Battery cell, method for manufacturing the battery cell, battery pack and vehicle including the battery cell

Abstract

A battery cell according to the present invention comprises: an electrode assembly provided by being wound around a central hole with a separator interposed between electrodes of different polarities; and a current collector plate electrically connected to a plurality of foil tabs provided on the electrodes, wherein the foil tabs are formed into a foil tab assembly by being joined by primary welding with each other while a first welding line is formed, and the current collector plate is joined by secondary welding with the foil tab assembly after the primary welding, while a second welding line is formed that intersects with the first welding line.

Description

Technology Field

[0001] The present invention relates to a battery cell, a method for manufacturing a battery cell, a battery pack including a battery cell, and an automobile, and more specifically, to a battery cell having effectively reduced electrical resistance, a method for manufacturing a battery cell, a battery pack including a battery cell, and an automobile. Background Technology

[0002] 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.

[0003] 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.

[0004] 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.

[0005] 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 laminated 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 then electrically connected to provide high voltage and high current.

[0006] Recently, with the increasing demand for rapid charging and high power output, the development of low-resistance battery cells is actively underway. However, achieving low resistance has been difficult with conventional battery cells. Specifically, the electrode assembly and current collector plate of conventional battery cells were not joined to each other but were simply connected by placing the current collector plate onto formed foil tabs and welding them together; the foil tabs were welded only when the current collector plate was welded. In such conventional battery cells, because the foil tabs were folded, lifting occurred without sufficient pressure, resulting in low electrical conductivity. Furthermore, the contact area between the foil tabs and the current collector plate was limited due to the weld bead size and the design limitations of the current collector plate, making it difficult to realize low-resistance battery cells. The problem to be solved

[0007] The present invention was conceived in consideration of the technical background described above, and has one objective of providing a battery cell with effectively reduced electrical resistance, a method for manufacturing a battery cell, a battery pack including a battery cell, and an automobile.

[0008] 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. means of solving the problem

[0009] A battery cell according to the present invention comprises: an electrode assembly provided by being wound around a central hole with a separator interposed between electrodes of different polarities; and a current collector plate electrically connected to a plurality of foil tabs provided on the electrodes, wherein the foil tabs are formed into a foil tab assembly by being joined by primary welding with each other while a first welding line is formed, and the current collector plate is joined by secondary welding with the foil tab assembly after the primary welding, while a second welding line is formed that intersects with the first welding line.

[0010] The first welding line above can be formed to connect all the foil tabs disposed at any one end of the electrode assembly.

[0011] The first welding line above can be formed in a spiral or concentric shape.

[0012] The above electrode includes a first electrode having a first polarity, and the current collector may include a first current collector electrically connected to the foil tab provided on the first electrode.

[0013] The above electrode includes a second electrode having a second polarity, and the current collector may include a second current collector electrically connected to the foil tab provided on the second electrode.

[0014] The above second welding line may be located on the radius of the electrode assembly.

[0015] The above foil tabs are formed along the forming progress line, and the above first welding line can be formed parallel to the forming progress line.

[0016] The above first welding may be performed during the forming process of the above foil tab.

[0017] A battery cell manufacturing method according to the present invention is a battery cell manufacturing method comprising an electrode assembly provided by winding around a winding center hole with a separator interposed between electrodes of different polarities, and a current collector plate electrically connected to a plurality of foil tabs provided on the electrodes, the method comprising: (a) a step in which the foil tabs are formed along a forming progress line; (b) a step in which the foil tabs are first welded together to form a foil tab assembly while a first welding line is formed; and (c) a step in which the current collector plate is secondarily welded together with the foil tab assembly while a second welding line is formed that intersects and connects with the first welding line after the first welding.

[0018] The above step (b) may be performed during the progress of the above step (a).

[0019] A battery pack according to the present invention comprises at least one battery cell according to the present invention.

[0020] The automobile according to the present invention includes at least one battery pack according to the present invention. Effects of the invention

[0021] According to the present invention, a battery cell with effectively reduced electrical resistance, a method for manufacturing a battery cell, a battery pack including a battery cell, and an automobile can be provided.

