battery manufacturing apparatus according to various embodiments of the present disclosure may include a mold portion that applies a primary pressure in a first direction to a molding region of a battery case, and applies a secondary pressure in a second direction opposite to the first direction to the molding region deformed by the primary pressure. The secondary battery manufacturing apparatus and the secondary battery manufacturing method according to various embodiments of the present disclosure can minimize pressure applied to a side wall of a battery case in a process of forming a final hemming portion by first performing pressurization in a direction opposite to a pressurization direction for forming the final hemming portion.

Description

Technical Field

[0001] This disclosure relates to the field of secondary battery technology, and in particular to a secondary battery manufacturing apparatus and a secondary battery manufacturing method. Background Technology

[0002] Various types of secondary batteries are used as energy sources in electric vehicles or electronic devices. Secondary batteries use electrode assemblies in the form of a jelly-roll, which consists of a negative electrode plate, a positive electrode plate, and a separator, or they use electrode assemblies manufactured by stacking the negative electrode plate, the positive electrode plate, and the separator in an appropriate order.

[0003] This electrode assembly is housed inside the battery casing and connected to the negative and positive terminals, and is sealed inside the casing while it is filled with electrolyte. Summary of the Invention

[0004] Technical problems to be solved

[0005] This disclosure provides a secondary battery manufacturing apparatus and a secondary battery manufacturing method that can minimize damage to the battery casing during the secondary battery manufacturing process.

[0006] Technical solution

[0007] A secondary battery manufacturing apparatus according to various embodiments of the present disclosure may include: a mold section that applies a primary pressure to a molding area of ​​a battery casing in a first direction, and applies a secondary pressure to the molding area, which is deformed by the primary pressure, in a second direction opposite to the first direction.

[0008] In an exemplary embodiment, the first direction may be a direction away from the central axis of the battery casing.

[0009] In an exemplary embodiment, the secondary pressure may be less than the primary pressure.

[0010] In an exemplary embodiment, the aforementioned molded region may be formed axially upward relative to the electrode assembly housed inside the aforementioned battery casing.

[0011] In an exemplary embodiment, the molding area may include the area in the sidewall of the battery casing where the rolled edge is formed.

[0012] In an exemplary embodiment, the molding area can protrude outward from the radial side of the battery casing under the action of the primary pressure, and the molding area can be recessed inward from the radial side of the battery casing under the action of the secondary pressure.

[0013] In an exemplary embodiment, the mold section can apply the primary pressure or the secondary pressure while rotating.

[0014] In an exemplary embodiment, the aforementioned mold portion can apply the aforementioned primary pressure while at least a portion is housed inside the aforementioned battery casing.

[0015] In an exemplary embodiment, a control unit is included, which controls the position of the mold part. The control unit can move the mold part from a first position for applying the primary pressure to the side wall of the battery casing to a second position for applying the secondary pressure to the side wall of the battery casing.

[0016] In an exemplary embodiment, the mold section may include a first mold section that applies the primary pressure and a second mold section that applies the secondary pressure.

[0017] In an exemplary embodiment, a support roller is included, which is disposed on the opposite side of the mold portion with respect to the battery casing. The support roller may be configured to support at least one of the upper or lower regions of the molding area.

[0018] In an exemplary embodiment, the device may include: a first rotating clamp that supports the outer side of the battery housing to rotate the battery housing during the application of the primary pressure; and a second rotating clamp that supports the inner side of the battery housing to rotate the battery housing during the application of the secondary pressure.

[0019] According to various embodiments of the present disclosure, a secondary battery manufacturing apparatus for forming a rolled edge portion in the battery casing of a secondary battery includes: a first mold, at least a portion of which is disposed inside the battery casing, for pressing a forming area of ​​the sidewall of the battery casing to protrude radially outward; and a second mold for pressing the forming area protruding radially outward under the action of the first mold to recess radially inward, wherein the direction of the pressure of the first mold and the direction of the pressure of the second mold may be opposite to each other.

[0020] A secondary battery manufacturing method according to various embodiments of the present disclosure may include: a first molding step, applying a pressure to a molding area of ​​the battery casing in a first direction; and a second molding step, applying a secondary pressure to the molding area, which has been deformed by the first pressure, in a second direction opposite to the first direction.

[0021] In an exemplary embodiment, the first direction may be a direction away from the central axis of the battery casing.

[0022] In an exemplary embodiment, the secondary pressure may be less than the primary pressure.

[0023] In an exemplary embodiment, the aforementioned molded region may be formed above the electrode assembly housed inside the aforementioned battery casing.

[0024] In an exemplary embodiment, during the first molding step, the molding area can protrude outward from the radial side of the battery casing under the action of the first pressure, and during the second molding step, the molding area can be recessed inward from the radial side of the battery casing under the action of the second pressure.

[0025] In an exemplary embodiment, after the first molding step is completed, a mold part moving step may be included, in which the mold part that has performed the first molding step is moved to a position for performing the second molding step.

[0026] In an exemplary embodiment, the second molding step may be performed after the deformation of the molding region begins in the first molding step.

