Current collector, and battery cell, battery pack and vehicle including same

Abstract

A battery cell according to an embodiment of the present invention comprises: an electrode assembly in which a first electrode, a second electrode, and a separator interposed therebetween are wound around a winding axis, wherein the first electrode includes a first uncoated portion that is not coated with an active material layer at the long-side end thereof along the winding direction and is exposed to the outside of the separator, at least a portion of the first uncoated portion itself being used as an electrode tab; a battery housing including an opening at one side thereof and configured to accommodate the electrode assembly through the opening; a cell terminal configured to pass through a surface located opposite to the opening of the battery housing; and a current collector including a first uncoated portion coupling portion disposed on one side of the electrode assembly and welded to the first uncoated portion, a terminal coupling portion spaced apart from the first uncoated portion coupling portion and welded to the cell terminal, and a connection region provided between the first uncoated portion coupling portion and the terminal coupling portion and having a plurality of slits spaced apart from each other at regular intervals in the circumferential direction and having a shape that is convex toward the inside in the radial direction.

Description

The entire house and the battery cells, battery packs and vehicles containing the same

[0001] The present invention relates to a battery cell, a battery pack, and a vehicle including the battery cell.

[0002] This application claims priority to Korean Patent Application No. 10-2024-0083964, filed on June 26, 2024, and Korean Patent Application No. 10-2025-0029163, filed on March 6, 2025, the entire contents of which are disclosed in the specification and drawings of the above applications are incorporated herein by reference.

[0003] Secondary batteries, which are highly applicable across a wide range of product groups and possess electrical properties such as high energy density, are widely used not only in portable devices but also in electric vehicles (EVs) and hybrid electric vehicles (HEVs) powered by electrical power sources. These secondary batteries not only offer the primary advantage of dramatically reducing fossil fuel use but also produce no byproducts from energy use, attracting attention as a new energy source for environmental friendliness and energy efficiency.

[0004] Currently, widely used types of secondary batteries include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. The operating voltage of these unit secondary battery cells, i.e., unit battery cells, is approximately 2.5 V to 4.5 V. Therefore, when a higher output voltage is required, a battery pack is configured by connecting multiple battery cells in series. In addition, a battery pack is configured by connecting multiple battery cells in parallel depending on the charge / discharge capacity required for the battery pack. Therefore, the number of battery cells included in the battery pack can be set in various ways depending on the required output voltage and / or charge / discharge capacity.

[0005] Meanwhile, the cathode current collector structure included in conventional cylindrical batteries was designed with a current path along the perimeter of the current collector plate to ensure fluidity between the cathode branch weld and the terminal weld. Consequently, the current path length increased, which had the problem of increasing the battery's internal resistance.

[0006] The present invention aims to provide a battery cell having a low resistance structure through a curved slit structure.

[0007] In addition, another object of the present invention is to secure fluidity in the direction of the winding axis through a collector structure including a plurality of slits.

[0008] Furthermore, another purpose of the present invention is to secure a welding area between the entire body and the non-conductive part to a certain level or more.

[0009] However, the technical problems to be solved by the present invention are not limited to the problems described above, and other problems not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0010] According to one embodiment of the present invention for solving the above-described problem, a battery cell comprises: an electrode assembly in which a first electrode, a second electrode, and a separator interposed therebetween are wound around a winding axis to define a core and an outer circumferential surface, wherein the first electrode has a first uncoated portion exposed to the outside of the separator and has no active material layer coated on a long side end thereof along the winding direction, and at least a portion of the first uncoated portion is used as an electrode tab in itself; a battery housing including an opening on one side thereof and configured to receive the electrode assembly through the opening; a cell terminal configured to pass through a surface of the battery housing located on an opposite side of the opening; And a current collector including a first non-coated portion coupling portion arranged on one side of the electrode assembly and configured to be welded to the first non-coated portion, a terminal coupling portion positioned spaced apart from the first non-coated portion coupling portion and configured to be welded to the cell terminal, and a connection region provided between the first non-coated portion coupling portion and the terminal coupling portion, the connection region having a plurality of slits spaced at a predetermined interval in the circumferential direction and having a convex shape toward the radially inward direction.

[0011] In one aspect of the present invention, the first non-conductive joints may be configured to be spaced apart at a constant interval along the circumferential direction.

[0012] In another aspect of the present invention, the first non-conductive bonding portion can form a ring-shaped region having a predetermined thickness.

[0013] In another aspect of the present invention, the slit may include a first line extending from one end toward the terminal coupling portion; and a second line extending from the first line toward the first non-conductive coupling portion.

[0014] Preferably, the slit may be configured such that its extension direction is changed at a point where the first line and the second line meet.

