Battery cell and method of manufacturing the same

Abstract

Disclosed are a battery cell and a method of manufacturing the same. The battery cell includes a can case in which an electrode assembly is accommodated, and the can case has a terminal hole; a current collector plate disposed at an axial end portion of the electrode assembly; an insulating member interposed between the can case and the current collector plate; an electrode terminal unit inserted into the terminal hole; and a terminal bolt unit fastened to the current collector plate through the electrode terminal unit, thereby being fixed by the current collector plate.

Description

Technical Field

[0001] This application claims priority to Korean Patent Application No. 10-2024-0081413, filed on June 21, 2024, and Korean Patent Application No. 10-2025-0061340, filed on May 21, 2025, the entire contents of which are disclosed in the aforementioned patent applications and are incorporated herein by reference as part of this specification.

[0002] This invention relates to a battery cell and a method for manufacturing the same, which is capable of: preventing diaphragm damage caused by welding heat by omitting the welding of electrode terminals to the current collector; enhancing the fastening force and structural rigidity of the electrode terminals relative to the can housing; extending the current path from the electrode terminals to the current collector; and allowing electrolyte to be injected through the electrode terminals. Background Technology

[0003] Typically, a cylindrical battery cell comprises a can housing and an electrode assembly. The can housing is manufactured by deep drawing a sheet of metal to form a circular bottom and cylindrical sidewall members connected to that circular bottom. The electrode assembly is housed within the can housing.

[0004] Typically, in a cylindrical battery cell, the can housing is electrically connected to the first electrode of the electrode assembly, and the cover assembly that closes the opening of the can housing is electrically connected to the second electrode of the electrode assembly. Therefore, the can housing can constitute the first electrode, and the cover assembly can constitute the positive electrode.

[0005] Recently, a novel cylindrical battery cell has been developed. This battery cell has electrode terminals mounted in terminal holes at the bottom of a can housing, and the opening of the can housing is sealed by a cap. An insulating gasket is inserted between the electrode terminals and the can housing. A first current collector and a second current collector, respectively connected to the first and second electrodes of an electrode assembly, are welded to the two axial ends of the electrode assembly. The first current collector can be welded to the cap, and the second current collector can be welded to the electrode terminals.

[0006] However, the high temperatures and debris generated during the welding of current collectors to the electrode terminals and caps within the battery cell can tear or damage the separator of the electrode assembly. When the separator is torn or damaged, the positive and negative electrodes may come into electrical contact with each other, causing a short circuit, which could lead to a fire.

[0007] Alternatively, the current collector can be welded using resistance welding, ultrasonic welding, or laser welding. However, welding defects may occur due to poor flatness or appearance of the current collector. When defects appear in the welded area of ​​the current collector, the tensile strength of the welded area is significantly reduced, which may lead to low voltage.

[0008] In the battery cell, an insulating element is installed to provide electrical insulation between the can housing and the current collector. The insulating element is inserted between the bottom of the can housing and the current collector. Because the insulating element is a flat plate with a certain thickness, and the current collector is also flat, an ultrasonic welding head must be used to forcefully press the current collector into contact with the electrode terminals. During this process, the current collector may deform.

[0009] Therefore, the current collector may be excessively deformed, and the welded area may be pre-tensioned, which can adversely affect the weld strength. Additionally, vibrations or shocks generated during battery cell use can affect the welded area, potentially leading to weld detachment or current collector cracking. In particular, repeated and continuous tensile and stress forces can cause fatigue failure. When this occurs, the electrical connection between the electrode terminals and the current collector is damaged, potentially causing the battery cell to lose its function.

[0010] The background technology of this invention is disclosed in Korean Patent Application Publication No. 2022-0113654 (publication date: August 16, 2022, entitled "Fixing structure for electrode terminals, and battery, battery pack and vehicle including the fixing structure"). Summary of the Invention

[0011] Technical issues

[0012] To address the aforementioned problems, the present invention aims to provide a battery cell and a method for manufacturing the same, wherein the electrode terminals are electrically connected to the current collector without welding, thereby eliminating the welding process.

[0013] The purpose of this invention is to provide a battery cell and a method for manufacturing the same, wherein damage to the separator of the electrode assembly is prevented by not generating welding spatter or welding heat.

[0014] The purpose of this invention is to provide a battery cell that can significantly reduce the risk of short circuits or fires, and a method for manufacturing the same.

[0015] The purpose of this invention is to provide a battery cell and its manufacturing method that can significantly improve the bonding strength and structural rigidity of the electrode terminals.

[0016] The purpose of this invention is to provide a battery cell and a method thereof that can prevent the electrode terminals from popping out or detaching from the terminal holes of the battery casing during thermal runaway of the battery cell.

[0017] The purpose of this invention is to provide a battery cell and a method for manufacturing the same, wherein the connection between the electrode terminals and the current collector can be stably maintained even under vibration or impact.

[0018] The technical problem to be solved by the present invention is not limited to the above-described objectives. Other objectives and advantages not described herein may be understood through the following description and will become clearer through embodiments of the present invention. Furthermore, it is apparent that the objectives and advantages of the present invention may be achieved by the means specified in the claims and combinations thereof.

[0019] Technical solution

[0020] This invention can be applied to battery cells with a structure in which electrode terminals are electrically connected to current collectors.

[0021] The battery cell includes an electrode assembly and a housing that internally houses the electrode assembly.

[0022] The tank shell is provided with terminal holes.

[0023] The terminal hole may be located at the bottom of the tank shell. Preferably, the terminal hole may be circular in shape and located at the center of the tank shell.

[0024] The current collector is mounted on the electrode assembly. The current collector is electrically connected to the first electrode of the electrode assembly.

[0025] The current collector is located at the axial end of the electrode assembly.

[0026] The electrode terminal is inserted into the terminal hole. The electrode terminal can pass through the terminal hole.

[0027] A terminal bolt is provided at the electrode terminal, which passes through the electrode terminal and is fastened to the current collector.

[0028] The terminal bolts are constrained by the manifold at least.

[0029] Terminal bolts allow the current collector to contact the electrode terminals in the axial direction.

