Battery cells, battery packs including the battery cells, and vehicles.

Abstract

A battery cell, a battery pack including the battery cell, and a vehicle are disclosed. According to one embodiment of the invention, the battery cell includes: an electrode assembly having a structure in which a positive electrode plate, a negative electrode plate, and a separator inserted between the positive and negative electrode plates are wound in one direction; a battery can housing the electrode assembly; a cell terminal electrically connected to the positive electrode plate; and a riveting washer inserted between the cell terminal and the battery can, wherein the riveting washer has a reduced thickness portion.

Description

Technical Field

[0001] This application is based on and claims priority to Korean Patent Application No. 10-2024-0105656 filed with the Korean Intellectual Property Office on August 7, 2024 and Korean Patent Application No. 10-2025-0104255 filed on July 30, 2025, the disclosures of which are incorporated herein by reference in their entirety.

[0002] This disclosure relates to a battery cell, a battery pack including the battery cell, and a vehicle, and more specifically, to a battery cell capable of blocking current flow in a battery cell in which a thermal event occurs, and a battery pack including the battery cell and a vehicle. Background Technology

[0003] Secondary batteries offer high applicability across product categories and have electrical characteristics such as high energy density, making them widely used not only in portable devices but also in electric vehicles (EVs) or hybrid electric vehicles (HEVs) powered by electric power sources.

[0004] Such secondary batteries are gaining attention as a new energy source for enhancing environmental sustainability and energy efficiency, not only because of their major advantage of significantly reducing the use of fossil fuels, but also because they do not produce byproducts from energy use.

[0005] Currently widely used rechargeable batteries include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. The operating voltage of these rechargeable battery cells is approximately 2.5 V to 4.5 V.

[0006] Therefore, when a higher output voltage is required, a battery module or battery pack can be configured by connecting multiple battery cells in series. Alternatively, a battery module or battery pack can be configured by connecting multiple battery cells in parallel according to the required charge / discharge capacity of the battery pack. Thus, the number of battery cells included in a battery module or battery pack can be set in various ways based on at least one of the required output voltage and charge / discharge capacity.

[0007] Secondary battery cells can be classified into cylindrical, prismatic, and pouch-type battery cells. In the case of cylindrical battery cells, the positive and negative plates are wound together to form a wound-core electrode assembly with a separator, which acts as an insulator, inserted between them. The electrode assembly, along with the electrolyte, is then inserted into a battery can to form a battery. Furthermore, cylindrical battery cells may include current collectors for electrically connecting the positive and negative plates, respectively.

[0008] Additionally, the cylindrical battery cell may include cell terminals riveted through through holes formed in the battery can, and riveting washers inserted between the cell terminals and the through holes. Here, the riveting washers are used to electrically insulate the cell terminals of the positive electrode and the battery can of the negative electrode.

[0009] Figure 1 It is a cross-sectional view of a conventional battery cell before the cell terminals, riveting washers, and battery can are riveted together. Figure 2 This is a cross-sectional view of a conventional battery cell after the cell terminals, riveting washers, and battery can are riveted together.

[0010] refer to Figure 1 and Figure 2 In a conventional cylindrical battery cell 1, the riveting gasket 2 is formed to be flat and thick, with no variation in thickness. Therefore, when a thermal event occurs, only a very small portion of the riveting gasket 2 melts.

[0011] Furthermore, if the riveting washer 2 is only partially melted by heat and loses its electrical insulation properties, electrical contact will occur between the positive cell terminal 3 and the negative battery canister 4, resulting in the flow of internal short-circuit current.

[0012] However, since only a very small portion of the riveting washer 2 is melted, the amount of internal short-circuit current flowing at this time is insufficient to melt the fused portion formed at the busbar. Here, if the internal short-circuit current continues to flow to other battery cells connected to the battery cell that has already experienced a thermal event, a thermal anomaly may occur in the battery cell 1 that has not experienced a thermal event, generating a flame, which could eventually lead to a chain reaction of fire. Summary of the Invention

[0013] Technical issues

[0014] Therefore, this disclosure is dedicated to providing a battery cell in which the riveting gasket can be easily melted by heat, as well as a battery pack and a vehicle including the battery cell.

[0015] Furthermore, this disclosure also aims to provide a battery cell, a battery pack including the battery cell, and a vehicle, wherein the battery cell can quickly cut off the current flow of a battery cell that has already experienced a thermal event by making the positive cell terminal and the negative battery canister through a large-area electrical contact via a molten riveting washer, thereby allowing a high current to flow through the busbar to break the fusion portion formed at the busbar.

