Battery cell, battery pack, and vehicle comprising same

Abstract

A battery cell according to the present invention comprises: an electrode assembly provided by being wound around a central axis of a winding center hole in a state in which a separator is interposed between electrodes having different polarities; a can housing accommodating the electrode assembly and having an opening formed at at least one end portion thereof; a can lid welded and coupled to an end portion of the can housing at a side of the opening; a welded tab portion formed by welding at least some of a plurality of foil tabs formed on the electrodes to each other; and a lead tab welded and coupled to the welded tab portion and the can lid, wherein the can lid includes a first half lid and a second half lid respectively divided and disposed at opposite sides of the lead tab.

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. 10-2025-0011848 filed on January 24, 2025, and all contents disclosed in the specification 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 the central axis of a winding center hole with a separator interposed between electrodes of different polarities; a can housing that accommodates the electrode assembly and has an opening formed at least one end; a can lid welded to the end of the can housing on the side of the opening; a welded tab portion formed by welding at least some of a plurality of foil tabs formed on the electrodes together; and a lead tab welded to the welded tab portion and the can lid, wherein the can lid has a first half-lid and a second half-lid divided and disposed on each side of the lead tab.

[0012] When viewed from the direction of the central axis of the winding center hole, the first half-pill, the lead tab, and the second half-pill are configured to form a circle, and the first half-pill and the second half-pill may each have a shape symmetrical to one another.

[0013] The first half-and-second

[0014] The first half-pill and the second half-pill may each further have a butt portion formed on at least a part of the edge so as to be placed on the end of the opening side of the can housing.

[0015] At least a portion of the lead tab may penetrate between the first half-tab and the second half-tab and be exposed to the outside of the battery cell.

[0016] The lead tab may have a thickness in the direction toward the first half-ply and the second half-ply, a width in the direction parallel to the central axis of the winding center hole, and a length in a direction perpendicular to the thickness direction and the width direction of the lead tab, respectively.

[0017] The welding tab portion is formed by first welding at least some of the plurality of foil tabs in a bent and laminated state together, the lead tab is joined by second welding to the welding tab portion, the first half-flute and the second half-flute are each joined by third welding to the lead tab and the can housing, and the third welding may be performed after the first welding.

[0018] The above second welding may be performed simultaneously with the above first welding or the above third welding.

[0019] 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.

[0020] The above welding tab portion can be positioned to cover the above winding center hole.

[0021] The plurality of foil tabs formed on the electrode can be formed with equal lengths.

[0022] The above opening is formed at one end and the other end of the can housing, respectively, and the welding tab portion includes a first welding tab portion disposed on one side of the electrode assembly; and a second welding tab portion disposed on the other side of the electrode assembly, and the lead tab includes a first lead tab welded to the first welding tab portion; and a second lead tab welded to the second welding tab portion, and the can lid may include a first can lid having a first-1 half-fried and a second-1 half-fried portion divided and disposed on each side of the first lead tab; and a second can lid having a first-2 half-fried and a second-2 half-fried portion divided and disposed on each side of the second lead tab.

[0023] A battery pack according to the present invention comprises at least one battery cell according to the present invention.

[0024] The automobile according to the present invention includes at least one battery pack according to the present invention.

[0025] According to the present invention, a battery cell with improved productivity, a battery pack, and an automobile including the same can be provided.

[0026] 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.

[0027] 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.

[0028] 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, wherein an electrical connection structure can be effectively and simply implemented.

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

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] FIG. 1 is a perspective view showing the overall appearance of a battery cell according to one embodiment of the present invention.

[0035] FIG. 2 is a side cross-sectional view showing the appearance of an electrode assembly according to one embodiment of the present invention.

[0036] FIG. 3 is a side view showing an electrode unfolded according to one embodiment of the present invention.

[0037] FIG. 4 is a side cross-sectional view showing an enlarged portion of a battery cell according to one embodiment of the present invention.