[0030] The electrode terminal may include: a terminal head that compresses the periphery of a terminal hole; and a terminal insertion portion that extends from the terminal head and inserts into the terminal hole.

[0031] The terminal head can extend radially outward from the axial outer end of the terminal insertion portion.

[0032] Terminal bolts pass through the terminal insertion portion to secure it to the manifold.

[0033] The electrode terminal may also include a plastically deformable portion that extends from the terminal insertion portion and is bent to compress the periphery of the terminal hole while facing the terminal head.

[0034] The plastic deformation portion may include: a plastic deformation rib, which is arranged in the circumferential direction at the end of the terminal insertion portion.

[0035] The plastic deformation ribs extend continuously or intermittently in the circumferential direction. For example, multiple plastic deformation ribs can be arranged in a circumferential direction, or a single plastic deformation rib with a circular tube shape extending in the circumferential direction can be arranged.

[0036] The terminal insertion part may be provided with a bolt hole for inserting the bolt body of the terminal bolt.

[0037] In some embodiments, the inner diameter of the bolt hole may be smaller than the outer diameter of the bolt body, so that the periphery of the bolt hole undergoes plastic deformation as the bolt body is inserted.

[0038] In some embodiments, the diameter of the bolt hole may be equal to or greater than the diameter of the terminal bolt.

[0039] The terminal head may be provided with a receiving groove for accommodating the bolt head of the terminal bolt.

[0040] The manifold may be equipped with a constraint tab into which terminal bolts are screwed.

[0041] In some embodiments, the manifold has a flat plate shape, and the height of the constraint tabs may be equal to or less than the thickness of the manifold.

[0042] In some embodiments, the manifold may include: a flat plate portion having a flat plate shape; and a protrusion portion that protrudes axially from the flat plate portion at a position corresponding to a terminal hole, and a restraining tab extends through the protrusion portion.

[0043] In some embodiments, the battery cell may further include a sealing member installed between the bolt head of the terminal bolt and the bottom surface of the receiving groove of the terminal head.

[0044] In some embodiments, the battery cell may further include a gasket inserted between the inner peripheral surface of the terminal hole and the outer peripheral surface of the electrode terminal to electrically insulate the electrode terminal from the can housing and seal the can housing.

[0045] The present invention provides a method for manufacturing a battery cell having the above-described structure. The method for manufacturing the battery cell may include: preparing a can housing having terminal holes; inserting a gasket into the terminal holes in an axial direction; inserting an electrode terminal into the terminal holes from the axially outer side of the terminal holes; and constraining the electrode terminal in the terminal holes by bending the plastic deformation portion of the electrode terminal radially outward.

[0046] The method for manufacturing a battery cell includes: inserting an electrode assembly with a current collector welded on it into a can housing, and arranging the constraint tabs of the current collector to correspond to the bolt holes of the electrode terminals.

[0047] The method for manufacturing a battery cell includes: after passing the terminal bolt through the bolt hole, tightening the terminal bolt to the restraint tab.

[0048] The method of manufacturing a battery cell may also include: providing a terminal bolt having a bolt body, the diameter of which is larger than the diameter of the bolt hole, such that the periphery of the bolt hole is plastically deformed as the bolt body is inserted.

[0049] The method of manufacturing a battery cell may further include: providing a current collector, the current collector comprising: a flat plate portion having a flat plate shape; and a protrusion portion protruding axially from the flat plate portion at a position corresponding to a terminal hole to extend the axial section of the current collector where the constraint tab is fastened to the current collector.

[0050] Beneficial effects

[0051] According to the present invention, since the terminal bolts are fastened to the current collector, there is no need to weld the electrode terminals to the current collector, thereby eliminating the welding process.

[0052] According to the present invention, since the welding process between the electrode terminals and the current collector can be omitted, damage to the diaphragm in the electrode assembly can be prevented, and the risk of short circuit or thermal runaway between electrodes can be significantly reduced.

[0053] According to the present invention, since the terminal bolts are fastened to the current collector, it is not necessary to forcefully contact the current collector with the electrode terminals in the axial direction for welding. Therefore, pre-tensioning of the current collector can be prevented.

[0054] According to the present invention, since the terminal bolts are screwed into the constraint tabs provided in the protrusions of the current collector, the bonding force between the electrode terminals and the current collector and the structural rigidity can be significantly improved.

[0055] According to the present invention, due to the significantly improved bonding force and structural rigidity of the electrode terminals, it is possible to prevent the electrode terminals from popping out or detaching from the terminal holes of the can housing during battery thermal runaway.

[0056] In addition to the aforementioned beneficial effects, the specific effects of the present invention will be further explained when describing the specific details of the present invention. Attached Figure Description

[0057] Figure 1 This is an exploded perspective view schematically showing the electrodes and separators that are separated from each other, constituting the battery cell according to the present invention.

[0058] Figure 2 It is shown schematically. Figure 1 A three-dimensional diagram showing the electrodes and diaphragms stacked on top of each other.

[0059] Figure 3 This is a schematic perspective view of a cylindrical electrode assembly according to the present invention.

[0060] Figure 4 This is a schematic cross-sectional view of a battery cell according to a first embodiment of the present invention.

[0061] Figure 5 It is shown schematically. Figure 4 A cross-sectional view of the connection structure of the electrode terminals of a battery cell.

[0062] Figure 6 It is shown schematically. Figure 5 An exploded view of the electrode terminals of a battery cell.

[0063] Figure 7 It is shown schematically. Figure 5 A cross-sectional view of the electrode terminals of a battery cell.

[0064] Figure 8 It is shown schematically. Figure 5 A top view of the electrode terminals of a battery cell.

[0065] Figure 9 This is a schematic cross-sectional view of a can housing with electrode terminals inserted into its terminal holes according to the present invention.

[0066] Figure 10 This is a schematic cross-sectional view of an electrode terminal according to the invention, which is inserted into a terminal hole in the can housing and has its plastically deformed portion bent outward.

[0067] Figure 11 This is a schematic cross-sectional view illustrating an electrode assembly in an insert can housing according to the present invention.