[0016] In addition, this disclosure also aims to provide a battery cell, a battery pack including the battery cell, and a vehicle, which can prevent a chain reaction of fire in other battery cells that have not yet experienced a thermal event when a thermal event occurs in one battery cell.

[0017] However, the technical problems that this disclosure seeks to solve are not limited to those described above, and those skilled in the art will clearly understand from the description of the invention below that there are other problems not mentioned above.

[0018] Technical solution

[0019] In one aspect of this disclosure, a battery cell is provided, the battery cell comprising: an electrode assembly having a structure in which a positive electrode plate, a negative electrode plate, and a separator inserted between the positive electrode plate and the negative electrode plate are wound in one direction; a battery can configured to house the electrode assembly; a cell terminal electrically connected to the positive electrode plate; and a riveting washer inserted between the cell terminal and the battery can, wherein the riveting washer has a thickness reduction portion formed therein.

[0020] In one implementation, the reduced thickness portion can be formed as a stepped groove portion.

[0021] In one embodiment, the reduced thickness portion can be formed on the inner side of the contact surface between the riveting washer and the battery cell terminal.

[0022] In one embodiment, the riveting washer may include a first portion having a reduced thickness portion therein and a second portion extending from the first portion.

[0023] In this implementation, the first part and the second part may be made of different materials.

[0024] In one implementation, the first part may be made of a material with higher thermal conductivity than the second part.

[0025] In one embodiment, the first part may be coated with a material having heat transfer properties.

[0026] In an implementation, the first part may be made of a material with a melting point lower than that of the second part.

[0027] In one implementation, when a thermal event occurs, the first part may melt before the second part, causing electrical contact between the cell terminals and the battery canister.

[0028] In one embodiment, a stepped protrusion may be formed at the cell terminal, and the stepped protrusion may be connected to a stepped groove portion.

[0029] In an implementation, the stepped protrusions may be made of a material with heat transfer properties.

[0030] In one embodiment, the stepped protrusions may be coated with a material having heat transfer properties.

[0031] In one implementation, multiple microgrooves may be formed in the stepped groove portion.

[0032] In another aspect of this disclosure, a battery pack including at least one of the aforementioned battery cells is provided, as well as a vehicle including at least one of the aforementioned battery cells.

[0033] Beneficial effects

[0034] The embodiments disclosed herein have the effect that the riveting gasket can be easily melted by heat.

[0035] Furthermore, the embodiments of this disclosure have the effect of quickly cutting off the current flow of a battery cell that has already experienced a thermal event by making the positive electrode cell terminal and the negative electrode battery cant through a large-area electrical contact via a molten riveting washer, thereby causing a high current to flow through the busbar to break the fused portion formed at the busbar.

[0036] Furthermore, embodiments of this disclosure have the effect of preventing chain fires in other battery cells that have not yet experienced a thermal event when a thermal event occurs in one battery cell.

[0037] However, the effects that can be obtained from this disclosure are not limited to those described above, and those skilled in the art will clearly understand from the description of the invention below that other effects not mentioned above will be apparent. Attached Figure Description

[0038] 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.

[0039] Figure 1 This is a cross-sectional view of a conventional battery cell before the cell terminals, riveting washers, and battery can are riveted together.

[0040] Figure 2 This is a cross-sectional view of a conventional battery cell after the cell terminals, riveting washers, and battery can are riveted together.

[0041] Figure 3 This is a cross-sectional view showing a battery cell according to an embodiment of the present disclosure.

[0042] Figure 4 It shows the basis Figure 3 A cross-sectional view of the battery cell in the modified implementation method.

[0043] Figure 5 This is a perspective cross-sectional view showing the cell terminals in a battery cell according to an embodiment of the present disclosure.

[0044] Figure 6This is a perspective view showing a cross-section of a riveting washer in a battery cell according to an embodiment of the present disclosure.

[0045] Figure 7 This is a cross-sectional view of a battery cell according to an embodiment of the present disclosure before the cell terminals, riveting washers, and battery can are riveted.

[0046] Figure 8 yes Figure 7 A magnified view of part A.

[0047] Figure 9 This is a cross-sectional view of a battery cell according to an embodiment of the present disclosure after the cell terminals, riveting washers, and battery can are riveted together.

[0048] Figure 10 yes Figure 9 A magnified view of part B.

[0049] Figure 11 It shows the basis Figure 6 A three-dimensional cross-sectional view of the riveting washer in the modified implementation method.

[0050] Figure 12 This is a schematic diagram illustrating the configuration of a battery pack including battery cells according to each embodiment of the present disclosure.