[0027] Technical effect

[0028] According to various embodiments of the present disclosure, the secondary battery manufacturing apparatus and method can minimize the pressure applied to the sidewall during the process of forming the final crimped portion on the sidewall of the battery casing by first applying pressure in the opposite direction to the pressure direction used for forming the final crimped portion.

[0029] In addition, it can minimize damage to the outer peripheral surface of the sidewalls (e.g., damage to the coating) that occurs during the forming of the rolled edge. Attached Figure Description

[0030] Figure 1 This is a schematic cross-sectional view of a secondary battery that can be manufactured by a secondary battery manufacturing apparatus and method according to exemplary embodiments of the present disclosure.

[0031] Figure 2 and Figure 3 This is a schematic diagram illustrating a secondary battery manufacturing apparatus and method according to exemplary embodiments of the present disclosure;

[0032] Figure 4 and Figure 5 This is a schematic diagram illustrating a secondary battery manufacturing apparatus and method according to exemplary embodiments of the present disclosure;

[0033] Figure 6 A flowchart illustrating a method for manufacturing a secondary battery according to an exemplary embodiment of the present disclosure;

[0034] Figure 7 This is a flowchart of a secondary battery manufacturing method according to an exemplary embodiment of the present disclosure. Detailed Implementation

[0035] As used in this specification, unless the context clearly indicates otherwise, the singular form may contain the plural form.

[0036] Furthermore, in the context of explaining and asserting the contents of this disclosure, expressions such as “comprise,” “consist of,” and “have” should be interpreted in a non-exclusive manner. Unless otherwise stated, they indicate that the corresponding component may exist, and therefore should be interpreted as including other components rather than excluding other components.

[0037] It should be understood that the accompanying drawings are only schematic representations of the features of this disclosure and may be scaled down or enlarged compared to the actual figures. They are also drawings that are exaggerated or omitted.

[0038] The secondary battery described in this disclosure can be any type of conventional battery capable of converting the chemical energy of the material stored in the battery into electrical energy and capable of being charged / discharged multiple times.

[0039] Figure 1 This is a schematic cross-sectional view of a secondary battery that can be manufactured by a secondary battery manufacturing apparatus and method according to exemplary embodiments of the present disclosure.

[0040] See Figure 1 The secondary battery 1, which can be manufactured by the secondary battery manufacturing apparatus and method according to various embodiments of the present disclosure, may include an electrode assembly 20, a battery casing 30, and a cover assembly 40.

[0041] First, the electrode assembly 20 may include a first electrode plate (not shown), a second electrode plate (not shown), and a diaphragm (not shown). The electrode assembly 20 may be wound around a winding shaft in a state where the first electrode plate and the second electrode plate are positioned without contacting each other by the diaphragm.

[0042] For example, the first electrode plate may be a negative electrode plate. In an exemplary embodiment, the first electrode plate may include a first coated portion having a negative electrode coating formed on a negative electrode current collector in the form of a metal foil, and a first uncoated portion having no negative electrode coating formed.

[0043] For example, the second electrode plate may be a positive electrode plate. The second electrode plate may include a second coated portion on a positive electrode current collector in the form of a metal foil coated with a positive electrode active material and a second uncoated portion on the positive electrode current collector without a positive electrode active material coated thereon.

[0044] The first uncoated portion and the second uncoated portion can be exposed at both ends of the axial direction of the electrode assembly to form electrode tabs.

[0045] The diaphragm is positioned between the first electrode plate and the second electrode plate to prevent the first electrode plate and the second electrode plate from short-circuiting due to electrical connection.

[0046] The battery casing 30 can be formed as a cylinder with an internal space. For example, the battery casing 30 can be formed as a shape with an open upper end in the axial direction. The battery casing 30 can be formed of a metallic material, and may include a plating to ensure corrosion resistance. Here, a cylindrical shape of the battery casing 30 is used as an example for ease of understanding, but this is only exemplary. It should be understood that the secondary battery manufacturing apparatus and method disclosed herein can be applied to battery casings 30 of any shape.

[0047] The battery housing 30 may include a bottom wall 32 and a side wall 31. The bottom wall 32 may be generally configured in a disk shape and is used to house electrode terminals 80. The side wall 31 may be a cylindrical portion extending upward from the periphery of the bottom wall 32. Electrode assemblies may be inserted into the interior of the battery housing 30 through its open upper end.

[0048] The sidewall 31 of the battery casing 30 may be formed with a beading part 35 and a crimping part 37.

[0049] The electrode assembly housed inside the battery casing 30 can be secured by the rolled edge 35 formed on the side wall 31 of the battery casing 30.

[0050] The rolled edge 35 is formed by a portion of the sidewall 31 above the electrode assembly 20 recessed radially inward, providing a portion for placing the cover assembly 40 and for securing the electrode assembly 20.

[0051] For example, the battery casing 30 can be electrically connected to the first electrode plate via the first current collector 60 connected to the rolled edge portion 35.

