Battery cell, battery pack including battery cell and vehicle

Abstract

A battery cell according to an embodiment of the present invention comprises: an electrode assembly in which a first electrode, a second electrode, and a separator interposed between the first electrode and the second electrode are wound around a winding axis; a can configured to accommodate the electrode assembly through an open end portion formed on one side of the can; a lead wire covering the open end portion and having a liquid injection hole; and a plug configured to seal the liquid injection hole. The plug may include: a lead coupling portion on the lead; an insertion portion positioned radially inward from the lead coupling portion and configured to protrude from the lead coupling portion and to be inserted into the liquid injection hole; and an edge portion located at an edge of the lead coupling portion and recessed more downward than the lead coupling portion in a winding axis direction.

Description

Technical Field

[0001] This disclosure relates to a battery cell, a battery pack including the battery cell, and a vehicle.

[0002] This application is based on and claims priority to Korean Patent Application No. 10-2024-0087170, filed with the Korean Intellectual Property Office on July 2, 2024, the disclosure of which is incorporated herein by reference in its entirety.

[0003] This application is based on and claims priority to Korean Patent Application No. 10-2025-0087109, filed with the Korean Intellectual Property Office on June 30, 2025, the disclosure of which is incorporated herein by reference in its entirety. Background Technology

[0004] Cylindrical battery cells store coiled electrode assemblies within a cylindrical metal can, resulting in greater impact resistance and temperature resistance compared to pouch cells. Consequently, the demand for can-type battery cells for vehicle battery packs is increasing.

[0005] The process of manufacturing battery cells using cylindrical cans involves deep drawing a sheet of metal to form a circular bottom and circular and tubular sidewalls integrally connected thereto, inserting electrode assemblies into them, and covering the open ends of the sidewalls with a cap.

[0006] Crimping or seam welding can be used to secure the cover covering the open end to the battery canister.

[0007] Figure 1 This illustrates a conventional method of securing the cap and battery can by rolling the edges.

[0008] refer to Figure 1 Edge crimping is a method of securing the cap 40 by inserting a sealing ring 91 and physically pressing the edge of the cap 40 against the open end of the tank 10. Since edge crimping is a physical fixing method without applying heat, it can be performed while the electrolyte is contained within the tank 10. Therefore, the advantage of the edge crimping method is that it eliminates the need for a separate electrolyte injection port structure and its associated sealing mechanism. However, edge crimping is structurally more complex than welding, which may reduce the internal volume of the tank 10 available for accommodating the electrode assembly 20.

[0009] On the other hand, seam welding, which involves aligning the end edges of the battery can's sidewalls with the edge of the lid and welding them along the peripheral edge, provides a simpler fixing structure, thus ensuring a larger volume of electrode assemblies to be stored inside the battery can. Therefore, for battery cans of the same volume, seam welding is more advantageous in ensuring greater capacity.

[0010] When the periphery of the open end of a battery can is connected to a cover by seam welding, a method may be adopted, which includes: preparing a battery can or a cover having an injection hole at the bottom, storing an electrode assembly inside the battery can, seam welding the battery can and the cover, injecting electrolyte through the injection hole, and sealing the injection hole after injection is completed.

[0011] However, when welding the injection port cap and cover to seal the injection port, weld seams generated during the welding process may protrude from the surface of the cap or injection port cap. This can reduce the contact area between the battery cell cover and the heat sink used for bottom cooling of the battery pack. Since the cooling performance of the battery pack is proportional to the contact area between the heat sink and the cover, this can reduce the cooling performance of the battery pack.

[0012] Therefore, there is a need to develop an injection hole sealing structure that prevents welds or other defects from protruding from the cap or injection hole cover. Summary of the Invention

[0013] Technical issues

[0014] This disclosure aims to address the problems of the prior art, and therefore aims to provide a battery cell with an improved injection hole sealing structure and a method for manufacturing the same.

[0015] In addition, this disclosure also provides an injection hole sealing structure that maximizes the contact area between the heat sink and the cover of the battery cell in a battery pack comprising multiple battery cells.

[0016] This disclosure relates to providing a battery cell including such a sealed structure and a method for manufacturing the same.

[0017] Furthermore, this disclosure also provides a battery cell with high energy density by removing the pressing and rolling structures from the battery cell, and a vehicle equipped with a battery pack including the battery cell.

[0018] The technical problems to be solved by this disclosure are not limited to those described above, and those skilled in the art will clearly understand other problems not mentioned above based on the following description of the invention. Furthermore, it will be understood that the foregoing and other objects and advantages of this disclosure can be achieved by the features defined in the appended claims and combinations thereof.

[0019] Technical solution

[0020] In one aspect of this disclosure, a battery cell is provided, comprising: an electrode assembly constructed by winding a first electrode, a second electrode, and a separator between the first and second electrodes about a winding axis; a can configured to receive the electrode assembly through an open end formed on one side; a cap configured to cover the open end and having an injection port formed therein; and a plug configured to seal the injection port, wherein the plug may include: a cap coupling portion located on the cap; an insertion portion located radially inward of the cap coupling portion and protruding from the cap coupling portion to be inserted into the injection port; and an edge portion located at an edge of the cap coupling portion and recessed further downward in the winding axis direction than the cap coupling portion.

[0021] The edge portion can be constructed as a loop along the circumferential edge of the plug.

[0022] The edge portion can be formed by forging the edge of the cover connection portion.

[0023] The maximum recessed depth of the edge portion in the direction of the winding axis can be in the range of 20% to 60% of the thickness of the cover connection portion in the direction of the winding axis.

[0024] The weld formed during the welding of the plug and the cap can be configured to be located on the edge portion.

[0025] The maximum recessed depth of the edge portion in the direction of the winding axis can be greater than the maximum thickness of the weld formed along the direction of the winding axis.

[0026] The edge portion may include an edge side surface extending downward from the upper surface of the cover connection portion and an edge bottom surface extending radially outward from the lower end of the edge side surface.

[0027] The cap may include a body and a plug connection portion, the plug connection portion being recessed downwards from the body in the direction of the winding axis around the injection hole, and the plug connection portion being configured such that the cap connection portion is mounted on the plug connection portion.

[0028] The height of the upper surface of the cap connecting portion of the plug in the direction of the winding axis is less than the height of the upper surface of the body of the cap in the direction of the winding axis.

[0029] The cap connection portion of the plug and the body of the cap can be welded together while being adjacent to each other in the radial direction.

[0030] The edge portion may include an edge inclined surface that slopes downward from the upper surface of the cover connection portion and radially outward.

[0031] The insertion portion is configured to be inserted into the injection hole via an interference fit to initially seal the injection hole.

[0032] The cap connecting portion and the insertion portion may have the same thickness in the direction of the winding axis and may be integrally formed.

[0033] In another aspect of this disclosure, a battery pack including battery cells according to embodiments of this disclosure is provided.

[0034] In another aspect of this disclosure, a vehicle is provided that includes a battery pack according to an embodiment of this disclosure.

[0035] Beneficial effects

[0036] According to one aspect of this disclosure, an injection hole sealing structure and method are provided for improving the reliability of injection hole sealing.

[0037] According to one aspect of this disclosure, an injection hole sealing structure and method are provided for maximizing the contact area between the heat sink and the cover and / or plug of the battery cell in a battery pack.

[0038] According to one aspect of this disclosure, an injection hole sealing structure and method are provided for ensuring the flatness of a battery cell.