[0051] Figure 13 This is a diagram used to illustrate a vehicle including a battery pack according to each embodiment of the present disclosure. Detailed Implementation

[0052] Preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Before description, it should be understood that the terminology used in the specification and appended claims should not be construed as limited to its general and dictionary meaning, but rather is interpreted according to the meaning and concept corresponding to the technical aspects of the present disclosure, based on the principle that inventors are allowed to appropriately define terms for best interpretation. Therefore, the description presented herein is merely a preferred example for illustrative purposes and is not intended to limit the scope of the present disclosure; thus, it should be understood that other equivalents and modifications may be made thereto without departing from the scope of the present disclosure.

[0053] In the accompanying drawings, for ease of explanation and clarification, the dimensions of corresponding elements or specific portions of each element have been enlarged, omitted, or simplified. Therefore, the size of the corresponding element does not perfectly reflect its actual size. Descriptions of related known functions or configurations that may obscure the subject matter of this disclosure will be omitted.

[0054] In this specification, when a component is described as being "engaged to" or "connected to" another component, it should be understood that the component may be directly engaged or connected to the other component, or they may be indirectly engaged or connected via a connecting member disposed between them.

[0055] Furthermore, the description of common components in any embodiment of this disclosure can also be applied to common components in other embodiments. For example, the configuration of a second embodiment that is the same as that described in the first embodiment can be referenced to the previously described first embodiment, and the same configuration can also be applied to the second embodiment. Moreover, the description of the second embodiment applicable to the first embodiment can also be applied to the first embodiment. This also applies to other embodiments.

[0056] Figure 3 This is a cross-sectional view showing a battery cell according to an embodiment of the present disclosure, and Figure 4 It shows the basis Figure 3 A cross-sectional view of the battery cell in the modified implementation method.

[0057] refer to Figure 3 and Figure 4 According to embodiments of the present disclosure, the battery cell 10 may include a cover 700 connected to the battery can 200 to seal an opening formed in the battery can 200. Furthermore, depending on the connection method of the cover 700, the battery cell 10 can be classified as a type in which the crimped portion 220 and the rolled edge portion 210 are not formed in the battery can 200 (see [link to relevant documentation]). Figure 3 ), and the type in which the crimped portion 220 and the rolled portion 210 are formed in the battery can 200 (see Figure 4 ).

[0058] refer to Figure 3 If the rolled edge portion 210 and the crimped portion 220 are not formed in the battery can 200, the cover portion 700 can be connected to the battery can 200 by direct welding using various welding methods (e.g., seam welding).

[0059] If the battery canister 200 and cover 700 of the battery cell 10 are welded by seam welding, the cover 700 can be joined to the side of the battery canister 200 by welding (e.g., horizontal welding). That is, the cover 700 can be joined so as to contact the inside of the side of the opening portion of the battery canister 200.

[0060] Alternatively, although not shown in the accompanying drawings, the cover 700 may be attached to the upper surface of the battery canister 200 by welding (e.g., vertical welding). That is, the cover 700 may be mounted and welded to the upper side of the opening portion of the battery canister 200.

[0061] The cover 700 can have various shapes, such as a plate shape, but the shape of the cover 700 is not limited to this.

[0062] The welding method of the cover 700 and the battery canister 200 can vary, and for example, the cover 700 can be joined to the battery canister 200 by butt welding, but is not limited thereto.

[0063] The cover 700 and the battery canister 200 can be connected by a method other than welding, and the connection method is not limited to this. By connecting the cover 700 and the battery canister 200, the sealing characteristics of the battery cell 10 can be guaranteed.

[0064] The cover 700 can be made of a metallic material. Therefore, the cover 700 can be conductive. For example, the cover 700 can contain aluminum. The cover 700 can be electrically connected to the battery canister 200. At the same time, since the battery canister 200 is also made of a conductive metal, the cover 700 connected to the battery canister 200 can also be configured to have the same polarity as the battery canister 200.

[0065] In this way, with the cover 700 directly welded to the battery can 200 by seam welding, the fixing structure is simple, which makes it possible to further ensure the volume of the electrode assembly 100 that can be accommodated inside the battery can 200, and therefore, it is more advantageous in ensuring the capacity compared to the same volume of the battery can 200, thus having the effect of improving energy density.

[0066] Additionally, refer to Figure 4 In the case where the crimping portion 220 and the rolled edge portion 210 are formed on the battery can 200, the crimping portion 220 is formed on the battery can 200 to fix the cover portion 700. Moreover, the rolled edge portion 210 is formed by pressing the outer periphery of the battery can 200 inward to support the electrode assembly 100 so that the electrode assembly 100 does not come out of the battery can 200.

[0067] The cover 700 can be made of, for example, a metallic material to ensure rigidity. Furthermore, the cover 700 can be separable from the electrode assembly 100 and can be configured to be non-polar. In other words, the cover 700 can be non-polar, even if it is made of a conductive metallic material.