[0052] The crimping portion 37 may be a portion of the upper end of the side wall 31 bent into the cover assembly 40. The crimping portion 37 may be formed by bending the upper end of the side wall 31 toward the inside of the battery casing 30 while the cover assembly 40 is placed on the aforementioned rolled edge portion 35. By forming the crimping portion 37 into the cover assembly 40, the cover assembly 40 can be fixed and the inside of the battery casing 30 can be sealed.

[0053] After the electrode assembly and electrolyte are placed inside the battery casing 30, the cover assembly 40 can be attached to the opening 51 to seal the battery casing 30. For example, the cover assembly 40 can be placed in the rolled edge 35.

[0054] The cover assembly 40 may include a cover plate 41 and a sealing gasket 42.

[0055] The cover plate 41 can be a circular plate to correspond to the shape of the opening 51. The periphery of the cover plate 41 can be covered by a sealing gasket 42.

[0056] For example, after the sealing gasket 42 is placed on the rolled edge 35, the cover plate 41 can be placed on top of the sealing gasket 42.

[0057] The sealing gasket 42 can be bent together with the opening 51 of the battery casing 30 by a pressing process while it is disposed between the cover plate 41 and the battery casing 30.

[0058] Electrode terminals 80, which connect to the second electrode plate, can be provided on the bottom wall 32 of the battery casing 30. For example, the electrode terminals 80 can be connected to the second electrode plate via a second current collector 70. The second current collector 70 can be insulated from the battery casing 30 via an insulator 72. The electrode terminals 80 can be configured to be insulated from the battery casing 30 via an insulating gasket 81.

[0059] The structure of the secondary battery 1 described above is merely an example to help understand this disclosure, and the scope of this disclosure is not limited to the detailed structure of the secondary battery 1.

[0060] In describing various embodiments of this disclosure, the axial direction may refer to the central axis around which the wound electrode assembly 20 is wound (e.g., ...). Figure 1 The direction in which C extends is parallel to the direction in which the radial direction is parallel to the direction that is close to or far from the central axis.

[0061] On the other hand, since the central axis of the cylindrical battery casing 30 and the central axis of the electrode assembly 20 are formed on the same axis, the axial direction in this disclosure can be understood as the direction parallel to the direction in which the central axis of the cylindrical battery casing 30 extends, and the radial direction can also be understood as the direction parallel to the direction from the central axis of the cylindrical battery casing 30 toward the sidewall 31.

[0062] On the other hand, during the manufacturing process of the secondary battery, the rolled edge portion 35 of the battery casing 30 is recessed between the electrode assembly and the crimping portion 37 to fix the electrode assembly, and can also serve as a buffer to prevent external forces applied to the electrode assembly during the formation of the crimping portion 37.

[0063] Typically, for the rolled edge portion 35, the sidewall 31 can be formed by contacting and pressing with a rolling edge mold while the battery casing 30 is rotating, so that the sidewall 31 is recessed inward toward the center of the battery casing 30. Here, the method of forming the rolled edge portion 35 by pressing the sidewall 31 inward with a rolling edge mold can be described as an "intaglio forming method".

[0064] However, these methods can cause damage to the area of ​​the sidewall 31 that contacts the crimping die during the forming process of the crimped portion 35. For example, the outer surface of the sidewall 31 may have a coating for corrosion resistance, but the coating may be damaged due to contact and pressure from the crimping die.

[0065] This disclosure provides a secondary battery manufacturing apparatus and method that can minimize damage to the sidewall 31 during the forming process of the rolled edge 35.

[0066] In various embodiments of this disclosure, the method of applying external pressure and internal pressure sequentially to the sidewall 31 to form the rolled edge 35 differs from the intaglio forming method. Here, it can be described as a "composite forming method".

[0067] More specifically, in this disclosure, when forming the rolled edge 35 on the sidewall 31, by first forming in the opposite direction (e.g., radially outward) of the desired forming direction (e.g., radially inward), and then forming a second time in the desired direction, the necessary stress required for the sidewall 31 to deform in order to form the rolled edge 35 is reduced, thereby reducing the stress borne by the outer surface of the forming area. Therefore, in this disclosure, compared to the "intaglio forming method," the rolled edge 35 can be formed into the desired shape with less stress, thereby minimizing damage to the outer surface of the sidewall 31 caused by contact with the rolled edge mold.

[0068] Figures 2 to 5 This is a schematic diagram illustrating a secondary battery manufacturing apparatus and method according to exemplary embodiments of the present disclosure.

[0069] Secondary battery manufacturing equipment

[0070] First see Figures 2 to 5 The present disclosure will specifically describe a secondary battery manufacturing apparatus according to various embodiments thereof.

[0071] See Figures 2 to 5 The secondary battery manufacturing apparatus according to an exemplary embodiment of the present disclosure may include a mold section 100, a support roller 200, and a control section (not shown). Additionally, the secondary battery manufacturing apparatus may also include a rotary fixture 300 for rotating the battery casing 30 during the forming process of the rolled edge 35.