[0038] FIG. 5 is a perspective view showing a disassembled lead tab and can lid according to one embodiment of the present invention.

[0039] FIG. 6 is a cross-sectional perspective view showing a first half-fridge according to a modified example of an embodiment of the present invention.

[0040] FIG. 7 is a cross-sectional perspective view showing a first half-fridge according to another variation of one embodiment of the present invention.

[0041] FIG. 8 is a side cross-sectional view showing the process of forming a weld tab portion in an electrode assembly according to one embodiment of the present invention.

[0042] FIG. 9 is a plan view showing an electrode assembly according to one embodiment of the present invention.

[0043] FIG. 10 is a side cross-sectional view showing a lead tab coupled to a welded tab portion in a battery cell according to one embodiment of the present invention.

[0044] FIG. 11 is a side cross-sectional view showing the first half-fridge and the second half-fridge coupled to the lead tab in a battery cell according to one embodiment of the present invention.

[0045] FIG. 12 is a side cross-sectional view showing an enlarged view of another part of a battery cell according to one embodiment of the present invention, in which a welded tab is connected to a rivet terminal.

[0046] FIG. 13 is a side cross-sectional view showing the overall appearance of a battery cell according to another embodiment of the present invention.

[0047] FIG. 14 is a drawing showing a battery pack according to one embodiment of the present invention.

[0048] FIG. 15 is a drawing showing an automobile according to one embodiment of the present invention.

[0049] 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.

[0050] 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.

[0051] 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).

[0052]

[0053] 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, FIG. 4 is a side cross-sectional view showing an enlarged portion of a battery cell according to one embodiment of the present invention, and FIG. 5 is a perspective view showing a disassembled appearance of a lead tab and a can lid according to one embodiment of the present invention.

[0054] Hereinafter, a battery cell (1) according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 5. A battery cell (1) according to an embodiment of the present invention may include an electrode assembly (10), a can housing (20), a can lid (30), a welding tab portion (13), and a lead tab (40).

[0055] 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 negative electrode and the second polarity may be a positive 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.

[0056] 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.

[0057] 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 negative active material may be laminated on the retaining portion (111) of the first electrode (11a), and a positive active material may be laminated on the retaining portion (111) of the second electrode (11b).

[0058] 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 and 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.

[0059] 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.

[0060] 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.

[0061] 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, in particular, when the electrode (11) is a second electrode (11b), and may prevent the respective retaining portions (111) of the second electrode (11b) and the first electrode (11a) from coming into contact with each other.

[0062] 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.

[0063] The can housing (20) can accommodate the electrode assembly (10). The can housing (20) may be provided in a hollow cylindrical shape to accommodate the electrode assembly (10), for example. An opening (21) may be formed on one side of the can housing (20) (for example, the side in the +Z direction to the upper side). A closing part (22) may be formed on the other side of the can housing (20) (for example, the side in the -Z direction to the lower side). On the other side of the can housing (20), a closing part (22) may not be formed, and an opening (21) identical to the opening (21) formed on one side of the can housing (20) may be formed. The can housing (20) may include a metal material. For example, the can housing (20) may include nickel-plated steel (NPS) material or SUS material.

[0064] A can lid (30) can be attached to the end of the opening (21) of the can housing (20). The can lid (30) can be welded to the opening (21). Specifically, the edge of the can lid (30) can be welded to the end of the can housing (20) that forms the opening (21). The can lid (30) can cover at least a portion of the opening (21). The can lid (30) can be made of the same material as the can housing (20).

[0065] 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).

[0066] 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 one side (+Z direction side) and the second welding tab section (13b) is shown positioned on the other side (-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.