[0015] For example, the slit may be configured to have a convex shape radially inward at a point where the first line and the second line meet.

[0016] In one aspect of the present invention, one end of the slit may be configured to pass through a virtual first concentric circle centered on the center of the entire body.

[0017] In another aspect of the present invention, the point where the first line and the second line meet may be configured to pass through a virtual second concentric circle centered on the center of the entire body and having a smaller radius than the first concentric circle.

[0018] In another aspect of the present invention, the other end of the slit may be configured to pass through a virtual third concentric circle centered on the center of the collector and having a radius larger than the first concentric circle.

[0019] In one aspect of the present invention, the first concentric circle may be configured to coincide with a boundary point of the terminal joint portion and the connection area.

[0020] In another aspect of the present invention, the third concentric circle may be configured to coincide with a boundary point of the first non-width joint portion and the connection area.

[0021] In another aspect of the present invention, the connection region may include a first slit and a second slit spaced apart from the first slit by a predetermined distance, and may include a bridge portion provided in a region between the first slit and the second slit.

[0022] Meanwhile, the present invention provides a battery pack comprising: at least one battery cell according to the above-described embodiment; and a pack housing accommodating a plurality of the battery cells.

[0023] In addition, the present invention provides a vehicle including at least one battery pack according to the above-described embodiment.

[0024] Meanwhile, the present invention provides a current collector applied to a battery cell including an electrode assembly having a first unlined portion and a second unlined portion, a battery housing accommodating the electrode assembly through an opening formed on one side thereof and electrically connected to the second unlined portion, and a cell terminal electrically connected to the first unlined portion, the current collector comprising: a first unlined portion joining portion arranged on one side of the electrode assembly and configured to be welded to the first unlined portion; a terminal joining portion positioned spaced apart from the first unlined portion joining portion and configured to be welded to the cell terminal; and a connecting region provided between the first unlined portion joining portion and the terminal joining portion, the connecting region having a plurality of slits spaced apart at a predetermined interval in the circumferential direction and having a convex shape toward the radially inward direction.

[0025] According to the present invention, a battery cell having a low resistance structure can be provided.

[0026] In addition, according to the present invention, the fluidity of the entire collector in the direction of the winding axis can be secured.

[0027] Furthermore, according to the present invention, a welding area between the current collector and the non-conductive portion can be secured to a certain level or higher. Accordingly, welding quality can be improved.

[0028] However, the effects that can be obtained through the present invention are not limited to the effects described above, and other technical effects that are not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0029] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention described below, serve to further understand the technical idea of ​​the present invention, and therefore, the present invention should not be interpreted as being limited to matters described in such drawings.

[0030] FIG. 1 is a drawing showing the appearance of a battery cell according to one embodiment of the present invention.

[0031] FIG. 2 is a cross-sectional view showing the internal structure of a battery cell according to one embodiment of the present invention.

[0032] FIG. 3 is a drawing for explaining an electrode assembly, cell terminal, and current collector included in the battery cell of FIG. 1.

[0033] Figure 4 is a drawing for explaining a conventional collector.

[0034] FIG. 5 is a drawing for explaining a collector according to one embodiment of the present invention.

[0035] FIG. 6 is a drawing for explaining a collector according to another embodiment of the present invention.

[0036] FIG. 7 is a drawing for explaining a collector according to another embodiment of the present invention.

[0037] FIG. 8 is a drawing for explaining the shape of a current collector welded to an electrode assembly according to one embodiment of the present invention.

[0038] FIG. 9 is a drawing for explaining a battery pack including a battery cell according to one embodiment of the present invention.

[0039] FIG. 10 is a drawing for explaining a vehicle including the battery pack of FIG. 9.

[0040] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, it should be noted that the terms and words used in this specification and claims should not be interpreted as limited to their typical or dictionary meanings, and should be interpreted with meanings and concepts that conform to the technical spirit of the present invention based on the principle that the inventor can appropriately define the concept of the term to best explain his or her own invention. Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are only some of the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention. Therefore, it should be understood that various equivalents and modified examples may exist as of the time of this application.

[0041] Additionally, to facilitate understanding of the invention, the attached drawings are not drawn to scale and some components may have exaggerated dimensions. Furthermore, identical components may be assigned the same reference numbers in different embodiments.

[0042] The statement that two compared objects are identical means "substantially identical." Therefore, "substantially identical" may include deviations considered low in the art, such as deviations of less than 5%. Furthermore, uniformity of a parameter over a given region may also mean uniformity on average.

[0043] Although terms like "first" and "second" are used to describe various components, these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless otherwise specified, a "first" component may also be a "second" component.

