Battery cell, battery pack, and vehicle including same

Abstract

A battery cell according to the present invention comprises: an electrode assembly that is wound around a winding center hole and in which a separator is interposed between electrodes having different polarities; a welding tab part formed by welding at least some of a plurality of foil tabs formed on the electrodes to each other; and a can housing having an accommodation space in which the electrode assembly is accommodated, the welding tab part being welded and coupled to the can housing.

Description

Battery cells, battery packs, and automobiles including the same

[0001] The present invention relates to a battery cell, a battery pack, and an automobile including the same, and more specifically, to a battery cell, a battery pack, and an automobile including the same, having improved productivity and reduced electrical resistance.

[0002] This application is a priority claim application for Korean Patent Application No. 10-2024-0179907 filed on December 5, 2024, and all contents disclosed in the specification and drawings of said application are incorporated into this application by reference.

[0003] Recently, as the demand for portable electronic products such as laptops, video cameras, and mobile phones has increased rapidly, and the development of electric vehicles, energy storage batteries, robots, and satellites has accelerated, research on high-performance secondary batteries capable of repeated charging and discharging is actively underway.

[0004] Currently commercialized rechargeable batteries include nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and lithium-ion batteries. Among these, lithium-ion batteries are gaining attention for their advantages, such as the ability to freely charge and discharge with almost no memory effect compared to nickel-based batteries, a very low self-discharge rate, and high energy density.

[0005] These lithium-ion secondary batteries primarily use lithium-based oxides and carbon materials as the positive and negative active materials, respectively. Additionally, the lithium-ion secondary battery comprises an electrode assembly in which a positive plate and a negative plate, each coated with the positive and negative active materials, are arranged with a separator in between, and an outer casing that seals and encloses the electrode assembly together with an electrolyte.

[0006] Meanwhile, lithium-ion rechargeable batteries can be classified according to the shape of the battery case into pouch-type rechargeable batteries, in which the electrode assembly is embedded in an aluminum laminate sheet pouch, and can-type rechargeable batteries, in which the electrode assembly is embedded in a metal can. Furthermore, can-type rechargeable batteries can be further classified into cylindrical batteries and prismatic batteries depending on the shape of the metal can. These lithium-ion rechargeable batteries are utilized as battery modules or battery packs, which are assembled into a dense structure by overlapping or stacking multiple battery cells—either directly or mounted in cartridges—and electrically connected to provide high voltage and high current.

[0007] Conventional cylindrical secondary batteries may include an electrode assembly, a can housing, and a current collector. The electrode assembly may be provided wound with a separator interposed between electrodes of different polarities. The can housing may be configured to accommodate the electrode assembly. The current collector may be configured to be electrically connected to the electrode assembly and the can housing, respectively. The current collector may be positioned between the electrode assembly and the can housing, and may be welded and joined to a plurality of foil tabs of the electrode assembly and the can housing, respectively.

[0008] The present invention was conceived in consideration of the technical background described above, and has one objective of providing a battery cell with improved productivity, a battery pack, and an automobile including the same.

[0009] In addition, another purpose is to provide a battery cell with reduced electrical resistance, a battery pack, and a vehicle including the same.

[0010] The technical problems that the present invention aims to solve are not limited to those described above, and other unmentioned problems will be clearly understood by those skilled in the art from the description of the invention below.

[0011] A battery cell according to the present invention comprises: an electrode assembly provided by being wound around a central winding hole with a separator interposed between electrodes of different polarities; a welded tab portion formed by welding together at least some of a plurality of foil tabs formed on the electrodes; and a can housing having a receiving space for accommodating the electrode assembly and having the welded tab portion welded and joined thereto.

[0012] The welded tab portion is formed by first welding at least some of the plurality of foil tabs in a bent and laminated state together, and the welded tab portion and the can housing can be joined by second welding together after the first welding.

[0013] The above-mentioned welding tab portion may be formed by welding at least a portion of a plurality of the foil tabs together while they are bent and stacked in both directions.

[0014] The above welding tab and the above can housing can be joined by welding to each other by a welding rod inserted into the above winding center hole.

[0015] The above can housing has a closure formed on one side to cover the receiving space, and the welding tab can be welded and joined to the closure.

