Battery cell, battery pack, and vehicle including same

Abstract

A battery cell according to the present invention comprises: an electrode assembly wound about a winding center hole in a state in which a separator is interposed between a first electrode and a second electrode; and a first current-collecting plate that is electrically connected to a plurality of first foil tabs provided on the first electrode and is provided with at least one slit configured to form a fusing induction part. The first foil tabs are welded to each other along at least one foil tab welding line extending to the inside of a slit-corresponding region that corresponds to the slit, and the first current-collecting plate is separately welded and joined to the first foil tabs that are welded to each other.

Description

Battery cells, battery packs, and automobiles including the same

[0001] The present invention relates to a battery cell, a battery pack, and a vehicle including the same, and more specifically, to a battery cell, a battery pack, and a vehicle including the same in which electrical resistance is effectively reduced.

[0002] This application is a priority claim application for Korean Patent Application No. 10-2024-0184706 filed on December 12, 2024, 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] 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 a pouch made of aluminum laminate sheets, 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.

[0007] Recently, with the increasing demand for rapid charging and high power output, the development of low-resistance battery cells is actively underway. However, in conventional battery cells, the electrode assembly and the current collector plate are not joined to each other but are instead joined by welding the current collector plate to foil tabs that are simply formed. In such conventional battery cells, the length of the welding beads of the foil tabs is inevitably limited because the foil tabs are not joined to each other in the area corresponding to the slit. To reduce the electrical resistance of a battery cell, it is essential to reduce the ohmic resistance, which accounts for more than 50% of the total resistance. However, in conventional battery cells, the welding bead length of the foil tabs is limited as described above, which limits the reduction of the electrical resistance of the battery cell; consequently, it has been difficult to implement low-resistance battery cells.

[0008] In addition, if an event occurs and a high current exceeding the allowable current flows through the battery cell, the temperature of the battery cell rises abnormally, which may lead to disassembly and explosion of the battery cell. To prevent this, the battery cell may have a so-called fusing function that disconnects the circuit to cut off the high current when a high current exceeding the allowable current flows. Conventional battery cells could be configured to perform this fusing function by having a part such as a slit provided in the current collector plate.

[0009] The present invention was conceived in consideration of the technical background described above, and has one objective of providing a battery cell, a battery pack, and an automobile including the same, in which electrical resistance is effectively reduced.

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

[0011] A battery cell according to the present invention comprises: an electrode assembly provided by being wound around a central winding hole with a separator interposed between a first electrode and a second electrode; and a first current collector plate electrically connected to a plurality of first foil tabs provided on the first electrode and having at least one slit formed through it, wherein the first foil tabs are welded together along at least one foil tab welding line formed extending to the inner side of a slit-corresponding area corresponding to at least the slit, and the first current collector plate is separately welded to the first foil tabs in a welded state.

[0012] At least one of the above slits may be configured to form a fusing guide.

[0013] A plurality of the first foil tabs are welded together in a first welding manner along the foil tab welding line, and the first collector plate can be joined by being welded secondarily to the first foil tabs that were welded in the first welding manner after the first welding.

[0014] The length of the weld bead formed by the first welding above may be formed to be longer than the length of the weld bead formed by the second welding above.

[0015] The above foil tab welding line may be formed to extend through the above slit corresponding area.

[0016] The above foil tab welding line can be formed by extending to the above winding center hole.

[0017] The above foil tab welding line includes a first foil tab welding line located on the radius of the electrode assembly, and the first foil tab welding line may be formed to have the longest length among the foil tab welding lines.

[0018] The above foil tab welding line may further include a second foil tab welding line located on at least one side of the left and right of the first foil tab welding line.

[0019] The above fusing guide may be formed so that its width narrows as it moves away from the center of the first collector plate.

[0020] The above slit may be provided in a convex shape toward the center of the first collector plate.

[0021] The above slit may be provided in an angled shape toward the center of the first collector plate.

[0022] The above slit may be provided as a single piece.

[0023] The first current collector plate may further comprise a rotation alignment guide portion configured to guide rotational alignment between the first current collector plate and the electrode assembly.