[0067] The lead tab (40) can be welded to the weld tab portion (13). By being welded to the weld tab portion (13), the lead tab (40) can be electrically connected at once to a plurality of foil tabs (113) formed on the electrode (11) of the electrode assembly (10). The lead tab (40) can function as a tab that can electrically connect the battery cell (1) and the external circuit of the battery cell (1). Additionally, the lead tab (40) can be welded to the can lid (30). That is, the lead tab (40) can be welded to the weld tab portion (13) and the can lid (30), respectively. The lead tab (40) can be connected to the can lid (30) to seal the can lid (30).

[0068] The lead tab (40) may be configured to have a predetermined volume. The lead tab (40) may be configured to have a predetermined rigidity. For example, the lead tab (40) may be provided as a predetermined volume body including a metal material.

[0069] The can lid (30) may be provided with a first half-lid (31) and a second half-lid (32). The first half-lid (31) and the second half-lid (32) may be divided and placed on each side of the lead tab (40). For example, the first half-lid (31) may be placed on the -X direction side of the lead tab (40), and the second half-lid (32) may be placed on the +X direction side of the lead tab (40). The lead tab (40) may be placed between the first half-lid (31) and the second half-lid (32) along the X-axis direction. By the lead tab (40), the first half-lid (31) and the second half-lid (32) may be divided and partitioned from each other.

[0070] In a battery cell (1) according to one embodiment of the present invention, a welded tab portion (13) in which foil tabs (113) are welded is welded to a lead tab (40), the lead tab (40) is welded to a can lid (30), and the can lid (30) is welded to a can housing (20), so that the electrode assembly and the can housing can be electrically connected without including a configuration such as a current collector plate of a conventional battery cell. Accordingly, in a battery cell (1) according to one embodiment of the present invention, since the current collector plate can be omitted, the production process of the battery cell (1) can be simplified and production costs can be reduced, thereby improving the productivity of the battery cell (1).

[0071] In addition, the welding length of the foil tabs (113) can be extended to the inside of the winding center hole (C) by means of the welding tab portion (13), so that the electrical resistance of the battery cell (1) can be significantly reduced. Furthermore, since the foil tabs (113) can be rigidly configured with the welding tab portion (13), the rigidity of the battery cell (1) can be improved.

[0072] In addition, a battery cell (1) can be provided in which an electrical connection structure between external circuits can be effectively and easily implemented by means of a lead tab (40).

[0073] In addition, as the can lid (30) is equipped with a first half-lid (31) and a second half-lid (32), the can lid (30) can be easily and strongly coupled to the can housing (20), thereby improving the structural stability of the battery cell (1), and the gap between the can lid (30) and the lead tab (40) and between the can lid (30) and the can housing (20) is minimized, thereby providing a battery cell (1) with improved sealing power.

[0074]

[0075] Meanwhile, among the plurality of foil tabs (113) of the electrode assembly (10), excluding the foil tabs (113) formed as welded tab portions (13), at least some of the remaining foil tabs (113) can be welded and joined in a stacked state. For example, some of the plurality of 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).

[0076]

[0077] When viewed from the central axis (A) direction to the Z-axis direction of the winding center hole (C), the first half-pill (31), lead tab (40), and second half-pill (32) may be configured to form a circle. Additionally, the first half-pill (31) and the second half-pill (32) may have shapes that are symmetrical to each other.

[0078] The first half-round (31) may have a roughly semicircular shape. Specifically, the first half-round (31) may have a roughly semicircular shape in which the width of the most convex part is slightly smaller than the radius. And, the second half-round (32) may have a shape symmetrical to this first half-round (31).

[0079] When the can lid (30) is configured as described above, the can lid (30) can be connected to the can housing (20) more easily and strongly, thereby further improving the structural stability of the battery cell (1), and the can lid (30) and the lead tab (40) and the can lid (30) and the can housing (20) can be sealed more effectively.

[0080] In addition, the first half (31) and the second half (32) are provided as identical parts and can be shared with each other, so the productivity of the battery cell (1) can be further improved.