[0016] The above-mentioned closure is electrically connected to the electrode assembly and has a rivet terminal, at least a portion of which is exposed to the outside of the can housing, and the welding tab is welded to the rivet terminal and may not be joined to the remaining portion of the closure excluding the rivet terminal.

[0017] The battery cell according to the present invention may further include an insulator disposed between the electrode assembly and the can housing and configured to insulate the electrode assembly and the can housing from each other.

[0018] The above insulator may have an exposure hole configured so that at least a portion of the welding tab portion can be exposed to the can housing.

[0019] The above welding tab portion can be positioned to cover the above winding center hole.

[0020] The plurality of foil tabs formed on the electrode can be formed with equal lengths.

[0021] A battery pack according to the present invention comprises at least one battery cell according to the present invention.

[0022] The automobile according to the present invention includes at least one battery pack according to the present invention.

[0023] According to the present invention, a battery cell with improved productivity, a battery pack, and an automobile including the same can be provided.

[0024] In addition, according to one aspect of the present invention, a battery cell with reduced electrical resistance, a battery pack, and an automobile including the same can be provided.

[0025] In addition, according to one aspect of the present invention, a battery cell with improved energy density, a battery pack, and a vehicle including the same can be provided.

[0026] In addition, according to one aspect of the present invention, a battery cell with improved rigidity, a battery pack, and an automobile including the same can be provided.

[0027] In addition, according to one aspect of the present invention, a battery cell with improved quality, a battery pack, and a vehicle including the same can be provided.

[0028] In addition, according to one aspect of the present invention, a battery cell with improved welding quality, a battery pack, and an automobile including the same can be provided.

[0029] In addition, according to one aspect of the present invention, a battery cell, a battery pack, and an automobile including the same can be provided, with improved ease of welding.

[0030] The effects of the present invention are not limited to the effects described above, and unmentioned effects will be clearly understood by those skilled in the art from this specification and the attached drawings.

[0031] The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the detailed description of the invention provided below; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings.

[0032] FIG. 1 is a perspective view showing the overall appearance of a battery cell according to one embodiment of the present invention.

[0033] FIG. 2 is a side cross-sectional view showing the appearance of an electrode assembly according to one embodiment of the present invention.

[0034] FIG. 3 is a side view showing an electrode unfolded according to one embodiment of the present invention.

[0035] FIG. 4 is a side cross-sectional view showing an enlarged portion of a battery cell according to one embodiment of the present invention.

[0036] FIG. 5 is a side cross-sectional view showing the appearance of foil tabs before being bent and stacked in an electrode assembly according to one embodiment of the present invention.

[0037] FIG. 6 is a side cross-sectional view showing foil tabs being bent in an electrode assembly according to one embodiment of the present invention.

[0038] FIG. 7 is a side cross-sectional view showing the weld tab portion formed in an electrode assembly according to one embodiment of the present invention.

[0039] FIG. 8 is a side cross-sectional view showing a welded tab portion being welded to a can housing in a battery cell according to one embodiment of the present invention.

[0040] FIG. 9 is a plan view showing an electrode assembly according to one embodiment of the present invention.

[0041] FIG. 10 is a side cross-sectional view showing an enlarged portion of a battery cell according to another embodiment of the present invention.

[0042] FIG. 11 is a perspective view showing an insulator of a battery cell according to another embodiment of the present invention.

[0043] FIG. 12 is a drawing showing a battery pack according to one embodiment of the present invention.

[0044] FIG. 13 is a drawing showing an automobile according to one embodiment of the present invention.

[0045] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, and should be interpreted in a meaning and concept consistent with the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.

[0046] Therefore, it should be understood that the embodiments described in this specification and the configurations illustrated in the drawings are merely some of the most preferred embodiments of the invention and do not represent all of the technical ideas of the invention, and that various equivalents and modifications that can replace them may exist at the time of filing this application.

[0047] In this specification, unless otherwise specified, the X-axis and Y-axis directions may be left-right and front-back directions, or front-back and left-right directions, respectively, and the Z-axis direction orthogonal to the XY plane may be up-down direction (vertical direction).