[0024] A battery pack according to the present invention comprises at least one battery cell according to the present invention.

[0025] The automobile according to the present invention includes at least one battery pack according to the present invention.

[0026] According to the present invention, a battery cell, a battery pack, and an automobile including the same can be provided, in which electrical resistance is effectively reduced.

[0027] 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, which can stably secure fusing performance.

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

[0029] In addition, according to one aspect of the present invention, a battery cell, a battery pack, and an automobile including the same can be provided, wherein a first current collector plate of various types can be applied.

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

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

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

[0033] FIG. 2 is a side cross-sectional view showing the internal appearance of a battery cell according to one embodiment of the present invention.

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

[0035] FIG. 4 is a plan view showing a first current collector plate according to one embodiment of the present invention.

[0036] FIG. 5 is a plan view showing an electrode assembly according to one embodiment of the present invention.

[0037] FIG. 6 is a plan view showing a first current collector plate coupled to an electrode assembly in a battery according to one embodiment of the present invention.

[0038] FIG. 7 is a side cross-sectional view showing the first foil tabs welded first in the BB' section of FIG. 6.

[0039] FIG. 8 is a side cross-sectional view showing the state in which the first current collector plate is secondarily welded and joined to the first foil tabs that were first welded in the BB' cross-section of FIG. 6.

[0040] FIG. 9 is a side cross-sectional view showing the state in which a first current collector plate is welded and joined to the first foil tabs in a conventional battery cell.

[0041] FIG. 10 is a plan view showing a first current collector plate according to another embodiment of the present invention.

[0042] FIG. 11 is a plan view showing a first current collector plate according to another embodiment of the present invention.

[0043] FIG. 12 is a plan view showing a first current collector plate according to a modified example of an embodiment of the present invention.

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

[0045] FIG. 14 is a drawing showing an automobile according to one embodiment of the present invention.

[0046] 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.

[0047] 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.

[0048] 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).

[0049]

[0050] 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, and FIG. 3 is a side view showing an electrode unfolded according to one embodiment of the present invention.

[0051] Referring to FIGS. 1 to 3, a battery cell (1) according to one embodiment of the present invention may include an electrode assembly (10) and a first current collector plate (20).

[0052] 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.

[0053] 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.

[0054] 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).

[0055] 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.

[0056] 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.

[0057] 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 (e.g., toward the +X direction of FIG. 3). The plurality of foil tabs (113) may be formed by at least one notching portion (114) formed by notching processing. However, in FIG. 3, the plurality of foil tabs (113) are shown in a form in which their length increases as they go from the winding center hole (C) side toward the outer circumference side, but this is merely an example, and the length, shape, number, and arrangement pattern of the foil tabs (113) are not limited thereto and can be implemented in various variations that conform to the technical concept.

[0058] The foil tab (113) of the first electrode (11a) among the foil tabs (113) may be referred to as the first foil tab (113a) (see FIG. 5 and FIG. 6), and the foil tab (113) of the second electrode (11b) may be referred to as the second foil tab (not shown). The first foil tabs (113a) may be placed on the top of the electrode assembly.

[0059] 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.

[0060] 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.

[0061] The first current collector plate (20) can be electrically connected to the first electrode (11a) of the electrode assembly (10). The first current collector plate (20) can be placed on the upper side (+Z direction side) of the electrode assembly (10). The first current collector plate may be an anode current collector plate.

[0062]

[0063] FIG. 4 is a plan view showing a first current collector plate according to an embodiment of the present invention, FIG. 5 is a plan view showing an electrode assembly according to an embodiment of the present invention, FIG. 6 is a plan view showing the first current collector plate coupled to the electrode assembly in a battery according to an embodiment of the present invention, FIG. 7 is a side cross-sectional view showing the first foil tabs welded first in the BB' section of FIG. 6, FIG. 8 is a side cross-sectional view showing the state in which the first current collector plate is welded secondarily to the first foil tabs welded first in the BB' section of FIG. 6, and FIG. 9 is a side cross-sectional view showing the state in which the first current collector plate is welded to the first foil tabs in a conventional battery cell.