[0068] Figure 12 and Figure 13 This is a cross-sectional view schematically illustrating the process of inserting a terminal bolt into a constraint tab in a manifold hole according to the present invention.

[0069] Figure 14 This is a schematic cross-sectional view of a battery cell according to a second embodiment of the present invention.

[0070] Figure 15 It is shown schematically. Figure 14 A cross-sectional view of the connection structure of the electrode terminals of a battery cell.

[0071] Figure 16 This is a schematic cross-sectional view of a battery cell according to a third embodiment of the present invention.

[0072] Figure 17 It is shown schematically. Figure 16 A cross-sectional view of the connection structure of the electrode terminals of a battery cell.

[0073] [Explanation of reference numerals in the attached figures]

[0074] 1: Battery cell; 10: Tank shell; 11: Side wall component; 12: Bottom component; 14: Terminal hole; 20: Electrode assembly; 21: First electrode; 22: Second electrode; 23: Metal foil; 24: Active material layer; 25: Coated part; 26: Uncoated part; 27: Tab (cut tab); 28: Separator; 29: Core; 30: Current collector; 31: Flat plate; 32: Current collector hole; 33: Constraint tab; 35: Protrusion; 40: Insulator; 50: Gasket; 60: Electrode terminal; 61: Terminal head; 62: Receiving groove; 63: Terminal insertion part; 64: Bolt hole; 65: Plastic deformation part; 70: Terminal bolt; 71: Bolt head; 73: Bolt body; 74: Bolt thread; 80: Sealing component. Detailed Implementation

[0075] Preferred embodiments of the present invention will now be described.

[0076] This invention is not limited to the embodiments disclosed below, but can be implemented in various ways and with many different forms. The embodiments described herein are only intended to make the disclosure of the invention complete and to fully inform those skilled in the art of the scope of the invention. Therefore, the invention is not limited to the embodiments disclosed below, and it should be understood that the invention includes not only replacing or adding the configuration of one embodiment to the configuration of another embodiment, but also all changes and equivalents contained within the technical concept and scope of the invention.

[0077] The accompanying drawings are provided only to facilitate understanding of the embodiments disclosed herein. It should be understood that the technical concepts disclosed herein are not limited to the drawings, but rather encompass all changes, equivalents, and substitutions within the spirit and scope of the invention. In the drawings, for ease of understanding, the dimensions or thicknesses of constituent elements may be exaggerated to appear larger or smaller, but this should not be construed as limiting the scope of protection of the invention.

[0078] The terminology used herein is for illustrative purposes only and is not intended to limit the invention. Furthermore, unless the context clearly indicates otherwise, singular expressions include plural expressions. In this document, terms such as “comprising” and “consisting of” are intended to indicate the presence of features, values, steps, operations, constituent elements, components, or combinations thereof described in the specification. That is, it should be understood that the use of terms such as “comprising” and “consisting of” herein does not preclude the possibility of the presence or addition of one or more other features, values, steps, operations, constituent elements, components, or combinations thereof.

[0079] While terms including ordinal numbers such as "first" and "second" may be used to describe various constituent elements, these constituent elements are not limited by these terms. These terms are only used to distinguish one constituent element from another.

[0080] It should be understood that when an element is said to be "connected" to another element, the element can be directly connected to the other element, or there may be intermediate elements in between. On the other hand, when an element is said to be "directly connected" to another element, it should be understood that there are no intermediate elements in between.

[0081] When an element is described as being "above" or "below" another element, it should be understood that the element may be directly above or below the other element, and there may also be intermediate elements in between.

[0082] Unless otherwise defined, all terms used herein, including technical and scientific terms, shall have the meaning commonly understood by one of ordinary skill in the art to which this invention pertains. Terms such as those defined in common dictionaries shall be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and unless expressly limited herein, terms such as those defined in common dictionaries shall not be interpreted as having an idealized or overly formalized meaning.

[0083] The battery cell according to the first embodiment of the present invention will now be described.

[0084] The battery cell according to an embodiment of the present invention will now be described.

[0085] Figure 1 This is an exploded perspective view schematically showing the electrodes and separator that are separated from each other, constituting a battery cell according to the present invention. Figure 2 It is shown schematically. Figure 1 A three-dimensional diagram showing the electrodes and diaphragm stacked on top of each other, and Figure 3 This is a schematic perspective view of a cylindrical electrode assembly according to the present invention.

[0086] Reference Figures 1 to 3 According to an embodiment of the present invention, the cylindrical battery cell 1 includes: an electrode assembly 20; and a housing 10 for accommodating the electrode assembly 20.

[0087] Tank shell 10 (reference) Figure 4 It is cylindrical. The can housing 10 is made of conductive material and is electrically connected to the negative current collector 30 of the electrode assembly 20.

[0088] like Figure 2 As shown, the electrode assembly 20 includes a first electrode 21, a second electrode 22, and a diaphragm 28, each having a predetermined width and extending along the length direction. The electrode assembly 20 is formed as shown... Figure 2 The stacked body shown consists of a first electrode 21, a diaphragm 28, a second electrode 22, and a diaphragm 28 stacked sequentially, and as shown in the figure. Figure 3 The laminate is shown to be manufactured into a core form by winding it around a mandrel. The electrode assembly 20 is cylindrical and has a core 29 at its center as an empty space.

[0089] The first electrode 21 can be a positive electrode, and the second electrode 22 can be a negative electrode, or vice versa.

[0090] The first electrode 21 and the second electrode 22 are manufactured in sheet form. The electrode sheet is manufactured by coating an active material layer 24 onto the surface of a metal foil 23. The electrode has a coated portion 25 with the active material layer 24 coated on it and an uncoated portion 26 without the active material layer 24 coated on it. The positive electrode may have an uncoated portion 26 at its first end in the width direction, and the negative electrode may have an uncoated portion 26 at its second end in the width direction.

[0091] The uncoated portion 26 protrudes or extends from the laminate along its width. The uncoated portion 26 itself serves as a tab.