[0039] According to one aspect of this disclosure, a portion of the plug is inserted into the injection hole to ensure a temporary seal, thereby preventing external leakage of electrolyte vapors. Furthermore, the cap portion and the edge of the plug are thermally bonded to ensure a high final seal. Because thermal bonding occurs simultaneously with preventing external leakage of electrolyte vapors, weld defects and ignition can be prevented, for example, when laser welding is used for thermal bonding.

[0040] However, the effects obtainable under this disclosure are not limited to those described above, and those skilled in the art will clearly understand other effects not mentioned above based on the following description of the invention. Attached Figure Description

[0041] The accompanying drawings illustrate preferred embodiments of the present disclosure and, together with the foregoing disclosure, serve to provide a further understanding of the technical features of the present disclosure; therefore, the present disclosure is not to be construed as limited to the drawings.

[0042] Figure 1 This diagram illustrates a conventional method of securing the cap and battery can using rolled edges.

[0043] Figure 2This is a perspective view of a battery cell according to an embodiment of the present disclosure.

[0044] Figure 3 This is a perspective view of the first and second electrodes and the separator according to embodiments of the present disclosure before they are laminated to manufacture an electrode assembly to be stored in a battery can.

[0045] Figure 4 It is Figure 3 A three-dimensional view of an electrode assembly manufactured by winding stacked components into a core shape.

[0046] Figure 5 and Figure 6 This is a perspective view showing the state in which the current collector is coupled to the corresponding end of the electrode assembly according to an embodiment of the present disclosure.

[0047] Figure 7 This is a cross-sectional view showing the process of housing the electrode assembly inside the battery canister.

[0048] Figure 8 This is a cross-sectional view showing a container storing electrode assemblies covered and sealed with a lid according to an embodiment of the present disclosure.

[0049] Figure 9 This is a cross-sectional view showing the state in which the injection hole of the cap according to an embodiment of the present disclosure is sealed by a plug.

[0050] Figure 10 yes Figure 9 An enlarged cross-sectional view of the connection between the cap and the plug.

[0051] Figure 11 This is a cross-sectional view of the plug according to an embodiment of the present disclosure.

[0052] Figure 12 This is a cross-sectional view of plugs and caps connected to each other according to an embodiment of the present disclosure.

[0053] Figure 13 This is a cross-sectional view of the connection structure of the cover and plug according to another embodiment of the present disclosure.

[0054] Figure 14 This is a cross-sectional view of the connection structure of the cover and plug according to another embodiment of the present disclosure.

[0055] Figure 15 This is a cross-sectional view of the welded cap and plug according to another embodiment of the present disclosure.

[0056] Figure 16 This is a cross-sectional view of the connection structure of the cover and plug according to another embodiment of the present disclosure.

[0057] Figure 17This is a cross-sectional view of the welded cap and plug according to another embodiment of the present disclosure.

[0058] Figure 18 This is a cross-sectional view of a plug according to another embodiment of the present disclosure.

[0059] Figure 19 This is a cross-sectional view showing a cap and plug connected to each other according to another embodiment of the present disclosure.

[0060] Figure 20 This is a flowchart of a method for manufacturing a battery cell that utilizes the injection hole sealing structure disclosed herein.

[0061] Figure 21 This is a diagram illustrating a battery pack according to an embodiment of the present disclosure.

[0062] Figure 22 It shows including Figure 21 A picture of a vehicle with a battery pack. Detailed Implementation

[0063] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0064] This disclosure is not limited to the embodiments described below, but can be modified and implemented in various different forms. The embodiments are provided merely to ensure the completeness of the disclosure and to fully convey the scope of the invention to those skilled in the art. Therefore, this disclosure is not limited to the embodiments described below, and it should be understood that components of one embodiment can be substituted or added to components of another embodiment, thereby covering all modifications, equivalents, and substitutions falling within the technical concept and scope of this disclosure.

[0065] Furthermore, this disclosure may include various embodiments. Repeated descriptions of substantially the same or similar structures are omitted from the various embodiments, and descriptions will be based on the differences.

[0066] The accompanying drawings are provided only to facilitate understanding of the embodiments disclosed herein, and the technical concepts disclosed herein should not be construed as being limited to the drawings. It should be understood that all modifications, equivalents, and substitutions falling within the concepts and scope of this disclosure are permitted. In the drawings, the dimensions or thickness of elements may be exaggerated or reduced for clarity and ease of understanding, but this should not be construed as limiting the scope of this disclosure.

[0067] The terminology used herein is intended only to describe particular implementations and methods of execution and is not intended to limit the scope of this disclosure. Furthermore, unless the context clearly indicates otherwise, the singular forms used herein are intended to include the plural forms as well. Terms such as “comprising” or “including” as used herein are intended to specify the presence of the stated feature, integer, step, operation, element, component, or combination thereof, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

[0068] Ordinal terms such as "first" and "second" can be used to describe various components, but components are not limited by these terms. These terms are only used to distinguish one component from another. Therefore, unless otherwise explicitly stated, the first component can be the same as the second component.

[0069] Throughout this specification, unless otherwise expressly stated, each component may be singular or plural.

[0070] Unless the context clearly indicates otherwise, the singular expressions used herein are intended to include the plural expressions. In this application, terms such as “comprising” or “including” should not be construed as necessarily covering all the various components or steps described herein, and some components or steps may be omitted, or additional components or steps may be further included.

[0071] When a particular component is stated to be "connected to" or "linked to" another component, it should be understood that the component may be directly connected to or linked to the other component, and alternatively, one or more other components may exist between them. On the other hand, when a particular component is described as being "directly connected to" or "directly linked to" another component, it should be understood that there are no other components between them.

[0072] When a particular component is described as being "above" or "below" another component, it should be understood that the component may be located directly above or below the other component, or alternatively, one or more other components may exist between them.

[0073] Unless otherwise defined, all terms used herein, including technical and scientific terms, shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. Unless expressly defined otherwise in this application, terms generally defined in common dictionaries shall be interpreted as having a meaning consistent with the context of the relevant field and shall not be interpreted in an idealized or overly formal sense.

[0074] Furthermore, although terms such as up, down, left, right, forward, and back are used in this specification to indicate directions, it will be apparent to those skilled in the art to which this disclosure pertains that these terms are merely for convenience of interpretation with reference to the accompanying drawings and may vary depending on the position, arrangement, or rotation of the target object or the position of the observer.

[0075] Throughout this specification, unless otherwise stated, the expression “A and / or B” may refer to A, B, or both A and B, and the expression “C to D” may refer to a range of values ​​including C and below D.

[0076] In describing embodiments, the term "winding axis direction" refers to the direction in which the axis extends through the winding center of the wound core electrode assembly, and the term "radial direction" refers to the direction approaching (centripetal) or away from (eccentric) the axis. The term "circumferential" refers to the direction around the axis.

[0077] Figure 2 This is a perspective view of a battery cell according to an embodiment of the present disclosure. Figure 3 This is a perspective view of the first and second electrodes and the separator according to embodiments of the present disclosure before they are laminated to manufacture an electrode assembly to be stored in a battery can. Figure 4 It is Figure 3 A three-dimensional view of an electrode assembly manufactured by winding stacked components into a core shape. Figure 5 and Figure 6 This is a perspective view showing the state in which the current collector is coupled to the corresponding end of the electrode assembly according to an embodiment of the present disclosure. Figure 7 This is a cross-sectional view showing the process of housing the electrode assembly inside the battery canister. Figure 8 This is a cross-sectional view showing a container storing electrode assemblies covered and sealed with a lid according to one embodiment of the present disclosure.