[0044] Throughout the specification, unless otherwise specifically stated, each element may be singular or plural.

[0045] Any configuration being placed "on (or below)" a component or "on (or below)" a component may mean not only that any configuration is placed in contact with the upper surface (or lower surface) of said component, but also that other configurations may intervene between said component and any configuration placed on (or below) said component.

[0046] Additionally, when it is described that a component is "connected," "coupled," or "connected" to another component, it should be understood that the components may be directly connected or connected to one another, but that other components may also be "interposed" between the components, or that each component may be "connected," "coupled," or "connected" through another component.

[0047] Throughout the specification, when we refer to "A and / or B", this means A, B, or A and B, unless otherwise stated, and when we refer to "C through D", this means C or more and D or less, unless otherwise stated.

[0048] For convenience of explanation, in this specification, the direction along the longitudinal direction of the winding axis of the electrode assembly (10) wound in the form of a jelly roll is referred to as the axial direction. In addition, the direction surrounding the winding axis is referred to as the circumferential direction or the peripheral direction. In addition, the direction approaching or away from the winding axis is referred to as the radial direction. Among these, the direction approaching the winding axis is particularly referred to as the centripetal direction, and the direction away from the winding axis is referred to as the centrifugal direction.

[0049]

[0050] FIG. 1 is a drawing showing the appearance of a battery cell (1) according to one embodiment of the present invention, and FIG. 2 is a cross-sectional view showing the internal structure of a battery cell (1) according to one embodiment of the present invention.

[0051] Referring to FIGS. 1 and 2, a battery cell (1) according to one embodiment of the present invention includes an electrode assembly (10), a battery housing (20), a cell terminal (30), and a current collector (40). In addition to the above-described components, the battery cell (1) may further include an insulating gasket (G2) and / or an insulator (50).

[0052]

[0053] Referring to Fig. 2, the electrode assembly (10) includes a first electrode having a first polarity, a second electrode having a second polarity, and a separator interposed between the first electrode and the second electrode. The first electrode is an anode or a cathode, and the second electrode corresponds to an electrode having a polarity opposite to that of the first electrode.

[0054] The electrode assembly (10) may have, for example, a jelly-roll structure. That is, the electrode assembly (10) may be manufactured by stacking a first electrode plate and a second electrode plate in a sheet shape at least once with a separator interposed therebetween, and winding the stack in one direction with the center of the winding (C) as the standard. In this case, an additional separator may be provided on the outer circumferential surface of the electrode assembly (10) for insulation from the battery housing (20). Any jelly-roll structure known in the art may be applied to the present invention without limitation.

[0055] The first electrode includes a first electrode plate and a first electrode active material applied on one or both surfaces of the first electrode plate. At one end of the first electrode plate in the width direction (in the direction parallel to the Z-axis), there is a first uncoated portion (11) on which the first electrode active material is not applied. The first uncoated portion (11) functioning as a first electrode tab is hereinafter referred to as a first uncoated portion (11). The first uncoated portion (11) is provided at an upper portion in the height direction (in the direction parallel to the Z-axis) of the electrode assembly (10) accommodated in the battery housing (20). That is, the first electrode plate includes a first uncoated portion (11) on which an active material layer is not coated at a long end and which is exposed to the outside of the separator, and a part of the first uncoated portion (11) is used as an electrode tab in and of itself. The first uncoated portion (11) may be, for example, a positive electrode tab.

[0056] Meanwhile, at least a portion of the first non-coated portion (11) may include a plurality of segments (11a) divided along the winding direction of the electrode assembly (10). In this case, the plurality of segments (11a) may be bent along the radial direction of the electrode assembly (10). The plurality of bent segments (11a) may be overlapped in multiple layers. In this case, the first non-coated portion joining portion (41) described later may be joined to an area where the plurality of segments (11a) are overlapped in multiple layers.

[0057] The second electrode includes a second electrode plate and a second electrode active material applied on one or both surfaces of the second electrode plate. On the other end of the second electrode plate in the width direction (in the direction parallel to the Z-axis), there is a non-coated portion on which the second electrode active material is not applied. The non-coated portion functioning as a second electrode tab is hereinafter referred to as a second non-coated portion (12). The second non-coated portion (12) is provided at the lower portion in the height direction (in the direction parallel to the Z-axis) of the electrode assembly (10) accommodated in the battery housing (20). That is, the second electrode plate includes a second non-coated portion (12) on which an active material layer is not coated on a long end and which is exposed to the outside of the separator, and at least a portion of the second non-coated portion (12) is used as an electrode tab in its own right. The second non-coated portion (12) may be, for example, a negative electrode tab.