[0092] The uncoated portion 26 may be provided with slits at predetermined intervals to form flag-shaped slit tabs 27. Multiple slit tabs 27 may be arranged in a serrated pattern along the length of the electrode.

[0093] In this embodiment, a cutout tab 27 having an isosceles trapezoidal shape is taken as an example. However, the cutout tab 27 can have various shapes such as semicircle, semi-ellipse, triangle, rectangle, parallelogram, etc.

[0094] In this embodiment, a cut-out tab 27 with the same width and arranged along the length direction is taken as an example. However, the width of the cut-out tab 27 may gradually increase from the core towards the outer periphery or increase in a stepwise manner.

[0095] In this embodiment, a slit tab 27 with a gradually increasing height from the core towards the outer periphery is used as an example. However, the height of the slit tab 27 can be constant or can gradually decrease.

[0096] In this embodiment, the structure in which the cut tab 27 is removed from a predetermined section at the radial and centrifugal ends of the uncoated portion 26 is taken as an example. However, it is obvious that the cut tab 27 may not be removed from the radial end of the uncoated portion 26, nor may it be removed from the centrifugal end of the uncoated portion 26.

[0097] In the wound electrode assembly 20, such as Figure 3 As shown, the notched tab 27 can be bent and flattened in the radial direction. The notched tab 27 can be bent radially inward or radially outward. In this embodiment, the structure of the notched tab 27 being bent radially inward is taken as an example.

[0098] The slit tabs 27 can be bent one by one during the process of forming the core-type electrode assembly 20 by winding the laminate. Alternatively, all the slit tabs 27 can be bent at once after the core-type electrode assembly 20 has been formed by winding the laminate.

[0099] The cut tabs 27 of the first electrode 21 and the cut tabs 27 of the second electrode 22 are folded and overlapped in the radial direction, thereby forming a plane substantially perpendicular to the axial direction at the two axial ends of the electrode assembly 20.

[0100] like Figure 4 As shown, the current collector 30 can be coupled to a substantially flat surface formed by the curved cut-out tabs 27 exposed at the two axial ends of the electrode assembly 20.

[0101] In this embodiment, the current collector 30 coupled to the first axial end of the electrode assembly 20 can be a negative current collector, and the current collector coupled to the second axial end of the electrode assembly 20 can be a positive current collector. However, the current collector 30 coupled to the first axial end can be a positive current collector, and the current collector coupled to the second axial end can be a negative current collector.

[0102] The positive current collector may include aluminum, and the negative current collector may include copper. However, the materials are not limited to these.

[0103] The manifold 30 can be manufactured by punching, trimming, punching, and bending a metal sheet. However, it is obvious that the manufacturing process is not limited to these steps.

[0104] The tank shell 10 includes: a bottom member 12; a side wall member 11 connected to the bottom member 12 and extending in an axial direction; and a cover (not shown) covering the open end of the side wall member 11.

[0105] The bottom member 12 may have a disk shape, and the side wall member 11 may have a cylindrical shape. The bottom member 12 and the side wall member 11 may be integrally formed or connected by welding.

[0106] The bottom member 12 and the side wall member 11 can be manufactured by deep drawing a nickel-plated steel sheet and trimming it with a punch while holding the front end of the side wall member 11 with a blank holder. It is obvious that the material of the tank shell 10 is not limited to this.

[0107] According to this embodiment of the cylindrical battery cell 1, the current collector 30 is attached to the first axial end of the electrode assembly 20, i.e., the bottom side. For example, the back side of the current collector 30 can be welded to the tab 27 by irradiating the surface of the current collector 30 with a laser. The periphery of the current collector 30 corresponds to the tab 27 of the electrode assembly 20, and the center of the current collector 30 is arranged to seal the core 29 of the electrode assembly 20.

[0108] Figure 4 This is a schematic cross-sectional view of a battery cell according to a first embodiment of the present invention. Figure 5 It is shown schematically. Figure 4A cross-sectional view of the electrode terminal connection structure of a battery cell. Figure 6 It is shown schematically. Figure 5 An exploded view of the electrode terminals of a battery cell. Figure 7 It is shown schematically. Figure 5 A cross-sectional view of the electrode terminals of the battery cell, and Figure 8 It is shown schematically. Figure 5 A top view of the electrode terminals of a battery cell.

[0109] Reference Figures 4 to 8 According to the first embodiment of the present invention, the battery cell 10 includes: a can housing 10; a current collector 30; an insulating component 40; an electrode terminal 60; and a terminal bolt 70.

[0110] The can housing 10 can internally house the electrode assembly 20. The can housing 10 may have a cylindrical shape. The can housing 10 may include a bottom member 12 and side wall members 11. The bottom member 12 of the can housing 10 is provided with a terminal hole 14. The terminal hole 14, having a circular shape, may be located at the center of the bottom member 12.

[0111] The current collector 30 may be coupled to the axial end of the electrode assembly 20. The current collectors 30 coupled to the two axial ends of the electrode assembly 20 may be a positive current collector and a negative current collector, respectively. The positive current collector may include aluminum, and the negative current collector may include copper. However, the materials are not limited to these.

[0112] The manifold 30 can be manufactured by punching, trimming, punching and / or bending a metal sheet. The diameter of the manifold 30 is smaller than the diameter of the electrode assembly 20 and the diameter of the inner circumferential surface of the tank shell 10.

[0113] An insulating element 40 may be disposed between the tank housing 10 and the manifold 30. The insulating element 40 is made of insulating material to electrically insulate the bottom member 12 of the tank housing 10 from the manifold 30. The insulating element 40 may have a disc shape with a diameter larger than that of the manifold 30.

[0114] The battery cell 1 includes a gasket 50 inserted between the periphery of the electrode terminal 60 and the terminal hole 14. The gasket 50 electrically insulates the periphery of the electrode terminal 60 from the terminal hole 14.

[0115] The gasket 50 can be fitted into the terminal hole 14 in contact with the inner circumferential surface of the terminal hole 14. The gasket 50 is made of insulating material. The gasket 50 may have a tubular shape for insertion into the terminal hole 14 and a flange provided at one end. This flange is the portion that contacts the outer surface of the can housing 10. The gasket 50 may be integrally made of an elastic (stretchable) compressible material.