[0048]

[0049] FIG. 1 is a perspective view showing the overall appearance of a battery cell according to one embodiment of the present invention, FIG. 2 is a side cross-sectional view showing the appearance of an electrode assembly according to one embodiment of the present invention, FIG. 3 is a side view showing an electrode unfolded according to one embodiment of the present invention, and FIG. 4 is a side cross-sectional view showing an enlarged portion of a battery cell according to one embodiment of the present invention.

[0050] Hereinafter, a battery cell (1) according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 4. A battery cell (1) according to an embodiment of the present invention may include an electrode assembly (10), a welding tab portion (13), and a can housing (20).

[0051] The electrode assembly (10) may include an electrode (11) and a separator (12). The electrode (11) may include electrodes (11) of different polarities. Specifically, the electrode (11) may include a first electrode (11a) and a second electrode (11b). The first electrode (11a) may have a first polarity, and the second electrode (11b) may have a second polarity opposite to the first polarity. For example, the first polarity may be a positive electrode and the second polarity may be a negative electrode. The separator (12) may be interposed between electrodes (11) of different polarities. The separator (12) may be interposed between the first electrode (11a) and the second electrode (11b). The separator (12) may be an insulator.

[0052] The electrode assembly (10) may have a jelly-roll structure. That is, the electrode assembly (10) may be manufactured by winding a laminate formed by stacking at least once with a separator (12) interposed between a sheet-shaped first electrode (11a) and a second electrode (11b) around the central axis (A) of the winding center hole (C). Any jelly-roll structure known in the art may be applied to the present invention without limitation.

[0053] The electrode (11) may have a retaining portion (111) and a non-retaining portion (112). The retaining portion (111) may be a portion on at least one surface of the electrode (11) where an active material layer is laminated. For example, a positive active material may be laminated on the retaining portion (111) of the first electrode (11a), and a negative active material may be laminated on the retaining portion (111) of the second electrode (11b).

[0054] The unladen portion (112) may be a part of the electrode (11) where no active material is laminated. The electrode (11) may have a predetermined length "I" width, and the unladen portion (112) may be formed on one long side of the electrode (11). For example, as shown in FIG. 3, the unladen portion (112) may be formed on the long side in the Z-axis direction.

[0055] At least a portion of the unoccupied portion (112) may be exposed to the outside of the separator (12). The unoccupied portion (112) may be used as an electrode (11) tab.

[0056] The unwound portion (112) may be provided with a plurality of foil tabs (113). The foil tabs (113) may be exposed to the outside of the separator (12). The plurality of foil tabs (113) may be arranged in a line from the winding center hole (C) side toward the outer circumference side (e.g., toward the +X direction side of FIG. 3). The plurality of foil tabs (113) may be formed by at least one notched portion (114) formed by a notching process.

[0057] The electrode (11) may be provided with an insulating coating portion (115). The insulating coating portion (115) may be placed at the boundary between the uninsulated portion (112) and the retaining portion (111). The insulating coating portion (115) may be provided when the electrode (11) is the first electrode (11a), and may prevent the respective retaining portions (111) of the first electrode (11a) and the second electrode (11b) from coming into contact with each other.

[0058] The description of the electrode (11) above and below may be applied commonly to both the first electrode (11a) and the second electrode (11b) unless otherwise noted.

[0059] The welded tab portion (13) may be formed by welding at least some of the plurality of foil tabs (113) together. Specifically, the welded tab portion (13) may be provided in the form of a lump or cluster of welded foil tabs (113).

[0060] The welding tab section (13) may include a first welding tab section (13a) and a second welding tab section (13b). The first welding tab section (13a) may be a welding tab section (13) in which foil tabs (113) of the first electrode (11a) are welded, and the second welding tab section (13b) may be a welding tab section (13) in which foil tabs (113) of the second electrode (11b) are welded. In FIG. 2, the first welding tab section (13a) is shown positioned on the +Z direction side and the second welding tab section (13b) is shown positioned on the -Z direction side, but this is merely an example, and the first welding tab section (13a) and the second welding tab section (13b) may be positioned opposite to FIG. 2. The following description of the welding tab section (13) may be applied commonly to both the first welding tab section (13a) and the second welding tab section (13b) unless otherwise noted.