[0072] The mold part 100 includes a pressure surface 110, which is used to contact the battery casing 30 and apply pressure to the battery casing 30, and can be configured to rotate around a rotation axis parallel to the central axis of the battery casing 30.

[0073] For example, the shape of the pressure surface 110 of the mold section 100 can be set to correspond to the specific shape of the rolled edge section 35 to be formed.

[0074] The mold section 100 can apply pressure to the molding area of ​​the battery casing 30 while rotating around the rotation axis. The mold section 100 can deform the molding area of ​​the sidewall 31 by rolling friction on the inner or outer peripheral surface of the sidewall 31.

[0075] The molding area may refer to any side portion of the battery casing 30. For example, the molding area may refer to one side portion of the sidewall 31 of the battery casing 30. For example, the molding area may include a portion for forming a rolled edge 35 in the sidewall 31 of the battery casing 30. Here, the molding area may be described as the portion above the electrode assembly in the sidewall 31. However, this is only exemplary, and the molding area may be applied to any part of the battery casing 30 that needs to be deformed, for example, it may also refer to one side portion of the bottom wall 32 of the battery casing 30.

[0076] For example, the mold section 100 can apply pressure to the molding area of ​​the battery casing 30 in a first direction.

[0077] The first direction can refer to a direction opposite to the direction of final deformation. For example, the first direction can refer to the radially outward direction away from the central axis of the battery casing 30. However, it is not limited to this. For example, if the direction to be formed is radially outward, the first direction can refer to the radially inward direction toward the central axis of the battery casing 30.

[0078] A primary pressure can be a deformation force used to create internal stress within the forming area in the direction opposite to the final deformation to be formed.

[0079] Furthermore, the mold section 100 can apply secondary pressure to the molding area of ​​the battery casing 30 in a second direction opposite to the first direction. For example, the mold section 100 can apply secondary pressure to the molding area that has been deformed by primary pressure in a second direction opposite to the first direction.

[0080] The second direction can be the direction of the final deformation. For example, the second direction can refer to the radially inward side near the central axis of the battery casing 30. However, it is not limited to this. For example, if the first direction refers to the radially inward side, the second direction can also refer to the radially outward side opposite to it.

[0081] The secondary pressure can be a deformation force used to deform the forming area in the direction of the final desired deformation. For example, in this disclosure, the secondary pressure may be less than the primary pressure described above, but it is not limited thereto.

[0082] For example, the mold portion 100 may be disposed inside the battery casing 30. In the first molding step, the mold portion 100 may be at least partially housed inside the battery casing 30, and the pressure surface 110 may contact the inner circumferential surface of the side wall 31 to apply pressure. In the first molding step, the mold portion 100 may be disposed at a first position inside the battery casing 30.

[0083] For example, the mold part 100 may be provided outside the battery casing 30. In the second molding step, the mold part 100 may be provided at a second position outside the battery casing 30.

[0084] The pressure applied to the molding area by the mold section 100 can be controlled by the control unit. The duration of pressure applied to the molding area by the mold section 100 can also be controlled by the control unit.

[0085] The displacement of the mold section 100 can be controlled by the control unit. For example, the mold section 100 can be moved from a first position to a second position to sequentially perform the first molding step and the second molding step.

[0086] In an exemplary embodiment, the mold portion 100 may include a first mold portion 100a and a second mold portion 100b.

[0087] The first mold part 100a can be disposed in a first position inside the battery casing 30 to perform the first molding step. The second mold part 100b can be disposed in a second position outside the battery casing 30 to perform the second molding step.

[0088] For example, when viewed from above, the first mold section 100a and the second mold section 100b can be arranged parallel to each other with reference to the central axis of the battery casing 30, but they are not limited to this.

[0089] In an exemplary embodiment, the molding area of ​​the battery casing 30 can protrude and deform radially outward under the action of the primary pressure, and the molding area can be recessed and deformed radially inward under the action of the secondary pressure.

[0090] With the side wall 31 of the aforementioned outer casing as a reference, the support roller 200 can be disposed on the opposite side of the aforementioned mold section 100. The support roller 200 can support the side wall 31 in the opposite direction to the pressure generated by the mold section 100, thereby preventing unnecessary deformation of the side wall 31.

[0091] For example, the support roller 200 may be configured to support at least one region in the upper or lower region of the area where a primary pressure or the aforementioned secondary pressure is applied to the side wall 31 of the battery casing 30 (e.g., the forming region).

[0092] For example, in the first molding step, since the molding area of ​​the sidewall 31 is deformed to bulge outward in a radial direction, the support roller 200 can support the sidewall 31 in a manner that does not interfere with the first molding part 35A that bulges outward from the sidewall 31 in a radial direction.

[0093] For example, the support roller 200 may include an interference prevention groove (not shown) that is configured to be adjacent to the outer peripheral surface of the sidewall 31 and to prevent interference with the first forming part 35A when supporting the upper and lower parts of the forming area.

[0094] In an exemplary embodiment, the support roller 200 may be configured to support the upper and lower regions of the area (e.g., the forming region) where a primary pressure or the aforementioned secondary pressure is applied to the sidewall 31 of the battery casing 30.