[0064] Hereinafter, with reference to FIGS. 4 to 6, a first current collector plate (20) according to an embodiment of the present invention will be described in detail.

[0065] The first current collector plate (20) can be electrically connected to the first foil tab (113a). By doing so, the first current collector plate (20) can be electrically connected to the first electrode (11a).

[0066] The first current collector plate (20) may have at least one slit (21). The slit (21) may be formed by penetrating the first current collector plate (20). At least a portion of the electrode assembly (10) may be exposed in the vertical direction through the slit (21).

[0067] The slit (21) may have the shape of a hole that extends along a predetermined curve or straight line. It may have a length along the direction of extension of the slit (21) and a width along a direction perpendicular to the direction of extension, and the length may be greater than the width. Meanwhile, the width does not need to be very short compared to the length, and any hole shape in which the width is shorter than the length may be included in the slit (21).

[0068] Referring to FIGS. 5 and 6, a plurality of first foil tabs (113a) may be welded together along at least one foil tab welding line (WL). The term foil tab welding line (WL) should be understood as a welding line where welding is performed only between the first foil tabs (113a). That is, the foil tab welding line (WL) should not be understood as a welding line where welding is performed between the first foil tabs (113a) and the first collector plate.

[0069] For reference, FIG. 5 shows, for example, a plurality of first foil tabs (113a) welded together along a foil tab welding line (WL) at the top of an electrode assembly (10). Also, the foil tab welding line (WL) shown in FIG. 6 indicates a welding line formed at the top of the electrode assembly (10) positioned below the first current collector plate (20), and does not indicate a welding line between the first current collector plate (20) and the electrode assembly (10).

[0070] The foil tab welding line (WL) may extend at least to the inner side of the slit corresponding area (A). Here, "inner side" may mean the radially inner side. Here, the slit corresponding area (A) may be understood as the area corresponding to the slit (21) at the top of the electrode assembly (10) where the first foil tabs (113a) are arranged. That is, the slit corresponding area (A) may be defined as the area where the top of the electrode assembly (10) and the slit (21) overlap each other when viewed from the vertical direction or the Z-axis direction. The foil tab welding line (WL) may extend at least radially inward from the radially outer edge of this slit corresponding area (A).

[0071] The foil tab welding line (Wl) may be extended radially inward beyond the radially outer edge of the slit corresponding area (A), or extended further inward beyond the radially inner edge of the slit corresponding area (A), or extended to a length that does not exceed the radially inner edge of the slit corresponding area (A).

[0072] Additionally, the first collector plate (20) can be joined by being separately welded to the first foil tabs (113a) that are welded to each other. That is, the welding between the first foil tabs (113a) and the welding between the first collector plate (20) and the first foil tabs (113a) can be performed as separate processes.

[0073] Hereinafter, the length of the weld bead between the first foil tabs (113a) is defined as L1, and the length of the weld bead between the first collector plate (20) and the first foil tabs (113a) is defined as L2.

[0074] For reference, in FIGS. 8 and 9, L2 and L1 are depicted as overlapping each other, but this depiction is for convenience of explanation only, and in reality, L2 and L1 may overlap each other or may not overlap each other.

[0075] Referring to FIG. 9, in a conventional battery cell (1'), a plurality of first foil tabs (113a') are simply formed or folded without being joined to each other, and a first current collector plate (20') is placed thereon, and the plurality of first foil tabs (113a) and the first current collector plate (20') are joined by welding together simultaneously. That is, the plurality of first foil tabs (113a') are joined to each other in a manner where they are welded together simultaneously when the first current collector plate (20') is welded.

[0076] Accordingly, the length (L1) of the weld bead of the first foil tabs (113a') had to be formed substantially identically to the length (L2) of the weld bead between the first collector plate (20') and the first foil tabs (113a'). Furthermore, when welding the first collector plate (20') and the first foil tabs (113a'), due to process reasons or welding quality reasons, the weld could not be formed beyond the slit (21') and the slit corresponding area (A') radially inward. In other words, the length (L2) of the weld bead could not be formed to a length extending beyond the slit (21') radially inward. Specifically, for example, in order to weld the first collector plate (20') and the first foil tab (113a') together, the welding heat must penetrate the first collector plate (20'), which is relatively thicker than the first foil tab (113a'), and reach the first foil tab (113a'), so the strength of the welding may need to be relatively strong. Accordingly, if a welding of relatively strong strength is directly exposed to the first foil tab (113a') through the slit (21'), there is a risk that the first foil tab (113a') or other parts of the electrode assembly, such as a separator, may be damaged by excessive welding heat.