[0078] The following is for reference Figures 2 to 8 A detailed description will be given of an embodiment of the battery cell 1 that utilizes the sealing structure of the injection hole 42 according to the present disclosure.

[0079] The battery cell 1 can be manufactured by storing the cylindrical electrode assembly 20 inside the cylindrical battery canister 10.

[0080] The battery cell 1 of this embodiment may include an electrode assembly 20, current collectors 31 and 32 electrically connected to the electrode assembly 20, and a tank 10 for containing the electrode assembly 20 and the current collectors 31 and 32.

[0081] The can 10 may include a sidewall 11 extending along a winding axis between a first end and a second end, and a bottom 12 connected to the first end of the sidewall 11 and extending radially. The second end of the sidewall 11 in the winding axis direction may be open.

[0082] After the electrode assembly 20 is inserted into the canister 10, the open end of the side wall 11 can be sealed by covering it with the cap 40.

[0083] The bottom 12 can be configured as a disk with a hole in the center, and the sidewall 11 can be in the shape of a circular tube.

[0084] The bottom 12 and sidewalls 11 can be manufactured by deep drawing a nickel-plated steel sheet into a specific shape, and then trimming the ends of the sidewalls 11 with a punch while holding the sidewalls 11 in a blank holder. However, the material of the can 10 is not limited to this.

[0085] The first electrode terminal 13 can be fitted into the hole. The first electrode terminal 13 can be riveted to the bottom 12 and the terminal gasket 14 is located between the first electrode terminal 13 and the bottom 12. The terminal gasket 14 is located between the first electrode terminal 13 and the bottom 12, thereby sealing the inside and outside of the can 10 to prevent electrolyte leakage and electrically insulating the first electrode terminal 13 and the bottom 12 from each other.

[0086] However, the connection method between the first electrode terminal 13 and the bottom 12 is not limited to this. For example, various other fixing methods (e.g., bolt-nut connection, glass seal or chrome plating and PP-MAH heat bonding) for sealing the gap between the first electrode terminal 13 and the bottom 12 and electrically insulating them from each other can be applied to the connection described above.

[0087] The first electrode terminal 13 may have a first polarity, and the can 10 may have a second polarity. That is, the bottom 12 of the can 10, the side wall 11 connected thereto, and the cover 40 connected to the side wall 11, which will be described below, may all have a second polarity.

[0088] Therefore, the battery cell 1 may have both a first electrode terminal 13 and a second electrode terminal 15, the second electrode terminal 15 being located at the end in the winding axis direction (i.e., at the closed end where the bottom 12 is provided). Then, the busbar connected to the first electrode terminal 13 and the busbar connected to the second electrode terminal 15 may both be located at the upper part of the battery cell 1.

[0089] For example, the first electrode terminal 13 can be the positive terminal and the second electrode terminal 15 can be the negative terminal, and vice versa.

[0090] Electrode assembly 20 is stored in tank 10.

[0091] The electrode assembly 20 can be configured as a core in which a first electrode 21, a second electrode 22, and a diaphragm 28 between the first electrode 21 and the second electrode 22 are wound around a winding axis. The outer surface of the electrode assembly 20 can be formed into a circle along its circumferential direction. However, the structure of the electrode assembly 20 is not limited to this embodiment and can have any winding structure known in the art.

[0092] Specifically, such as Figure 3 As shown, the electrode assembly 20 can be manufactured as a cylindrical core, which is obtained by preparing a first electrode 21, a second electrode 22, and a diaphragm 28 having a predetermined width and extending a predetermined length along the winding direction, sequentially stacking the first electrode 21, the diaphragm 28, the second electrode 22, and the diaphragm 28 to form a laminate, and then winding the laminate around the winding axis, as shown. Figure 4 As shown. The structure of the electrode assembly 20 is not limited to the embodiments described herein, and it may have any winding structure known in the art.

[0093] The first electrode 21 can be a positive electrode, and the second electrode 22 can be a negative electrode, or vice versa.

[0094] The first electrode 21 and the second electrode 22 are manufactured in the form of sheets. The electrode sheets are manufactured by coating an active material layer 24 onto the surface of a metal foil 23. The electrode sheets have 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 sheet has an uncoated portion 26 on one side in the width direction, and the negative electrode sheet has an uncoated portion 26 on the other side in the width direction.

[0095] The uncoated portion 26 protrudes and protrudes from the laminate along its width. The uncoated portion 26 itself serves as an electrode tab.

[0096] Cutouts can be formed at predetermined intervals in the uncoated portion 26 to form flag-shaped cutout tabs 27.

[0097] In this embodiment, the notched tab 27 is exemplified as having an isosceles trapezoidal shape. However, it can also have various shapes, such as a semicircle, a semi-ellipse, a triangle, a rectangle, or a parallelogram.

[0098] Furthermore, in this embodiment, the slit tabs 27 arranged along the longitudinal direction have the same width. However, the width of the slit tabs may also gradually or progressively increase from the winding core toward the outer periphery.

[0099] In this embodiment, the height of the cut tab 27 is illustrated as gradually increasing from the winding core toward the outer periphery. However, the height of the cut tab may also be constant or gradually decreasing.

[0100] Furthermore, in this embodiment, a structure is illustrated in which the cut tab 27 is removed from a defined interval at the radial end and a defined interval at the distal end of the uncoated portion 26. However, it should be understood that the cut tab may not be removed from the radial end of the uncoated portion, and the cut tab may not be removed from the distal end of the uncoated portion.

[0101] like Figure 4 As shown, in the wound electrode assembly 20, the cut-out tab 27 can be bent radially and flattened. The cut-out tab 27 can be bent radially inward or outward. This embodiment illustrates a structure in which the cut-out tab 27 is bent radially inward.

[0102] During the process of winding the laminate to form the wound electrode assembly 20, the slit tabs 27 can be bent separately. Alternatively, after the laminate is wound to form the wound electrode assembly 20, the slit tabs 27 can be bent and processed simultaneously.

[0103] The cut tabs 27 of the first electrode 21 and the second electrode 22, which are bent and overlap each other in the radial direction, can respectively provide planes that are approximately perpendicular to the winding axis direction at both ends of the electrode assembly 20.

[0104] like Figure 5 and Figure 6 As shown, the first current collector 31 and the second current collector 32 can be respectively coupled to a generally flat surface provided by bending the cut tabs 27 exposed at both ends in the winding axis direction of the electrode assembly 20.

[0105] In this embodiment, a first current collector 31 is exemplified as the positive current collector, and a second current collector 32 is exemplified as the negative current collector. The first current collector 31 may be made of aluminum, and the second current collector 32 may be made of copper.

[0106] Current collectors 31 and 32 can be manufactured by stamping, trimming, piercing, and bending metal plates.

[0107] Reference Figure 5 The first current collector 31 may include a first terminal connection portion 312 extending radially from the center, an annular portion 313 connecting the distal edge of the first terminal connection portion 312 in the circumferential direction, and a first electrode connection portion 314 extending from the annular portion 313 toward the center but not connected to the first terminal connection portion 312. The central portion of the first terminal connection portion 312 may cover at least a portion of the central winding hole H of the electrode assembly 20.

[0108] Before inserting the electrode assembly 20 into the canister 10, the first electrode connection portion 314 is joined to the cut tab 27 of the first electrode 21 of the electrode assembly 20 by means of laser welding or the like. The laser welding line can extend radially.

