Clamp for manufacturing rechargeable batteries

Abstract

The present invention relates to a jig for manufacturing a rechargeable battery. The jig for manufacturing a rechargeable battery according to an embodiment of the present invention includes a plurality of pressing portions for pressing a periphery of a welding portion of a cylindrical rechargeable battery, and a jig plate that supports the plurality of pressing portions and includes a flow path for circulating a refrigerant therein.

Description

Technical Field

[0001] Cross-references to related applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2020-0180717, filed on December 22, 2020, with the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference.

[0003] The present invention relates to a fixture for manufacturing rechargeable batteries, and more specifically, to a fixture for manufacturing rechargeable batteries that prevents the gasket in a rechargeable battery, including a sealing gasket, from being damaged by welding. Background Technology

[0004] In recent years, the demand for portable electronic products, such as laptops, cameras, and mobile phones, has increased rapidly, and the development of electric vehicles, energy storage batteries, robots, and satellites is active. As a result, much research has been conducted on rechargeable batteries that can be used as the power source for these products.

[0005] The electrode assembly installed in the battery case is a power generation element constructed with a stacked structure, including a positive electrode, a separator, and a negative electrode. This power generation element can be repeatedly charged and discharged. Electrode assemblies are categorized into wound, stacked, and stacked / folded types. A wound type is obtained by inserting a separator between an elongated positive electrode coated with active material and an elongated negative electrode, and then winding them together. A stacked type is a structure in which multiple positive and negative electrodes of predetermined dimensions are sequentially stacked with separators inserted between them. A stacked / folded type is a hybrid structure of wound and stacked types. Among these, the wound type electrode assembly has the advantages of being easy to manufacture and having a high energy density per unit weight.

[0006] Rechargeable batteries are categorized by their casing shape into cylindrical, prismatic, and pouch batteries. In cylindrical batteries, the electrode assembly is housed in a cylindrical metal canister; in prismatic batteries, the electrode assembly is housed in a square metal canister; and in pouch batteries, the electrode assembly is housed in a pouch-shaped casing made of aluminum laminates. Cylindrical batteries offer the following advantages: they have relatively high capacity and a stable structure.

[0007] Figure 1 This is a partial cross-sectional view of the upper part of a conventional cylindrical rechargeable battery.

[0008] Reference Figure 1 The wound electrode assembly 5 is housed in the cylindrical box 2, and the cover assembly 3 is mounted on the open upper part of the cylindrical box 2, thereby enabling the manufacture of a cylindrical rechargeable battery 1.

[0009] The cover assembly 3 includes an upper end cover 31 and an internal pressure-reducing safety vent 32, and the upper end cover 31 can be tightly attached to the internal pressure-reducing safety vent 32.

[0010] Safety vent 32 can be electrically connected to electrode assembly 5 via current interruption device (CID) 6. The edge of current interruption device 6 can be surrounded by CID pad 7.

[0011] On the other hand, regarding the connection between the cover assembly 3 and the cylindrical box 2, a gasket is positioned between the cover assembly 3 and the cylindrical box 2, and then the upper part of the cylindrical box 2 is bent to form a press-fit connection between the cover assembly 3 and the cylindrical box 2. The press-fit portion 22 can be formed in the cylindrical box 2 by the press-fit connection. In order to ensure a stable connection of the cover assembly 3 and prevent the electrode assembly 5 from flowing, a curled portion 21 can be formed below the press-fit portion 22, in which a portion of the cylindrical box 2 is recessed along the central direction of the electrode assembly 5.

[0012] At this time, the gasket 4 is installed on the inner surfaces of the crimping portion 22 and the curling portion 21 to enhance the sealing performance between the cover assembly 3 and the cylindrical box 2. However, when constructing a battery module or the like by connecting multiple cylindrical rechargeable batteries 1, welding may be performed on the upper end cap 31 of the cover assembly 3 or on the upper end of the crimping portion 22 of the cylindrical box 2. At this time, the gasket 4 may be damaged due to the heat generated during the welding process.