[0077] Accordingly, the length (L2) of the weld bead between the first collector plate (20') and the first foil tabs (113a') was limited to a length that does not exceed the slit (21') and the slit-corresponding area (A'). As a result, the length (L1') of the weld bead of the first foil tabs (113a') was also limited to a length that does not exceed the slit (21') and the slit-corresponding area (A'), thereby limiting the reduction in the electrical resistance of the battery cell (1').

[0078] However, referring to FIG. 8, a battery cell (1) according to one embodiment of the present invention may have first foil tabs (113a) welded together along a foil tab welding line (WL) (e.g., a first foil tab welding line (WL1) described later) that extends at least to the inner side of a slit-corresponding area (A), and a first current collector plate (20) may be joined to the first foil tabs (113a) welded together by a separate welding process. Here, the length (L1) of the welding bead of the first foil tabs (113a) may be substantially the same as the length of the foil tab welding line (WL). As a result, the length (L1) of the welding bead of the first foil tabs (113a) may be formed independently without being dependent on the length (L2) of the welding bead between the first current collector plate (20) and the first foil tabs (113a).

[0079] Therefore, in a battery cell (1) according to one embodiment of the present invention, the length (L1) of the weld bead of the first foil tabs (113a) can be formed to be longer than the length of the slit (21) and the slit-corresponding area (A), so that the electrical resistance of the battery cell (1) can be effectively reduced compared to a conventional battery cell (1').

[0080] In this regard, the internal resistance of the battery cell (1) was measured when the length (L2) of the weld bead was formed to be 8.5 mm. In the conventional battery cell (1'), the length (L1) of the weld bead was formed to be 8.5 mm, which is the same as the length (L2) of the weld bead, and the internal resistance (DCIR) of the conventional battery cell (1') was measured to be approximately 3.0 mΩ.

[0081] On the other hand, in a battery cell (1) according to one embodiment of the present invention, even when the length (L2) of the weld bead is formed to be 8.5 mm, the length (L1) of the weld bead could be formed to be, for example, 12 mm or longer, which is much longer than 8.5 mm. When the length (L1) of the weld bead is 12 mm, the internal resistance (DCIR) of the battery cell (1) is measured to be about 2.7 mΩ to about 2.8 mΩ, and it was found that the internal resistance is formed to be much lower than the internal resistance of the conventional battery cell (1'), which is about 3.0 mm.

[0082]

[0083] Referring to FIGS. 4 and 6, the slit (21) may be configured to form a fusing induction section (22). The fusing induction section (22) may be a part configured to cut off the high current when a high current exceeding a preset allowable current flows.

[0084] The fusing guide (22) may be provided as a portion formed with a relatively narrow circumferential width on the inner side of the first collector plate (20). For example, the fusing guide (22) may be formed between any two circumferentially adjacent slits (21), as shown in FIG. 4.

[0085] The circumferential width of the fusing guide can be formed to be narrower than the other parts of the first collector plate (20) (e.g., the circumferential width of one slit (21)).

[0086] Meanwhile, the first current collector plate (20) may be provided with an electrode coupling part (23) and a terminal coupling part (24). The electrode coupling part (23) may be a part that is electrically connected to the first electrode (11a) by being coupled to the first electrode (11a). The terminal coupling part (24) may be a part that is coupled to the rivet terminal (40) described later. The terminal coupling part (24) may be positioned approximately in the center of the electrode coupling part (23). A fusing induction part (22) may be positioned between the electrode coupling part (23) and the terminal coupling part (24) so ​​as to connect the electrode coupling part (23) and the terminal coupling part (24) to each other. In this case, a current path may be formed sequentially in the order of the electrode coupling part (23), the fusing induction part (22), and the terminal coupling part (24).