[0109] Reference Figure 6 The second current collector 32 may include an inner ring portion 321, a second electrode connection portion 323, and a second terminal connection portion 324. The inner ring portion 321 defines a hole 322 corresponding to the central winding hole H of the electrode assembly 20 and is configured to surround the central winding hole H. The second electrode connection portion 323 extends radially from the inner ring portion 321, and the second terminal connection portion 324 is located further outward than the second electrode connection portion 323 and is connected to the inner ring portion 321. The second terminal connection portion 324 may have an outer ring form to surround the edge of the second current collector 32.

[0110] Before the electrode assembly 20 is inserted into the canister 10, the second electrode connection portion 323 can be joined to the cut tab 27 of the second electrode 22 of the electrode assembly 20 by means of laser welding or the like. The laser welding line can extend radially.

[0111] However, the shape and structure of the first current collector 31 and the second current collector 32 are not limited to the embodiments described above, and can be designed differently. In another possible structure, the second current collector 32 may not be included. In this case, the cover 40, described later, serves as the second current collector.

[0112] like Figure 7 As shown, the electrode assembly 20 can be housed within the canister 10, while the first current collector 31 is aligned to be oriented toward the bottom 12 of the canister 10. In this case, an insulator 19 can be inserted between the first current collector 31 and the bottom 12 of the canister 10 to electrically insulate the first current collector 31 from the bottom 12.

[0113] With the electrode assembly 20 housed within the container 10, the cut tab 27 of the second electrode 22 and the second current collector 32 can be configured to face the open end of the sidewall 11.

[0114] The first terminal connection portion 312 of the first current collector 31 can be joined to the first electrode terminal 13 fixed to the tank 10 by resistance welding, ultrasonic welding, laser welding, etc. A welding apparatus for welding the first current collector 31 and the first electrode terminal 13 can be used to approach the rear surface of the center of the first terminal connection portion 312 of the first current collector 31 through the opening of the tank 10, the hole 322 of the second current collector 32, and the central winding hole H of the electrode assembly 20, thereby performing welding. Alternatively, the first current collector 31 and the first electrode terminal 13 can also be joined using other methods such as brazing or soldering. That is, any method for electrically connecting and fixing the first current collector 31 and the first electrode terminal 13 can be applied. However, this disclosure is not intended to exclude structures where the positive electrode tab is directly electrically connected to the positive terminal in the absence of a positive current collector.

[0115] With the electrode assembly 20 housed within the container 10, the open end of the container 10 can be covered and sealed by the cap 40, such as... Figure 8 As shown.

[0116] The can 10 and the cap 40 can be thermally joined. Alternatively, the periphery of the front end of the side wall 11 of the battery can 10 can be brought into contact with the periphery of the cap 40, and then welded along the periphery. The open end of the can 10 and the cap 40 can be joined at the contact point therebetween. For example, the open end of the can 10 and the cap 40 can be joined by welding at the connection point between them. For example, butt welding can be used to join the cap 40 to the can 10. This can be defined as a seam welding method. Due to the simplicity of the fixing structure, the larger electrode assembly 20 can be fixed inside the can 10. Therefore, the seam welding method may be more advantageous in ensuring capacitance compared to a can 10 of the same volume.

[0117] Specifically, the periphery of the opening end of the tank 10 and the cover 40 can be fixed by seam welding as follows: prepare the cover 40 with an injection hole 42, insert the electrode assembly 20 into the tank 10, seam weld the tank 10 and the cover 40, inject electrolyte through the injection hole 42 provided in the cover 40, and seal the injection hole 42 with a plug 50 or the like after the electrolyte injection is completed.

[0118] According to the configuration implemented above in this disclosure, the battery cell 1 can have a larger internal capacity while maintaining the same external dimensions as a battery cell 1 using the pressing and rolling methods. Therefore, the energy density of the battery cell 1 can be increased. However, the canister 10 and the cover 40 can be joined by various joining methods other than welding, and the joining methods are not limited to these. By joining the canister 10 and the cover 40, the battery cell 1 can ensure airtightness.

[0119] The second terminal connection portion 324 of the second manifold 32 and the second end of the sidewall 11 can be joined by methods such as welding. The edges of the can 10 and the lid 40 can also be joined and sealed by methods such as welding. For example, the lid 40 can be joined to the can 10 after the second manifold 32 is joined to the can 10. As another example, the lid 40 can be joined to the can 10 after the second manifold 32 is joined to the lid 40. As yet another example, the second manifold 32, the can 10, and the lid 40 can be welded simultaneously.

[0120] The edge of the cap 40 can be engaged with and electrically connected to the edge of the opening end of the can 10. The inner surface of the can 10 or the cap 40 can be electrically connected to the second current collector 32. Since the second current collector 32 is engaged with the cut-out tab 27 of the second electrode 22 of the electrode assembly 20 housed within the can 10 of the battery cell 1, the cap 40 can also be electrically connected to the cut-out tab 27 of the second electrode 22 of the electrode assembly 20 when it is electrically connected to the second current collector 32. In a configuration excluding the second current collector 32, the shape of the cap 40 can be modified so that the cap 40 is directly electrically connected to the cut-out tab 27 of the second electrode 22 of the electrode assembly 20. After sealing the can 10 with the cap 40, electrolyte can be injected into the can 10 through the injection hole 42 formed in the cap 40.

[0121] The cover 40 can be made of a metallic material. Therefore, the cover 40 can be conductive. For example, the cover 40 can include aluminum. The cover 40 can be made of, for example, low-carbon steel. The cover 40 can be made of, for example, nickel-plated steel, cold-rolled steel (SPCC or SPCE), or stainless steel (SUS). The cover 40 can be manufactured, for example, by pressing a metal sheet.

[0122] Figure 9 This is a cross-sectional view showing the state in which the injection hole of the cap according to an embodiment of the present disclosure is sealed by a plug. Figure 10 yes Figure 9 An enlarged cross-sectional view of the connection between the cap and the plug. Figure 11 This is a cross-sectional view of the plug according to an embodiment of the present disclosure. Figure 12 This is a cross-sectional view of plugs and caps connected to each other according to an embodiment of the present disclosure.

[0123] refer to Figures 9 to 12 According to this disclosure, the battery cell 1 may include an electrode assembly 20, a can 10, a cap 40 having an injection hole 42, and a plug 50.

[0124] The cover 40 may have an injection hole 42 formed in at least a portion thereof. The injection hole 42 may be formed in the center of the cover 40. In this case, the injection hole 42 may be closed by a plug 50, described later. For example, the plug 50 may be press-fitted into the injection hole 42. By blocking the injection hole 42 with the plug 50, the battery cell 1 can ensure airtightness.

[0125] The injection hole 42 can be used, for example, as an electrolyte injection port. The center of the injection hole 42 can be aligned with the center of the central winding hole H of the electrode assembly 20. That is, the injection hole 42 of the cover 40 can be located above the central winding hole H of the electrode assembly 20 in the winding axis direction.

[0126] Reference Figure 9 and Figure 10The plug 50 can be configured to seal the injection port 42. That is, the plug 50 can be configured to be inserted into the injection port 42. At least a portion of the plug 50 can pass through the injection port 42. By inserting the plug 50 into the injection port 42 of the cover 40, the sealing of the battery cell 1 can be ensured. The plug 50 can pass through the injection port 42 formed in the cover 40 to seal the exterior and interior of the can 10, thereby preventing electrolyte leakage.

[0127] This structure eliminates the need for edge pressing and curling, thus simplifying the manufacturing process. Furthermore, it prevents a decrease in energy density due to increased dead space within the battery in the winding axis direction of the electrode assembly 20. In other words, the structure disclosed herein can improve the energy density of the battery cell 1.