[0061] The can housing (20) may be configured to accommodate the electrode assembly (10). The can housing (20) may have a receiving space in which the electrode assembly (10) is accommodated. The can housing (20) may be provided, for example, in a hollow cylindrical shape to accommodate the electrode assembly (10).

[0062] A welding tab (13) can be welded and joined to the can housing (20). For example, the welding tab (13) can be welded and joined to any bottom surface of the upper part of the can housing (20). The welding tab (13) can be directly welded and joined to the can housing (20). That is, the welding tab (13) and the can housing (20) can be welded and joined while in contact with each other.

[0063] Conventional battery cells could include a configuration such as a current collector plate positioned between an electrode assembly and a can housing. The electrode assembly and the can housing could be electrically connected to each other through the current collector plate. The current collector plate could be welded and joined to a plurality of foil tabs of the electrode assembly and the can housing, respectively, and the welding process of the current collector plate and the foil tabs and the welding process of the current collector plate and the can housing could each be carried out as separate processes.

[0064] However, in the battery cell (1) according to the present invention, the welding tab portion (13) in which foil tabs (113) are welded can be welded to the can housing (20), so that the electrode assembly (10) and the can housing (20) can be electrically connected without including a configuration such as a current collector plate. Therefore, the current collector plate can be omitted, so the production process of the battery cell (1) can be simplified and production costs can be reduced, and thus the productivity of the battery cell (1) can be improved.

[0065] In addition, the foil tab (113) of the electrode assembly (10) and the can housing (20) can be directly welded together and electrically connected without a configuration such as a current collector plate, so the electrical resistance of the battery cell (1) can be significantly reduced compared to a conventional battery cell.

[0066] In addition, since a configuration such as a collector plate is not required, the space for accommodating the electrode assembly (11) inside the can housing (20) is increased, and the energy density of the battery cell (1) can be improved.

[0067] In addition, since multiple foil tabs (113) are welded together to form a welded tab portion (13), the rigidity of the foil tabs (113) is improved, and as a result, the effect of improving the rigidity of the battery cell (1) can be expected.

[0068]

[0069] Meanwhile, among the foil tabs (113) of the electrode assembly (10), excluding the foil tabs (113) formed as welded tab portions (13), at least some of the foil tabs (113) may be welded and joined in a stacked state. For example, some of the foil tabs (113) of the electrode assembly (10) may be welded and joined as welded tab portions (13), while others may be welded and joined in an up-and-down direction in a form other than welded tab portions (13).

[0070]

[0071] FIG. 5 is a side cross-sectional view showing the appearance of foil tabs before they are bent and stacked in an electrode assembly according to an embodiment of the present invention, FIG. 6 is a side cross-sectional view showing the appearance of foil tabs being bent in an electrode assembly according to an embodiment of the present invention, FIG. 7 is a side cross-sectional view showing the appearance of a welded tab portion being formed in an electrode assembly according to an embodiment of the present invention, and FIG. 8 is a side cross-sectional view showing the appearance of a welded tab portion being welded to a can housing in a battery cell according to an embodiment of the present invention.

[0072] Hereinafter, a battery cell (1) according to one embodiment of the present invention will be described in more detail with reference to FIGS. 5 to 8.

[0073] In a battery cell (1) according to one embodiment of the present invention, the welding tab portion (13) is formed by primary welding, and the welding tab portion (13) and the can housing (20) can be joined to each other by secondary welding.

[0074] First, the first welding process will be described in detail. First, the multiple foil tabs (113) of the electrode assembly (10) may be provided in an unbent form, as shown in FIG. 5.

[0075] Next, a plurality of foil tabs (113) can be folded inward and stacked as shown in FIG. 6. As shown in FIG. 6, the process of folding and stacking the plurality of foil tabs (113) can be a so-called pre-forming process. The plurality of foil tabs (113) can be folded toward the winding center hole (C) or center axis (A) when viewed from the side (e.g., Y-axis direction or X-axis direction).

[0076] Next, at least some of the plurality of foil tabs (113) in a folded and laminated state may be welded together to form a welded tab portion (13), as shown in FIG. 7, and this welding may be a primary welding. The primary welding may be performed prior to the secondary welding described later, and may be so-called pre-welding. The primary welding may be applied to at least the foil tabs (113) in the area corresponding to the winding center hole (C) among the plurality of foil tabs (113) in a folded and laminated state.