[0116] Electrode terminal 60 is inserted into terminal hole 14 and undergoes plastic deformation, extending beyond the periphery of terminal hole 14 to secure it to bottom member 12 of can housing 10. Here, the two axial ends of electrode terminal 60 are pressed against the periphery of terminal hole 14 in the axial direction. For example, electrode terminal 60 is electrically isolated from can housing 10 by gasket 50 and electrically connected to positive current collector 30 to serve as a positive terminal.

[0117] Terminal bolts 70 can be fastened to manifold 30 after passing through electrode terminals 60, thereby securing them to manifold 30. Terminal bolts 70 may include a bolt head 71 and a bolt body 73. The bolt head 71 may have a polygonal or circular cross-section. The bolt body 73 may extend axially from the bolt head 71. The surface of the bolt body 73 is provided with threads, and the axial length of the threads may be greater than the height of the manifold hole 32. In some embodiments, the threads may be provided along the entire length of the bolt body 73.

[0118] Therefore, since the terminal bolts 70 are fastened and constrained to the current collector 30, there is no need to weld the electrode terminals 60 to the current collector 30. Alternatively, the terminal bolts 70 can electrically connect the electrode terminals 60 to the current collector 30. The current collector 30 can be electrically connected to the electrode terminals 60 via the terminal bolts 70, or it can be directly connected to the electrode terminals 60. Therefore, unlike conventional battery cells, since welding the electrode terminals 60 to the current collector 30 can be omitted, damage to the separator of the electrode assembly 20 due to spatter or heat generated during welding can be prevented. Furthermore, it prevents the positive and negative electrodes from making electrical contact due to separator damage, and significantly reduces the possibility of short circuits or fires.

[0119] Furthermore, there is no need to use welding electrode rods to forcefully press and deform the manifold 30 to bring it into contact with the electrode terminal 60 for welding. Therefore, pre-tensioning of the manifold 30 can be prevented.

[0120] The manifold 30 may be provided with a restraining tab 33 into which a terminal bolt 70 is screwed. The restraining tab 33 may be located at the periphery of the inner circumferential surface of the manifold 30 defining the manifold hole 32. In one embodiment, the restraining tab 33 may be a thread having the same lead as the bolt thread 74 of the terminal bolt 70. The inner diameter of the restraining tab 33 is complementary to the outer diameter of the bolt thread 74, making it easy to achieve threaded engagement between the bolt thread 74 and the restraining tab 33. Therefore, wear and particle generation of the restraining tab 33 or the bolt thread 74 during threaded engagement can be prevented.

[0121] The inner diameter D1 of the constraint tab 33 can be the same as or slightly larger than the diameter D2 of the bolt hole 64 of the electrode terminal 60.

[0122] The manifold 30 is flat, and the height of the constraint tab 33 can be the same as the thickness T1 of the manifold 30. Therefore, as the thickness T1 of the manifold 30 increases, the height P1 of the constraint tab 33 increases. The height P1 of the constraint tab 33 can be adjusted by taking into account the required tightening force between the terminal bolt 70 and the manifold 30.

[0123] The electrode terminal 60 includes a terminal head 61 and a terminal insertion portion 63.

[0124] The terminal head 61 can press against the periphery of the terminal hole 14. The outer diameter of the terminal head 61 can be larger than the inner diameter of the terminal hole 14. The terminal head 61 can be circular or polygonal. When the electrode terminal 60 is inserted into the terminal hole 14, the terminal head 61 is locked against the periphery of the terminal hole 14 to prevent further insertion.

[0125] Terminal insertion portion 63 extends axially from terminal head 61. Terminal insertion portion 63 is inserted into terminal hole 14. In a structure with insulating member 40, terminal insertion portion 63 can be inserted into insulating member 40. Terminal bolt 70 can pass through terminal insertion portion 63. Terminal insertion portion 63 can contact the periphery of the lower surface of current collector 30 without being inserted into current collector hole 32. Terminal insertion portion 63 can be cylindrical in shape.

[0126] The electrode terminal 60 may also include a plastically deformable portion 65 extending from the terminal insertion portion 63 and bending radially outward. Even after the external force is removed, the plastically deformable portion 65 remains bent. Before deformation, the plastically deformable portion 65 may be parallel to the end of the terminal insertion portion 63 in the axial direction. Since the plastically deformable portion 65 is held and constrained by the periphery of the terminal hole 14 while bending axially outward from the terminal insertion portion 63, the electrode terminal 60 is prevented from popping out or separating from the terminal hole 14 due to the internal gas pressure of the can housing 10.

[0127] As the plastic deformation portion 65 bends, it can press against the pad 50. In some embodiments, the plastic deformation portion 65 can press against the insulating member 40. In some embodiments, the plastic deformation portion 65 can press against both the pad 50 and the insulating member 40.

[0128] The plastic deformation portion 65 may include a plastic deformation rib extending axially at the end of the terminal insertion portion 63. In some embodiments, a plurality of plastic deformation ribs may be provided, arranged circumferentially along the terminal insertion portion 63. The plurality of plastic deformation ribs may be plastically deformed simultaneously by a pressing member in the core of the inserted electrode assembly. In some embodiments, the plastic deformation rib may have a cylindrical shape extending circumferentially along the terminal insertion portion 63. The plastic deformation rib may be plastically deformed by a pressing member in the core of the inserted electrode assembly.

[0129] The plastic deformation portion 65 and the terminal head 61 primarily restrain the electrode terminal 60 in the terminal hole 14. In addition, the terminal bolt 70 is fastened to the current collector plate 30 to secondarily restrain the electrode terminal 60 to the current collector plate 30. Therefore, the electrode terminal 60 can be prevented from separating or detaching from the terminal hole 14 or the current collector plate 30. Since the electrode terminal 60 is doubly restrained as described above, the binding force and structural rigidity of the electrode terminal 60 can be significantly improved.