[0081]

[0082] At least a portion of the lead tab (40) may be exposed to the outside of the battery cell (1). Specifically, at least a portion of the lead tab (40) may be exposed to the outside of the battery cell (1) by penetrating between the first half-tab (31) and the second half-tab (32).

[0083] For example, a portion of the lead tab (40) close to the weld tab (13) is not exposed to the outside of the battery cell (1), while another portion of the lead tab (40) far from the weld tab (13) can penetrate the can lid (30) and be exposed to the outside of the battery cell (1).

[0084] When the lead tab (40) is configured as described above, the electrical connection structure between the battery cell (1) and the external circuit can be implemented more effectively and simply.

[0085]

[0086] The lead tab (40) may have a thickness, width, and length. Accordingly, the lead tab (40) may have a three-dimensional shape as a predetermined volume. The lead tab (40) may, for example, have an elongated rectangular shape.

[0087] The lead tab (40) may have thickness in a direction toward the first half-fridge (31) and the second half-fridge (32). For example, the lead tab (40) may have thickness in the X-axis direction, and the thickness direction of the lead tab (40) may be formed parallel to the X-axis direction.

[0088] The lead tab (40) may have a width in a direction parallel to the central axis (A) of the winding center hole (C). For example, the lead tab (40) may have a width in the Z-axis direction, and the width direction of the lead tab (40) may be formed parallel to the Z-axis direction. The lead tab (40) may be formed such that its width is greater than its thickness.

[0089] The lead tab (40) may have a length in a direction perpendicular to the thickness direction and the width direction of the lead tab (40), respectively. For example, the lead tab (40) may have a length in the Y-axis direction, and the length direction of the lead tab (40) may be formed parallel to the Y-axis direction. The lead tab (40) may be formed such that its length is greater than its width.

[0090] When the lead tab (40) is configured as described above, the rigidity of the lead tab (40) can be reliably secured. Additionally, since a predetermined welding area can be formed between the lead tab (40) and the welding tab portion (13) and between the lead tab (40) and the can lid (30), the lead tab (40) can be effectively welded and joined with the welding tab portion (13) and the can lid (30).

[0091]

[0092] Meanwhile, the lead tab (40) may include a nickel material or an aluminum material. The nickel material may be a material with excellent conductivity, durability, mechanical strength, thermal stability, and weldability. The aluminum material may be a material with excellent conductivity, durability, lightness, thermal stability, and processability. As described below, the lead tab (40) may include a first lead tab (40a) welded to the first welding tab portion (13a) and a second lead tab (40b) welded to the second welding tab portion (13b). Furthermore, the first lead tab (40a) may include, for example, a nickel material, and the second lead tab (40b) may include, for example, an aluminum material.

[0093]

[0094] FIG. 6 is a cross-sectional perspective view showing a first half-fridge according to a modified example of an embodiment of the present invention.

[0095] Referring to FIG. 6, a first half-pill (31) according to a modified example of an embodiment of the present invention may further comprise an edge portion (33). The edge portion (33) may be formed on at least a portion of the edge of the first half-pill (31) so as to be fitted into the end of the opening portion (21) of the can housing (20). Specifically, the edge portion (33) may be formed along the circumferential direction on the outer curved portion of the edge of the first half-pill (31).

[0096] The edge portion (33) can be configured to be deformable in a direction parallel to the radial direction. For example, the cross-section of the edge portion (33) can be provided in a U shape. The edge portion (33) can be welded and joined to the end of the opening (21) of the can housing (20) while being fitted into the end of the opening (21) of the can housing (20).

[0097] Similar to the first half-drum (31), the second half-drum (32) may also be provided with an edge portion (33). The edge portion (33) of the second half-drum (32) may be provided symmetrically to the edge portion (33) of the first half-drum (31).

[0098] In this way, if the first half-lid (31) and / or the second half-lid (32) further have an edge portion (33), the can lid (30) can be welded to the can housing (20) in a strongly fitted state, so that the connection between the can lid (30) and the can housing (20) can be made strong and secure. In addition, the lead tab (40) can be connected in a strongly supported state between the first half-lid (31) and the second half-lid (32).