[0077] The weld tab portion (13) and the can housing (20) can be joined by welding as shown in FIG. 8, and this welding may be a secondary welding. The secondary welding may be performed after the primary welding in time. That is, after the weld tab portion (13) is formed by the primary welding first, the weld tab portion (13) and the can housing (20) can be joined to each other by the secondary welding.

[0078] When the battery cell (1) is provided as described above, the foil tabs (113) can be provided as a welded tab portion (13) with secured rigidity by being pre-welded by a first welding process, so that the possibility of welding defects and the difficulty of welding can be significantly reduced during the welding process between the electrode assembly (10) and the can housing (20) that proceeds thereafter, and thus the welding quality of the battery cell (1) can be improved.

[0079]

[0080] FIG. 9 is a plan view showing an electrode assembly according to one embodiment of the present invention.

[0081] Hereinafter, with reference to FIGS. 6, 7 and 9, the welding tab portion (13) of the battery cell (1) according to one embodiment of the present invention will be examined in more detail.

[0082] The welded tab portion (13) can be formed by welding at least a portion of a plurality of foil tabs (113) together while they are bent and stacked in both directions. Here, "both directions" can be understood as both directions toward the winding center axis (A). For example, as shown in FIG. 6, a plurality of foil tabs (113) can be bent and stacked in both directions parallel to the X-axis, and in this bent and stacked state, they can be welded to form the welded tab portion (13) as shown in FIG. 7.

[0083] As described above, a welded tab portion (13) formed by welding at least a portion of a plurality of foil tabs (113) together while they are bent and stacked in both directions can be formed in an elongated shape having a predetermined length, as shown in FIG. 9. For example, the welded tab portion (13) can be formed in a shape that extends long in the Y-axis direction when viewed from the Z-axis direction. Meanwhile, the welded tab portion (13) can pass through the winding center hole (C) when viewed from the Z-axis direction, and in this case, the length of the welded tab portion (13) can be formed to be approximately equal to the diameter of the electrode assembly (10) or slightly smaller than the diameter of the electrode assembly (10).

[0084] When the welding tab portion (13) is formed as described above, a device for bending and stacking multiple foil tabs (113) (e.g., a so-called forming device) only needs to be introduced from both sides of the electrode assembly (10), so the bending and stacking process of the foil tabs (113) becomes easier, and the welding tab portion (13) can also be formed more easily. Accordingly, the productivity of the battery cell (1) can be further improved.

[0085]

[0086] Referring to FIG. 8, the welding tab and the can housing can be joined by welding them together with a welding rod.

[0087] A welding rod (W) can be inserted into a winding center hole (C). After the welding rod (W) is inserted into the winding center hole (C) through the opening (22) (see FIG. 1) described later in the can housing (20), the welding tab (13) and the can housing (20) can be welded together. Here, the welding tab (13) may be provided in a state of primary welding, and the welding of the welding tab (13) and the can housing (20) by the welding rod (W) may be secondary welding.

[0088] As described above, when the welding tab portion (13) and the can housing (20) are welded together by the welding rod (W) inserted into the winding center hole (C), the welding tab portion (13) and the can housing (20) can be welded easily and securely, and when welding the welding tab portion (13) and the can housing (20), damage to the remaining parts of the electrode assembly (10), excluding the welding tab portion (13), can be effectively prevented by welding.

[0089]

[0090] Referring to FIG. 4, the can housing (20) may have a closing portion (21), and the welding tab portion (13) may be welded to the closing portion (21) and joined.

[0091] The closure portion (21) may be provided on one side of the can housing (20). For example, the closure portion (21) may be provided on the +Z direction side of the can housing (20). The closure portion (21) may be formed integrally with the can housing (20).

[0092] The welded tab portion (13) can be joined by welding to the closed portion (21). The welded tab portion (13) and the closed portion (21) can be joined by secondary welding.

[0093] As described above, when the can housing (20) is provided with a closing portion (21), when the electrode assembly (10) is received inside the can housing (20), it can be easily fixed in position by the closing portion (21), so the difficulty of welding between the welding tab portion (13) and the can housing (20) can be reduced.