[0130] In addition, since the plastic deformation portion 65 is in contact with one surface of the current collector plate 30, and the terminal bolt 70 is in contact with the current collector plate hole 32 and the electrode terminal 60, the contact area between the positive terminal formed by the electrode terminal 60 and the terminal bolt 70 and the current collector plate 30 can be increased. Therefore, since the conductive path is significantly increased, the resistance loss of the battery cell can be reduced.

[0131] A bolt hole 64 for inserting the bolt body 73 of the terminal bolt 70 may be provided in the terminal insertion portion 63. The bolt hole 64 may be arranged parallel to the axial direction of the terminal insertion portion 63 and correspond to the current collector plate hole 32.

[0132] The height P1 of the current collector plate hole 32 may be equal to or slightly smaller than the thickness T1 of the current collector plate 30.

[0133] The diameter D2 of the bolt hole 64 may be smaller than the diameter D3 of the bolt body 73 of the terminal bolt 70 (D2<D3). For example, the diameter D2 of the bolt hole 64 may be smaller than the diameter of the bolt body 73 by the thread height of the bolt body 73.

[0134] Therefore, the peripheral edge of the bolt hole 64 can be plastically deformed as the bolt body 73 is inserted. As the peripheral edge of the bolt hole 64 is plastically deformed, the plastically deformed portion of the bolt hole 64 can be press-fitted between the threads of the bolt body 73. In addition, as the bolt body 73 is press-fitted into the bolt hole 64, the terminal insertion portion 63 expands radially outward and presses against the inner peripheral surface of the terminal hole 14 in the radial direction. Since the terminal bolt 70 is compressed and fastened by the reaction force applied from the terminal insertion portion 63 toward the center, the fastening force between the terminal bolt 70 and the electrode terminal 60 can be significantly improved. Therefore, even if the battery cell is exposed to an environment with continuous vibration, the loosening of the terminal bolt 70 can be prevented in advance. In addition, since the bolt body 73 bites into the inner peripheral surface of the bolt hole 64, the sealing force between the bolt body 73 and the terminal insertion portion 63 can be improved.

[0135] The terminal head 61 may be provided with an accommodating groove 62 for accommodating the bolt head 71 of the terminal bolt 70. The accommodating groove 62 may have a circular cross-section so that the terminal bolt 70 can rotate. The depth of the accommodating groove 62 may be substantially the same as the thickness of the bolt head 71.

[0136] The battery cell 10 may also include a sealing member 80 mounted between the bolt head 71 of the terminal bolt 70 and the end of the receiving groove 62 of the terminal head 61. The sealing member 80 may be an O-ring. The sealing member 80 seals the gap between the bolt head 71 and the receiving groove 62 to prevent electrolyte leakage. In addition, it prevents external air from entering the tank housing 10 through the gap between the bolt head 71 and the receiving groove 62.

[0137] The method for manufacturing the battery cell according to the first embodiment of the present invention will now be described.

[0138] Figure 9 This is a schematic cross-sectional view of a can housing with electrode terminals inserted into terminal holes according to the present invention. Figure 10 This is a schematic cross-sectional view of an electrode terminal according to the invention, which is inserted into a terminal hole in the can housing and whose plastically deformed portion is bent outwards. Figure 11 This is a schematic cross-sectional view illustrating the electrode assembly inserted into the can housing according to the invention, and Figure 12 and Figure 13 This is a cross-sectional view schematically illustrating the process of inserting a terminal bolt into a constraint tab in a manifold hole according to the present invention.

[0139] Reference Figure 9 Prepare a tank shell 10 with terminal holes 14 (refer to) Figure 9 Terminal hole 14 is located at the center of the bottom member 12 of the tank housing 10. Terminal hole 14 is located at the bottom of the tank housing 10.

[0140] Insert the gasket 50 into the terminal hole 14 in the axial direction. Stop inserting the gasket 50 when the flange of the gasket 50 contacts the outer surface of the can housing 10.

[0141] After inserting the gasket 50 into the terminal hole 14, the insulating member 40 is placed on the inner surface of the bottom member 12. The insulating member 40 has a hole at its center, the size of which is suitable for the terminal insertion portion 63 of the electrode terminal 60 to pass through.

[0142] With the gasket 50 inserted into the terminal hole 14, the electrode terminal 60 is inserted into the terminal hole 14 from the axially outer side of the terminal hole 14. The electrode terminal 60 is provided with a terminal head 61, a terminal insertion portion 63 extending in the axial direction, and a plastically deformable portion 65 extending from the axial end of the terminal insertion portion 63. The terminal insertion portion 63 and the plastically deformable portion 65 pass through the gasket 50. The gasket 50 electrically insulates the electrode terminal 60 from the can housing 10.

[0143] Reference Figure 10The plastic deformation portion 65 of the electrode terminal 60 is bent radially outward to secure the electrode terminal 60 to the terminal hole 14. Here, the pressing member (not shown) is lowered toward the interior of the can housing 10 to cause the plastic deformation portion 65 to bend radially outward. The plastic deformation portion 65 bends radially to press the gasket 50. In some embodiments, the insulating member 40 may be pressed simultaneously.

[0144] Reference Figure 11 The electrode assembly with the welded manifold 30 is inserted into the tank shell 10. The manifold 30 is positioned to face the electrode terminal 60, and the manifold hole 32 of the manifold 30 is aligned with the bolt hole 64 of the electrode terminal 60.

[0145] A constraint protrusion 33 located at the periphery of the manifold hole 32 is concentric with the bolt hole 64. Here, the inner diameter D1 of the constraint protrusion 33 is the same as or slightly larger than the diameter D2 of the bolt hole 64, and the diameter D3 of the terminal bolt 70 is larger than the diameter D2 of the bolt hole 64 (see reference). Figure 6 ).

[0146] Reference Figure 12 and Figure 13 After the terminal bolt 70 is passed through the bolt hole 64, the terminal bolt 70 is tightened to the restraining tab 33. Since the diameter of the bolt hole 64 is smaller than the diameter of the bolt body 73 of the terminal bolt 70, the periphery of the bolt hole 64 is plastically deformed as the bolt body 73 is inserted into the bolt hole 64 and the restraining tab 33.