[0013] Damaged gasket 4 may cause deterioration of the sealing capability of the cylindrical rechargeable battery 1, and electrolyte may leak through the gap between the crimp portion 22 and gasket 4 or the gap between the cover assembly 3 and gasket 4. Leaking electrolyte may cause corrosion on the upper surface of the cylindrical rechargeable battery 1, and may also cause a short circuit in the upper portion of the cylindrical rechargeable battery 1. Summary of the Invention

[0014] Technical issues

[0015] The problem to be solved by the present invention is to provide a jig for manufacturing rechargeable batteries that can prevent the liner from being damaged by heat generated during the manufacturing process of rechargeable batteries, especially during welding.

[0016] However, the problems to be solved in the embodiments of the present invention are not limited to the above-described problems, and various extensions can be made within the scope of the technical spirit included in the present invention.

[0017] Technical solutions

[0018] A fixture for manufacturing a rechargeable battery according to an embodiment of the present invention includes: a plurality of pressing portions for pressing the periphery of a welded portion of a cylindrical rechargeable battery; and a fixture plate supporting the plurality of pressing portions and including a flow path for circulating a refrigerant.

[0019] It may also include a cooling device that circulates refrigerant into the interior of the clamping plate.

[0020] Multiple pressing parts and clamping plates may include copper alloys.

[0021] Copper alloys can include beryllium copper.

[0022] Multiple pressing portions may include a conveying portion corresponding to the welding portion, which conveys the laser beam.

[0023] The fixture plate may include multiple transfer holes, each corresponding to a transfer portion of a plurality of pressing portions.

[0024] A cylindrical rechargeable battery may include: an electrode assembly; a battery case housing the electrode assembly and having an open upper portion; a cover assembly coupled to the open upper portion of the battery case; a gasket positioned between the battery case and the cover assembly; and a crimping portion formed by inserting the gasket between the battery case and the cover assembly and crimping the battery case and the cover assembly together, wherein the welded portion may be the upper portion of the crimping portion.

[0025] In the welded section, the crimped part and the connecting member can be joined together.

[0026] The connecting component can be electrically connected to the negative terminal of the electrode assembly.

[0027] The connecting component may be a strip of metal wire, and the width of the metal wire is 0.1 mm or greater.

[0028] Beneficial effects

[0029] According to an embodiment of the present invention, when manufacturing a rechargeable battery, even if the welding process is applied to the crimping portion of the upper part of the pad and the temperature rises, the pad can be cooled rapidly, thus preventing physical deformation of the pad, which is made of polymer material, and preventing damage to the pad.

[0030] The effects of the present invention are not limited to those described above, and those skilled in the art will clearly understand other unmentioned effects based on the following description. Attached Figure Description

[0031] Figure 1This is a partial cross-sectional view of the upper part of a conventional cylindrical rechargeable battery.

[0032] Figure 2 This is a partial perspective view of a rechargeable battery. According to an embodiment of the present invention, a fixture for manufacturing a rechargeable battery can be applied to the rechargeable battery.

[0033] Figure 3 It shows along Figure 2 A partial cross-sectional view of a portion of the cross-section cut by the section line A-A'.

[0034] Figure 4 This is a top view of the clamping plate and cooling device of a fixture for manufacturing a rechargeable battery according to an embodiment of the present invention.

[0035] Figure 5 This is a front view of a fixture for manufacturing a rechargeable battery according to an embodiment of the present invention. Detailed Implementation

[0036] The invention will be described more fully below with reference to the accompanying drawings, in which exemplary embodiments of the invention are illustrated. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention.

[0037] For clarity of description, parts irrelevant to the description have been omitted from the drawings, and similar reference numerals denote similar elements throughout the specification.

[0038] Furthermore, for better understanding and ease of description, the dimensions and thicknesses of the elements shown in the figures are arbitrarily illustrated, and the invention is not necessarily limited thereto. In the figures, the thicknesses of layers, films, panels, regions, etc., are exaggerated for clarity.

