Battery cell and battery pack and vehicle comprising same

Abstract

A battery cell, and a battery pack and a vehicle comprising same are disclosed. A battery cell, according to one embodiment of the present invention, comprises: an electrode assembly having a structure in which a positive electrode plate, a negative electrode plate, and a separator interposed between the positive electrode plate and the negative electrode plate are wound in one direction; a battery can in which the electrode assembly is received; a cell terminal electrically connected to the positive electrode plate; and a rivet gasket interposed between the cell terminal and the battery can, wherein the rivet gasket has a thickness-reduced portion.

Description

Battery cells and battery packs and vehicles containing the same

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

[0002] The present invention relates to a battery cell, a battery pack including the same, and a vehicle, and more particularly, to a battery cell capable of blocking current flow in a battery cell in which a thermal event has occurred, and a battery pack including the same and a vehicle.

[0003] Secondary batteries, which have high applicability according to product group and electrical characteristics such as high energy density, are widely used not only in portable devices but also in electric vehicles (EVs) and hybrid electric vehicles (HEVs) driven by electrical power sources.

[0004] These secondary batteries are attracting attention as a new energy source for environmental friendliness and energy efficiency because they not only have the primary advantage of drastically reducing the use of fossil fuels, but also have the advantage of producing no byproducts from energy use.

[0005] Commonly used secondary battery types include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. The operating voltage of these unit secondary battery cells ranges from approximately 2.5 V to 4.5 V.

[0006] Therefore, when a higher output voltage is required, multiple battery cells are connected in series to form a battery module or battery pack. Furthermore, depending on the required charge / discharge capacity, a number of battery cells are connected in parallel to form a battery module or battery pack. Accordingly, the number and electrical connection configuration of battery cells included in a battery module or battery pack can be varied depending on at least one of the required output voltage and charge / discharge capacity.

[0007] Cylindrical, prismatic, and pouch-shaped secondary battery cells are known types. Cylindrical battery cells are formed by interposing a separator, which serves as an insulator, between the positive and negative plates. This separator is then rolled to form a jelly-roll-shaped electrode assembly. This assembly, along with an electrolyte, is then inserted into a battery can to form the battery. Furthermore, cylindrical battery cells may use a current collector to electrically connect the positive and negative plates.

[0008] Additionally, the cylindrical battery cell may include a cell terminal riveted through a through hole formed in the battery can, and a rivet gasket interposed between the cell terminal and the through hole. Here, the rivet gasket is used to electrically insulate the positive cell terminal from the negative battery can.

[0009] Fig. 1 is a cross-sectional view of a conventional battery cell before a cell terminal, a rivet gasket, and a battery can are riveted, and Fig. 2 is a cross-sectional view of a conventional battery cell after a cell terminal, a rivet gasket, and a battery can are riveted.

[0010] Referring to FIGS. 1 and 2, in a conventional cylindrical battery cell (1), the rivet gasket (2) is formed flat and thick and has no change in thickness, so that when a thermal event occurs, only a very small portion of the rivet gasket (2) melts.

[0011] And, if the rivet gasket (2) is only partially melted by heat and loses its electrical insulation function, electrical contact occurs between the positive cell terminal (3) and the negative battery can (4), causing an internal short-circuit current to flow.

[0012] However, since only a very small portion of the rivet gasket (2) is melted, the amount of internal short-circuit current flowing at this time is insufficient to melt the fusing portion formed on the bus bar. Here, if the internal short-circuit current continues to flow to other battery cells connected to the battery cell where the thermal event occurred, a thermal abnormality may occur in the battery cell (1) where the thermal event did not occur, generating a flame, which may ultimately lead to a chain reaction of fire.

[0013] Accordingly, the technical problem to be solved by the present invention is to provide a battery cell in which a rivet gasket can be easily melted by heat, and a battery pack and a vehicle including the same.

[0014] In addition, the technical problem to be solved by the present invention is to provide a battery cell, a battery pack and an automobile including the same, which can quickly cut off the current flow of a battery cell in which a thermal event has occurred by causing a positive cell terminal and a negative battery can to electrically contact each other over a large area by melting a rivet gasket, thereby causing a large current to flow through a bus bar, and causing a fusing portion formed in the bus bar to break.

[0015] In addition, a technical problem to be solved by the present invention is to provide a battery cell capable of preventing a chain reaction of fire in other battery cells in which a thermal event has not occurred when a thermal event occurs in one battery cell, and a battery pack and a vehicle including the same.