[0095] For example, such as Figures 2 to 4 As shown, the support roller 200 may include: a first support roller 210, which is configured to support the upper region of the forming area of ​​the sidewall 31 of the battery casing 30; and a second support roller 220, which is configured to support the lower region of the forming area of ​​the sidewall 31 of the battery casing 30.

[0096] The control unit can be configured to control the pressure, pressurization time and / or position of the mold section 100.

[0097] For example, the control unit can control the secondary pressure applied in the second forming step S930 to be less than the primary pressure applied in the first forming step S910. In this disclosure, as described above, this is because the internal stress remaining inside the first formed portion 35A formed in the first forming step S910 allows the rolled edge portion 35 to be processed with less pressure in the second forming step S930. Therefore, in this disclosure, even if the control unit controls the secondary pressure to be less than the primary pressure, the desired deformation amount corresponding to the desired shape of the rolled edge portion 35 can be achieved.

[0098] In addition, the control unit can be configured to control the position of the support roller 200 according to the position of the mold unit 100.

[0099] For example, such as Figure 2 and Figure 3 As shown, when the first molding step S910 and the second molding step S930 are performed by a mold unit 100, the control unit can move the mold unit 100 from a first position for applying pressure once in the first molding step S910 to a second position for applying pressure twice.

[0100] In addition, the control unit can control the pressure application time of the mold section 100. The control unit can control the application of pressure from the first mold section 100a to the second mold section 100b.

[0101] The rotary clamp 300 may include a first rotary clamp 310 and a second rotary clamp 320.

[0102] The first rotating fixture 310 may be configured to rotate the battery casing 30 during the first molding step. For example, the first rotating fixture 310 may be located outside the battery casing 30. For example, the first rotating fixture 310 may support one side of the exterior of the battery casing 30 to rotate the battery casing 30.

[0103] Since the battery mold portion 100 is located inside the battery housing 30 in the first molding step of this disclosure, the first rotating clamp 310 for rotating the battery housing 30 supports one side of the outer side of the battery housing 30. However, it is not limited to this; the first rotating clamp 310 may be configured to support one side of the inner side of the battery housing 30 in a position that does not interfere with the mold portion 100, thereby allowing it to rotate.

[0104] The second rotary fixture 320 may be configured to rotate the battery casing 30 during the second molding step. For example, at least a portion of the second rotary fixture 320 may be disposed inside the battery casing 30. For example, the second rotary fixture 320 may support one side of the interior of the battery casing 30 to rotate the battery casing 30. For example, as... Figure 3 As shown in (a), the second rotating clamp 320 may be configured to support the open upper end of the battery housing 30 to rotate the battery housing 30, but is not limited thereto.

[0105] Alternatively, the second rotary clamp 320 may be the same component as the first rotary clamp 310 described above. In this case, during the first molding step, the first rotary clamp 310 and the second rotary clamp 320 may be configured to support the battery casing 30 at a position that does not interfere with the mold section 100.

[0106] Secondary battery manufacturing method

[0107] Hereinafter, a method for manufacturing a secondary battery using a secondary battery manufacturing apparatus according to various embodiments of the present disclosure will be specifically described based on the aforementioned structure of the secondary battery.

[0108] Figure 6 This is a flowchart of a secondary battery manufacturing method according to an exemplary embodiment of the present disclosure. Figure 7 This is a flowchart of a secondary battery manufacturing method according to an exemplary embodiment of the present disclosure.

[0109] See Figure 6 and Figure 7The secondary battery manufacturing method according to an exemplary embodiment of the present disclosure may include a first forming step for forming a sidewall 31 of the battery casing 30 in a direction opposite to the forming direction of the final rolled edge portion 35, and a second forming step for forming the sidewall 31 again in the forming direction of the final rolled edge portion 35.

[0110] First molding step (creating residual stress)

[0111] A secondary battery manufacturing method according to an exemplary embodiment of the present disclosure may include a first molding step. The first molding step may be a step for forming internal residual stress in the battery casing 30 in the opposite direction before forming the rolled edge 35 on the battery casing 30.

[0112] For example, in the first molding step, the mold section 10 can form the first molding section 35A by applying pressure to the inner circumferential surface of the sidewall 31 at a first position inside the battery casing 30. The first position can be a position inside the battery casing 30 at a height corresponding to the height of the molding area of ​​the sidewall 31.

[0113] See also Figure 2 and Figure 3 An exemplary description will be provided of the case where the first molding step and the second molding step of this disclosure are performed sequentially by a mold unit 100.

[0114] See Figure 2 In (a), during the first molding step, the mold part 100 can form the first molding part 35A by contacting and pressing the inner peripheral surface of the side wall 31 through rolling friction.

[0115] In the first molding step, the sidewall 31 of the battery casing 30 may protrude and deform in a direction opposite to the molding direction of the final rolled edge 35 (e.g., radially inward). That is, the direction of the primary pressure applied to the sidewall 31 in the first molding step may be opposite to the direction of the secondary pressure applied to the sidewall 31 in the second molding step.