[0068] The fact that the cover 700 is not polarized means that the cover 700 is electrically isolated from the battery canister 200 and the cell terminals 400. Therefore, the cover 700 does not have to be polarized, and its material does not necessarily have to be a conductive metal.

[0069] The cover 700 can be mounted on and supported by the rolled edge portion 210 formed on the battery can 200. Furthermore, the cover 700 is secured by a crimp portion 220. A sealing gasket 230 can be inserted between the cover 700 and the crimp portion 220 of the battery can 200 to ensure the airtightness of the battery can 200. That is, the sealing gasket 230 can be arranged to be inserted between the edge of the cover 700 and the opening of the battery can 200. Here, Figure 4 The reference numeral 710 in the attached figure indicates the vent notch.

[0070] In the following text, for ease of explanation, an example is given in which the cover 700 is directly welded to the battery can 200 by a seam welding method. Figure 3 This invention describes a battery cell 10 according to an embodiment of the present disclosure, but the scope of the present disclosure is not limited thereto.

[0071] refer to Figure 3 According to an embodiment of the present disclosure, the battery cell 10 includes an electrode assembly 100, a battery canister 200, a cell terminal 400, and a riveting washer 800.

[0072] Reference Figure 3 The electrode assembly 100 has a structure in which a positive electrode plate 110, a negative electrode plate 120, and a diaphragm 130 inserted between the positive electrode plate 110 and the negative electrode plate 120 are wound in one direction. In addition, a central hole 140 is formed at the center of the electrode assembly 100, and the electrode assembly 100 can be formed as a wound core type.

[0073] For example, the electrode assembly 100 can be manufactured by winding a stack formed by sequentially stacking the negative electrode plate 120, the separator 130, the positive electrode plate 110, and the separator 130 at least once. Here, the positive electrode plate 110 and the negative electrode plate 120 can be formed in sheet form.

[0074] In other words, the electrode assembly 100 used in this embodiment can be a wound electrode assembly 100. In this case, an additional diaphragm can be provided on the outer surface of the electrode assembly 100 for insulation from the battery canister 200. That is, the electrode assembly 100 can have any wound structure known in the related art.

[0075] The positive electrode active material is coated onto one or both sides of the positive electrode plate 110, and a first uncoated portion 111 on which the positive electrode active material is not coated may be formed at the end of the positive electrode plate 110. Here, the positive electrode active material coated on the positive electrode plate 110 may be any active material known in the art, without limitation.

[0076] As described above, a positive electrode plate 110 having a first uncoated portion 111 formed thereon can be disposed in a battery cell 10. However, the battery cell 10 according to embodiments of the present disclosure also includes embodiments in which a positive electrode plate 110 in which the first uncoated portion 111 is not formed. However, for ease of explanation, the following description will focus on the case where the first uncoated portion 111 is formed on the positive electrode plate 110.

[0077] The negative electrode active material is coated onto one or both sides of the negative electrode plate 120, and a second uncoated portion 121 on which the negative electrode active material is not coated may be formed at the end of the negative electrode plate 120. Here, any negative electrode active material known in the art can be used on the negative electrode plate 120 without limitation.

[0078] As described above, a negative electrode plate 120 having a second uncoated portion 121 formed thereon can be disposed in a battery cell 10. However, the battery cell 10 according to embodiments of the present disclosure includes embodiments with respect to a negative electrode plate 120 in which the second uncoated portion 121 is not formed. However, for ease of explanation, the following description will focus on the case where the second uncoated portion 121 is formed on the negative electrode plate 120.

[0079] At least one of the positive electrode plate 110 and the negative electrode plate 120 may include an uncoated portion of uncoated active material at its long side end along the winding direction. The first uncoated portion 111 and the second uncoated portion 121 may be exposed to the outside of the separator 130 while forming multiple winding turns at the center of the electrode assembly 100, and may serve as electrode tabs themselves. Furthermore, the first uncoated portion 111 and the second uncoated portion 121 may be configured to face opposite directions.

[0080] In one embodiment, the first uncoated portion 111 and the second uncoated portion 121 may have notches at predetermined intervals to form flag-shaped slotted tabs. In the wound electrode assembly 100, the slotted tabs may be bent and flattened in the radial direction. For example, the slotted tabs may be bent inward or outward in the radial direction.

[0081] Furthermore, the slotted tabs can be bent one after another during the process of forming the wound electrode assembly 100 by winding the stacked parts. Alternatively, the slotted tabs can be bent all at once after the wound electrode assembly 100 has been formed by winding the stacked parts.