[0087] A battery cell (1) according to one embodiment of the present invention can not only effectively reduce the electrical resistance of the battery cell (1), but at the same time, the first current collector plate (20) can be equipped with a fusing induction part (22), thereby enabling stable fusing performance of the battery cell (1).

[0088]

[0089] Referring to FIGS. 5 to 8, a battery cell (1) according to one embodiment of the present invention can be manufactured by primary welding and secondary welding.

[0090] Specifically, as illustrated in FIGS. 5 and 7, in a battery cell (1) according to one embodiment of the present invention, first foil tabs (113a) can be welded along a foil tab welding line (WL) (e.g., first foil tab welding line (WL1)), and the welding can proceed as a first welding.

[0091] And, as illustrated in FIGS. 6 and 8, in a battery cell (1) according to one embodiment of the present invention, a first current collector plate (20) can be welded and joined to the first foil tabs (113a) that are pre-welded by a first welding, by a second welding that is separate from the first welding. Here, the second welding may be performed after the first welding in terms of time.

[0092] A battery cell (1) according to one embodiment of the present invention can be manufactured by the first welding and second welding as described above, so that, unlike a conventional battery cell (1'), the length (L1) of the welding beads of the first foil tabs (113a) can be maximized without being constrained by the shape of the first current collector plate (20).

[0093]

[0094] The length of the weld bead from the first welding may be the length (L1) of the weld bead of the first foil tabs (113a). The length of the weld bead from the second welding may be the length (L2) of the weld bead between the first collector plate (20) and the first foil tabs (113a).

[0095] The length of the weld bead formed by the first welding can be formed to be longer than the length of the weld bead formed by the second welding.

[0096]

[0097] Referring to FIGS. 4 to 6, the foil tab welding line (WL) can be formed to extend through the slit corresponding area (A).

[0098] Specifically, in a battery cell (1) according to one embodiment of the present invention, the first foil tabs (113a) can be welded together regardless of the welding process between the first foil tab (113a) and the first current collector plate (20), and it is also possible for the foil tab welding line (WL) to be extended and formed to penetrate the slit corresponding area (A). As a result, the length (L1) of the welding bead of the first foil tabs (113a) can be maximized.

[0099]

[0100] Referring to FIGS. 4 to 6, the foil tab welding line (WL) can be formed by extending to the winding center hole (C).

[0101] Specifically, in a battery cell (1) according to one embodiment of the present invention, the first foil tabs (113a) can be welded together regardless of the welding process between the first foil tab (113a) and the first current collector plate (20), and it is possible for the foil tab welding line (WL) to be formed extending to the winding center hole (C). As a result, the length (L1) of the welding bead of the first foil tabs (113a) can be maximized up to the maximum winding center hole (c).

[0102] Meanwhile, the statement that the foil tab welding line (WL) extends to the winding center hole (C) above may include the case where the foil tab welding line (WL) extends to the first foil tab (113a) corresponding to the winding turn number closest to the winding center hole (C).

[0103]

[0104] Referring to FIGS. 4 to 6, the foil tab welding line (WL) may include a first foil tab welding line (WL1).

[0105] The first foil tab welding line (WL1) may be located on the radius of the electrode assembly (10). That is, the first foil tab welding line (WL1) may be located on an imaginary straight line passing through the center of the electrode assembly (10) when viewed from the Z-axis direction.

[0106] The first foil tab welding line (WL1) may be formed to have the longest length among the foil tab welding lines (WL). Specifically, the foil tab welding lines (WL) may be formed as at least one, and the one with the longest radial length among them may be defined as the first foil tab welding line (WL1).

[0107] The internal resistance of the battery cell (1) can be formed with a negative correlation with the longest length of the welding bead in the radial direction of the electrode assembly (10). Therefore, if the longest first foil tab welding line (WL1) among the foil tab welding lines (WL) is formed long, the internal resistance of the battery cell (1) can be minimized accordingly.

[0108]

[0109] Referring to FIGS. 4 to 6, the foil tab welding line (WL) may further include a second foil tab welding line (WL2).