[0094]

[0095] Meanwhile, the can housing (20) may be provided with an opening (22). The opening (22) may be provided on the other side of the can housing (20). For example, the opening (22) may be provided on the -Z direction side of the can housing (20). An additional configuration or component capable of covering the opening (22) may be placed in the opening (22).

[0096]

[0097] Referring to FIG. 4, the closing portion (21) may be provided with a rivet terminal (211), and the welding tab portion (13) may be joined by welding to the rivet terminal (211).

[0098] The rivet terminal (211) can be electrically connected to the electrode assembly (10). The rivet terminal (211) can be electrically connected to the foil tab (113). The rivet terminal (211) can be electrically connected to the first electrode (11a), in which case it may have a first polarity. The rivet terminal (211) may be a positive terminal.

[0099] The rivet terminal (211) may be exposed to the outside of the can housing (20) in at least a portion. The rivet terminal (211) may be exposed to the outside of the can housing (20) by protruding outward from the closure (21) in at least a portion. The rivet terminal (211) may be provided in the form of a rivet. The rivet terminal (211) may be disposed through one side of the can housing (20) or through the closure (21). For example, the lower end of the rivet terminal (211) may be disposed in a state facing the electrode assembly (10) by penetrating the closure (21).

[0100] The welding tab portion (13) can be joined by welding to the rivet terminal (211). The welding tab portion (13) can be joined by direct welding to the rivet terminal (211). That is, no other components are interposed between the welding tab portion (13) and the rivet terminal (211), and the welding tab portion (13) and the rivet terminal (211) can be joined by welding to each other while in contact with each other.

[0101] The welding tab portion (13) may not be connected to the remaining part of the closing portion (21) excluding the rivet terminal (211). That is, the welding tab portion (13) may not be electrically connected to the part of the closing portion (21) excluding the rivet terminal (211).

[0102] When the battery cell (1) is configured as described above, the terminal of the battery cell (1) can be reliably provided as a rivet terminal (211), and the other part of the closed portion (21), excluding the rivet terminal (211), can be configured to have a polarity different from that of the rivet terminal (211) or not have a polarity.

[0103]

[0104] Meanwhile, the welding tab portion (13) may be compressed by the pressure of the rivet terminal (211) before being welded to the rivet terminal (211), and in this process, the rivet terminal (211) may be compressed and deformed, and in this case, the contact area and welding area between the rivet terminal (211) and the welding tab portion (13) may be increased.

[0105]

[0106] Meanwhile, an insulating gasket (30) may be further provided in the closing portion (21). The insulating gasket (30) may be placed between the closing portion (21) and the rivet terminal (211). The insulating gasket (30) may insulate the rivet terminal (211) and the closing portion (21) from each other.

[0107]

[0108] FIG. 10 is a side cross-sectional view showing an enlarged portion of a battery cell according to another embodiment of the present invention, and FIG. 11 is a perspective view showing an insulator of a battery cell according to another embodiment of the present invention.

[0109] Hereinafter, a battery cell (1) according to another embodiment of the present invention will be described in detail with reference to FIGS. 10 and 11. A battery cell (1) according to another embodiment of the present invention may further include an insulator (40).

[0110] The insulator (40) may be positioned between the electrode assembly (10) and the can housing (20). For example, the insulator (40) may be positioned between the upper portion of the electrode assembly (10) and the lower portion of the closure (21). Additionally, a portion of the insulator (40) may be positioned between the area adjacent to the upper portion of the side of the electrode assembly (10) and the inner surface of the can housing (20).

[0111] The insulator (40) can be configured to insulate the electrode assembly (10) and the can housing (20) from each other.

[0112] As described above, when the battery cell (1) further includes an insulator (40), the part of the can housing (20) that is welded to the welding tab (13) may have the same polarity as the welding tab (13), and other parts of the can housing (20) covered by the insulator (40) may have a different polarity from the welding tab (13) or may be configured not to have any polarity.

[0113]

[0114] The insulator (40) may be provided with an exposed hole (H). The exposed hole (H) may be configured so that at least a portion of the welding tab (13) is exposed to the can housing (20).