[0058] Meanwhile, at least a portion of the second non-coating portion (12) may include a plurality of segments (11a) divided along the winding direction of the electrode assembly (10). In this case, the plurality of segments (11a) may be bent along the radial direction of the electrode assembly (10). The plurality of bent segments (11a) may be overlapped in multiple layers. In this case, the second current collector may be coupled to an area where the plurality of segments (11a) are overlapped in multiple layers.

[0059] The first non-conductive portion (11) and the second non-conductive portion (12) extend in opposite directions along the height direction (parallel to the Z-axis) of the battery cell (1). The first non-conductive portion (11) extends toward the closed portion of the battery housing (20), and the second non-conductive portion (12) extends toward the open portion of the battery housing (20).

[0060] In the present invention, the positive electrode active material coated on the positive electrode plate and the negative electrode active material coated on the negative electrode plate can be used without limitation as long as they are active materials known in the art.

[0061]

[0062] FIG. 3 is a drawing for explaining an electrode assembly (10), a cell terminal (30), and a current collector (40) included in a battery cell (1) of FIG. 1.

[0063] Referring to FIG. 3, the structure of the electrode assembly (10) will be described in more detail. In the following description, the first electrode among the first and second electrodes described above will be described as an example, but the structure of the first electrode can be equally applied to the second electrode.

[0064] Preferably, the first non-woven portion (11) may include a plurality of segments (11a) that have been notched. The plurality of segments (11a) form a plurality of groups, and the segments (11a) belonging to each group may have substantially the same height (length in the Z direction) and / or width (length in the X direction) and / or spacing pitch. The number of segments (11a) belonging to each group may increase or decrease compared to that shown.

[0065] The non-coated portions (11, 12) can be bent along the radial direction of the electrode assembly (10), for example, from the outer circumference side to the core side. When the non-coated portions (11, 12) are bent, the radially adjacent segments (11a) overlap in multiple layers to form a bending surface at the upper and lower portions of the electrode assembly (10).

[0066]

[0067] Referring to FIGS. 1 and 2, the battery housing (20) may be configured to include an opening on one side and accommodate the electrode assembly (10) through the opening.

[0068] Specifically, the battery housing (20) is a roughly cylindrical container having an opening formed at the bottom, and is made of a conductive material such as metal, for example. The material of the battery housing (20) may be, for example, steel, stainless steel, or nickel-plated iron. The upper surface located opposite the opening will be referred to as a closed portion. The side wall portion and the closed portion of the battery housing (20) may be formed integrally. Alternatively, the side wall portion and the closed portion of the battery housing (20) may be provided separately and joined to each other by welding, etc. The upper surface of the battery housing (20) (the surface parallel to the XY plane), i.e., the outer surface (20a) of the closed portion, may have a roughly flat shape. The battery housing (20) accommodates the electrode assembly (10) through the opening formed at the bottom, and also accommodates an electrolyte.

[0069] The above battery housing (20) is electrically connected to the electrode assembly (10). The battery housing (20) is electrically connected, for example, to the second non-conductive portion (12) of the electrode assembly (10). In this case, the battery housing (20) has the same polarity as the second non-conductive portion (12).

[0070]

[0071] Referring to FIGS. 1 to 3, the cell terminal (30) is made of a conductive metal material. For example, aluminum (Al) may be used as the material for the cell terminal (30). If the material for the cell terminal (30) is aluminum, processing may be facilitated during rivet processing. The cell terminal (30) may be made of 10-series aluminum, which has a relatively low electrical resistance.

[0072] The above cell terminal (30) passes through the upper surface of the battery housing (20), i.e., the surface (parallel to the XY plane) located on the opposite side of the opening of the battery housing (20). The cell terminal (30) is electrically connected to, for example, the first non-polarized portion (11) of the electrode assembly (10). In this case, the cell terminal (30) has the first polarity. Therefore, the cell terminal (30) can function as a first electrode terminal in the battery cell (1) of the present invention.

[0073] When the cell terminal (30) has the first polarity as described above, the cell terminal (30) is electrically insulated from the battery housing (20) having the second polarity. Electrical insulation between the cell terminal (30) and the battery housing (20) can be achieved in various ways. For example, insulation can be achieved by interposing an insulating gasket (G2) between the cell terminal (30) and the battery housing (20). Alternatively, insulation can be achieved by forming an insulating coating layer on a portion of the cell terminal (30). Alternatively, a method of structurally firmly fixing the cell terminal (30) so that contact between the cell terminal (30) and the battery housing (20) is impossible can be applied. Alternatively, a plurality of methods among the methods described above can be applied together. The cell terminal (30) can be riveted onto the closing portion of the battery housing (20).