[0082] The slotted tabs of the first uncoated portion 111 and the second uncoated portion 121, which are folded and overlapped in the radial direction, can each provide a plane substantially perpendicular to the axial direction at the two axial ends of the electrode assembly 100.

[0083] Furthermore, the diaphragm 130 may be formed of a single or multiple porous polymer membrane, which is made of, for example, a polyolefin-based polymer such as ethylene homopolymer, propylene homopolymer, ethylene-butene copolymer, ethylene-hexene copolymer or ethylene-methacrylate copolymer.

[0084] As another example, the diaphragm 130 can be formed from a conventional porous nonwoven fabric, such as a nonwoven fabric made of high-melting-point glass fiber, polyethylene terephthalate fiber, etc.

[0085] At least one surface of the diaphragm 130 may include a coating of inorganic particles. Furthermore, the diaphragm 130 itself may be formed from a coating of inorganic particles. The particles constituting the coating may have a structure in which they are bonded with a binder to form interstitial volumes between adjacent particles.

[0086] Furthermore, the central hole 140 of the electrode assembly 100 can be used to weld the cell terminal 400 (positive terminal) and the positive current collector 300. That is, the electrode assembly 100 can be configured to weld the cell terminal 400 and the positive current collector 300 by irradiating a laser beam through the central hole 140 of the electrode assembly 100.

[0087] refer to Figure 3 The electrode assembly 100 is stored in the battery can 200. For example, the battery can 200 can be formed in a cylindrical shape such that the electrode assembly 100 is stored inside the battery can 200 and electrically connected to the negative electrode plate 120 of the electrode assembly 100. Therefore, the battery can 200 can have the same polarity as the negative electrode plate 120, i.e., negative polarity.

[0088] Here, the diameter of the battery canister 200 is larger than the diameter of the electrode assembly 100.

[0089] If the size of the electrode assembly 100 is increased while the size of the battery can 200 is determined according to the standard, the total capacity of the battery cell 10 increases, but the gap between the battery can 200 and the electrode assembly 100 decreases. Therefore, it is necessary to adjust the size of the insulator 700 inserted between the battery can 200 and the positive current collector 300 appropriately.

[0090] The battery canister 200 may have a closed portion and an open portion positioned facing each other. The electrode assembly 100 is received through the open portion formed in the battery canister 200, and the electrolyte is also injected through the open portion formed in the battery canister 200.

[0091] In other words, the battery can 200 is a generally cylindrical container in which an opening is formed, and it can be made of a conductive material such as metal. The battery can 200 can be made of conductive metals such as aluminum, steel or stainless steel, but is not limited to these.

[0092] Furthermore, the battery canister 200 may have a closed portion. The closed portion may be partially formed on the opposite side of the open portion. A through-hole may be formed in the closed portion. Additionally, as... Figure 3As shown, the cell terminal 400 is connected to the through hole, and the cell terminal 400 can be electrically connected to the positive current collector 300 via the through hole. Additionally, refer to... Figure 3 As will be explained later in each embodiment of this disclosure, the insulator 600 can be inserted between the battery canister 200 and the positive current collector 300. This also applies to... Figure 2 This also applies to Figure 4 .

[0093] The battery canister 200 may include a bottom portion and a sidewall portion, and the bottom portion and sidewall portion of the battery canister 200 may be manufactured by forming a metal sheet having nickel plated on a steel surface using a deep drawing process, and by finishing the front end of the sidewall portion with a punch while holding it with a blank holder. However, the materials and manufacturing methods of the battery canister 200 are not limited thereto.

[0094] refer to Figure 3 The battery cell 10 may include a positive current collector 300. The positive current collector 300 is electrically connected to the positive plate 110. For example, refer to Figure 3 The positive current collector 300 is connected to the positive electrode plate 110 of the electrode assembly 100.

[0095] The positive current collector 300 is made of a conductive metal material and is connected to the first uncoated portion 111 of the electrode assembly 100. The positive current collector 300 can be coupled to a connection surface formed by bending the end of the first uncoated portion 111 in a direction parallel to the positive current collector 300. The bending direction of the first uncoated portion 111 can be, for example, toward the central wound portion of the electrode assembly 100.

[0096] When the first uncoated portion 111 is bent as described above, the space occupied by the first uncoated portion 111 can be reduced, thereby increasing the energy density. In addition, the bonding area between the first uncoated portion 111 and the positive current collector 300 can be increased, resulting in increased bonding strength and reduced resistance.

[0097] The cell terminal 400 is made of a conductive metal material and is connected to a through hole formed in the closed portion of the battery canister 200, so that it can be electrically connected to the positive current collector 300 through the through hole. In addition, the cell terminal 400 is electrically connected to the positive electrode plate 110 of the electrode assembly 100 through the positive current collector 300, thereby having positive polarity.