[0147] Here, the end of the bolt body 73 is screwed into the restraining tab 33, and the bolt body 73 presses the terminal insertion portion 63 radially outward to push the terminal insertion portion 63 outward. Correspondingly, the deformed portion of the terminal insertion portion 63 presses against the bolt body 73 while being pushed into the threads of the bolt body 73. To achieve this, the electrode terminal 60 can be made of a metal softer than the terminal bolt 70. Therefore, the electrode terminal 60, the manifold 30, and the tank housing 10 are fixed to each other by the threaded engagement force between the terminal bolt 70 and the restraining tab 33 and the pressing force between the terminal bolt 70 and the terminal insertion portion 63.

[0148] Therefore, due to the significantly improved bonding force and structural rigidity of the electrode terminals 60, it is possible to prevent the electrode terminals 60 from popping out or detaching from the terminal holes 14 during battery thermal runaway.

[0149] Next, the battery cell according to the second embodiment of the present invention will be described. Since the second embodiment is substantially the same as the first embodiment except for the electrode terminal 60 and the terminal bolt 70, the same reference numerals are given to the same elements and their descriptions are omitted.

[0150] Figure 14This is a schematic cross-sectional view of a battery cell according to a second embodiment of the present invention, and Figure 15 It is shown schematically. Figure 14 A cross-sectional view of the connection structure of the electrode terminals of a battery cell.

[0151] Reference Figure 14 and Figure 15 According to a second embodiment of the present invention, the battery cell 1 includes: a can housing 10; a current collector 30; an insulating component 40; an electrode terminal 60; and a terminal bolt 70.

[0152] The electrode terminal 60 includes a terminal head 61 and a terminal insertion portion 63. Additionally, the electrode terminal 60 may also include a plastically deformable portion 65.

[0153] The terminal insertion portion 63 may be provided with a bolt hole 64 for inserting the bolt body 73 of the terminal bolt 70. The bolt hole 64 may be arranged parallel to the axial direction of the terminal insertion portion 63 and aligned with the manifold hole 32 in the axial direction.

[0154] The diameter D2 of the bolt hole 64 can be substantially the same as or slightly larger than the diameter D3 of the bolt body 73 of the terminal bolt 70 (D2=D3). Here, the inner diameter of the restraining tab 33 can be smaller than the diameter of the bolt hole 64. Furthermore, a bolt thread 74 is provided on the outer circumferential surface of the bolt body 73, and the axial length P2 of the bolt thread 74 can be slightly greater than the height P1 of the restraining tab 33. It is evident that the bolt thread 74 can be provided along the entire length of the bolt body 73.

[0155] Since the diameter D3 of the bolt body 73 is equal to or slightly smaller than the diameter D2 of the bolt hole 64, the bolt hole 64 undergoes almost no plastic deformation when the bolt body 73 is screwed into the restraining tab 33. Furthermore, when the bolt head 71 and the manifold 30 press the terminal insertion portion 63 from both axial ends through a threaded connection, the terminal insertion portion 63 can be compressed towards the bolt body 73 while simultaneously contracting axially. To achieve this, the electrode terminal 60 can be made of a metal softer than the terminal bolt 70. Therefore, the electrode terminal 60, the manifold 30, and the tank housing 10 are fixed together by the threaded connection force between the terminal bolt 70 and the restraining tab 33, and by the pressing force between the terminal bolt 70 and the terminal insertion portion 63.

[0156] Here, the elastic force of the sealing member 80 is transmitted to the constraint tab 33 of the manifold 30 through the terminal bolt 70, causing the manifold 30 to contact the electrode terminal 60. Additionally, this elastic force can be used as a tension force to prevent the terminal bolt 70 from loosening.

[0157] Next, the battery cell according to the third embodiment of the present invention will be described. Since the third embodiment is substantially the same as the first embodiment except for the current collector 30, the same reference numerals are given to the same elements and their descriptions are omitted.

[0158] Figure 16 This is a schematic cross-sectional view of a battery cell according to a third embodiment of the present invention, and Figure 17 It is shown schematically. Figure 16 A cross-sectional view of the connection structure of the electrode terminals of a battery cell.

[0159] Reference Figure 16 and Figure 17 According to the third embodiment of the present invention, the battery cell 1 includes: a can housing 10; a current collector 30; an insulating component 40; an electrode terminal 60; and a terminal bolt 70.

[0160] The electrode terminal 60 includes a terminal head 61 and a terminal insertion portion 63. Additionally, the electrode terminal 60 may also include a plastically deformable portion 65.

[0161] The manifold 30 includes: a plate-shaped flat portion 31; and a protrusion 35 protruding from the plate portion 31 at a position corresponding to the terminal hole 14. The plate portion 31 may have a flat annular shape, and the protrusion 35 may have an annular shape defining the manifold hole 32. The plate portion 31 and the protrusion 35 are concentric with the manifold hole 32.

[0162] The thickness T2 of the protrusion 35 can be greater than the thickness T1 of the flat plate 31. For example, the thickness T2 of the protrusion 35 can be approximately 10% to 100% of the thickness T1 of the flat plate 31. When the flat plate 31 is thicker, the thickness T1 of the flat plate 31 can approach 100% of the thickness T2 of the protrusion 35, and when the flat plate 31 is thinner, the thickness T1 of the flat plate 31 can approach 10% of the thickness T2 of the protrusion 35.

[0163] The constraint tab 33 is disposed on the inner circumferential surface of the manifold hole 32. As the thickness T2 of the protrusion 35 increases, the height P2 of the constraint tab 33 can increase. Since the terminal bolt 70 is screwed into the constraint tab 33, the fastening force between the constraint tab 33 and the terminal bolt 70 can increase proportionally to the height P2 of the constraint tab 33.

[0164] The inner diameter D1 of the manifold hole 32 can be the same as or slightly smaller than the diameter D2 of the bolt hole 64. The height P2 of the manifold hole 32 and the restraining tab 33 can be the same as or slightly smaller than the thickness T2 of the protrusion 35.