[0116] The first molding step can be performed while the battery casing 30 is rotated by the first rotating jig 310.

[0117] In the first molding step, pressure can be applied once to the inner circumferential surface of the side wall 31 of the battery casing 30 in a radially outward direction through the mold part 100.

[0118] Here, the area in the side wall 31 of the battery casing 30 that is pressurized by the mold section 100 can be described as the molding area. In the first molding step, the inner circumferential surface of the molding area in the side wall 31 can be pressurized by the mold section 100.

[0119] In the first molding step, the molding area of ​​the sidewall 31 can be deformed radially outward by the pressure of the mold part 100.

[0120] Through the first molding step, a first molding portion 35A protruding radially outward can be formed on the side wall 31 of the battery casing 30. Residual stress accumulates inside the first molding portion 35A during the deformation process under pressure.

[0121] For example, the shape of the first forming part 35A may be the same as that of the second forming part 35B described below, except for the direction of protrusion, but it is not limited thereto. Here, the first forming part 35A may be described as a relief shape.

[0122] In the first molding step, since the mold section 100 needs to apply pressure to the inner peripheral surface of the side wall 31 of the battery casing 30, the mold section 100 can be installed inside the battery casing 30. At this time, the position where the mold section 100 applies pressure to the inner peripheral surface of the side wall 31 inside the battery casing 30 can be described as the first position. For example, the first position could be a height inside the battery casing 30 corresponding to the height of the molding area of ​​the side wall 31. For example, the first position could be a position where the pressure surface 110 of the mold section 100 is adjacent to the side wall 31.

[0123] In the first molding step, the pressure surface 110 of the mold part 100 rotates while in contact with the inner circumferential surface of the side wall 31, so that the side wall 31 can be deformed into a relief shape through rolling friction.

[0124] During the first molding step, when the mold section 100 applies pressure to the inner circumferential surface of the sidewall 31, the outer circumferential surface of the sidewall 31 can be supported by the support roller 200. The support roller 200 can support the sidewall 31 in the opposite direction to the pressure generated by the mold section 100, thereby preventing unnecessary deformation of the sidewall 31.

[0125] See Figure 2 (b) After the first molding part 35A is formed by the mold part 100, the control part can move the mold part 100 to a ready position so as to remove it from the inside of the battery casing 30. For example, the ready position can be a position adjacent to the central axis of the battery casing 30.

[0126] In an exemplary embodiment, the first molding step of this disclosure can be performed with the electrode assembly not inserted into the battery casing 30. This is to prevent contamination of the electrode assembly by foreign matter that may occur during the process, and to prevent interference between the mold portion 100 and the electrode assembly. Therefore, in this case, the electrode assembly can be inserted after the first molding step is completed. However, this is not a limitation; the first molding step can also be performed with the electrode assembly already contained within the casing.

[0127] Typically, in the manufacturing process of a secondary battery, pressure is applied to the sidewall 31 of the battery casing 30 in a radially inward direction so that the direction of the concave edge 35 is the same as that of the crimped edge 35, thereby forming the crimped edge 35.

[0128] However, in this disclosure, the first forming part 35A with a relief shape is first formed by applying pressure to the sidewall 31 in the opposite radial direction.

[0129] The first molding step provided in this disclosure is to utilize the Bauschinger effect when processing the second molding part 35B in the second molding step, so as to minimize damage to the molding area of ​​the battery casing 30 while molding the rolled edge 35.

[0130] Specifically, the Bauschinger effect refers to the phenomenon that after processing a metallic material in one direction, deformation in the opposite direction becomes easier. For example, when a metallic material is deformed in the tensile direction, internal defects such as dislocations are generated and move, resulting in work hardening. During this process, residual stress remains within the material. This residual stress affects the microstructure of the material, reducing its resistance to deformation in the opposite direction (compression). That is, when processing in the compressive direction after tensile deformation, the yield strength in the compressive direction decreases due to the interaction between the existing residual stress and dislocations, making the material more susceptible to deformation in the compressive direction.

[0131] According to an exemplary embodiment, in this disclosure, when designing the required deformation amount of the rolled edge portion 35 of the battery casing 30, due to the residual internal stress in the first forming portion 35A that deforms under pressure in the opposite direction, the rolled edge portion 35 with the required deformation amount can be processed in the second forming step of forming the final rolled edge portion 35 even if only a pressure smaller than that used to form the first forming portion 35A is applied. Therefore, in this disclosure, even when processing the rolled edge portion 35 with the same deformation amount, the pressure applied to the outer peripheral surface of the sidewall 31 can be minimized by the Bauschinger effect, and damage to the sidewall 31 (e.g., damage to the plating) generated during processing can be minimized.

[0132] Second forming step (forming the curled edge)

[0133] A secondary battery manufacturing method according to various embodiments of the present disclosure may include a second molding step. The second molding step may be a step for forming a final rolled edge 35 using the residual stress formed on the sidewall 31 (e.g., the molding area) of the battery casing 30 by the first molding step.