[0099]

[0100] FIG. 7 is a cross-sectional perspective view showing a first half-fridge according to another variation of one embodiment of the present invention.

[0101] Referring to FIG. 7, the first half-pill (31) according to another variation of an embodiment of the present invention may further comprise a butt portion (34). The butt portion (34) may be formed on at least a portion of the edge of the second half-pill (32) so as to be placed on the end of the opening (21) of the can housing (20). Specifically, the butt portion (34) may be formed along the circumferential direction on the outer curved portion of the edge of the first half-pill (31).

[0102] The butt portion (34) may be configured, for example, such that the thickness of the cross-section becomes thinner as it extends radially outward. The butt portion (34) may be configured in various forms, such as having a stepped cross-section so that at least a portion of it can be inserted into the inner diameter of the end of the opening (21) of the can housing (20), although not shown in the drawing, and simultaneously rest on the end of the opening (21) of the can housing (20). The butt portion (34) may be welded and joined to the end of the opening (21) of the can housing (20) while resting on the end of the opening (21) of the can housing (20).

[0103] Similar to the first half-frid (31), the second half-frid (32) may also be provided with a butt portion (34). The butt portion (34) of the second half-frid (32) may be provided symmetrically to the butt portion (34) of the first half-frid (31).

[0104] In this way, if the first half-lid (31) and / or the second half-lid (32) further have a butt portion (34), the internal space of the battery cell (1) can be further expanded, and the manufacturing and dimensional management of the can lid (30) can be made easier.

[0105]

[0106] FIG. 8 is a side cross-sectional view showing the process of forming a weld tab portion in an electrode assembly according to an embodiment of the present invention, FIG. 9 is a plan view showing an electrode assembly according to an embodiment of the present invention, FIG. 10 is a side cross-sectional view showing a lead tab coupled to a weld tab portion in a battery cell according to an embodiment of the present invention, and FIG. 11 is a side cross-sectional view showing a first half-tab and a second half-tab coupled to a lead tab in a battery cell according to an embodiment of the present invention.

[0107] With reference to FIGS. 8 to 11, a battery cell (1) according to one embodiment of the present invention will be described in more detail.

[0108] In a battery cell (1) according to one embodiment of the present invention, the welding tab portion (13) is formed by primary welding, the lead tab (40) is joined by secondary welding with the welding tab portion (13), and the first half-tab (31) and the second half-tab (32) can each be joined by tertiary welding with the lead tab (40) and the can housing (20).

[0109] First, the first welding process will be described in detail. First, the plurality of foil tabs (113) of the electrode assembly (10) may be provided in an unbent form, as shown in FIG. 8 (a). Next, the plurality of foil tabs (113) may be folded inward and stacked, as shown in FIG. 8 (b). As shown in FIG. 8 (b), the process of folding and stacking the plurality of foil tabs (113) may be a so-called pre-forming process. The plurality of foil tabs (113) may 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). 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. 8 (c), and this welding may be a first welding. The first welding may be performed prior to the third welding described later, and may be so-called pre-welding. The first 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.

[0110] Next, the secondary welding is described in detail. The lead tab (40) and the welding tab (13) can be joined by welding as shown in FIG. 10, and this welding may be a secondary welding. The lead tab (40) and the welding tab (13) may be secondary welded while in contact with each other. For example, the end of the lead tab (40) that is close to the electrode assembly (10) may be secondary welded by being in contact with the end of the welding tab (13) that is far from the electrode assembly (10). The lead tab (40) and the welding tab (13) may also be secondary welded by being in surface contact with each other. For example, when the lead tab (40) presses the welding tab (13), the welding tab (13) may be slightly deformed by the pressure and come into surface contact with the lead tab (40), and secondary welding may proceed in this state.