[0022] In addition, according to one aspect of the present invention, a battery cell with improved welding quality between an electrode assembly and a current collector plate, a method for manufacturing a battery cell, a battery pack including a battery cell, and an automobile can be provided.

[0023] In addition, according to one aspect of the present invention, a battery cell with increased welding strength between an electrode assembly and a current collector plate, a method for manufacturing a battery cell, a battery pack including a battery cell, and an automobile can be provided.

[0024] In addition, according to one aspect of the present invention, a battery cell with increased rigidity, a method for manufacturing a battery cell, a battery pack including a battery cell, and an automobile can be provided.

[0025] In addition, according to one aspect of the present invention, a battery cell with improved productivity, a method for manufacturing a battery cell, a battery pack including a battery cell, and an automobile can be provided.

[0026] 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. Brief explanation of the drawing

[0027] 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. 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 internal appearance of a battery cell 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 plan view showing a current collector plate coupled to an electrode assembly in a battery cell according to one embodiment of the present invention. FIG. 5 is a plan view showing an example of an electrode assembly according to an embodiment of the present invention. FIG. 6 is a plan view showing another example of an electrode assembly according to one embodiment of the present invention. FIG. 7 is a plan view showing a first current collector plate according to one embodiment of the present invention. FIG. 8 is a plan view showing a second current collector plate according to one embodiment of the present invention. FIG. 9 is a plan view showing an example of an electrode assembly included in a battery cell according to another embodiment of the present invention. FIG. 10 is a flowchart illustrating a method for manufacturing a battery cell according to one embodiment of the present invention. FIG. 11 is a timeline of a battery cell manufacturing method according to another embodiment of the present invention. FIG. 12 is a drawing showing a battery pack according to one embodiment of the present invention. FIG. 13 is a drawing showing an automobile according to one embodiment of the present invention. Specific details for implementing the invention

[0028] 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.

[0029] 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.

[0030] 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).

[0032] 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 internal appearance of a battery cell 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 plan view showing a current collector plate coupled to an electrode assembly in a battery cell according to one embodiment of the present invention.

[0033] 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) and a current collector plate (CC).

[0034] 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.

[0035] 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 a winding center hole (C). Any jelly-roll structure known in the art may be applied to the present invention without limitation.

[0036] 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).

[0037] The unoccupied 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 unoccupied portion (112) may be formed on one long side of the electrode (11). For example, as shown in FIG. 3, the unoccupied portion (112) may be formed on the long side in the Z-axis direction. The unoccupied portion (112) of the first electrode (11a) may be formed on the long side in the +Z direction as in FIG. 3. The unoccupied portion (112) of the second electrode (11b) may be formed on the long side in the -Z direction, unlike FIG. 3.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] The current collector plate (CC) can be electrically connected to the electrode assembly (10). The current collector plate (CC) can be electrically connected to a plurality of foil tabs (113) provided on the electrode (11) of the electrode assembly (10). The current collector plate (CC) can be positioned on the +Z direction side (e.g., the upper side in FIG. 2) and / or the -Z direction side (e.g., the lower side in FIG. 2) of the electrode assembly (10).

[0043] Foil tabs (113) can be joined by primary welding. Specifically, foil tabs (113) placed at at least one end of the electrode assembly (10) can be joined by primary welding. For example, foil tabs (113) of the first electrode (11a) placed at the +Z direction side end of the electrode assembly (10) can be joined by primary welding to each other. For example, foil tabs (113) of the second electrode (11b) placed at the -Z direction side end of the electrode assembly (10) can be joined by primary welding to each other.

[0044] In the above, the term "first welding" can be understood as being performed prior to the "second welding" described later, in terms of process sequence or chronological order.

[0045] The foil tabs (113) can be joined by primary welding to form a foil tab assembly (FA). The foil tab assembly (FA) can be formed, for example, at the +Z direction side end and / or the -Z direction side end of the electrode assembly (10).

[0046] A first welding line (WL1) may be formed during the first welding process of the foil tabs (113). The first welding line (WL1) can be understood as a weld bead formed on the foil tabs (113) by the first welding.