[0016] However, the technical problems to be solved by the present invention are not limited to the problems described above, and other problems not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0017] According to one aspect of the present invention, a battery cell can be provided, comprising: an electrode assembly having a structure in which a positive electrode plate, a negative electrode plate, and a separator interposed between the positive electrode plate and the negative electrode plate are wound in one direction; a battery can in which the electrode assembly is accommodated; a cell terminal electrically connected to the positive electrode plate; and a rivet gasket interposed between the cell terminal and the battery can, wherein a thickness reducing portion is formed in the rivet gasket.

[0018] In one embodiment, the thickness reduction portion may be formed as a step groove portion.

[0019] In one embodiment, the thickness reduction portion may be formed on the inner side of the contact surface between the rivet gasket and the cell terminal.

[0020] In one embodiment, the rivet gasket may include a first portion having the thickness reduction portion formed therein; and a second portion extending from the first portion.

[0021] In one embodiment, the first portion and the second portion may be formed of different materials.

[0022] In one embodiment, the first portion may be formed of a material having a higher thermal conductivity than the second portion.

[0023] In one embodiment, the first portion may be coated with a material having a heat transfer function.

[0024] In one embodiment, the first portion may be formed of a material having a lower melting point than the second portion.

[0025] In one embodiment, when a thermal event occurs, the first portion may melt before the second portion to induce electrical contact between the cell terminal and the battery can.

[0026] In one embodiment, the cell terminal is formed with a step projection, and the step projection can be coupled to the step groove.

[0027] In one embodiment, the step projection may be formed of a material having a heat transfer function.

[0028] In one embodiment, the step projection may be coated with a material having a heat transfer function.

[0029] In one embodiment, a plurality of micro-grooves may be formed in the step groove portion.

[0030] Meanwhile, according to another aspect of the present invention, a battery pack including at least one of the above-described battery cells may be provided, and further, a vehicle including at least one of the above-described battery cells may be provided.

[0031] Embodiments of the present invention have the effect that the rivet gasket can be easily melted by heat.

[0032] In addition, embodiments of the present invention have the effect of quickly cutting off the current flow of a battery cell in which a thermal event has occurred by causing a large area of ​​electrical contact between a positive cell terminal and a negative battery can due to melting of a rivet gasket, thereby causing a large current to flow through a bus bar, thereby causing a fusing portion formed in the bus bar to break.

[0033] In addition, embodiments of the present invention have the effect of preventing chain fire in other battery cells where no thermal event has occurred when a thermal event occurs in one battery cell.

[0034] However, the effects that can be obtained through the present invention are not limited to the effects described above, and other technical effects not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0035] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention described below, serve to further understand the technical idea of ​​the present invention, and therefore, the present invention should not be interpreted as being limited to matters described in such drawings.

[0036] Figure 1 is a cross-sectional view of a conventional battery cell before the cell terminal, rivet gasket, and battery can are riveted.

[0037] Figure 2 is a cross-sectional view of a conventional battery cell after the cell terminal, rivet gasket, and battery can are riveted.

[0038] Figure 3 is a cross-sectional view of a battery cell according to one embodiment of the present invention.

[0039] FIG. 4 is a cross-sectional view of a battery cell according to a modified embodiment of FIG. 3.

[0040] FIG. 5 is a perspective view illustrating a cross-section of a cell terminal in a battery cell according to one embodiment of the present invention.

[0041] FIG. 6 is a perspective view illustrating a cross-section of a rivet gasket in a battery cell according to one embodiment of the present invention.

[0042] FIG. 7 is a cross-sectional view of a battery cell according to one embodiment of the present invention before a cell terminal, a rivet gasket, and a battery can are riveted.

[0043] Figure 8 is an enlarged view of part A of Figure 7.

[0044] FIG. 9 is a cross-sectional view of a battery cell according to one embodiment of the present invention after a cell terminal, a rivet gasket, and a battery can are riveted.

[0045] Figure 10 is an enlarged view of part B of Figure 9.

[0046] Fig. 11 is a perspective view showing a cross-section of a rivet gasket of a modified embodiment of Fig. 6.

[0047] FIG. 12 is a schematic diagram showing the configuration of a battery pack including battery cells according to each embodiment of the present invention.

[0048] FIG. 13 is a drawing for explaining a vehicle including a battery pack according to each embodiment of the present invention.