[0115] The exposed hole (H) may be provided in the form of a circular hole having an inner diameter corresponding to the outer diameter of the rivet terminal (211), for example, or having an inner diameter slightly larger than the outer diameter of the rivet terminal (211). In this case, the rivet terminal (211) may pass through the exposed hole (H) and come into contact with a part of the weld tab (13).

[0116] Unlike what is shown in the drawing, the exposed hole (H) may be provided in various forms, such as, for example, in the shape of a long hole.

[0117] The exposed hole (H) can be configured so that a welding tab (13) can be inserted. The welding tab (13) can pass through the exposed hole (H) and come into contact with the can housing (20).

[0118] As described above, when the insulator (40) is provided with an exposed hole (H), contact between the welding tab portion (13) and the can housing (20) can be reliably formed, while at the same time, the remaining part of the electrode assembly (10), excluding the welding tab portion (13), can be reliably insulated from the can housing (20).

[0119]

[0120] Referring to FIGS. 2, FIGS. 4 and FIGS. 7, etc., the welding tab portion (13) can be arranged to cover the winding center hole (C).

[0121] Specifically, the welding tab portion (13) can be positioned to pass through the central axis (A) of the winding center hole (C), and can be formed and positioned to cover the entire winding center hole (C) when viewed from the Z-axis direction.

[0122] When the welding tab portion (13) includes a first welding tab portion (13a) and a second welding tab portion (13b), at least one of the first welding tab portion (13a) and the second welding tab portion (13b) may be arranged to cover the winding center hole (C).

[0123] In the case of conventional battery cells, the foil tabs of the electrode assembly can only be welded and joined up to the outer periphery of the winding center hole, so some foil tabs located close to the winding center hole may not be welded and joined. However, in the battery cell (1) according to the present invention, as the welding tab portion (13) is arranged as described above, the foil tabs (113) of the electrode assembly (10) can be welded and joined up to the inner region of the outer periphery of the winding center hole (C), and as a result, all foil tabs (113) located close to the winding center hole (C) can be welded and joined, thereby drastically reducing the electrical resistance of the battery cell (1). Therefore, a low-resistance battery cell (1) can be realized.

[0124]

[0125] Referring to FIG. 3, a plurality of foil tabs (113) formed on the electrode (11) can be formed with equal lengths.

[0126] Here, the length of the foil tab (113) can be understood as the length in the Z-axis direction based on FIG. 3, and can be understood as the height (H) of the foil tab (113).

[0127] As described above, a plurality of foil tabs (113) can be formed by at least one notching portion (114) that is notched. In the case of electrodes of conventional battery cells, so-called pattern notching processing may be required so that a plurality of foil tabs are formed with different lengths. However, in the electrode (11) of the battery cell (1) according to the present invention, as described above, a plurality of foil tabs (113) can be formed with the same length, so that such pattern notching processing may not be necessary, and thus the process of forming a plurality of foil tabs (113) can be simplified.

[0128]

[0129] Meanwhile, the can housing (20) of the battery cell (1) according to the present invention may further include a beading portion and a crimping portion. The beading portion may be formed by indenting one side of the can housing (20) inwardly and may secure the electrode assembly (10). The crimping portion may be formed by extending and bending the end of the opening portion (22) of the can housing (20) inwardly and may be configured to cover at least a part of the opening portion (22) or to seal the opening portion (22). Of course, the can housing (20) may not be provided with the beading portion and the crimping portion as described above.

[0130]

[0131] FIG. 12 is a drawing showing a battery pack according to one embodiment of the present invention.

[0132] Referring to FIG. 12, the battery pack (3) according to the present invention may include at least one battery cell (1) according to the present invention. The battery pack (3) may include a pack case (2) that accommodates at least one battery cell (1).

[0133] In the drawing, for the convenience of drawing, components such as busbars, cooling units, and external terminals for electrical connection of battery cells (1) are omitted. The structure of a plurality of battery cells (1) for manufacturing the battery pack (3) has been described above as an example.

[0134]

[0135] FIG. 13 is a drawing showing an automobile according to one embodiment of the present invention.