[0047] The current collector plate (CC) can be joined by secondary welding with the foil tab assembly (FA). For example, the current collector plate (CC) can be joined by secondary welding with the foil tab assembly (FA) formed at the +Z direction side end and / or the -Z direction side end of the electrode assembly (10). The current collector plate (CC) and the foil tab assembly (FA) can be joined by secondary welding while facing each other.

[0048] In the above, the term "secondary welding" can be understood as being performed after the aforementioned primary welding in terms of process sequence or chronological order.

[0049] A second welding line (WL2) may be formed during the second welding process of the collector plate (CC) and the foil tab assembly (FA). The second welding line (WL2) can be understood as a weld bead formed between the collector plate (CC) and the foil tab assembly (FA) by the second welding.

[0050] The second welding line (WL2) may be formed to intersect and connect with the first welding line (WL1). For example, the first welding line (WL1) may extend in a direction approximately similar to the circumferential direction, and the second welding line (WL2) may intersect with this first welding line (WL1) and be formed to connect with the first welding line (WL1).

[0051] In conventional battery cells, since the foil tabs are welded only when the current collector plate and the foil tabs are welded together, only the weld bead corresponding to the second welding line is formed, and the weld bead corresponding to the first welding line cannot be formed. Consequently, not only could the electrical conductivity of the battery cell be low due to phenomena such as lifting of the foil tabs, but the contact area between the foil tabs and the current collector plate was also limited due to the limitations of the weld beads between the foil tabs and the current collector plate and the limitations of the current collector plate design, making it difficult to realize a low-resistance battery cell.

[0052] However, in a battery cell (1) according to one embodiment of the present invention, the foil tabs (113) can be pre-welded by a primary welding, so that the lifting phenomenon of the foil tabs (113) can be prevented, and an electron movement path can be secured in the foil tabs (113), so that the electrical conductivity of the battery cell (1) can be formed to be high.

[0053] In addition, after the foil tab assembly (FA) is formed by the first welding, the foil tab assembly (FA) and the current collector plate (CC) are joined by the second welding. This ensures that the contact area between the foil tab assembly (FA) and the current collector plate (CC) is securely secured regardless of the design of the current collector plate (CC), thereby ensuring an electron pathway between the foil tab assembly (FA) and the current collector plate (CC), and as a result, the electrical resistance inside the battery cell (1) can be effectively reduced.

[0054] In addition, since the second welding is performed while the lifting phenomenon of the foil tab (113) is prevented due to the first welding, the welding quality between the foil tab (113) and the collector plate (CC) can be improved.

[0055] In addition, the first welding line (WL1) and the second welding line (WL2) are formed to intersect each other, thereby ensuring electron movement paths of various directions and increased cross-sectional areas in the foil tabs (113) and the current collector plate (CC).

[0056] In addition, at the foil tabs (113) and the current collector plate (CC), the welding bead can be formed in a roughly grid or net shape along the first welding line (WL1) and the second welding line (WL2), so that the welding strength between the electrode assembly (10) and the current collector plate (CC) can be increased, and as the welding strength increases in this way, the rigidity of the battery cell (1) can also be increased.

[0058] The first welding line (WL1) can be formed to connect all foil tabs (113) placed at any one end of the electrode assembly (10) to each other.

[0059] Specifically, at one or more of the +Z direction side end and the -Z direction side end of the electrode assembly (10), the first welding line (WL1) can pass through all foil tabs (113) of the corresponding end so as to be able to join all foil tabs (113) of the corresponding end together.

[0060] When the first welding line (WL1) is formed in this manner, all foil tabs (113) can be welded together at any end of the electrode assembly (10), and this first welding line (WL1) can be connected by crossing with the second welding line (WL2). As a result, all foil tabs (113) at any end of the electrode assembly (10) can be electrically connected to the current collector plate (CC), thereby allowing the electrical resistance of the battery cell (1) to be reduced more effectively.

[0062] FIG. 5 is a plan view showing one example of an electrode assembly according to one embodiment of the present invention, and FIG. 6 is a plan view showing another example of an electrode assembly according to one embodiment of the present invention.