[0039] It will be understood that when an element, such as a layer, film, region, or substrate, is referred to as being "on" another element, the element may be located directly on the other element or there may be intermediate elements present. Conversely, when an element is referred to as being "directly on" another element, there are no intermediate elements present. Furthermore, in this specification, the terms "on" or "above" refer to being positioned on or below the target portion and do not necessarily mean being positioned on the upper side of the target portion based on the direction of gravity.

[0040] Furthermore, unless explicitly stated otherwise, the word “including” and variations thereof, such as “containing” or “comprising”, shall be understood to imply inclusion of the stated element but not exclusion of any other element.

[0041] Furthermore, throughout the instruction manual, the phrase "on a plane" means viewing the target portion from the top, and the phrase "on a cross-section" means viewing the cross-section formed by vertically cutting the target portion from the side.

[0042] Figure 2 This is a partial perspective view of a rechargeable battery. According to an embodiment of the present invention, a fixture for manufacturing a rechargeable battery can be applied to the rechargeable battery. Figure 3 It shows along Figure 2 A partial cross-sectional view of a portion of the cross-section cut by the section line A-A'.

[0043] According to this embodiment, a jig for manufacturing a rechargeable battery is used to press and support the crimping portion 220 and the connecting member 900 in a welding step. The welding step is used to weld and bond the connecting member 900 to the crimping portion 220, which is formed at the upper portion of the rechargeable battery by crimping the battery case 200 and the cover assembly 300. The resulting rechargeable battery 100 includes: an electrode assembly 500; a battery case 200, in which the electrode assembly 500 is housed and the upper portion of the battery case 200 is open; a cover assembly 300, which is coupled to the open upper portion of the battery case 200; and a gasket 400, which is positioned between the battery case 200 and the cover assembly 300.

[0044] The electrode assembly 500 can be formed of a wound electrode assembly having the following structure: in this structure, a spacer 530 is inserted between an elongated positive electrode 510 and an elongated negative electrode 520 and then wound. However, it is not limited to this; it can also be formed of a stacked electrode assembly including cell units, a stacked-folded electrode assembly, or a laminated-stacked electrode assembly. The stacked electrode assembly has a structure in which rectangular positive and rectangular negative electrodes are stacked with spacers inserted between them. In the stacked-folded electrode assembly, the cell units are wound through an elongated separator. In the laminated-stacked electrode assembly, the cell units are stacked and attached to each other with spacers inserted between them.

[0045] The cover assembly 300 includes an upper end cover 310 and a safety vent 320. The upper end cover 310 is positioned on the safety vent 320 and forms a structure that is in close contact with the safety vent 320 for electrical connection. The upper end cover 310 protrudes upward in the center and is electrically connected to the positive terminal 510 of the electrode assembly 500 via a positive terminal contact 511, thereby performing the function of a positive terminal through connection with an external circuit.

[0046] Furthermore, a negative terminal (not shown) can be attached to the bottom of the electrode assembly 500 and connected to the bottom of the battery case 200. As described above, since the negative terminal 520 is electrically connected to the battery case 200, as will be described later, the connecting member 900 functions as a negative terminal through connection with an external circuit by welding and connecting it to the crimp portion 220 of the battery case 200.

[0047] The battery box 200 may be cylindrical and may include a curled portion 210 and a crimped portion 220.

[0048] The coiled portion 210 refers to a portion of the battery case 200 that is recessed along the central direction of the electrode assembly 500, and the coiled portion 210 serves to securely connect the cover assembly 300 and prevent the electrode assembly 500 from flowing. Here, the central direction of the electrode assembly 500 can be represented as the radial direction from the outer peripheral surface of the wound electrode assembly 500 to the center.