[0098] In other words, the cell terminal 400 can be used as the positive terminal. Additionally, the battery canister 200 can be electrically connected to the negative plate 120 of the electrode assembly 100 as described above, thereby having negative polarity.

[0099] refer to Figure 3The battery cell 10 may include a negative current collector 500. The negative current collector 500 is electrically connected to a negative electrode plate 120. The negative current collector 500 may be connected to a second uncoated portion 121 of the electrode assembly 100. Here, the negative current collector 500 is made of a conductive metal material such as aluminum, steel, copper, or nickel, and may be electrically connected to the second uncoated portion 121 of the negative electrode plate 120.

[0100] The negative current collector 500 can be electrically connected to the battery canister 200. Therefore, the battery canister 200 can have a negative polarity. In addition, at least a portion of the edge of the negative current collector 500 can be directly welded to the inner wall surface of the battery canister 200, but is not limited thereto.

[0101] refer to Figure 3 The battery cell 10 may include an insulator 600. The insulator 600 is inserted between the battery canister 200 and the positive current collector 300 to prevent contact between the positive electrode of the electrode assembly 100 and the negative electrode of the battery canister 200, thereby blocking the electrical connection. Therefore, the insulator 600 may be made of a material with electrical insulating properties. The insulator 600 may have a central opening formed in a central portion, and the cell terminal 400 may be electrically connected to the positive current collector 300 through the central opening formed in the insulator 600.

[0102] Figure 5 This is a perspective cross-sectional view showing the cell terminals in a battery cell according to an embodiment of the present disclosure. Figure 6 This is a perspective view showing a cross-section of a riveting washer in a battery cell according to an embodiment of the present disclosure. Figure 7 This is a cross-sectional view of a battery cell according to an embodiment of the present disclosure before the cell terminals, riveting washers, and battery can are riveted together. Figure 8 yes Figure 7 A magnified view of part A. Figure 9 This is a cross-sectional view of a battery cell according to an embodiment of the present disclosure after the cell terminals, riveting washers, and battery canister have been riveted together. Figure 10 yes Figure 9 A magnified view of part B.

[0103] refer to Figures 5 to 10 A riveting washer 800 is inserted between the cell terminal 400 and the battery canister 200. The riveting washer 800 is an electrical insulator, which prevents the positive cell terminal 400 and the negative battery canister 200 from coming into contact with each other.

[0104] refer to Figure 7 and Figure 8The thickness reduction portion 811 can be formed in the riveting washer 800. The thickness reduction portion 811 can be configured in various ways and can be formed, for example, as a stepped groove portion 812. If the thickness reduction portion 811 is formed as a stepped groove portion 812, there is an effect of improving the sealing characteristics by engaging with the stepped protrusion 410 formed on the cell terminal 400, which will be described later.

[0105] Here, the riveting washer 800 is arranged to surround part of the battery can 200, and the stepped groove portion 812 may be formed in the adjacent area of ​​the battery can 200.

[0106] The thickness reduction portion 811 can be formed at various locations of the riveting washer 800. If the thickness reduction portion 811 is formed as a stepped groove portion 812, the stepped groove portion 812 can be formed, for example, on the inner side of the contact surface between the riveting washer 800 and the cell terminal 400.

[0107] Here, the riveting washer 800 can be made of various materials, such as polypropylene, polybutylene terephthalate, and polytetrafluoroethylene, which are electrically insulating polymer resins. However, the material of the riveting washer 800 is not limited to these.

[0108] refer to Figure 7 and Figure 8 The riveting washer 800 may include a first portion 810 and a second portion 820. Here, a thickness reduction portion 811 may be formed in the first portion 810. That is, the riveting washer 800 may have a stepped groove portion 812 formed in the first portion 810. In addition, the second portion 820 may extend from the first portion 810.

[0109] Here, the first part 810 and the second part 820 of the riveting washer 800 can be made of different materials. For example, the first part 810 can be made of a material with a higher thermal conductivity than the second part 820, and when a thermal event occurs in the battery cell 10, the heat generated by the thermal event is transferred more quickly through the first part 810, so the first part 810 can melt relatively easily.

[0110] Furthermore, if the first part 810 melts, the positive electrode cell terminal 400 and the negative electrode battery canister 200 make electrical contact over a large area, and thus a high current flows through the busbar. The high current flowing through the busbar in this way can quickly cut off the current flow of the battery cell 10 that has already experienced a thermal event by causing the fused portion formed at the busbar to break.

[0111] In other words, by rapidly breaking the fused portion, when a thermal event occurs in one battery cell, it can prevent a chain fire from spreading to other battery cells that have not experienced a thermal event.