[0165] The diameter D2 of the bolt hole 64 can be smaller than the diameter D3 of the bolt body 73. For example, the diameter D2 of the bolt hole 64 can be smaller than the height of the bolt thread 74 of the bolt body 73.

[0166] Therefore, the periphery of the bolt hole 64 can plastically deform as the bolt body 73 is inserted. As the periphery of the bolt hole 64 undergoes plastic deformation, the plastically deformed portion of the bolt hole 64 can be press-fitted into the threads of the bolt body 73. Furthermore, as the bolt body 73 is press-fitted into the bolt hole 64, the terminal insertion portion 63 expands radially outward and presses against the inner circumferential surface of the terminal hole 14 in the radial direction. Correspondingly, since the terminal bolt 70 is pressed and tightened by the reaction force applied from the terminal insertion portion 63 towards the center, the tightening force between the terminal bolt 70 and the electrode terminal 60 can be significantly improved. Therefore, even if the battery cell is exposed to a continuously vibrating environment, the loosening of the terminal bolt 70 can be prevented in advance. Additionally, since the bolt body 73 bites into the inner circumferential surface of the bolt hole 64, the sealing force between the bolt body 73 and the terminal insertion portion 63 can be improved.

[0167] On the other hand, Figure 16 and Figure 17 In this example, the protrusion 35 of the current collector 30 protrudes in a direction away from the electrode terminal 60. However, the protrusion may protrude in a direction toward the electrode terminal 60, or it may protrude in both directions toward and away from the electrode terminal 60.

[0168] Furthermore, in the third embodiment, the dimensional relationship between the diameter D2 of the bolt hole 64 and the diameter D3 of the bolt body 73 can be replaced by the dimensional relationship of the second embodiment. Similarly, the structure of the protrusion 35 in the third embodiment can be applied to the second embodiment. In this way, the features of the various embodiments can be applied interchangeably or additionally. Obviously, some features of the various embodiments can be omitted.

[0169] Although the invention has been described with reference to exemplary drawings, it should be understood that the invention is not limited to the embodiments and drawings disclosed in this specification, and those skilled in the art will understand that various modifications can be made without departing from the scope and concept of the invention. Furthermore, although the operational effects produced by the configuration of the invention are not explicitly described in the embodiments of the invention, it should be understood that the effects that can be expected from this configuration should also be recognized.

Claims

1. A battery cell, the battery cell comprising: A can housing, which internally houses an electrode assembly and is provided with terminal holes; A current collector, wherein the current collector is disposed at the axial end of the electrode assembly; Electrode terminals, wherein the electrode terminals are inserted into the terminal holes; as well as Terminal bolts pass through the electrode terminals and are fastened to and constrained by the current collector.

2. The battery cell according to claim 1, wherein, The electrode terminals include: Terminal head, the terminal head compressing the periphery of the terminal hole; and A terminal insertion portion that extends from the terminal head and is inserted into the terminal hole. The terminal bolt passes through the terminal insertion portion.

3. The battery cell according to claim 2, wherein, The electrode terminal further includes a plastic deformation portion that extends from the terminal insertion portion and is bent to compress the periphery of the terminal hole while facing the terminal head.

4. The battery cell according to claim 3, wherein, The plastic deformation portion includes a plastic deformation rib, which is arranged circumferentially at the end of the terminal insertion portion.

5. The battery cell according to claim 4, wherein, The plastic deformation ribs extend continuously or intermittently in the circumferential direction.

6. The battery cell according to claim 2, wherein, The terminal insertion part is provided with a bolt hole for inserting the bolt body of the terminal bolt.

7. The battery cell according to claim 6, wherein, The inner diameter of the bolt hole is smaller than the outer diameter of the bolt body, so that the periphery of the bolt hole undergoes plastic deformation as the bolt body is inserted.

8. The battery cell according to claim 6, wherein, The diameter of the bolt hole is equal to or greater than the diameter of the terminal bolt.

9. The battery cell according to claim 6, wherein, The terminal head is provided with a receiving groove for accommodating the bolt head of the terminal bolt.

10. The battery cell according to claim 1, wherein, The manifold is provided with a constraint tab for the terminal bolt to be screwed into.

11. The battery cell according to claim 10, wherein, The collector plate has a flat plate shape, and The height of the constraint tab is equal to or less than the thickness of the manifold.

12. The battery cell according to claim 10, wherein, The current collector includes: a flat plate portion having a flat plate shape; and a protrusion portion protruding axially from the flat plate portion at a position corresponding to the terminal hole. The restraining tab penetrates the protrusion.

13. The battery cell according to claim 1, wherein the battery cell further comprises: A sealing member is installed between the bolt head of the terminal bolt and the bottom surface of the receiving groove of the terminal head.

14. The battery cell according to claim 1, wherein the battery cell further comprises: A gasket is inserted between the inner peripheral surface of the terminal hole and the outer peripheral surface of the electrode terminal to electrically insulate the electrode terminal from the can housing and seal the can housing.

15. A method for manufacturing a battery cell, the method comprising: Prepare a tank shell with terminal holes; Insert the gasket into the terminal hole along the axial direction; Insert the electrode terminal into the terminal hole from the axial outside of the terminal hole; The electrode terminal is constrained in the terminal hole by bending the plastic deformation portion of the electrode terminal radially outward; The electrode assembly with the welded manifold plate is inserted into the tank shell, and the constraint tabs of the manifold plate are arranged to correspond to the bolt holes of the electrode terminals; and After passing the terminal bolt through the bolt hole, the terminal bolt is tightened to the restraint tab.

16. The manufacturing method according to claim 15, wherein, The diameter of the bolt hole is smaller than the diameter of the bolt body of the terminal bolt, so that the periphery of the bolt hole plastically deforms as the bolt body is inserted.

17. The manufacturing method according to claim 15, wherein, The current collector includes: a flat plate portion having a flat plate shape; and a protrusion portion protruding axially from the flat plate portion at a position corresponding to the terminal hole. The restraining tab penetrates the protrusion.

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