[0063] Referring to FIGS. 4 to 6, the first welding line (WL1) can be formed in a spiral or concentric shape. FIGS. 5 and 6 only show the +Z direction end of the electrode assembly (10) for convenience of explanation, but the following description of the first welding line (WL1) can be applied equally to the -Z direction end of the electrode assembly (10).

[0064] In particular, referring to FIG. 5, the first welding line (WL1) can be formed in a spiral shape. The first welding line (WL1) can be formed to extend spirally from a foil tab (113) located on the side of the winding center hole (C) to a foil tab (113) located on the outer side of the electrode assembly (10). The first welding line (WL1) can be formed to extend spirally from the foil tab (113) closest to the winding center hole (C) to the foil tab (113) closest to the outer side of the electrode assembly (10) (see FIG. 3). The first welding line (WL1) can be formed spirally so that all foil tabs (113) placed at any one end of the electrode assembly (10) can be joined together to form a foil tab assembly (FA).

[0065] When the first welding line (WL1) is formed in a spiral shape, at any one end of the electrode assembly (10), the first welding line (WL1) may be composed of a single one, as shown in FIG. 5. Alternatively, unlike as shown in FIG. 5, the first welding line (WL1) may be composed of multiple ones.

[0066] In particular, referring to FIG. 6, the first welding line (WL1) can be formed as a concentric circle. The first welding line (WL1) can be composed of multiple lines. The multiple first welding lines (WL1) can each be formed as a concentric circle structure by sharing the center of the winding center hole (C) but having different radii. Among the multiple first welding lines (WL1), the first welding line (WL1) closest to the winding center hole (C) can pass through the foil tab (113) closest to the winding center hole (C), and the first welding line (WL1) closest to the outer circumference can be formed to pass through the foil tab (113) closest to the outer circumference (see FIG. 3). The first welding line (WL1) can be formed in a concentric shape so as to combine all foil tabs (113) placed at one end of the electrode assembly (10) to form a foil tab assembly (FA).

[0067] When the first welding line (WL1) is formed in a spiral or concentric shape as described above, all foil tabs (113) placed at any one end of the electrode assembly (10) can be efficiently and reliably connected to each other. Furthermore, when the first welding line (WL1) is provided in this form, there is an advantage that the first welding line (WL1) and the second welding line (WL2) can be easily cross-connected to each other.

[0069] FIG. 7 is a plan view showing a first current collector plate according to one embodiment of the present invention, and FIG. 8 is a plan view showing a second current collector plate according to one embodiment of the present invention.

[0070] Referring to FIGS. 4 and 7, the current collector plate (CC) may include a first current collector plate (20). The first current collector plate (20) may be electrically connected to a foil tab (113) provided on the first electrode (11a). The first current collector plate (20) may be electrically connected to a foil tab assembly (FA) formed by combining foil tabs (113) provided on the first electrode (11a).

[0071] The first current collector plate (20) may be placed on the +Z direction side (e.g., the upper side) of the electrode assembly (10). The first current collector plate (20) may have a first polarity. The first current collector plate (20) may be a positive current collector plate (CC).

[0072] The first current collector plate (20) may have a first electrode coupling part (21) that can be electrically connected to a foil tab (113) provided on the first electrode (11a). The first electrode coupling part (21) may be provided in a plurality of divided portions, and the plurality of first electrode coupling parts (21) may be provided symmetrically with respect to the center (O1) of the first current collector plate (20).

[0073] At least one second welding line (WL2) may be formed in each first electrode coupling portion (21). In the first electrode coupling portion (21), at least one second welding line (WL2) may be formed approximately radially.

[0074] Referring to FIGS. 4 and 8, the current collector plate (CC) may include a second current collector plate (30). The second current collector plate (30) may be electrically connected to a foil tab (113) provided on the second electrode (11b). The second current collector plate (30) may be electrically connected to a foil tab assembly (FA) formed by combining the foil tabs (113) provided on the second electrode (11b).

[0075] The second current collector plate (30) may be placed on the -Z direction side (e.g., the lower side) of the electrode assembly (10). The second current collector plate (30) may have a second polarity. The second current collector plate (30) may be a negative current collector plate (CC).