[0128] The cap 40 may have radial steps formed around the periphery of the injection port 42. Specifically, the cap 40 may include a body 41 and a plug connection portion 43. The cap 40 may also be divided into a body 41 and a plug connection portion 43 based on the steps.

[0129] The body 41 can be configured to be attached to the tank 10. The edge of the body 41 can be in perpendicular contact with the open end of the tank 10. The body 41 can be welded to the periphery of the open end of the tank 10 in the circumferential direction, which can be defined as a seam weld (as described above).

[0130] The plug connecting portion 43 may be a portion that is recessed downwards from the body 41 in the direction of the winding axis, surrounding the injection hole 42. The plug connecting portion 43 may be located further inwards from the body 41 in the radial direction. The upper surface of the plug connecting portion 43 may be located lower than the upper surface of the body 41. That is, a step may be formed between the plug connecting portion 43 and the body 41, and this step may have an annular shape extending circumferentially around the injection hole 42. The step may be formed by forging.

[0131] The thickness of the plug connecting portion 43 in the winding axis direction can be made smaller than the thickness of the main body 41 in the winding axis direction. The plug 50 can be mounted on the plug connecting portion 43. The cap connecting portion 51 of the plug 50, described later, can be mounted on the plug connecting portion 43.

[0132] According to the above embodiments of this disclosure, the structure of the cap connection portion 51 for housing the plug 50 can be formed by forging the area surrounding the injection hole 42.

[0133] Furthermore, according to the above embodiments of this disclosure, the plug connection portion 43 to which the plug 50 is connected can be formed to be recessed downward toward the electrode assembly 20, thereby ensuring that the overall height of the battery cell 1 remains constant even when the plug 50 is connected. That is, when the plug 50 and the cover 40 are connected, the upper surface of the plug 50 does not need to protrude upwards more than the upper surface of the cover 40. In other words, no overall height difference is generated in the battery cell 1. Therefore, the contact portion and / or contact area with components located above the cover 40 (e.g., a heat sink) are not limited by the plug 50 and can be maximized. Therefore, improvements can be made to the battery cell 1 and / or battery pack (e.g., Figure 19 The cooling performance of the battery pack (P) in the battery pack.

[0134] The plug 50 may have radial steps. Specifically, the plug 50 may include a cap connection portion 51, an insertion portion 52, and an edge portion 53.

[0135] The cover connecting portion 51 can be located on the cover 40. The cover connecting portion 51 can be disposed on the plug connecting portion 43 of the cover 40. The cover connecting portion 51 can be configured to overlap with the plug connecting portion 43 of the cover 40 in the winding axis direction. Alternatively, the cover connecting portion 51 can be arranged parallel to the cover 40. The cover connecting portion 51 can be provided parallel to the body 41 of the cover 40.

[0136] The insertion portion 52 may be located radially inward than the cover connection portion 51. The insertion portion 52 may be a portion protruding from the cover connection portion 51 toward the electrode assembly 20. The insertion portion 52 may be a portion protruding downward from the cover connection portion 51. The lower surface of the insertion portion 52 may be located lower than the lower surface of the cover connection portion 51.

[0137] According to the implementation method, refer to Figure 10 The upper surface of the plug 50 can be a generally flat surface in the horizontal direction. That is, the upper surfaces of the insertion portion 52 and the cap connecting portion 51 can be disposed on the same horizontal plane. In this case, the thickness of the insertion portion 52 in the direction of its winding axis can be formed to be greater than the thickness of the cap connecting portion 51 in the direction of its winding axis. For example, the insertion portion 52 and the cap connecting portion 51 of the plug 50 can be formed using a forging process.

[0138] The insertion portion 52 can be configured to be inserted into the injection hole 42. For example, the insertion portion 52 can be inserted into the injection hole 42 by an interference fit. For example, the outer diameter of the insertion portion 52 can be formed to be approximately equal to or greater than the inner diameter of the injection hole 42. Therefore, the sealing force of the injection hole 42 can be adjusted by inserting the insertion portion 52 into the injection hole 42. The insertion portion 52 can be inserted into the injection hole 42 to initially seal the injection hole 42.

[0139] According to the above embodiments of this disclosure, since the plug 50 has an insertion portion 52, the plug 50 can be press-fitted into the injection hole 42 and held therein even before welding. Furthermore, it can prevent the plug 50 from separating from the injection hole 42 when transported to the welding apparatus. That is, before welding the cap 40 and the plug 50, the insertion portion 52 of the plug 50 can be press-fitted into the injection hole 42 to ensure a temporary sealing force. Therefore, it is possible to prevent the deterioration of the welding quality due to electrolyte vaporization. For example, in terms of the He leakage rate, the temporary sealing force ensured by press-fitting the plug 50 can be 10. -5 Up to 10 -3 atm·cc / s.

[0140] The cap connecting portion 51 of the plug 50 and the body 41 of the cap 40 can be configured to be radially abutted and welded together. The radially outward outer surface of the cap connecting portion 51 can face the radially inward inner surface of the body 41. Welding W can be performed between the radially outward outer surface of the cap connecting portion 51 and the radially inward inner surface of the body 41. For example, the cap connecting portion 51 can be joined to the cap 40 using butt welding W, and the welding W can be performed at the edges of the body 41 and / or the cap connecting portion 51. For example, the welding W can be performed using resistance welding, ultrasonic welding, or laser welding.

[0141] According to the configuration implemented above in this disclosure, the plug 50 and the cap 40 can be welded to ensure a final sealing force higher than the temporary sealing force. Therefore, high airtightness can be ensured. Furthermore, compared to ensuring the sealing force solely through press-fitting, the press-fitting force of the plug 50 can be significantly reduced, thereby preventing permanent deformation of the cap 40 or the can 10 due to the press-fitting force. For example, the final sealing force ensured by welding can have approximately 10... -7 A He leakage rate of atm.cc / s or less is achieved, ensuring high airtightness.

[0142] Furthermore, according to the above-described implementation of this disclosure, since welding is performed after ensuring a temporary sealing force, it is possible to prevent electrolyte vapor from leaking to the outside and igniting during the welding process. Therefore, events such as fires or explosions caused by thermal runaway in vehicles comprising multiple battery cells can be prevented or delayed.

[0143] Reference Figure 10 and Figure 11 In part A, edge portion 53 may be located at the edge of cover connecting portion 51. Edge portion 53 may refer to a groove or recessed structure located at the edge of cover connecting portion 51.

[0144] The edge portion 53 may be a portion that is more recessed downward from the upper surface of the plug 50 than other areas in the winding axis direction. The edge portion 53 may be a portion that is more recessed downward than the cap connecting portion 51 in the winding axis direction. For example, the height of the upper surface of the edge portion 53 in the winding axis direction may be lower than the height of the upper surface of the cap connecting portion 51 in the winding axis direction. That is, the cap connecting portion 51 may have a step formed at the edge of its upper surface.

[0145] For example, the edge portion 53 can be formed by forging the edge of the cap connecting portion 51. As another example, the edge portion 53 can be formed from the edge of the plug 50 using at least one of the methods of extrusion, pressing, and casting.

[0146] Edge portion 53 may be formed along the entire circumferential edge of plug 50 or at least a portion thereof. For example, edge portion 53 may be configured as a loop along the circumferential edge of plug 50. For example, edge portion 53 may be discontinuously formed as a plurality of arcs formed in some regions along the circumferential edge of plug 50. That is, edge portion 53 may be formed only in the region where welding is performed.