[0111] Next, the third welding is described in detail. The first half-fridge (31) and the second half-fridge (32) can each be welded and joined to the lead tab (40) and the can housing (20), as shown in FIG. 11, and this welding may be the third welding. Through the third welding, the first half-fridge (31) and the second half-fridge (32) are joined to the lead tab (40), and at the same time, the gap formed between them and the lead tab (40) can be sealed. Additionally, through the third welding, the first half-fridge (31) and the second half-fridge (32) are joined to the can housing (20), and at the same time, the gap formed between them and the can housing (20) can be sealed.

[0112] The third welding step can be performed after the first welding step in terms of time. That is, relatively speaking, the first welding step is the pre-weld, and the third welding step can be the post-weld.

[0113] Meanwhile, the third welding may include the 3-1st welding and the 3-2nd welding. The 3-1st welding may refer to the welding between the first half-fridge (31) and the second half-fridge (32) and the lead tab (40), and the 3-2nd welding may refer to the welding between the first half-fridge (31) and the second half-fridge (32) and the can housing (20).

[0114] As the foil tabs (113) can be provided as a welded tab section (13) with secured rigidity by being pre-welded by a first welding process, the possibility of welding defects and the difficulty of welding can be significantly reduced during the subsequent third welding process between the first half-lead (31) and the second half-lead (32) and the lead tab (40), thereby improving the welding quality and ease of welding of the battery cell (1).

[0115]

[0116] The second welding can be performed simultaneously with the first welding or the third welding.

[0117] The second welding can be performed simultaneously with the first welding. That is, a welding process combining FIG. 8 and FIG. 10 is also possible. Specifically, after a lead tab (40) is placed on a plurality of foil tabs (113) in which at least a portion is bent and laminated together, the lead tab (40) and the foil tabs (113) are welded, thereby forming a weld tab portion (13) and a welded joint of the lead tab (40) can be formed simultaneously. Then, a third welding process can be performed.

[0118] The second welding can be performed simultaneously with the third welding. That is, a welding process combining FIG. 10 and FIG. 11 is also possible. Specifically, after the first welding, a lead tab (40) is placed on the welding tab portion (13), and with the first half-tab (31) and the second half-tab (32) placed on each side of the lead tab (40), the first half-tab (31) and the second half-tab (32), the lead tab (40), and the welding tab portion (13) can be welded together simultaneously.

[0119] In this way, when the second welding is performed simultaneously with the first welding or the third welding, the time required for the welding process can be reduced, and thus the productivity of the battery cell (1) can be further improved.

[0120]

[0121] In particular, referring to FIGS. 8 and 9, the weld tab portion (13) may 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 the directions toward the central axis (A) of the winding center hole (C). For example, a plurality of foil tabs (113) may be formed as the weld tab portion (13) by bending them in both directions parallel to the X-axis and welding them together while they are stacked.

[0122] The weld tab portion (13) formed in this way can be formed in an elongated shape having a predetermined length, as shown in FIG. 9. For example, when viewed from the Z-axis direction, the weld tab portion (13) can be formed in a shape that is extended long in the Y-axis direction.

[0123] 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 be formed more easily. Accordingly, the productivity of the battery cell (1) can be further improved.

[0124]

[0125] In particular, referring to FIGS. 8 and 9, the welding tab portion (13) can be positioned to cover the winding center hole (C). Specifically, the welding tab portion (13) can be positioned to pass through the center axis (A) of the winding center hole (C), and can be formed and positioned to completely cover the winding center hole (C) when viewed from the Z-axis direction.

[0126] 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) 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, so the electrical resistance of the battery cell (1) can be drastically reduced. Therefore, a low-resistance battery cell (1) can be realized.

[0127]

[0128] Referring again to FIG. 3, a plurality of foil tabs (113) formed on the electrode (11) can be formed with equal lengths.

[0129] 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).

[0130] 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.