[0049] The crimping portion 220 refers to the portion positioned at the upper part of the curled portion 210 to surround the cover assembly 300, and the crimping portion 220 is used for a stable connection of the cover assembly 300. Specifically, the battery case 200 and the cover assembly 300 can be crimped together by inserting a gasket 400 between the battery case 200 and the cover assembly 300, so that the crimping portion 220 can be formed on the battery case 200. That is, the crimping portion 220 is formed by positioning the gasket 400 between the battery case 200 and the cover assembly 300 and bending the end of the battery case 200. In this way, the cover assembly 300 can be installed and the rechargeable battery 100 can be sealed. The gasket 400 is installed on the inner surface of the crimping portion 220 and the curled portion 210 to increase the sealing force between the cover assembly 300 and the battery case 200.

[0050] On the other hand, the current interruption device (CID) 700 and the CID gasket 800 can be positioned below the safety vent 320. The safety vent 320 is a current-passing thin-film structure and can form two indentations 321 and 322 with different depths.

[0051] The current interruption device 700 is a component of the conductive plate and may include an outer peripheral portion 710 and a blocking portion 720 surrounded by the outer peripheral portion 710. Furthermore, although not specifically illustrated, multiple through holes for venting gas may be formed. In abnormal operating conditions, when the pressure inside the rechargeable battery 100 increases, the blocking portion 720 separates from the outer peripheral portion 710 and may block the electrical connection between the external circuitry and the electrode assembly 500.

[0052] CID gasket 800 is a component surrounding the edge of current interruption device 700 and prevents safety vent 320 from contacting the outer peripheral portion 710.

[0053] On the other hand, when the rechargeable batteries 100 or more are assembled to form a battery module or battery pack, the connecting member 900 made of metal material can be welded to the upper part of the crimping portion 220 of the battery case 200 as a negative electrode connecting member. That is, a welded portion W is formed at the part where the upper part of the crimping portion 220 connects with the connecting member 900. In addition, the positive electrode connecting member (not shown) can be welded and connected to the upper central part of the upper end cover 310.

[0054] There are no particular restrictions on the welding method, and ultrasonic welding, laser welding, or resistance welding can be performed. In recent years, to manufacture high-performance and high-power battery modules, the width and thickness of the connecting member 900 made of metallic material to be welded to the rechargeable battery 100 have increased. In this case, strong welding conditions are required to weld the connecting member 900, with its increased thickness and width, to the upper portion of the press-fit portion 220. For example, the connecting member 900 can be a strip-shaped metal wire, and its thickness can be 0.1 mm or greater. For example, the thickness of the connecting member 900 can be between 0.1 mm and 20 mm, and preferably less than 10 mm. Furthermore, the width of the connecting member 900 can be 0.1 mm or greater, for example, between 0.1 mm and 20 mm, and preferably less than 10 mm. However, when welding is performed under strong welding conditions as described above to join the connecting member 900 with its increased thickness and width, high heat is generated during the process, which may cause damage to the gasket 400 adjacent to the welded portion. Damaged gasket 400 may cause deterioration of the sealing capability of rechargeable battery 100 and may cause electrolyte leakage into the gap between crimp 220 and gasket 400 or the gap between cover assembly 300 and gasket 400.

[0055] The gasket 400 according to this embodiment includes a polymer material and a resin and can be manufactured by injection molding. Specifically, it may include a polyolefin-based material or polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), perfluoroalkoxy compounds (PFA), etc., such as polyethylene, polypropylene, and polyisobutylene. In particular, polybutylene terephthalate (PBT) is an elastomer with good elasticity, and because the injection performance is improved when this material is included, the gasket 400 is easy to mold. In addition, it has a high melting point and can achieve high stability at high temperatures.

[0056] When the fixture for manufacturing rechargeable batteries according to this embodiment is applied, even if a strong weld is performed at the crimping portion 220 near the gasket 400 with the connecting member 900 made of metal material, damage to the gasket 400 can be prevented and the sealing ability of the gasket 400 can be maintained, thereby preventing electrolyte leakage.