[0147] Reference Figure 11 For example, the maximum recessed depth d1 of the edge portion 53 in the winding axis direction can be in the range of approximately 20% to 60% of the thickness d2 of the cover connecting portion 51 in the winding axis direction. For example, the maximum recessed depth d1 of the edge portion 53 in the winding axis direction can be in the range of approximately 30% to 50% of the thickness d2 of the cover connecting portion 51 in the winding axis direction.

[0148] According to the above embodiments of this disclosure, if the maximum recessed depth d1 of the edge portion 53 in the winding axis direction is less than 20% of the thickness d2 of the cover connecting portion 51 in the winding axis direction, it is likely to be less than the maximum height of the cover connecting portion 51. On the other hand, if the maximum recessed depth d1 of the edge portion 53 in the winding axis direction exceeds 60% of the thickness d2 of the cover connecting portion 51 in the winding axis direction, the electrolyte will vaporize due to welding heat, and the vaporized electrolyte gas can reach the edge portion 53, potentially deteriorating the welding performance.

[0149] In other words, this ratio can be configured to ensure that weld B is stably stored within edge portion 53, while suppressing unnecessary protrusion of plug 50 or cap 40 from the outer surface and maintaining a uniform overall cross-sectional shape. However, the above values ​​are merely exemplary ranges based on specific embodiments. In actual designs, various factors such as the applicable welding method (e.g., laser welding, resistance welding, etc.), welding quantity, shape and material of edge portion 53, and assembly tolerances can be comprehensively considered to appropriately modify and adjust the recess depth d1 to meet structural and functional requirements.

[0150] For example, the maximum horizontal length r1 of the edge portion 53 can be 5% to 30% of the horizontal spacing distance r2 between the cover connecting portion 51 and the insertion portion 52. For example, the maximum horizontal length r1 of the edge portion 53 can be 10% to 20% of the horizontal spacing distance r2 between the cover connecting portion 51 and the insertion portion 52. The horizontal spacing distance r2 between the cover connecting portion 51 and the insertion portion 52 can refer to the spacing distance between the outer surface of the cover connecting portion 51 and the outer surface of the insertion portion 52.

[0151] According to the above embodiments of this disclosure, if the maximum horizontal length r1 of the edge portion 53 is less than 5% of the horizontal distance r2 between the cap connecting portion 51 and the insertion portion 52, it may be difficult to adequately store the weld B. On the other hand, if the maximum horizontal length r1 of the edge portion 53 exceeds 30% of the horizontal distance r2 between the cap connecting portion 51 and the insertion portion 52, the injection hole 42 and the edge portion 53 cannot be adequately spaced radially, making it easy for the vaporized gas of the electrolyte caused by welding heat to reach the edge portion 53, thereby deteriorating the welding performance.

[0152] Reference Figure 11 The edge portion 53 may include an edge side surface 531 extending downward from the upper surface of the cover connection portion 51 and an edge bottom surface 532 extending radially outward from the lower end of the edge side surface 531. For example, as Figure 11 As shown, the edge side surface 531 can be a surface extending in a vertical direction parallel to the winding axis. For example, the edge bottom surface 532 can be a surface extending in a horizontal direction perpendicular to the winding axis. For example, the edge side surface 531 and the edge bottom surface 532 can intersect vertically. However, the shape of the edge portion 53 is not limited to the above embodiment and can be designed in various ways. For example, the edge side surface 531 can be a surface inclined at a predetermined angle (e.g., an acute angle) relative to the winding axis. For example, the edge bottom surface 532 can be a surface inclined at a predetermined angle (e.g., an acute angle) relative to the horizontal plane.

[0153] Reference Figure 12The weld B formed during the welding of the plug 50 and the cap 40 can be configured to be located on the edge portion 53. That is, when welding the cap connecting portion 51, the stepped edge portion 53 can accommodate the weld B. Specifically, the weld B can be located within the space surrounded by the inner surface of the body 41 of the cap 40 and the edge portion 53.

[0154] The plug 50 and cap 40 can be melted at a certain temperature or higher. The melting point of the plug 50 and / or cap 40 can be approximately 100°C to 1400°C. That is, the plug 50 and cap 40 can be welded and joined by applying heat of 100°C to 1400°C. In this case, the part where the plug 50 and cap 40 are joined by local heating to reach the melting point and then solidifying can be referred to as the weld.

[0155] The maximum recessed depth d1 of the edge portion 53 in the direction of the winding axis can be greater than the maximum thickness d3 of the weld B formed along the winding axis. That is, the weld B may not protrude upwards more than the upper surface of the plug 50 or the upper surface of the cap 40.

[0156] According to the configuration implemented above in this disclosure, the overall height difference of the battery cell 1 due to the presence and / or shape of the weld seam B can be avoided. In the case where the weld seam B protrudes outward from the plug 50, a large amount of coating agent (such as thermal paste) must be applied to form a flat surface. However, according to embodiments of this disclosure, even without applying a large amount of coating agent, the contact area with the heat sink can be increased.

[0157] According to the configuration implemented above in this disclosure, the flatness of the battery cell 1 can be ensured. Since the height of the battery cell 1 can be kept constant, this is potentially advantageous in terms of battery cell 1 management. That is, no overall height deviation can occur within the battery cell 1. Therefore, the contact portion and / or contact area with components located on the cover 40 (e.g., a heat sink) are not limited by weld B and can be maximized. Thus, the heat dissipation and cooling performance of the battery cell 1 and / or the battery pack can be improved.

[0158] Figure 13 This is a cross-sectional view of the connection structure of the cover and plug according to another embodiment of the present disclosure.

[0159] The height of the upper surface of the cap connecting portion 51 of the plug 50 in the direction of the winding axis can be equal to (refer to...) Figure 12 ) or less than (refer to) Figure 13 The height of the upper surface of the body 41 of the cover 40 in the direction of the winding axis.

[0160] Reference Figure 13The height of the upper surface of the cap connecting portion 51 of the plug 50 in the winding axis direction can be less than the height of the upper surface of the body 41 of the cap 40 in the winding axis direction. That is, the thickness d2 of the cap connecting portion 51 of the plug 50 in the winding axis direction can be less than the separation distance d4 between the upper surface of the cap connecting portion 43 of the cap 40 and the upper surface of the body 41 in the winding axis direction.

[0161] If the height of the plug 50 is greater than the height of the cap 40, there is a problem that the cap 40 cannot be fully melted during welding due to the plug 50. For example, when laser welding the plug 50 and the cap 40, a laser beam can be irradiated such that the center of the laser beam is aligned with the winding axis. In this case, the laser beam can be irradiated so that it travels downwards and radially outwards. That is, the laser beam can be irradiated at an angle relative to the horizontal plane. In this case, if the plug 50 is located higher than the cap 40, the laser beam will have difficulty fully irradiating the cap 40, resulting in poor weld quality.

[0162] According to the above-described implementation of the present disclosure, the height of the plug 50 in the winding axis direction is formed to be less than the height of the opposing cover 40 in the winding axis direction that contacts the plug 50, thereby enabling sufficient laser irradiation onto the cover 40 to improve welding quality.

[0163] Figure 14 This is a cross-sectional view of the connection structure of the cover and plug according to another embodiment of the present disclosure. Figure 15 This is a cross-sectional view of the welded cap and plug according to another embodiment of the present disclosure.

[0164] The edge portion 53 may include an edge inclined surface 533 that is inclined downward and radially outward from the upper surface of the cover connection portion 51.