[0110] The length of the second foil tab welding line (WL2) may be formed to be less than or equal to the length of the first foil tab welding line (WL1). Specifically, the radial length of the second foil tab welding line (WL2) may be formed to be equal to or shorter than the radial length of the first foil tab welding line (WL2). Unlike the first foil tab welding line (WL1), the second foil tab welding line (WL2) has a slit-corresponding area (A) radially inward.

[0111] The second foil tab welding line (WL2) may be located on at least one side of the left or right of the first foil tab welding line (WL1). Specifically, the second foil tab welding line (WL2) may be located at one or more locations on the left or right side in the circumferential direction of the first foil tab welding line (WL1).

[0112] As described above, when the foil tab welding line (WL) further includes a second foil tab welding line (WL2), the welding bond strength between the first current collector plate (20) and the electrode assembly (10) is increased, and the rigidity of the battery cell (1) can be increased.

[0113]

[0114] Referring to FIGS. 4 and FIGS. 6, the fusing induction portion (22) can be formed so that its width becomes narrower as it moves away from the center of the first collector plate (20).

[0115] Specifically, the fusing guide (22) may have a width along the circumferential direction, and this width may be formed to become narrower as it moves radially outward away from the central part of the first collector plate (20) (e.g., terminal coupling part (24)).

[0116] When the fusing induction part (22) is formed as described above, the cross-sectional area of ​​the current path is formed to a minimum at a location relatively far from the center of the first current collector plate (20), so that fusing can be effectively performed at that location.

[0117]

[0118] Referring to FIGS. 4 and FIGS. 6, the slit (21) may be provided in a convex shape toward the center of the first collector plate (20).

[0119] Specifically, the slit (21) may be provided in a convex shape toward the center of the first collector plate (20) so as to form a center of curvature at a position spaced apart from the center of the first collector plate (20) (e.g., terminal coupling part (24)).

[0120] When the slit (21) is configured as described above, the fusing guide (22) that can be formed between any two adjacent slits (21) can be formed such that its width becomes narrower as it moves away from the center of the first collector plate (20).

[0121]

[0122] FIG. 10 is a plan view showing a first current collector plate according to another embodiment of the present invention, and FIG. 11 is a plan view showing a first current collector plate according to yet another embodiment of the present invention.

[0123] Hereinafter, with reference to FIG. 10, a battery cell (1) according to another embodiment of the present invention will be described. In the battery cell (1) of another embodiment of the present invention, the slit (21) may be provided in an angled shape toward the center of the first collector plate (20).

[0124] For example, the slit (21) may be provided in an angled shape so as to be perpendicular toward the central part (e.g., electrode coupling part (23)) of the first current collector plate (20), as shown in FIG. 9.

[0125] Hereinafter, with reference to FIG. 11, a battery cell (1) according to another embodiment of the present invention will be described. In the battery cell (1) according to another embodiment of the present invention, the slit (21) may be provided as a single slit.

[0126] For example, the slit (21) may be provided in a roughly circular shape with a section broken, or in a 'C' shape, as shown in FIG. 11. In this case, it may be composed of a single fusing guide (22).

[0127] The first current collector plate (20) can be configured in various forms, as shown in the embodiments illustrated in FIGS. 10 and 11. The battery cell (1) according to the present invention can stably secure fusing performance while simultaneously effectively reducing electrical resistance, regardless of the shape of the first current collector plate (20) configured in various forms as described above.

[0128]

[0129] FIG. 12 is a plan view showing a first current collector plate according to a modified example of an embodiment of the present invention.

[0130] A first current collector plate (20) according to a modified example of one embodiment of the present invention may further be provided with a rotation alignment guide part (G). The rotation alignment guide part (G) may be configured to guide rotation alignment between the first current collector plate (20) and the electrode assembly (10).

[0131] Specifically, in order for a first current collector plate (20) having a slit (21) to be properly welded to an electrode assembly (10) in which a plurality of first foil tabs (113a) are welded along a foil tab welding line (WL), it is necessary for the electrode assembly (10) and the first current collector plate (20) to be rotated and aligned with each other in the correct position before the first current collector plate (20) is welded to the electrode assembly (10). A rotation alignment guide (G) may be configured to guide the rotation alignment of the first current collector plate (20) to the electrode assembly (10) in the correct position.