[0134] The second molding step can be performed after at least the first molding step has been completed. The second molding step can be performed after at least a portion of the battery casing 30 has begun to deform through the first molding step.

[0135] The second molding step can be performed by applying the second pressure in the opposite direction to the first pressure while the internal stress generated by the first pressure remains in the molding area of ​​the side wall 31 of the battery casing 30.

[0136] In the second molding step, the mold section 100 may apply a secondary pressure radially inward to the outer peripheral surface of the sidewall 31 of the battery casing 30. The direction of application of the secondary pressure may be opposite to the direction of application of the primary pressure. For example, the secondary pressure may be less than the primary pressure. However, here, as an example to minimize damage to the molded area of ​​the battery casing 30, it is explained that the applied secondary pressure is less than the primary pressure, but this is not a limitation. It should be understood that, in the second molding step, damage to the molded area can also be prevented by controlling the number of rotations or the rotation speed of the mold section 100.

[0137] The area where secondary pressure is applied can be at least the same area as the area where primary pressure is applied in the sidewall 31 of the battery casing 30. For example, in the second molding step, secondary pressure can be applied to the first molded portion 35A of the embossed shape formed by the first molding step.

[0138] In the second molding step, the first molded portion 35A, which protrudes outward in the first molding step, can be reversed by secondary pressure to protrude radially inward. Through the second molding step, a second molded portion 35B protruding radially inward can be formed on the sidewall 31 of the battery casing 30. The second molded portion 35B can be the final rolled edge portion 35. Here, the second molded portion 35B can be described as an intaglio shape.

[0139] For example, the shape of the second forming part 35B can be the same as that of the first forming part 35A, except for the direction of protrusion, but it is not limited to this.

[0140] In the second molding step, since the mold part 100 needs to pressurize the outer peripheral surface of the side wall 31 of the battery casing 30, the mold part 100 can be performed in a state where it is located outside the battery casing 30.

[0141] At this time, the position where the mold part 100 applies secondary pressure to the outer peripheral surface of the side wall 31 inside the battery casing 30 can be described as the second position. For example, the second position may be a position at a height corresponding to the height of the molding area of ​​the side wall 31 outside the battery casing 30. For example, the second position may be a position where the pressure surface 110 of the mold part 100 is disposed adjacent to the outer peripheral surface of the first molding part 35A.

[0142] See you again Figure 3 In (a) of the exemplary embodiment, the second molding step may be performed by moving the mold portion 100, which is in the ready position after the first molding portion 35A has been processed, to a second position outside the battery casing 30.

[0143] In this case, after completing the first molding step, the secondary battery manufacturing method may further include a mold section 100 moving step S920, which moves the mold section 100 that has performed the first molding step to a position for performing the second molding step.

[0144] In the second molding step, the mold part 100 at the second position can form the second molding part 35B by contacting and pressing the outer peripheral surface of the side wall 31 through rolling friction.

[0145] For example, the second molding step can be performed while the battery casing 30 is rotated by the second rotating jig 320.

[0146] See you again Figure 3 (b) In an exemplary embodiment, after the second forming portion 35B is formed, the control unit can terminate the forming process of the crimped portion 35 by moving the mold portion 100 to a termination position spaced apart from the side wall 31 of the battery casing 30.

[0147] See above. Figure 2 and Figure 3 This illustrates that the first molding step and the second molding step are performed through a mold section 100; however, this is only exemplary and the disclosure is not limited thereto.

[0148] Alternatively, for example, the first molding step and the second molding step can be performed sequentially by their respective mold sections 100.

[0149] exist Figure 4 and Figure 5 In the embodiments described herein, the only difference between the first molding step and the second molding step being performed by their respective mold sections 100 is that they are the same as those described above, and therefore repeated descriptions are omitted.

[0150] See you again Figure 4 and Figure 5The first molding step can be performed by a first mold section 100a located at a first position inside the battery casing 30. The second molding step can be performed by a second mold section 100b located at a second position outside the battery casing 30.

[0151] See Figure 4 When viewed from above, the first mold section 100a and the second mold section 100b can be arranged parallel to each other with the central axis of the battery casing 30 as a reference.

[0152] In this embodiment, since the control unit does not need to move the position of the mold unit 100 to perform the second molding step after the first molding step is completed, the speed of the entire process can be faster than in the aforementioned embodiment.

[0153] In an exemplary embodiment, the control unit can also control the second mold unit 100b to start a second molding step even if the first molding step performed by the first mold unit 100a has not been completed.

[0154] For example, the second molding step may begin after at least a portion of the battery casing 30 has begun to undergo deformation caused by a single pressure.

[0155] For example, the first molding part 35A can be formed along the periphery of the side wall 31 by the first mold part 100a during one rotation of the battery casing 30. Even if the battery casing 30 does not complete one rotation to form the first molding part 35A completely around the periphery, the control unit can still start pressurizing the first molding part 35A executed by the second mold part 100b.