[0057] In the following text, refer to Figure 4 and Figure 5 The configuration of the fixture used to manufacture rechargeable batteries is described in detail.

[0058] Figure 4 This is a top view of the clamping plate and cooling device of a fixture for manufacturing a rechargeable battery according to an embodiment of the present invention. Figure 5 This is a front view of a fixture for manufacturing a rechargeable battery according to an embodiment of the present invention.

[0059] like Figure 4 and Figure 5 As shown, a jig 10 for manufacturing a rechargeable battery according to an embodiment of the present invention includes: a plurality of pressing portions 40 for pressing around a welded portion W of a cylindrical rechargeable battery 100; and a jig plate 20 supporting the plurality of pressing portions 40 and including a flow path 23 for circulating a refrigerant.

[0060] The plurality of pressing portions 40 may include a cylindrical body portion 41 and a conveying portion 42, which is surrounded by the body portion 41 and formed to correspond to the welding portion W. A laser beam LB irradiated by the conveying portion 42 reaches the welding portion W, enabling welding to be performed. During this process, the body portion 41 is fixed by pressing the periphery of the welding portion W.

[0061] Multiple pressing portions 40 can be formed of a metal with high thermal conductivity. For example, they can include copper alloys, such as beryllium copper. In particular, in the case of beryllium copper, due to its high strength and high thermal conductivity, the heat generated during welding can be effectively transferred from the welding portion W to the clamp plate 20 while maintaining the strength of the pressing portion 40.

[0062] A clamp plate 20 is provided to support multiple pressing parts 40. For example, as Figure 5As shown, multiple pressing portions 40 can be configured to attach to the lower portion of a clamping plate 20 having a plate shape. In this case, multiple transfer holes 24 can be formed in the clamping plate 20, each transfer hole 24 corresponding to a transfer portion 42 among the multiple pressing portions 40. Therefore, by irradiating the clamping plate 20 with a laser beam LB, the laser beam LB can sequentially penetrate the transfer holes 24 and the transfer portions 42, and then reach the welding portion W. However, the welding system of the present invention is not limited to this, and various systems for welding the negative electrode portion of a rechargeable battery can be applied.

[0063] Furthermore, the clamping plate 20 can be made of a metal with high thermal conductivity. For example, it can include a copper alloy, such as beryllium copper. In particular, in the case of beryllium copper, since beryllium copper has both high strength and high thermal conductivity, the heat generated in the welded portion W can be effectively dissipated while maintaining the strength of the clamping plate 20.

[0064] A flow path 23 is formed inside the fixture plate 20 through which refrigerant can flow. The refrigerant circulating in the flow path 23 can be connected to an external cooling device 30 and circulate. That is, the refrigerant that has absorbed heat inside the fixture plate 20 is configured to be cooled in the cooling device 30 and then circulate again inside the fixture plate 20. Therefore, the heat generated during welding can be exchanged in the cooling device 30 through the structure in which the refrigerant circulates internally. That is, the refrigerant supplied by the cooling device 30 circulates inside the fixture plate 20 to cool the fixture plate 20, and when the fixture plate 20 is cooled, the plurality of pressing portions 40 attached to the fixture plate 20 are also cooled. Since the plurality of pressing portions 40 are in direct contact with the periphery of the welding portion W and pressurize the periphery of the welding portion W, the heat generated by the welding portion W can be cooled.

[0065] With this configuration, even if heat is generated in the weld portion W during welding, the heat can be rapidly transferred to the outside and cooled. That is, the heat generated in the weld portion W during welding is sequentially transferred to the weld portion W, the periphery of the weld portion, the pressing portion 40, the clamp plate 20, and the refrigerant in the flow path 23, and finally cooled by heat exchange in the cooling device 30. Therefore, damage to the gasket 400 located below the weld portion W due to the heat generated during welding can be prevented.