[0049] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Terms or words used in this specification and claims should not be interpreted as limited to their conventional or dictionary meanings, but should be interpreted with meanings and concepts that conform to the technical idea of ​​the present invention based on the principle that the inventor can appropriately define the concept of the term to best explain his or her own invention. Therefore, it should be understood that the embodiments described in this specification and the configurations illustrated in the drawings are only the most preferred embodiments of the present invention and do not represent all of the technical idea of ​​the present invention, and various equivalents and modifications may exist as of the time of this application.

[0050] In the drawings, the sizes of each component or specific parts of that component are exaggerated, omitted, or schematically illustrated for convenience and clarity of explanation. Therefore, the size of each component does not entirely reflect its actual size. If a detailed description of a related known function or configuration is deemed to unnecessarily obscure the gist of the present invention, such description will be omitted.

[0051] The term 'joint' or 'connection' as used herein includes not only cases where one member is directly joined or directly connected to another member, but also cases where one member is indirectly joined or indirectly connected to another member through a connecting member.

[0052] Meanwhile, the common elements described in one embodiment of the present invention can also be applied to other embodiments. For example, the common elements described in the first embodiment of the second embodiment can be replaced with the description of the first embodiment, but the common elements can also be applied to the second embodiment. Furthermore, the elements described in the second embodiment that are applicable to the first embodiment can also be applied to the first embodiment. The same applies to other embodiments.

[0053] FIG. 3 is a cross-sectional view of a battery cell according to one embodiment of the present invention, and FIG. 4 is a cross-sectional view of a battery cell according to a modified embodiment of FIG. 3.

[0054] Referring to FIGS. 3 and 4, a battery cell (10) according to one embodiment of the present invention may include a cap (700) coupled to the battery can (200) to seal an opening formed in the battery can (200). In addition, depending on the coupling method of the cap (700), the battery cell (10) may be divided into a type in which a crimping portion (220) and a beading portion (210) are not formed in the battery can (200) (see FIG. 3) and a type in which a crimping portion (220) and a beading portion (210) are formed in the battery can (200) (see FIG. 4).

[0055] Referring to FIG. 3, when the beading portion (210) and the crimping portion (220) are not formed on the battery can (200), the cap (700) can be directly welded to the battery can (200) through various welding methods, for example, seam welding.

[0056] When welding the battery can (200) and the cap (700) of the battery cell (10) by a deep welding method, the cap (700) can be joined to the side of the battery can (200) by welding (e.g., horizontal welding). That is, the cap (700) can be joined so as to be in contact with the inner side of the side of the opening of the battery can (200).

[0057] Alternatively, although not shown in the drawing, the cap (700) may be welded (e.g., vertically welded) to the upper surface of the battery can (200). That is, the cap (700) may be welded to and seated on the upper side of the opening of the battery can (200).

[0058] The cap (700) may have various shapes, for example, it may have a plate shape, but the shape of the cap (700) is not limited thereto.

[0059] The welding method of the cap (700) and the battery can (200) may vary, and for example, the cap (700) may be joined to the battery can (200) by butt welding, but is not limited thereto.

[0060] It goes without saying that the cap (700) and the battery can (200) may be joined by a joining form other than welding, and the joining form is not limited thereto. By joining the cap (700) and the battery can (200), the battery cell (10) can be guaranteed to be sealed.

[0061] The cap (700) may be made of a metal material. Therefore, the cap (700) may be conductive. For example, the cap (700) may include an aluminum material. The cap (700) may be electrically connected to the battery can (200). Meanwhile, since the battery can (200) is also made of a metal having conductivity, the cap (700) coupled to the battery can (200) may also be configured to have the same polarity as the battery can (200).

[0062] In this way, in the case of a seam welding method in which the cap (700) is directly welded to the battery can (200), the fixing structure is simple, so that the volume of the electrode assembly (100) that can be accommodated inside the battery can (200) can be secured more, and accordingly, it is more advantageous in securing electric capacity compared to the same volume of the battery can (200), so that there is an effect of improving the energy density.

[0063] And, referring to FIG. 4, in the case of a type in which a crimping portion (220) and a beading portion (210) are formed on the battery can (200), the crimping portion (220) is formed on the battery can (200) to secure the cap (700). And, the beading portion (210) is formed by pressing the outer circumference 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).

[0064] The cap (700) may be made of, for example, a metal material to ensure rigidity. Furthermore, the cap (700) may be separated from the electrode assembly (100) and provided as non-polar. That is, even if the cap (700) is provided as a conductive metal material, it may not have polarity.