[0165] The inclined edge surface 533 can be formed to extend continuously from the upper surface of the cover connecting portion 51 to its lower surface. Therefore, the maximum recess depth of the edge portion 53 in the winding axis direction can be further increased.

[0166] Reference Figure 15 This configuration can guide the weld B in a downward direction along the inclined surface 533 of the edge during the welding process between the cap 40 and the plug 50, so that the weld B can accumulate or gather in the lower region of the edge portion 53.

[0167] According to the above embodiments of this disclosure, a structural margin can be provided to effectively suppress the phenomenon that weld B unnecessarily protrudes upward from the upper surface of cover 40 or plug 50.

[0168] Furthermore, according to the above-described implementation of the present disclosure, the size and shape of the weld B can be controlled, and the weldable area expands in the direction of the winding axis according to the shape of the edge inclined surface 533, thereby improving the mechanical strength and joint reliability of the cover connection portion 51.

[0169] Figure 16 This is a cross-sectional view of the connection structure of the cover and plug according to another embodiment of the present disclosure. Figure 17 This is a cross-sectional view of the welded cap and plug according to another embodiment of the present disclosure.

[0170] The edge portion 53 may include a plurality of edge protrusions 534 that project outward from the radial outer surface of the cover connection portion 51.

[0171] Multiple edge protrusions 453 may be spaced apart from each other in a vertical direction. Multiple edge protrusions 453 may extend from the outer surface of the cover connection portion 51 to contact the body 41 of the cover 40. Multiple edge protrusions 453 may be configured to directly contact the body 41 of the cover 40, thereby optimizing the heat propagation path during laser welding. However, the array density, shape, and vertical spacing of the edge protrusions 453 can be designed in various ways.

[0172] For example, the edge protrusion 453 can be formed into a shape with a rectangular cross-section. However, the shape of the edge protrusion 453 is not limited to the above embodiment and can be designed in various ways.

[0173] According to the configuration implemented above in this disclosure, a plurality of edge protrusions 453 can be sequentially exposed to the laser beam from top to bottom, causing them to be partially and locally heated and melted, and the melted edge protrusions 453 can fall downwards and accumulate under the influence of gravity and surface tension. The melted edge protrusions 453 can be continuously solidified from below to form a weld B of a predetermined shape.

[0174] Furthermore, according to the above-described implementation of this disclosure, a structural margin can be provided to effectively suppress the weld B from unnecessarily protruding upward from the upper surface of the cover 40 or the plug 50. That is, the gap between the cover connecting portion 51 and the body 41 can be set to accommodate the weld B.

[0175] Furthermore, according to the above-described configuration of this disclosure, since the edge protrusion 453 itself is melted by welding, the size and shape of the weld B can be controlled. Additionally, since the weldable area expands in the direction of the winding axis, the mechanical strength and joint reliability of the cover connection portion 51 can be improved.

[0176] Figure 18 This is a cross-sectional view of a plug according to another embodiment of the present disclosure. Figure 19 This is a cross-sectional view showing a cap and plug connected to each other according to another embodiment of the present disclosure.

[0177] The structure of the cover 40 and the plug 50, and the welding of the cover 40 and the plug 50, are consistent with the reference. Figures 9 to 17 If the descriptions are the same, the repeated descriptions will be omitted.

[0178] The cap connecting portion 51 and the insertion portion 52 of the plug 50 may have approximately the same thickness in the direction of the winding axis. The cap connecting portion 51 and the insertion portion 52 of the plug 50 may be integrally formed. That is, the plug 50 may be bent between the cap connecting portion 51 and the insertion portion 52.

[0179] The plug 50 can be constructed by drawing. Drawing can refer to the process of stretching and thinning metal into a desired shape. Drawing can be a process of stretching and elongating material (e.g., sheet metal or wire metal) using a die. For example, deep drawing can be a method of forming a plate into a deep container shape using a punch or die. Specifically, the plug 50 can be manufactured by deep drawing. Specifically, the plug 50 can be manufactured by fixing the ends of a plate-shaped plug preform having a predetermined thickness and applying pressure to the center of the plug preform.

[0180] According to the structure implemented above using the drawing method of this disclosure, the radial separation distance between the cap connecting portion 51 and the insertion portion 52 can become relatively long compared to the forging method. Therefore, it is possible to prevent electrolyte vapor generated by welding heat from directly contacting the cap connecting portion 51. In other words, the electrolyte vaporization path can be extended. Therefore, welding defects caused by the heat of electrolyte vaporization can be prevented.

[0181] According to the above-described configuration of this disclosure, the plug 50 can be manufactured by stretch forming, thereby reducing its weight and contributing to a reduction in the overall weight of the battery cell 10. Furthermore, the manufacturing cost of the plug 50 can be reduced, and the simple and easy processing of the plug 50 can shorten manufacturing time.

[0182] Figure 20 This is a flowchart of a method for manufacturing a battery cell using the injection hole sealing structure disclosed herein. Reference will be made below. Figure 20 A method for manufacturing battery cells according to embodiments of the present disclosure is described. For ease of explanation, please refer to... Figures 1 to 19 The attached diagram.

[0183] First, an electrode assembly 20 (S1) can be prepared, which includes a can 10 (the can 10 having a first electrode terminal 13 that is insulated and sealed to a bottom 12) and a first current collector 31 and a second current collector 32 that are respectively welded to the first electrode and the second electrode at opposite ends.

[0184] The method may then include the step of covering the open end with a cap 40 while the electrode assembly 20 is housed in the can 10 (S2).

[0185] The electrode assembly 20 can be housed inside the canister 10, while the first current collector 31 is aligned and oriented toward the bottom 12 of the canister 10. At this time, an insulator 19 can be inserted between the first current collector 31 and the bottom 12 of the canister 10 to electrically insulate the first current collector 31 from the bottom 12.

[0186] The edge of the lid 40 can be joined to the can 10 (S3). The lid 40 and the can 10 can be heat-jointed.

[0187] The periphery of the front end of the side wall 11 of the battery can 10 can be brought into contact with the periphery of the edge of the cover 40 and then welded circumferentially. The open end of the can 10 and the cover 40 can be joined at the point of contact therebetween. For example, the open end of the can 10 and the cover 40 can be joined by welding at the connection point between them. For example, butt welding can be used to join the cover 40 to the can 10. This can be defined as a seam welding method.

[0188] Alternatively, the first current collector 31 can be thermally bonded to the first electrode terminal 13 before the edge of the cap 40 is joined to the can 10. Additionally, the opening of the can 10 can be sealed by covering it with the cap 40, and the second current collector 32 can be joined to the cap 40 and / or the can 10 as the second electrode terminal 15, thereby electrically connecting the can 10 and the cap 40, and the cap 40 can be thermally bonded to the can 10.

[0189] The method may then include injecting electrolyte into the battery tank 10 through the injection hole 42 of the cover 40 (S4).

[0190] Next, the process may include the step of inserting the plug 50 into the injection port 42 after the electrolyte has been injected (S5). The insertion portion 52 of the plug 50 may be configured to be inserted into the injection port 42. For example, the insertion portion 52 may be inserted into the injection port 42 by an interference fit. The insertion portion 52 may be inserted into the injection port 42 to initially seal the injection port 42.

[0191] According to the above embodiments of this disclosure, since the plug 50 has an insertion portion 52, the plug 50 can be press-fitted into the injection hole 42 and held therein even before welding. Furthermore, it can prevent the plug 50 from separating from the injection hole 42 when transported to the welding apparatus. That is, before welding the cap 40 and the plug 50, the insertion portion 52 of the plug 50 can be press-fitted into the injection hole 42 to ensure a temporary sealing force.