[0076] The second current collector plate (30) may have a second electrode coupling part (31) that can be electrically connected to a foil tab (113) provided on the second electrode (11b). The second electrode coupling part (31) may be provided in a plurality of divided portions, and the plurality of second electrode coupling parts (31) may be provided symmetrically with respect to the center (O2) of the second current collector plate (30).

[0077] At least one second welding line (WL2) may be formed in each second electrode coupling portion (31). In the second electrode coupling portion (31), at least one second welding line (WL2) may be formed approximately radially.

[0078] As described above, the battery cell (1) according to one embodiment of the present invention can be applied in cases where the current collector (CC) is a positive current collector (CC) and / or a negative current collector (CC).

[0080] Referring to FIGS. 4, 7 and 8, the second welding line (WL2) may be located on the radius of the electrode assembly (10).

[0081] Specifically, when viewed from the longitudinal direction or Z-axis direction of the winding center hole (C), the second welding line (WL2) can be formed by extending toward the center of the winding center hole (C) in a direction parallel to the radial direction of the electrode assembly (10).

[0082] When the second welding line (WL2) is formed as described above, the second welding line (WL2) can connect each foil tab (113) corresponding to a plurality of winding turns over the shortest distance, thereby allowing the electrical resistance inside the battery cell (1) to be reduced more effectively. In addition, when the second welding line (WL2) is provided in this form, there is an advantage that the second welding line (WL2) and the first welding line (WL1) can be easily cross-connected to each other.

[0083] The second welding line (WL2) may be formed by being located on the radius of the electrode assembly (10) and extending to the winding center hole (C). When the second welding line (WL2) is formed in this way, the current collector plate (CC) can be welded to the foil tab (113) corresponding to the winding turn number closest to the winding center hole (C), thereby minimizing the electrical resistance inside the battery cell (1).

[0085] FIG. 9 is a plan view showing an example of an electrode assembly included in a battery cell according to another embodiment of the present invention.

[0086] Hereinafter, with reference to FIG. 9, a battery cell (1) according to another embodiment of the present invention will be described in detail.

[0087] In a battery cell (1) according to another embodiment of the present invention, foil tabs (113) may be formed along a forming progress line (FL). As previously described, the electrode assembly (10) may be wound around a center hole (C) with a laminate having a separator (12) interposed between electrodes (11) of different polarities (first electrode (11a) and second electrode (11b)), and in this wound state, the foil tabs (113) of the laminate may be formed inwardly (for example, toward the center hole (C)).

[0088] The forming progress line (FL) can be understood as an imaginary line that corresponds to the direction in which the forming of the foil tab (113) proceeds. The forming progress line (FL) may be formed spirally, starting from the outer side as shown in FIG. 9, for example, and following the winding direction or circumferential direction of the electrode (11) and separator (12) laminate. The forming progress line (FL) may also be formed spirally, starting from the winding center hole (C) side, for example, unlike FIG. 9. However, the shape of the forming progress line (FL) is not limited to these.

[0089] The first welding line (WL1) can be formed parallel to the forming progress line (FL). For example, if the forming progress line (FL) is formed in a spiral shape, the first welding line (WL1) can also be formed in a spiral shape parallel to the forming progress line (FL) (see FIG. 5).

[0090] Multiple foil tabs (113) can be sequentially stacked along the forming line (FL). Accordingly, as described above, when the first welding line (WL1) is formed parallel to the forming line (FL), the first welding line (WL1) can be formed to pass through all the sequentially stacked foil tabs (113), so that as many foil tabs (113) as possible can be efficiently welded and joined.

[0092] FIG. 10 is a flowchart illustrating a method for manufacturing a battery cell according to one embodiment of the present invention.

[0093] Hereinafter, with reference to FIG. 10, a method for manufacturing a battery cell (1) according to an embodiment of the present invention will be described in detail. A method for manufacturing a battery cell (1) according to an embodiment of the present invention may include steps (a), (b), and (c).