[0065] The fact that the cap (700) does not have polarity means that the cap (700) is electrically insulated from the battery can (200) and the cell terminal (400). As such, the cap (700) does not have to have polarity, and its material does not necessarily have to be a conductive metal.

[0066] The cap (700) may be supported by being seated on the beading portion (210) formed on the battery can (200). In addition, the cap (700) is fixed by the crimping portion (220). A sealing gasket (230) may be interposed between the cap (700) and the crimping portion (220) of the battery can (200) to ensure airtightness of the battery can (200). That is, the sealing gasket (230) may be arranged to be interposed between the edge of the cap (700) and the opening of the battery can (200). Here, reference numeral 710 of FIG. 4 denotes a vent notch.

[0067] For convenience of explanation below, a battery cell (10) according to one embodiment of the present invention will be described with a focus on an embodiment (Fig. 3) in which a cap (700) is directly welded to a battery can (200) by a seam welding method, but the scope of the present invention is not limited thereto.

[0068] Referring to FIG. 3, a battery cell (10) according to one embodiment of the present invention includes an electrode assembly (100), a battery can (200), a cell terminal (400), and a rivet gasket (800).

[0069] Referring to FIG. 3, the electrode assembly (100) has a structure in which a positive electrode plate (110), a negative electrode plate (120), and a separator (130) interposed 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 in the center of the electrode assembly (100), and can be formed in a jelly roll type.

[0070] For example, the electrode assembly (100) can be manufactured by winding a laminate formed by sequentially stacking a negative electrode plate (120), a separator (130), a positive electrode plate (110), and a separator (130) at least once. Here, the positive electrode plate (110) and the negative electrode plate (120) can be formed in a sheet shape.

[0071] That is, the electrode assembly (100) applied to the present embodiment may be a coiled type electrode assembly (100). In this case, an additional separator may be provided on the outer circumferential surface of the electrode assembly (100) for insulation from the battery can (200). That is, the electrode assembly (100) may have a coiled structure well known in the related technical field without limitation.

[0072] A positive electrode plate (110) may have a positive electrode active material applied to one or both sides, and a first non-coated portion (111) on which the positive electrode active material is not applied may be formed at an end of the positive electrode plate (110). Here, any positive electrode active material known in the art may be used without limitation as long as it is coated on the positive electrode plate (110).

[0073] As described above, a positive electrode plate (110) having a first non-conductive portion (111) formed thereon may be provided, but a battery cell (10) according to an embodiment of the present invention includes an embodiment of a positive electrode plate (110) in which a first non-conductive portion (111) is not formed. However, for convenience of explanation, the following description will focus on a case in which a first non-conductive portion (111) is formed on the positive electrode plate (110).

[0074] A negative electrode plate (120) may have a negative electrode active material applied to one or both sides, and a second non-coated portion (121) on which the negative electrode active material is not applied may be formed at an end of the negative electrode plate (120). Here, any negative electrode active material known in the art may be used without limitation as long as it is coated on the negative electrode plate (120).

[0075] As described above, a negative electrode plate (120) having a second non-conductive portion (121) formed thereon may be provided, but a battery cell (10) according to an embodiment of the present invention includes an embodiment of a negative electrode plate (120) in which a second non-conductive portion (121) is not formed. However, for convenience of explanation, the following description will focus on a case in which a second non-conductive portion (121) is formed on the negative electrode plate (120).

[0076] At least one of the positive electrode plate (110) and the negative electrode plate (120) may include a non-coated portion, which is not coated with an active material, at a long side end in the winding direction. The first non-coated portion (111) and the second non-coated portion (121) may be exposed to the outside of the separator (130) while forming a plurality of winding turns based on the center of the electrode assembly (100), and may be used as an electrode tab in and of themselves. In addition, the first non-coated portion (111) and the second non-coated portion (121) may be configured to face in opposite directions.

[0077] In one embodiment, the first uncoated portion (111) and the second uncoated portion (121) may be provided with notches at predetermined intervals to form flag-shaped notched tabs. In the jelly-roll-shaped electrode assembly (100), the notched tabs may be bent radially to be flattened. For example, the notched tabs may be bent radially inward or outward.

[0078] In addition, the notching tabs can be bent one by one during the process of forming a jelly roll-shaped electrode assembly (100) by winding the laminate. Alternatively, the notching tabs can be bent all at once after the laminate is wound to form a jelly roll-shaped electrode assembly (100).

[0079] The notching tabs of the first non-conductive portion (111) and the notching tabs of the second non-conductive portion (121), which are folded and covered in the radial direction, can provide a plane that is substantially perpendicular to the axial direction at both axial ends of the electrode assembly (100).