[0066] When the rechargeable battery 100 is manufactured using the fixture 10 used for manufacturing rechargeable batteries, damage to the pad 400 due to welding can be prevented, thus preventing electrolyte leakage through the gap between the crimp portion 220 and the pad 400 or the gap between the cover assembly 300 and the pad 400. Furthermore, while preventing damage to the pad 400 as described above, the thickened connecting member 900 can be securely connected to the battery case 200 for higher output, and then a stable electrical connection to the outside can be achieved. Moreover, since welding can be performed without damaging the pad 400 due to heat, the rechargeable battery 100 can be arranged and welded in one direction. When welding is performed by arranging it in one direction, the busbars can be minimized, the cooling structure of the module with multiple rechargeable batteries 100 can be improved, and there is the advantage that no additional parts are needed to change the polarity of the electrodes.

[0067] In this example implementation, directional terms such as front, back, left, right, up, and down are used, but these terms are only for ease of explanation and may vary depending on the location of the target or the observer's position.

[0068] Rechargeable batteries manufactured using the fixture for manufacturing rechargeable batteries according to the present embodiment described above can be aggregated in multiples to form a battery module. This battery module can be mounted with various control and protection systems, such as a battery management system (BMS) and a cooling system, to form a battery pack.

[0069] Rechargeable batteries, battery modules, or battery packs can be used in a variety of devices. Specifically, battery modules or battery packs can be used in vehicles such as electric bicycles, electric vehicles, and hybrid vehicles, but are not limited to these, and can be used in various devices that can use rechargeable batteries.

[0070] While the invention has been described in conjunction with embodiments now considered practical, it should be understood that the invention is not limited to the disclosed embodiments. Rather, the invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

[0071] Figure label:

[0072] 10: Fixtures used in the manufacture of rechargeable batteries

[0073] 20: Fixture plate

[0074] 23: Flow path

[0075] 30: Cooling device

[0076] 40: Pressing part

[0077] 100: Rechargeable battery

[0078] 200: Battery Box

[0079] 300: Cover component

[0080] 400: Padding

[0081] 500: Electrode assembly

Claims

1. A fixture for manufacturing rechargeable batteries, the fixture comprising: Multiple pressing portions are used to press the periphery of the welded portion of the cylindrical rechargeable battery; as well as A clamping plate supports and cools the plurality of pressing portions and includes a flow path for the circulation of refrigerant. The plurality of pressing portions include a conveying portion corresponding to the welding portion, the conveying portion conveying a laser beam. The clamp plate includes a plurality of transfer holes, each of which corresponds to a transfer portion of each of the plurality of pressing portions. The plurality of pressing portions are attached to the lower portion of the clamp plate, which has a plate shape.

2. The fixture for manufacturing rechargeable batteries according to claim 1, wherein the fixture further comprises: A cooling device that circulates refrigerant into the interior of the clamp plate.

3. The fixture for manufacturing rechargeable batteries according to claim 1, wherein, The plurality of pressing parts and the clamp plate comprise a copper alloy.

4. The fixture for manufacturing rechargeable batteries according to claim 3, wherein, The copper alloy includes beryllium copper.

5. The fixture for manufacturing rechargeable batteries according to claim 1, wherein, The cylindrical rechargeable battery includes: Electrode assembly; A battery case that houses the electrode assembly, and the battery case having an open upper portion; A cover assembly, the cover assembly being connected to the open upper portion of the battery compartment; A gasket, the gasket being positioned between the battery compartment and the cover assembly; and A crimping portion is formed by inserting the gasket between the battery compartment and the cover assembly and crimping the battery compartment and the cover assembly together. The welded portion is the upper part of the crimped portion.

6. The fixture for manufacturing rechargeable batteries according to claim 5, wherein, In the welded portion, the crimping part and the connecting member are connected.

7. The fixture for manufacturing rechargeable batteries according to claim 6, wherein, The connecting member is electrically connected to the negative terminal of the electrode assembly.

8. The fixture for manufacturing rechargeable batteries according to claim 6, wherein, The connecting member is a strip of metal wire, and the width of the metal wire is 0.1 mm or greater.

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