[0192] Finally, the method may include the step of welding the plug 50 and the cap 40 (S6).

[0193] A seal can be achieved by press-fitting the plug 50 into the injection hole 42 to first ensure a temporary sealing force, and then welding the cap connection portion 51 of the plug 50 to the cap 40 to obtain a final sealing force.

[0194] For example, the cap connecting portion 51 of the plug 50 can be laser welded to the body 41 of the cap 40. Laser welding can be defined as a process of melting and joining metals using a high-energy-density laser beam.

[0195] According to the above-implemented structure of this disclosure, since welding is performed after ensuring a temporary sealing force, the formation of gas channels or cracks can be prevented during the welding process, thereby preventing defects in the cover connection portion 51.

[0196] Furthermore, according to the above-described implementation of the present disclosure, since welding is performed after ensuring a temporary sealing force, it is possible to prevent electrolyte vapor from leaking to the outside and igniting during the welding process.

[0197] Figure 21 This is a diagram illustrating a battery pack according to an embodiment of the present disclosure. Figure 22 It shows that it has Figure 21 A diagram of a vehicle with a battery pack.

[0198] Reference Figure 21 The battery pack P according to this disclosure may include at least one battery cell 1 as described above. Furthermore, the battery pack P according to this disclosure may include a battery pack housing 2 capable of accommodating one or more battery cells 1. As shown, the battery pack P can be configured using a battery module as an intermediate assembly, or it can be configured directly without using a battery module. Since the battery cell 1 itself has a large volume, there are no difficulties in implementing the battery pack P even without using an intermediate structure such as a battery module.

[0199] In addition to battery cell 1, battery pack P may also include various other components of battery pack P known at the time of filing of this disclosure, such as BMS, relays, current sensors, etc.

[0200] The battery pack P may include multiple battery cells 1. The battery cells 1 can be arranged in a predetermined number of rows, such that both the first electrode terminal 13 and the second electrode terminal 15 of each battery cell 1 are located on the upper side. Therefore, when electrically connecting multiple battery cells 1, the positive and negative terminals can be connected from one direction, thus simplifying the electrical connection structure. This increases the number of battery cells 1 that can be installed in the same space, thereby improving energy density and facilitating electrical wiring. Therefore, excellent space efficiency and high electrical wiring efficiency significantly improve the efficiency of the electric vehicle assembly process and the assembly and maintenance of the battery pack P. Furthermore, as mentioned above, each battery cell 1 can have a higher energy density than before. A battery pack P with this higher energy density can store the same amount of energy while reducing its volume and weight.

[0201] Therefore, as Figure 18 As shown, when a battery pack P equipped with such battery cell 1 is installed in a vehicle M that uses electricity as its energy source, the driving range per unit of energy of the vehicle can be further increased.

[0202] Additionally, the battery pack P may further include a heat sink. The battery pack housing 2 can store the heat sink. The heat sink may, for example, be located at the bottom of the battery cell 1. In this case, the heat sink can contact the cover of the battery cell 1 (e.g., Figure 12 (40) and / or plugs (e.g., Figure 12 The plug 50 in the middle). According to the above-implemented structure of this disclosure, the upper surface of the plug 50 may not protrude upward beyond the upper surface of the cover 40. In addition, the weld (e.g., Figure 12 The weld seam B in the cover 40 does not protrude upwards beyond the upper surface of the cover 40. In other words, since the overall height of the battery cells 1 is uniform, the contact portion and / or contact area between the cover 40 and the heat sink can be maximized, rather than being limited by the plug 50 and / or weld seam B. This improves the cooling performance of the battery cells 1 and / or the battery pack P.

[0203] Reference Figure 22 The vehicle M according to this disclosure may include at least one battery pack P according to this disclosure.

[0204] The battery cell 1 according to this disclosure can be applied to vehicles such as electric vehicles or hybrid vehicles. That is, a vehicle M according to this disclosure may include the battery cell 1 according to this disclosure or the battery pack P according to this disclosure. Furthermore, in addition to the battery cell 1 or the battery pack P, the vehicle M according to this disclosure may also include various other components included in the vehicle. For example, in addition to the battery cell 1 of this disclosure, the vehicle M according to this disclosure may further include a vehicle body, a motor, control devices such as an electronic control unit (ECU), etc. The vehicle M includes four-wheeled vehicles and two-wheeled vehicles. According to embodiments of this disclosure, the vehicle M can be operated by power supplied from the battery pack P.

[0205] As described above, although this disclosure has been described with reference to limited embodiments and drawings, this disclosure is not limited thereto, and various modifications and changes can be made without departing from the technical spirit of this disclosure and the equivalent scope of the claims described below by those skilled in the art to which this disclosure pertains.

Claims

1. A battery cell, the battery cell comprising: An electrode assembly constructed by winding a first electrode, a second electrode, and a diaphragm between the first electrode and the second electrode around a winding axis; A can, the can being configured to receive the electrode assembly through an open end formed on one side; A cap, the cap being configured to cover the open end and the cap having an injection hole formed therein; and A plug configured to seal the injection port. The plug includes: a cap connecting portion located on the cap; an insertion portion located radially inside the cap connecting portion and protruding from the cap connecting portion for insertion into the injection hole; and an edge portion located at the edge of the cap connecting portion and recessed further downward in the winding axis direction than the cap connecting portion.

2. The battery cell according to claim 1, in, The edge portion is constructed in the form of a loop along the circumferential edge of the plug.

3. The battery cell according to claim 1, in, The edge portion is formed by forging the edge of the cover connection portion.

4. The battery cell according to claim 1, in, The maximum recessed depth of the edge portion in the winding axis direction is in the range of 20% to 60% of the thickness of the cover connection portion in the winding axis direction.

5. The battery cell according to claim 1, in, The weld formed during the welding of the plug and the cap is configured to be located on the edge portion.

6. The battery cell according to claim 5, in, The maximum recessed depth of the edge portion in the direction of the winding axis is greater than the maximum thickness of the weld formed along the direction of the winding axis.

7. The battery cell according to claim 6, in, The edge portion includes an edge side surface extending downward from the upper surface of the cover connection portion and an edge bottom surface extending radially outward from the lower end of the edge side surface.

8. The battery cell according to claim 1, in, The cap includes a body and a plug connection portion, the plug connection portion being recessed downwards from the body in the direction of the winding axis around the injection hole, and the plug connection portion being configured such that the cap connection portion is mounted on the plug connection portion.

9. The battery cell according to claim 8, in, The height of the upper surface of the cap connecting portion of the plug in the direction of the winding axis is less than the height of the upper surface of the body of the cap in the direction of the winding axis.

10. The battery cell according to claim 8, in, The cap connecting portion of the plug is welded to the body of the cap while being adjacent to each other in the radial direction.

11. The battery cell according to claim 1, in, The edge portion includes an edge inclined surface that slopes downward from the upper surface of the cover connection portion and radially outward.

12. The battery cell according to claim 1, in, The insertion portion is configured to be inserted into the injection hole via an interference fit to initially seal the injection hole.

13. The battery cell according to claim 1, in, The cap connecting portion and the insertion portion have the same thickness in the winding axis direction and are integrally formed.

14. A battery pack comprising at least one battery cell according to any one of claims 1 to 13.

15. A vehicle comprising at least one battery cell according to any one of claims 1 to 13.

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