[0080] In addition, the separation membrane (130) may be a porous polymer film, for example, a porous polymer film made of a polyolefin polymer such as an ethylene homopolymer, a propylene homopolymer, an ethylene / butene copolymer, an ethylene / hexene copolymer, an ethylene / methacrylate copolymer, etc., which may be used alone or in a laminated manner.

[0081] As another example, the separator (130) may be a conventional porous nonwoven fabric, for example, a nonwoven fabric made of high-melting-point glass fiber, polyethylene terephthalate fiber, etc.

[0082] At least one surface of the separator (130) may include a coating layer of inorganic particles. Furthermore, the separator (130) itself may be formed of a coating layer of inorganic particles. The particles constituting the coating layer may have a structure in which they are combined with a binder such that an interstitial volume exists between adjacent particles.

[0083] In addition, the center hole (140) of the electrode assembly (100) is also used for welding 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 through the center hole (140).

[0084] Referring to FIG. 3, an electrode assembly (100) is housed in a battery can (200). For example, the battery can (200) is formed in a cylindrical shape, and the electrode assembly (100) is housed inside the battery can (200) and can be electrically connected to the negative electrode plate (120) of the electrode assembly (100). Accordingly, the battery can (200) can have the same polarity as the negative electrode plate (120), i.e., a negative electrode.

[0085] Here, the diameter of the battery can (200) is formed to be larger than the diameter of the electrode assembly (100).

[0086] 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, so it is necessary to appropriately adjust the size of the insulator (600) interposed between the battery can (200) and the positive electrode collector (300).

[0087] The battery can (200) may be formed with a closed portion and an open portion positioned so as to face each other. The electrode assembly (100) is housed through the open portion formed in the battery can (200), and the electrolyte is also injected through the open portion formed in the battery can (200).

[0088] That is, the battery can (200) is a roughly cylindrical container with an opening formed therein, and may be made of a conductive material such as metal, for example. The material of the battery can (200) may be made of a conductive metal such as aluminum, steel, stainless steel, etc., but is not limited thereto.

[0089] In addition, a closed portion may be formed in the battery can (200). 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. In addition, as shown in FIG. 3, a cell terminal (400) may be coupled to the through hole, and the cell terminal (400) may be electrically connected to the positive electrode collector plate (300) through the through hole. In addition, referring to FIG. 3, an insulator (600) according to each embodiment of the present invention, which will be described later, may be interposed between the battery can (200) and the positive electrode collector plate (300). The same applies to FIG. 4.

[0090] The battery can (200) may include a bottom portion and a side wall portion, and the bottom portion and the side wall portion of the battery can (200) may be manufactured by forming a metal sheet having a nickel plated surface of steel using a deep drawing process, and trimming the front end of the side wall portion with a punch while holding it with a blank holder. However, the material and manufacturing method of the battery can (200) are not limited thereto.

[0091] Referring to FIG. 3, the battery cell (10) may have a positive electrode collector plate (300). The positive electrode collector plate (300) is electrically connected to the positive electrode plate (110). For example, referring to FIG. 3, the positive electrode collector plate (300) is connected to the positive electrode plate (110) of the electrode assembly (100).

[0092] The positive electrode collector plate (300) is made of a conductive metal material and is connected to the first non-coated portion (111) of the electrode assembly (100). The positive electrode collector plate (300) can be connected to a bonding surface formed by bending an end of the first non-coated portion (111) in a direction parallel to the positive electrode collector plate (300). The bending direction of the first non-coated portion (111) may be, for example, a direction toward the winding center of the electrode assembly (100).

[0093] When the first non-conductive portion (111) has a folded shape like this, the space occupied by the first non-conductive portion (111) is reduced, which can lead to an improvement in energy density. In addition, the increase in the bonding area between the first non-conductive portion (111) and the positive electrode current collector (300) can lead to an improvement in bonding strength and a reduction in resistance.

[0094] The cell terminal (400) is made of a conductive metal material and is coupled to a through hole formed in the closed portion of the battery can (200) so as to be electrically connected to the positive electrode collector plate (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 electrode collector plate (300), thereby having a positive polarity.

[0095] That is, the cell terminal (400) can function as a positive terminal. In addition, the battery can (200) is electrically connected to the negative plate (120) of the electrode assembly (100) as described above, thereby having a negative polarity.