[0131]

[0132] FIG. 12 is a side cross-sectional view showing an enlarged view of another part of a battery cell according to one embodiment of the present invention, in which a welded tab is connected to a rivet terminal.

[0133] Referring to FIG. 12, a battery cell (1) according to one embodiment of the present invention may further include a rivet terminal (221). A can housing (20) may have a closed portion (22) on the other side (e.g., the side in the -Z direction or the lower side), in which case an open portion (21) may be provided only on one side of the can housing (20). The rivet terminal (221) may be disposed through the closed portion (22). The rivet terminal (221) may be provided in the form of a rivet. Some part of the rivet terminal (221) may be welded and joined to a weld tab portion (13), and other part may be exposed to the outside of the can housing (20). Here, the weld tab portion (13) may be a second weld tab portion (13b) (see FIG. 2). No other components are interposed between the rivet terminal (221) and the weld tab portion (13), and they may be directly joined to each other. An insulating gasket (50) that insulates the rivet terminal (221) and the closure (22) from each other may be additionally placed between them.

[0134]

[0135] FIG. 13 is a side cross-sectional view showing the overall appearance of a battery cell according to another embodiment of the present invention.

[0136] Hereinafter, with reference to FIG. 13, a battery cell (1) according to another embodiment of the present invention will be described in detail.

[0137] A battery cell (1) according to another embodiment of the present invention may have a lead tab (40) comprising a first lead tab (40a) and a second lead tab (40b), and a can lid (30) comprising a first can lid (30a) and a second can lid (30b).

[0138] In a battery cell (1) according to another embodiment of the present invention, an opening (21) may be formed at one end and the other end of a can housing (20), respectively. As previously described, the welding tab portion (13) may include a first welding tab portion (13a) disposed on one side of the electrode assembly (10) and a second welding tab portion (13b) disposed on the other side of the electrode assembly (10).

[0139] The first lead tab (40a) may be a lead tab (40) welded to the first welding tab portion (13a), and the second lead tab (40b) may be a lead tab (40) welded to the second welding tab portion (13b). The second lead tab (40b) may be provided to be vertically symmetrical with respect to the first lead tab (40a).

[0140] The first can lid (30a) may have a first-1 half-lid (31a) and a second-1 half-lid (32a) that are divided and disposed on each side of the first lid tab (40a). The first-1 half-lid (31a) may be configured identically to the first half-lid (31) described above. The second-1 half-lid (32a) may be configured identically to the second half-lid (32) described above.

[0141] The second can lid (30b) may have a first-2 half-lid (31b) and a second-2 half-lid (32b) that are divided and disposed on each side of the second lid tab (40b). The first-2 half-lid (31b) and the second-2 half-lid (32b) may each be provided to be vertically symmetrical with respect to the first-1 half-lid (31a) and the second-1 half-lid (32a).

[0142] In accordance with another embodiment of the present invention, the battery cell (1) can be configured such that one side and the other side of the battery cell (1) have the same structure as each other, or the battery cell (1) can be configured to be vertically symmetrical.

[0143]

[0144] Meanwhile, a battery cell (1) according to another embodiment of the present invention may further include a component such as an insulator capable of insulating the first lead tab (40a) and the second lead tab (40b) from each other.

[0145]

[0146] FIG. 14 is a drawing showing a battery pack according to one embodiment of the present invention.

[0147] Referring to FIG. 14, 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).

[0148] In the drawing, for the convenience of drawing, components such as busbars, cooling units, and external terminals for electrical connection of battery cells (1) have been omitted. The structure of a plurality of battery cells (1) for manufacturing the battery pack (3) has been described above as an example.

[0149]

[0150] FIG. 15 is a drawing showing an automobile according to one embodiment of the present invention.

[0151] Referring to FIG. 15, 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.

[0152] 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).

[0153]

[0154] 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.

[0155] 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.