[0132] For example, the rotation alignment guide (G) can be formed in a groove shape as shown in FIG. 12. In this case, equipment such as a jig capable of gripping the first collector plate (20) can be accurately fitted into the rotation alignment guide (G) in the correct position, and in this state, the first collector plate (20) can be easily rotated and aligned according to the driving or rotation of the equipment such as the jig.

[0133] Meanwhile, FIG. 12 is merely an example, and the rotation alignment guide (G) can be applied in various forms capable of guiding the rotation alignment of the first collector plate in addition to the groove form. For example, unlike the one shown in FIG. 12, the rotation alignment guide (G) can be implemented in various forms such as a hole or a notch.

[0134] Additionally, the rotation alignment guide (G) may be provided at the edge of the first collector plate (20) as shown in FIG. 12. However, FIG. 12 is merely an example, and the rotation alignment guide (G) may be provided at a part other than the edge of the first collector plate (20).

[0135] In addition, the first collector plate (20) may be implemented in various rotational alignment methods, such as rotational alignment by the rotational alignment guide part (G) being fitted into equipment such as the jig, as well as rotational alignment by vision recognition using optical equipment such as a camera.

[0136]

[0137] Meanwhile, referring again to FIGS. 1 and FIGS. 2, the battery cell (1) according to the present invention may further include a can housing (30), a rivet terminal (40), an insulating gasket (50), an insulator (60), a second current collector plate (70), and a cap plate (80).

[0138] The can housing (30) may be configured to accommodate an electrode assembly (10). The can housing (30) may have a receiving space in which the electrode assembly (10) is accommodated. For example, the can housing (30) may be provided in a hollow cylindrical shape to accommodate the electrode assembly (10). A closed portion (31) may be formed on one side of the can housing (30), and an open portion (32) may be formed on the other side. An indented beading portion (33) may be formed on the side adjacent to the open portion (32) of the can housing (30). The beading portion (33) may secure the electrode assembly (10). A crimping portion (34) that extends and is bent toward the open portion (32) may be formed at the end of the can housing (30) on the side of the open portion (32). The crimping portion (34) may seal the cap plate (80) described later.

[0139] The rivet terminal (40) may be a terminal electrically connected to the electrode assembly (10). The rivet terminal (40) may be positioned through the closure (31). At least a portion of the rivet terminal (40) may protrude and be exposed to the outside of the closure (31). The rivet terminal (40) may be provided in the form of a rivet. The rivet terminal (40) may be coupled to a terminal coupling portion (24) located approximately in the center of the first current collector plate (20). The rivet terminal (40) may have a first polarity by being electrically connected to the first electrode (11a) through the first current collector plate (20).

[0140] An insulating gasket (50) may be placed between the rivet terminal (40) and the closure (31). The insulating gasket (50) may be configured to insulate the rivet terminal (40) and the closure (31) from each other.

[0141] An insulator (60) may be placed between the electrode assembly (10) and the can housing (30). An insulator (60) may be placed between the upper portion of the electrode assembly (10) and the lower portion of the closure (31). The insulator (60) may be configured to insulate the electrode assembly (10) and the can housing (30) from each other.

[0142] The second current collector plate (70) can be electrically connected to the second electrode (11b) of the electrode assembly (10). The second current collector plate (70) can be coupled to the second foil tab (not shown) of the second electrode (11b). The second current collector plate (70) can be positioned on the lower side (-Z direction) of the electrode assembly (10). That is, the second current collector plate (70) can be positioned in the electrode assembly (10) at a location opposite to the first current collector plate (20). The second current collector plate (70) can be a negative current collector plate.

[0143] A cap plate (80) may be placed in the opening (32) of the can housing (30). The cap plate (80) may cover the opening (32). The cap plate (80) 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 (34). A separate insulating gasket may be placed between the cap plate (80) and the crimping portion (34).

[0144]

[0145] FIG. 13 is a drawing showing a battery pack according to one embodiment of the present invention.