[0094] Step (a) may be a step in which foil tabs (113) are formed along a forming line (FL). Step (a) may be performed after a laminate in which a separator (12) is interposed between electrodes (11) is wound. In Step (a), the foil tabs (113) may be maintained in a folded and laminated state, and the lifting phenomenon of the foil tabs (113) described above may occur at this step.

[0095] (b) Step (b) may be a step in which foil tabs (113) are joined to each other by primary welding as a first welding line (WL1) is formed to form a foil tab assembly (FA). The first welding line (WL1) may be formed in a spiral or concentric shape. The first welding line (WL1) may be formed to join all foil tabs (113) placed at any one end of the electrode assembly (10). The first welding line (WL1) may be formed parallel to the forming progress line (FL).

[0096] (c) Step may be a step in which, after the first welding of the current collector plate (CC), a second welding line (WL2) is formed that intersects with the first welding line (WL1) and is secondarily welded to the foil tab assembly (FA). The second welding line (WL2) may be located on the radius of the electrode assembly (10).

[0097] Step (b) is completed before Step (c), and Step (c) can begin after Step (b) is completed.

[0099] FIG. 11 is a timeline of a battery cell manufacturing method according to another embodiment of the present invention.

[0100] Hereinafter, with reference to FIGS. 9 to 11, a battery cell (1) and a method for manufacturing the battery cell (1) according to another embodiment of the present invention will be described in detail.

[0101] In a battery cell (1) according to another embodiment of the present invention, a first welding step may be performed during the forming process of the foil tab (113). Specifically, the first welding step may be started before all foil tabs (113) placed at any end of the electrode assembly (10) are formed. At this time, the first welding line (WL1) may be formed parallel to the forming progress line (FL). For example, as shown in the example in FIG. 9, the first welding line (WL1) may be formed along the circumferential direction parallel to the forming progress line (FL). The foil tabs (113) are formed along the forming progress line (FL), and the first welding step may be performed immediately after the foil tabs (113) are formed.

[0102] A method for manufacturing a battery cell (1) according to another embodiment of the present invention, as illustrated in FIG. 11, wherein step (b) may be performed during the progress of step (a) in the method for manufacturing a battery cell (1) according to one embodiment of the present invention described above (see FIG. 10).

[0103] According to another embodiment of the present invention, the battery cell (1) and the method for manufacturing the battery cell (1) can be carried out together for at least a portion of time with the forming process of the foil tabs (113), thereby saving time required for manufacturing the battery cell (1) and improving the productivity of the battery cell (1).

[0105] Meanwhile, referring again to FIGS. 1 and FIGS. 2, the battery cell (1) according to the present invention may further include a can housing (40), a rivet terminal (50), an insulating gasket (60), an insulator (70), and a cap plate (80).

[0106] The can housing (40) may be configured to accommodate an electrode assembly (10). The can housing (40) may have a receiving space in which the electrode assembly (10) is accommodated. The can housing (40) may be provided, for example, in a hollow cylindrical shape to accommodate the electrode assembly (10). A closed portion (41) may be formed on one side of the can housing (40) (e.g., the +Z direction side), and an open portion (42) may be formed on the other side (e.g., the -Z direction side). An indented beading portion (43) may be formed on the side adjacent to the open portion (42) of the can housing (40). The beading portion (43) may secure the electrode assembly (10). A crimping portion (44) that extends and is bent toward the open portion (42) may be formed at the end of the can housing (40) on the side of the open portion (42). The crimping part (44) can seal the cap plate (80) described later.

[0107] The rivet terminal (50) may be a terminal electrically connected to the electrode assembly (10). The rivet terminal (50) may be positioned through the closure (41). At least a portion of the rivet terminal (50) may protrude and be exposed to the outside of the closure (41). The rivet terminal (50) may be provided in the form of a rivet. The rivet terminal (50) may be electrically connected to the first current collector plate (20). The rivet terminal (50) may be electrically connected to the first electrode (11a) through the first current collector plate (20), may have a first polarity, and may be configured as a positive terminal.

[0108] An insulating gasket (60) may be placed between the rivet terminal (50) and the closure (41). The insulating gasket (60) may be configured to insulate the rivet terminal (50) and the closure (41) from each other.