[0112] For example, the first part 810 and the second part 820 can be made of different materials by double injection molding or insert molding. However, the molding method for the first part 810 and the second part 820 made of different materials is not limited to this.

[0113] In a modified embodiment, the first portion 810 may be coated with a material having heat transfer properties. If the first portion 810 is coated with a material having heat transfer properties in this manner, as described above, the heat generated by the thermal event is transferred through the first portion 810 more quickly, and therefore the first portion 810 can melt relatively easily.

[0114] In another modified embodiment, the first portion 810 may be made of a material with a lower melting point than the second portion 820. If the first portion 810 is made of a material with a lower melting point than the second portion 820 as described above, the first portion 810 is more likely to melt in the event of a thermal event, thereby allowing a high current to flow easily to the busbar through the first portion 810. In addition, as described above, by breaking the fused portion formed at the busbar, the current flow to the battery cell 10 in which the thermal event occurs can be quickly cut off.

[0115] In other words, when a thermal event occurs, the first part 810 can be configured to melt before the second part 820 to induce electrical contact between the cell terminal 400 and the battery canister 200.

[0116] refer to Figures 7 to 10 A stepped protrusion 410 can be formed in the cell terminal 400, and the stepped protrusion 410 can be connected to the stepped recess portion 812. That is, the stepped protrusion 410 formed in the cell terminal 400 is connected to make close contact with the stepped recess portion 812 formed in the riveting washer 800.

[0117] Here, the stepped protrusion 410 can be made of a material with heat transfer properties. If the stepped protrusion 410 is made of a material with heat transfer properties, similar to the first part 810 of the aforementioned riveting washer 800 being made of a material with heat transfer properties, when a thermal event occurs in the battery cell 10, the heat generated by the thermal event is transferred more quickly through the stepped protrusion 410, and therefore, the stepped groove portion 812 connected to the stepped protrusion 410 can be easily melted.

[0118] Furthermore, if the stepped groove portion 812 melts, a high current can easily flow to the busbar through the stepped groove portion 812, and similar to the above description, the current flow of the battery cell 10 in which the thermal event occurs is quickly cut off by breaking the fused portion formed in the busbar.

[0119] In a modified embodiment, the stepped protrusion 410 may be coated with a material having heat transfer properties. If the stepped protrusion 410 is coated with a material having heat transfer properties, the heat generated by a thermal event is transferred more quickly through the stepped protrusion 410, and therefore the stepped groove portion 812 connected to the stepped protrusion 410 can be easily melted.

[0120] If the stepped groove portion 812 is formed in the riveting washer 800 in this manner, the stepped groove portion 812 (which is the thickness reduction portion 811) is thinner than the other portions of the riveting washer 800, i.e., for example, since the first portion 810 is thinner than the second portion 820, the stepped groove portion 812 of the riveting washer 800 can completely melt when a thermal event occurs in either of the battery cells 10.

[0121] Here, if the riveting washer 800 completely melts, the battery can 200 and the cell terminal 400 can make contact over a large area, and when a short circuit occurs, the fused portion of the busbar breaks.

[0122] More specifically, in the past, when multiple battery cells were connected in series or parallel via busbars, if a thermal event occurred in one battery cell, the current could continue to flow to other battery cells that had not experienced a thermal event. In this case, even battery cells that were not affected by the thermal event could potentially lead to a chain reaction that could cause a fire.

[0123] However, since the battery cell 10 according to the embodiments of the present disclosure has a reduced thickness portion 811 formed in the riveting washer 800, the riveting washer 800 can melt quickly and completely as described above when a thermal event occurs in any of the battery cells 10.

[0124] In addition, in this way, if the riveting washer 800 is completely melted, the negative battery can 200 and the positive cell terminal 400 will come into contact. Here, since the riveting washer 800 blocking the battery can 200 and the cell terminal 400 is completely removed, large-area contact between the battery can 200 and the cell terminal 400 becomes possible.

[0125] Furthermore, if the battery canister 200 and cell terminal 400 of the battery cell 10 where a thermal event occurs can make large-area contact, then when a short circuit occurs, a high current flows to the busbar, and the high current flowing to the busbar causes the fused portion formed in the busbar to break.

[0126] In other words, if the high current from the battery cell 10 where the thermal event has occurred physically disconnects the busbar, the current flow to other battery cells 10 that have not experienced a thermal event is blocked. This not only protects the other battery cells 10, but also has the effect of preventing chain fires.

[0127] In other words, under normal circumstances when the battery cell 10 is working properly, short circuits of the battery cell 10 must be prevented. However, in the event of a thermal event in one of the battery cells 10, it is advantageous to protect the other battery cells 10 by configuring the battery canister 200 and the cell terminal 400 to make large-area contact to generate a high current to cut off the fused portion of the busbar, rather than restoring the battery cell 10 damaged by the thermal event.