[0096] Referring to FIG. 3, the battery cell (10) may include a negative electrode collector plate (500). The negative electrode collector plate (500) is electrically connected to the negative electrode plate (120). The negative electrode collector plate (500) may be connected to the second non-conductive portion (121) of the electrode assembly (100). Here, the negative electrode collector plate (500) is made of a conductive metal material such as aluminum, steel, copper, or nickel, and may be electrically connected to the second non-conductive portion (121) of the negative electrode plate (120).

[0097] The negative electrode collector plate (500) may be electrically connected to the battery can (200). As a result, the battery can (200) may have a negative polarity. In addition, at least a portion of the edge portion of the negative electrode collector plate (500) may be directly welded to the inner wall surface of the battery can (200), but is not limited thereto.

[0098] Referring to FIG. 3, the battery cell (10) may include an insulator (600). The insulator (600) is interposed between the battery can (200) and the positive electrode collector plate (300) to prevent contact between the positive electrode portion of the electrode assembly (100) and the negative electrode portion of the battery can (200), thereby blocking electrical connection. Accordingly, the insulator (600) may be made of a material having electrical insulation performance. The insulator (600) may have a hollow portion formed in the center thereof, and the cell terminal (400) may be electrically connected to the positive electrode collector plate (300) through the hollow portion formed in the insulator (600).

[0099] FIG. 5 is a perspective view showing a cross-section of a cell terminal in a battery cell according to an embodiment of the present invention, FIG. 6 is a perspective view showing a cross-section of a rivet gasket in a battery cell according to an embodiment of the present invention, FIG. 7 is a cross-sectional view showing a battery cell before a cell terminal, a rivet gasket, and a battery can are riveted in a battery cell according to an embodiment of the present invention, FIG. 8 is an enlarged view of part A of FIG. 7, FIG. 9 is a cross-sectional view showing a battery cell after a cell terminal, a rivet gasket, and a battery can are riveted in a battery cell according to an embodiment of the present invention, and FIG. 10 is an enlarged view of part B of FIG. 9.

[0100] Referring to FIGS. 5 to 10, a rivet gasket (800) is interposed between the cell terminal (400) and the battery can (200). The rivet gasket (800) is an electrical insulator and prevents the positive cell terminal (400) and the negative battery can (200) from contacting each other.

[0101] Referring to FIGS. 7 and 8, a thickness reduction portion (811) may be formed in the rivet gasket (800). The thickness reduction portion (811) may be configured in various ways, and may be formed, for example, as a step groove portion (812). When the thickness reduction portion (811) is formed as a step groove portion (812), it has the effect of improving sealing characteristics by interlocking with the step protrusion portion (410) formed in the cell terminal (400) described below.

[0102] Here, the rivet gasket (800) is arranged to surround a portion of the battery can (200), and the step groove (812) can be formed in an adjacent area of ​​the battery can (200).

[0103] The thickness reduction portion (811) can be formed at various locations of the rivet gasket (800). When the thickness reduction portion (811) is formed as a step groove portion (812), the step groove portion (812) can be formed, for example, on the inner side of the contact surface between the rivet gasket (800) and the cell terminal (400).

[0104] Here, the rivet gasket (800) may be composed of various materials, for example, at least one of polypropylene, polybutylene terephthalate, and polyfluoroethylene, which are electrically insulating polymer resins. However, the material of the rivet gasket (800) is not limited thereto.

[0105] Referring to FIGS. 7 and 8, the rivet gasket (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 rivet gasket (800) may have a step groove portion (812) formed in the first portion (810). In addition, the second portion (820) may extend from the first portion (810).

[0106] Here, the first portion (810) and the second portion (820) of the rivet gasket (800) may be formed of different materials. For example, the first portion (810) may be formed of a material having a higher thermal conductivity than the second portion (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 portion (810), and thus the first portion (810) may be relatively easily melted.

[0107] And, when the first part (810) is melted, the positive cell terminal (400) and the negative battery can (200) make electrical contact over a large area, and thus, a large current flows through the bus bar. In this way, the large current flowing through the bus bar can quickly cut off the current flow of the battery cell (10) where a thermal event has occurred by rupturing the fusing portion formed in the bus bar.

[0108] That is, by rapid rupture of the fusing unit, when a thermal event occurs in one battery cell, chain fire of other battery cells where no thermal event has occurred can be prevented.

[0109] For example, the first part (810) and the second part (820) may be formed of different materials by double injection molding or insert molding. However, the molding method of the first part (810) and the second part (820) formed of different materials is not limited thereto.