[0136] Referring to FIG. 13, a battery pack (3) according to one embodiment of the present invention may be applied to a vehicle (4), such as an electric vehicle or a hybrid vehicle. That is, the vehicle (4) according to the present invention may include a battery pack (3) according to the present invention. The battery pack (3) may be installed in a vehicle body frame or trunk space under the vehicle seat. In addition, the vehicle (4) according to the present invention may include various other components included in the vehicle (4) in addition to the battery pack (3). For example, the vehicle (4) according to one embodiment of the present invention may include, in addition to the battery pack (3) according to the present invention, a vehicle body, a motor, a control device such as an ECU (electronic control unit), etc.

[0137] In addition, it is obvious that the battery pack (3) according to the present invention may also be provided in other devices, mechanisms, and facilities, such as an energy storage system using a secondary battery, in addition to a vehicle (4).

[0138]

[0139] In this specification, terms indicating directions such as up, down, left, right, front, and back have been used; however, these terms are used merely for convenience of explanation, and it is obvious to those skilled in the art that they may vary depending on the location of the object or the position of the observer.

[0140] As described above, although the present invention has been explained by limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical spirit of the present invention and the equivalent scope of the claims described below by those skilled in the art to which the present invention belongs.

[0141] [Explanation of the symbol]

[0142] 1 : Battery cell

[0143] 2 : Pack Case

[0144] 3 : Battery pack

[0145] 4 : Cars

[0146] 10 : Electrode assembly

[0147] 11: Electrode

[0148] 111 : Maintenance part

[0149] 112 : Mujibu

[0150] 113 : Foil Tab

[0151] 114 : Notching part

[0152] 115 : Insulating coating part

[0153] 12: Separator

[0154] 13: Welding tab

[0155] 20 : Can housing

[0156] 21 : Closure

[0157] 211 : Rivet terminal

[0158] 22 : Open part

[0159] 30: Insulating gasket

[0160] 40: Insulator

[0161] 41 : Exposed hole

[0162] C: Winding center hole

[0163] A : Central axis

[0164] W : Welding rod

Claims

1. An electrode assembly provided by being wound around a central hole with a separator interposed between electrodes of different polarities; A welded tab portion formed by welding at least some of the plurality of foil tabs formed on the electrode; and A battery cell characterized by including a can housing having a receiving space for accommodating the electrode assembly and a welding tab portion welded and joined thereto.

2. In Paragraph 1, The above welding tab portion is, At least some of the plurality of foil tabs in a folded and laminated state are formed by primary welding together, The above-mentioned welding tab and the above-mentioned can housing are, A battery cell characterized by being joined by secondary welding to each other after the above primary welding.

3. In Paragraph 1, The above welding tab portion is, A battery cell characterized by being formed such that at least a portion of the plurality of foil tabs are welded together while being folded and stacked in both directions.

4. In Paragraph 1, The above-mentioned welding tab and the above-mentioned can housing are, A battery cell characterized by being joined together by welding rods inserted into the above-mentioned center hole.

5. In Paragraph 1, The above can housing is, It is provided with a closure formed on one side to cover the above-mentioned receiving space, and The above welding tab portion is, A battery cell characterized by being welded and joined to the above-mentioned closure.

6. In Paragraph 5, The above-mentioned closure is, It has a rivet terminal electrically connected to the electrode assembly and having at least a portion exposed to the outside of the can housing, and The above welding tab portion is, A battery cell characterized by being joined by welding to the above-mentioned rivet terminal and not joined to the remaining part of the above-mentioned closure excluding the above-mentioned rivet terminal.

7. In Paragraph 1, A battery cell characterized by further including an insulator disposed between the electrode assembly and the can housing and configured to insulate the electrode assembly and the can housing from each other.

8. In Paragraph 7, The above insulator is, A battery cell characterized by having an exposure hole configured such that at least a portion of the above-mentioned welding tab portion can be exposed to the can housing.

9. In Paragraph 1, The above welding tab portion is, A battery cell characterized by being positioned to cover the above-mentioned winding center hole.

10. In Paragraph 1, The plurality of foil tabs formed on the electrode are, Battery cells characterized by being formed with equal lengths.

11. A battery pack characterized by including at least one battery cell according to any one of claims 1 to 10.

12. An automobile characterized by including at least one battery pack according to claim 11.

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