[0156] [Explanation of the symbol]

[0157] 1 : Battery cell

[0158] 2 : Pack Case

[0159] 3 : Battery pack

[0160] 4 : Cars

[0161] 10 : Electrode assembly

[0162] 11: Electrode

[0163] 111 : Maintenance part

[0164] 112 : Mujibu

[0165] 113 : Foil Tab

[0166] 114 : Notching part

[0167] 115 : Insulating coating part

[0168] 12 : Separator

[0169] 13: Welding tab

[0170] 20 : Can housing

[0171] 21 : Opening

[0172] 22 : Closure

[0173] 221 : Rivet terminal

[0174] 30 : Can lid

[0175] 31: First Half-Fried

[0176] 32: The Second Half-Fried

[0177] 33 : Edge part

[0178] 34 : Butt

[0179] 40 : Lead tab

[0180] 50: Insulating gasket

[0181] C: Winding center hole

[0182] A : Central axis

Claims

1. An electrode assembly provided by being wound around the central axis of a central hole, with a separator interposed between electrodes of different polarities; A can housing that accommodates the electrode assembly and has an opening formed at at least one end; A can lid welded to the opening side end of the above-mentioned can housing; A welded tab portion formed by welding at least some of the plurality of foil tabs formed on the electrode; and It includes the above-mentioned welding tab portion and the lead tab welded to the above-mentioned can lid, and The above can lid is, A battery cell characterized by having a first half-fridge and a second half-fridge each divided and disposed on both sides of the lead tab.

2. In Paragraph 1, When viewed from the direction of the central axis of the above-mentioned winding center hole, The first half-dial, the lead tab, and the second half-dial are configured to form a circle, and A battery cell characterized in that the first half-and-second half-and-second half-and-second each have shapes that are symmetrical to one another.

3. In Paragraph 1, The first half-frid and the second half-frid are, respectively, A battery cell characterized by further comprising an edge portion formed on at least a part of the edge so as to be deformable in a direction parallel to the radial direction and to be fitted into the open end of the can housing.

4. In Paragraph 1, The first half-frid and the second half-frid are, respectively, A battery cell characterized by further comprising a butt portion formed on at least a part of the edge so as to be placed on the open end of the can housing.

5. In Paragraph 1, At least a portion of the above lead tab, A battery cell characterized by penetrating between the first half and the second half and being exposed to the outside of the battery cell.

6. In Paragraph 1, The above lead tab is, Having thickness in the direction toward the first half-fridge and the second half-fridge, It has a width in a direction parallel to the central axis of the above-mentioned winding center hole, A battery cell characterized by having a length in a direction perpendicular to the thickness direction and the width direction of the lead tab, respectively.

7. 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 lead tab is, It is joined by secondary welding to the above-mentioned welding tab, and The first half-frid and the second half-frid are, respectively, The above lead tab and the above can housing are joined by tertiary welding, and The above third welding is, A battery cell characterized by proceeding after the above-mentioned first welding.

8. In Paragraph 7, The above secondary welding is, A battery cell characterized by proceeding simultaneously with the above-mentioned first welding or the above-mentioned third welding.

9. 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.

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

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

12. In Paragraph 1, The above opening is, Each is formed at one end and the other end of the above-mentioned can housing, and The above welding tab portion is, It includes a first welding tab portion disposed on one side of the electrode assembly; and a second welding tab portion disposed on the other side of the electrode assembly. The above lead tab is, A first lead tab welded to the first welding tab portion; and a second lead tab welded to the second welding tab portion, comprising The above can lid is, A first can lid having a first-1 half-frid and a second-1 half-frid, each divided and disposed on both sides of the first lead tab; and A battery cell characterized by including a second can lid having a first-2 half-fridge and a second-2 half-fridge that are divided and disposed on each side of the second lead tab.

13. A battery pack characterized by including at least one battery cell according to any one of claims 1 to 12.

14. An automobile characterized by including at least one battery pack according to paragraph 13.

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