[0110] In a modified embodiment, the first portion (810) may be coated with a material having a heat transfer function. In this way, when the first portion (810) is coated with a material having a heat transfer function, similarly to the above, heat generated by a thermal event is transferred more quickly through the first portion (810), and thus the first portion (810) can be relatively easily melted.

[0111] In another modified embodiment, the first portion (810) may be formed of a material having a lower melting point than the second portion (820). In this way, when the first portion (810) is formed of a material having a lower melting point than the second portion (820), the first portion (810) melts more easily when a thermal event occurs, thereby allowing a large current to easily flow to the busbar through the first portion (810). In addition, as described above, the current flow of the battery cell (10) in which the thermal event occurred can be quickly cut off by breaking the fusing portion formed in the busbar.

[0112] That is, when a thermal event occurs, the first part (810) may be configured to melt before the second part (820) to induce electrical contact between the cell terminal (400) and the battery can (200).

[0113] Referring to FIGS. 7 to 10, a step projection (410) may be formed on the cell terminal (400), and the step projection (410) may be coupled to a step groove (812). That is, the step projection (410) formed on the cell terminal (400) is coupled so as to be in close contact with the step groove (812) formed on the rivet gasket (800).

[0114] Here, the step protrusion (410) may be formed of a material having a heat transfer function. When the step protrusion (410) is formed of a material having a heat transfer function, similarly to the first part (810) of the aforementioned rivet gasket (800) being formed of a material having a heat transfer function, when a thermal event occurs in the battery cell (10), the heat generated by the thermal event is transferred more quickly through the step protrusion (410), and accordingly, the step groove (812) coupled to the step protrusion (410) can be easily melted.

[0115] And, when the step groove (812) is melted, a large current easily flows to the bus bar through the step groove (812), and the contents of quickly blocking the current flow of the battery cell (10) where a thermal event has occurred by breaking the fusing portion formed in the bus bar are similar to those described above.

[0116] In a modified embodiment, the step projection (410) may be coated with a material having a heat transfer function. When the step projection (410) is coated with a material having a heat transfer function in this way, heat generated by a thermal event is transferred more quickly through the step projection (410), and thus the step groove (812) coupled to the step projection (410) can be easily melted.

[0117] In this way, when a step groove portion (812) is formed in the rivet gasket (800), since the thickness of the step groove portion (812), which is a thickness reduction portion (811), is thinner than the thickness of other parts of the rivet gasket (800), that is, for example, since the thickness of the first portion (810) is thinner than the thickness of the second portion (820), when a thermal event occurs in any one of the battery cells (10), the step groove portion (812) of the rivet gasket (800) can be completely melted.

[0118] Here, when the rivet gasket (800) is completely melted, the battery can (200) and the cell terminal (400) can come into contact over a wide area, and a short circuit occurs, causing the fusing portion of the bus bar to break.

[0119] To elaborate on this, in the past, when multiple battery cells were connected in series or parallel through a bus bar, if a thermal event occurred in one battery cell, current could continue to flow to other battery cells where no thermal event occurred, and in this case, even battery cells that had no problem because no thermal event occurred could cause a chain reaction of fire.

[0120] However, in the case of the battery cell (10) according to one embodiment of the present invention, since a thickness reduction portion (811) is formed in the rivet gasket (800), when a thermal event occurs in any one of the battery cells (10), the rivet gasket (800) can be quickly and completely melted as described above.

[0121] And, in this way, when the rivet gasket (800) is completely melted, the negative battery can (200) and the positive cell terminal (400) come into contact, and here, since the rivet gasket (800) that was blocking the battery can (200) and the cell terminal (400) is completely removed, a large-area contact is possible between the battery can (200) and the cell terminal (400).

[0122] And, when the battery can (200) and cell terminal (400) of the battery cell (10) where a thermal event has occurred are able to make contact over a large area, a short circuit occurs and a large current flows toward the bus bar side, and the large current flowing toward the bus bar side thus breaks the fusing part formed on the bus bar.

[0123] That is, when a large current from a battery cell (10) in which a thermal event has occurred physically cuts off the bus bar, the flow of current to other battery cells (10) in which a thermal event has not occurred is blocked, thereby protecting other battery cells (10) and preventing chain fire.

[0124] That is, in a normal situation where the battery cell (10) operates normally, a short circuit of the battery cell (10) must be prevented. However, in a situation where a thermal event has occurred in one of the battery cells (10), it is advantageous to protect other battery cells (10) by configuring the battery can (200) and the cell terminal (400) to have a large-area contact to generate a large current to cut the fusing part of the bus bar rather than recovering the battery cell (10) damaged by the thermal event.