[0109] An insulator (70) may be placed between the electrode assembly (10) and the can housing (40). An insulator (70) may be placed between the upper portion of the electrode assembly (10) and the lower portion of the closure (41). The insulator (70) may be configured to insulate the electrode assembly (10) and the can housing (40) from each other.

[0110] A cap plate (80) may be placed in the opening (42) of the can housing (40). The cap plate (80) may cover the opening (42). The cap plate may be provided with a notching process so that it can be ruptured when the internal pressure of the battery cell (1) increases. The cap plate (80) may be sealed by a crimping portion (44). A separate insulating gasket may be placed between the cap plate (80) and the crimping portion (44).

[0112] FIG. 12 is a drawing showing a battery pack according to one embodiment of the present invention.

[0113] 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).

[0114] 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.

[0116] FIG. 13 is a drawing showing an automobile according to one embodiment of the present invention.

[0117] 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.

[0118] 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).

[0120] 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.

[0121] 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. Explanation of the symbols

[0122] 1 : Battery cell 2 : Pack Case 3 : Battery pack 4 : Cars 10 : Electrode assembly 11: Electrode 11a: First electrode 11b : Second electrode 111 : Maintenance part 112 : Mujibu 113 : Foil Tab 114 : Notching part 115 : Insulating coating part 12 : Separator 20 : 1st tribunal 21: First electrode coupling part 30 : 2nd edition 31 : Second electrode coupling part 40 : Can housing 41 : Closure 42 : Open part 43 : Bidding Section 44 : Crimping part 50 : Rivet terminal 60 : Insulating gasket 70: Insulator 80 : Cap plate C: Winding center hole CC : Collection board FA: Foil tab assembly WL1: 1st welding line WL2: 2nd welding line FL: Forming progress line

Claims

Claim 1 A battery cell comprising: an electrode assembly provided by being wound around a central hole with a separator interposed between electrodes of different polarities; and a current collector plate electrically connected to a plurality of foil tabs provided on the electrodes, wherein the foil tabs are formed into a foil tab assembly by being joined by primary welding with each other while a first welding line is formed, and the current collector plate is joined to the foil tab assembly by secondary welding after the primary welding while a second welding line is formed that intersects with the first welding line. Claim 2 A battery cell according to claim 1, wherein the first welding line is formed to connect all the foil tabs disposed at any one end of the electrode assembly. Claim 3 A battery cell according to paragraph 2, wherein the first welding line is formed in a spiral or concentric shape. Claim 4 A battery cell according to claim 1, wherein the electrode comprises a first electrode having a first polarity, and the current collector comprises a first current collector electrically connected to the foil tab provided on the first electrode. Claim 5 A battery cell according to claim 1, wherein the electrode comprises a second electrode having a second polarity, and the current collector comprises a second current collector electrically connected to the foil tab provided on the second electrode. Claim 6 A battery cell according to claim 1, wherein the second welding line is located on the radius of the electrode assembly. Claim 7 A battery cell according to claim 1, characterized in that the foil tabs are formed along a forming progress line, and the first welding line is formed parallel to the forming progress line. Claim 8 A battery cell according to claim 1, characterized in that the primary welding is performed during the forming process of the foil tab. Claim 9 A battery cell manufacturing method comprising an electrode assembly provided by being wound around a central hole with a separator interposed between electrodes of different polarities, and a current collector plate electrically connected to a plurality of foil tabs provided on the electrodes, the method comprising: (a) a step in which the foil tabs are formed along a forming progress line; (b) a step in which the foil tabs are first welded together to form a foil tab assembly while a first welding line is formed; and (c) a step in which the current collector plate is secondarily welded together with the foil tab assembly while a second welding line is formed that intersects and connects with the first welding line after the first welding. Claim 10 A battery cell manufacturing method according to claim 9, wherein the above step (b) is performed during the progress of the above step (a). Claim 11 A battery pack characterized by including at least one battery cell according to any one of claims 1 to 8. Claim 12 An automobile characterized by including at least one battery pack according to claim 11.

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