[0128] Figure 11 It shows the basis Figure 6 A three-dimensional cross-sectional view of the riveting washer in the modified implementation method.

[0129] refer to Figure 11 Multiple microgrooves 815 can be formed in the first part 810. That is, multiple microgrooves 815 can be formed in the stepped groove part 812.

[0130] If multiple microgrooves 815 are formed in the stepped groove portion 812 in this manner, the stepped groove portion 812 may be more prone to breakage in the event of a thermal event.

[0131] In other words, since the multiple microgrooves 815 act as stress concentration or melting weakening areas during the melting process of the stepped groove portion 812, the entire stepped groove portion 812 breaks rapidly, and thus a large-area electrical contact is formed between the positive cell terminal 400 and the negative battery canister 200, thereby allowing high current to flow to the busbar.

[0132] Figure 12 This is a schematic diagram illustrating the configuration of a battery pack including battery cells according to each embodiment of the present disclosure.

[0133] refer to Figure 12 The battery pack 20 according to embodiments of the present disclosure may include one or more battery cells 10 according to each embodiment of the present disclosure described above. Furthermore, the battery pack 20 may also include a battery pack housing 21 for storing the battery cells 10 and various devices for controlling the charging and discharging of the battery cells 10, such as a BMS, a current sensor, and a fuse.

[0134] Figure 13 This is a diagram used to illustrate a vehicle including a battery pack according to each embodiment of the present disclosure.

[0135] refer to Figure 13The vehicle 30 according to embodiments of this disclosure may include one or more battery cells 10 according to each of the above embodiments or one or more battery packs 20 according to each of the above embodiments. Here, vehicle 30 includes various vehicles designed to use electricity, such as electric vehicles or hybrid vehicles.

[0136] Although directional terms such as up, down, left, right, front, and back are used in this specification, it will be apparent to those skilled in the art to which this disclosure pertains that these terms are merely for ease of interpretation with reference to the accompanying drawings and may vary depending on the position of the target object or the observer's position.

[0137] As described above, although this disclosure has been described with reference to limited embodiments and accompanying drawings, this disclosure is not limited thereto, and various modifications and variations can be made by those skilled in the art to which this disclosure pertains without departing from the technical concept of this disclosure and the equivalent scope of the appended claims. Therefore, the foregoing embodiments should be considered in a descriptive sense only and not for limiting purposes. That is, the true scope of the technical concept of this disclosure is defined by the claims, and all variations or modifications equivalent to them should be interpreted as included within the scope of this disclosure.

[0138] Industrial applicability

[0139] This disclosure relates to a battery cell, a battery pack including the battery cell, and a vehicle, and particularly to industries related to secondary batteries.

Claims

1. A battery cell, the battery cell comprising: An electrode assembly having a structure in which a positive electrode plate, a negative electrode plate, and a diaphragm inserted between the positive electrode plate and the negative electrode plate are wound in one direction; A battery can, the battery can being configured to house the electrode assembly; A cell terminal, wherein the cell terminal is electrically connected to the positive electrode plate; as well as A riveting washer is inserted between the cell terminal and the battery canister. The riveting washer has a thickness reduction portion formed therein.

2. The battery cell according to claim 1, in, The reduced thickness portion is formed as a stepped groove portion.

3. The battery cell according to claim 1, in, The reduced thickness portion is formed on the inner side of the contact surface between the riveting washer and the battery cell terminal.

4. The battery cell according to claim 1, in, The riveting washer includes: The first portion, wherein the thickness reduction portion is formed in the first portion; and The second part extends from the first part.

5. The battery cell according to claim 4, in, The first part and the second part are made of different materials.

6. The battery cell according to claim 5, in, The first part is made of a material with higher thermal conductivity than the second part.

7. The battery cell according to claim 4, in, The first part is coated with a material that has heat transfer properties.

8. The battery cell according to claim 4, in, The first part is made of a material with a lower melting point than the second part.

9. The battery cell according to claim 8, in, When a thermal event occurs, the first portion melts before the second portion, causing electrical contact between the cell terminals and the battery canister.

10. The battery cell according to claim 2, in, A stepped protrusion is formed at the battery cell terminal, and The stepped protrusion is connected to the stepped groove portion.

11. The battery cell according to claim 10, in, The stepped protrusions are made of a material with heat transfer properties.

12. The battery cell according to claim 10, in, The stepped protrusions are coated with a material that has heat transfer properties.

13. The battery cell according to claim 2, in, Multiple microgrooves are formed in the stepped groove portion.

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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