[0146] Referring to FIG. 13, 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).

[0147] 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.

[0148]

[0149] FIG. 14 is a drawing showing an automobile according to one embodiment of the present invention.

[0150] Referring to FIG. 14, a battery pack (3) according to one embodiment of the present invention can 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.

[0151] 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).

[0152]

[0153] 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.

[0154] 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.

[0155] [Explanation of the symbol]

[0156] 1 : Battery cell

[0157] 2 : Pack Case

[0158] 3 : Battery pack

[0159] 4 : Cars

[0160] 10 : Electrode assembly

[0161] 11: Electrode

[0162] 11a: First electrode

[0163] 11b : Second electrode

[0164] 111 : Maintenance part

[0165] 112 : Mujibu

[0166] 113 : Foil Tab

[0167] 113a : 1st foil tab

[0168] 114 : Notching part

[0169] 115 : Insulating coating part

[0170] 12 : Separator

[0171] 20 : 1st tribunal

[0172] 21: Slit

[0173] 22 : Fusing induction section

[0174] 23 : Electrode coupling part

[0175] 24 : Terminal connection part

[0176] 30 : Can housing

[0177] 31 : Closure

[0178] 32 : Open part

[0179] 33 : Bidding Section

[0180] 34 : Crimping part

[0181] 40 : Rivet terminal

[0182] 50 : Insulating gasket

[0183] 60: Insulator

[0184] 70 : 2nd edition

[0185] 80 : Cap plate

[0186] C: Winding center hole

[0187] WL: Foil tab welding line

[0188] WL1: 1st Foil Tab Welding Line

[0189] WL2: 2nd Foil Tab Welding Line

[0190] A : Slit-corresponding area

[0191] G: Rotation alignment guide part

Claims

1. An electrode assembly provided by being wound around a central winding hole with a separator interposed between a first electrode and a second electrode; and It includes a first current collector plate that is electrically connected to a plurality of first foil tabs provided on the first electrode and has at least one slit formed through it, The above first foil tabs are, They are welded together along at least one foil tab welding line that extends to the inner side of a slit-corresponding area corresponding to the above slit, and The above-mentioned first collector plate is, A battery cell characterized by being separately welded to the first foil tabs that are welded to each other.

2. In Paragraph 1, At least one of the above slits is, A battery cell characterized by being configured to form a fusing induction portion.

3. In Paragraph 1, The above first foil tab is, Multiple pieces are primarily welded together along the above foil tab welding line, and The above-mentioned first collector plate is, A battery cell characterized by being joined to the first foil tabs welded in the first step after the first welding.

4. In Paragraph 3, The length of the weld bead from the above first welding is, A battery cell characterized by being formed to be longer than the length of the weld bead formed by the above secondary welding.

5. In Paragraph 1, The above foil tab welding line is, A battery cell characterized by being formed to extend through the above-mentioned slit-corresponding area.

6. In Paragraph 1, The above foil tab welding line is, A battery cell characterized by being formed extending to the above-mentioned center hole of the winding.

7. In Paragraph 1, The above foil tab welding line is, It includes a first foil tab welding line located on the radius of the electrode assembly, and The above-mentioned first foil tab welding line is, A battery cell characterized by having the longest length among the above foil tab welding lines.

8. In Paragraph 7, The above foil tab welding line is, A battery cell characterized by further including a second foil tab welding line located on at least one side of the left and right of the first foil tab welding line.

9. In Paragraph 2, The above fusing induction unit is, A battery cell characterized by being formed such that the width narrows as it moves away from the center of the first collector plate.

10. In Paragraph 1, The above slit is, A battery cell characterized by being provided in a convex shape toward the center of the first collector plate.

11. In Paragraph 1, The above slit is, A battery cell characterized by being provided in an angled shape toward the center of the first collector plate.

12. In Paragraph 1, The above slit is, A battery cell characterized by being provided as a single unit.

13. In Paragraph 1, The above-mentioned first collector plate is, A battery cell characterized by further comprising a rotation alignment guide portion configured to guide rotational alignment between the first current collector plate and the electrode assembly.

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

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

Images