[0156] In this embodiment, since the process is performed by a separate mold section 100, as long as at least a portion of the battery casing 30 is formed into the first molded portion 35A by the first mold section 100a, the control section can control the second mold section 100b to apply secondary pressure to the formed first molded portion 35A.

[0157] For example, such as Figure 4 As shown, when the first mold section 100a and the second mold section 100b are arranged side by side when viewed from above, the first molding section 35A can be formed by the first mold section 100a while the battery casing 30 is rotating, and pressure can be applied by the second mold section 100b from the moment when the battery casing 30 has only rotated 0.5 revolutions.

[0158] Therefore, according to this embodiment, the secondary battery manufacturing method can ensure a faster manufacturing speed. Alternatively, depending on the requirements, the manufacturing speed can be further improved by changing the configuration of the first mold section 100a and the second mold section 100b.

[0159] As described above, in the secondary battery manufacturing apparatus and method according to various embodiments of the present disclosure, a first forming step S910, which deforms in the opposite direction, is performed before the second forming step S930 for forming the final rolled edge portion 35. This minimizes the pressure applied to the outer peripheral surface of the sidewall 31 during the forming of the rolled edge portion 35 on the sidewall 31 of the battery casing 30, and minimizes damage to the sidewall 31 (e.g., damage to the plating) that occurs during forming.

[0160] While the foregoing has described how all components constituting the embodiments of this disclosure are combined or work in combination, this disclosure is not necessarily limited to these embodiments. That is, all components may work by more than one selective combination, provided they are within the scope of the purpose of this disclosure. All terms, including technical or scientific terms, are to have the same meaning as commonly understood by one of ordinary skill in the art, unless otherwise defined. Terms in common use, such as those defined in dictionaries, should be interpreted as meaning consistent with the context of the relevant art and should not be interpreted as having an idealized or overly formal meaning unless expressly defined in this disclosure.

[0161] The above description is merely illustrative of the technical concept of this disclosure. Those skilled in the art can make various modifications and variations within the scope of the essential characteristics of this disclosure. Therefore, the embodiments disclosed herein are intended to illustrate, but not limit, the technical concept of this disclosure, and the scope of the technical concept of this disclosure is not limited to these embodiments.

Claims

1. A secondary battery manufacturing apparatus, comprising: The mold section applies a first pressure to the forming area of ​​the battery casing in a first direction, and applies a second pressure to the forming area, which is deformed by the first pressure, in a second direction opposite to the first direction.

2. The secondary battery manufacturing apparatus according to claim 1, wherein, The first direction is the direction away from the central axis of the battery casing.

3. The secondary battery manufacturing apparatus according to claim 1, wherein, The secondary pressure is less than the primary pressure.

4. The secondary battery manufacturing apparatus according to claim 1, wherein, The shaped region is formed axially upward relative to the electrode assembly housed inside the battery casing.

5. The secondary battery manufacturing apparatus according to claim 1, wherein, The forming area includes the area in the sidewall of the battery casing where the rolled edge is formed.

6. The secondary battery manufacturing apparatus according to claim 1, wherein, The forming area protrudes radially outward from the battery casing under the primary pressure, and the forming area indents radially inward from the battery casing under the secondary pressure.

7. The secondary battery manufacturing apparatus according to any one of claims 1-6, comprising: The control unit is used to control the position of the mold section. The control unit is used to move the mold unit from a first position for applying the primary pressure to the side wall of the battery casing to a second position for applying the secondary pressure to the side wall of the battery casing.

8. The secondary battery manufacturing apparatus according to any one of claims 1-6, The mold section includes a first mold section for applying the primary pressure and a second mold section for applying the secondary pressure.

9. The secondary battery manufacturing apparatus according to any one of claims 1-6, comprising: A first rotating clamp supports one side of the outer side of the battery housing to rotate the battery housing during the application of the primary pressure; as well as A second rotating clamp supports one side of the inside of the battery casing to rotate the battery casing during the application of the secondary pressure.

10. A method for manufacturing a secondary battery, comprising: In the first molding step, pressure is applied once to the molding area of ​​the battery casing in the first direction; as well as In the second forming step, a second pressure is applied to the forming area that has been deformed by the first pressure in a second direction opposite to the first direction.

11. The method for manufacturing a secondary battery according to claim 10, wherein, The first direction is the direction away from the central axis of the battery casing.

12. The method for manufacturing a secondary battery according to claim 10, wherein, The secondary pressure is less than the primary pressure.

13. The method for manufacturing a secondary battery according to claim 10, wherein, The shaped area is formed above the electrode assembly housed inside the battery casing.

14. The method for manufacturing a secondary battery according to claim 10, wherein, In the first molding step, under the action of the pressure, the molding area deforms and bulges outward radially from the battery casing. In the second molding step, under the action of the secondary pressure, the molding area is deformed and recessed towards the radially inward side of the battery casing.

15. The method for manufacturing a secondary battery according to any one of claims 10-14, After completing the first molding step, the process includes: The mold part moving step involves moving the mold part that has performed the first molding step to a position for performing the second molding step.

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