[0125] Fig. 11 is a perspective view showing a cross-section of a rivet gasket of a modified embodiment of Fig. 6.

[0126] Referring to Fig. 11, a plurality of micro-grooves (815) may be formed in the first portion (810). That is, a plurality of micro-grooves (815) may be formed in the step groove portion (812).

[0127] In this way, when a plurality of micro-grooves (815) are formed in the step groove portion (812), the step groove portion (812) can be more easily broken when a thermal event occurs.

[0128] That is, as the step groove portion (812) is melted, the entire step groove portion (812) is rapidly broken as the plurality of micro-grooves (815) act as stress concentration or melting weakening areas, and as a result, a large area of ​​electrical contact is formed between the positive cell terminal (400) and the negative battery can (200), allowing a large current to flow to the bus bar.

[0129] FIG. 12 is a schematic diagram showing the configuration of a battery pack including battery cells according to each embodiment of the present invention.

[0130] Referring to FIG. 12, a battery pack (20) according to one embodiment of the present invention may include one or more battery cells (10) according to each embodiment of the present invention as described above. In addition, the battery pack (20) may further include a pack case (21) for storing the battery cells (10), and various devices for controlling charging and discharging of the battery cells (10), such as a BMS, a current sensor, a fuse, etc.

[0131] FIG. 13 is a drawing for explaining a vehicle including a battery pack according to each embodiment of the present invention.

[0132] Referring to FIG. 13, a vehicle (30) according to one embodiment of the present invention may include one or more battery cells (10) according to each embodiment described above or one or more battery packs (20) according to each embodiment. Here, the vehicle (30) includes various types of vehicles that are designed to use electricity, such as electric vehicles or hybrid vehicles, for example.

[0133] In this specification, when terms indicating directions such as up, down, left, and right are used, these terms are only for convenience of explanation, and it is obvious to those skilled in the art that these terms may vary depending on the location of the target object or the location of the observer.

[0134] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and those skilled in the art to which the present invention pertains may make various modifications and variations within the scope of the technical spirit of the present invention and the equivalent scope of the claims to be described below. Therefore, the embodiments disclosed above should be considered from an illustrative rather than a restrictive perspective. In other words, the true scope of the technical spirit of the present invention is set forth in the claims, and all differences within the scope of equivalents thereof should be construed as being included in the present invention.

[0135] The present invention relates to a battery cell and a battery pack and an automobile including the same, and is particularly applicable to industries related to secondary batteries.

Claims

1. An electrode assembly having a structure in which a positive electrode plate, a negative electrode plate, and a separator interposed between the positive electrode plate and the negative electrode plate are wound in one direction; A battery can in which the electrode assembly is housed; a cell terminal electrically connected to the above positive electrode; and A rivet gasket interposed between the cell terminal and the battery can, A battery cell characterized in that a thickness reduction portion is formed in the above rivet gasket.

2. In paragraph 1, A battery cell characterized in that the thickness reduction portion is formed as a step groove portion.

3. In paragraph 1, A battery cell characterized in that the thickness reduction portion is formed on the inner side of the contact surface between the rivet gasket and the cell terminal.

4. In paragraph 1, The above rivet gasket, A first part in which the thickness reduction part is formed; and A battery cell characterized by comprising a second portion extending from the first portion.

5. In paragraph 4, A battery cell characterized in that the first part and the second part are formed of different materials.

6. In paragraph 5, A battery cell characterized in that the first part is formed of a material having a higher thermal conductivity than the second part.

7. In paragraph 4, A battery cell characterized in that the first part is coated with a material having a heat transfer function.

8. In paragraph 4, A battery cell characterized in that the first part is formed of a material having a lower melting point than the second part.

9. In paragraph 8, A battery cell characterized in that when a thermal event occurs, the first portion melts before the second portion, thereby inducing electrical contact between the cell terminal and the battery can.

10. In paragraph 2, A step protrusion is formed on the above cell terminal, A battery cell characterized in that the step projection is coupled to the step groove.

11. In paragraph 10, A battery cell characterized in that the above-mentioned step protrusion is formed of a material having a heat transfer function.

12. In paragraph 10, A battery cell characterized in that the above-mentioned step protrusion is coated with a material having a heat transfer function.

13. In paragraph 2, A battery cell characterized in that a plurality of micro-grooves are formed in the above-mentioned step 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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