[0074] Referring to FIGS. 2 and 3, the bonding between the bottom surface of the central region of the cell terminal (30) and the current collector (40) can be achieved by, for example, laser welding, spot welding, or ultrasonic welding.

[0075] The above welding can be performed by irradiating a laser through a hole formed in the winding center (C) of the electrode assembly (10) or by inserting a tool for ultrasonic welding or spot welding to form a welding bead on one side of the current collector (40) (the side facing the hole formed in the winding center (C) of the electrode assembly (10).

[0076] According to this structure, the battery cell (1) according to one embodiment of the present invention can ensure smooth current flow at the joint portion of the current collector (40) and the cell terminal (30) when a large amount of current flows due to rapid charging, thereby bringing about effects such as shortening the charging time and reducing the amount of heat generated.

[0077] Meanwhile, the insulating gasket (G2) may be interposed between the outer surface (20a) of the closed portion of the battery housing (20) and the cell terminal (30). The insulating gasket (G2) may be made of, for example, a resin material having insulating and elastic properties. Accordingly, the insulating gasket (G2) may electrically insulate between the battery housing (20) and the cell terminal (30).

[0078]

[0079] Figure 4 is a drawing for explaining a conventional collector.

[0080] Referring to Fig. 4, in the conventional current collector, the first non-conductive coupling portion (41) and the terminal coupling portion (42) are indirectly connected via the edge portion of the current collector (40) and the bridge portion (43B). That is, current flows from the first non-conductive coupling portion (41) via the edge portion, through the bridge portion (43B), and to the terminal coupling portion (42).

[0081] With this structure, the current path is formed through the outside of the current collector, so its length increases. As a result, the internal resistance of the battery increases. In addition, with the above structure, the possible bonding area with the first non-conductive portion (11) is narrow and limited. Therefore, with the conventional current collector, there was a problem in that it was difficult to avoid an increase in internal resistance because the welding area between the first non-conductive portion (11) and the current collector (40) was limited.

[0082]

[0083] FIG. 5 is a drawing for explaining a current collector (40) according to one embodiment of the present invention, and FIG. 6 is a drawing for explaining a current collector (40) according to another embodiment of the present invention. FIG. 7 is a drawing for explaining a current collector (40) according to yet another embodiment of the present invention.

[0084] Referring to FIGS. 3 and 5 to 7, the current collector (40) is coupled to the upper portion of the electrode assembly (10). The current collector (40) is made of a conductive metal material and is connected to the first non-conductive portion (11). More specifically, the current collector (40) can be welded to the upper portion of the electrode assembly (10). The current collector (40) is made of a conductive metal material. For example, aluminum (Al) can be used as the material of the current collector (40). For example, the current collector (40) can include an Al1100-H14 material. The current collector (40) electrically connects the first non-conductive portion (11) of the electrode assembly (10) and the cell terminal (30).

[0085] The current collector (40) may be welded to a bonding surface (bent surface) formed by bending an end of the first non-coated portion (11) in a direction parallel to the current collector (40). The bending direction of the first non-coated portion (11) may be the radial direction of the electrode assembly (10). The bending direction of the first non-coated portion (11) may be, for example, a direction toward the winding center (C) of the electrode assembly (10). When the first non-coated portion (11) has such a bent shape, the space occupied by the first non-coated portion (11) is reduced, which may lead to an improvement in energy density. In addition, the increase in the bonding area between the first non-coated portion (11) and the current collector (40) may lead to an improvement in bonding strength and a reduction in contact resistance.

[0086] Referring back to FIG. 3, at least a portion of the first non-coated portion (11) and / or the second non-coated portion (12) may include a plurality of segments (11a) divided along the winding direction of the electrode assembly (10). In this case, the plurality of segments (11a) may be bent along the radial direction of the electrode assembly (10). The plurality of bent segments (11a) may be overlapped in multiple layers. In this case, the first non-coated portion joining portion (41) of the current collector (40) described later may be joined to an area where the plurality of segments (11a) are overlapped in multiple layers.

[0087]

[0088] Referring again to FIGS. 5 to 7, the current collector (40) includes a first non-conductive coupling portion (41), a terminal coupling portion (42), and a connection area (43).

[0089] The first non-coated portion coupling part (41) may be positioned on one side of the electrode assembly (10). For example, referring to FIG. 2, the first non-coated portion coupling part (41) may be coupled on one of the two axial sides of the electrode assembly (10) on which the first non-coated portion (11) is positioned.

[0090] The first non-woven part joining portion (41) extends inward from the first non-woven part joining portion (41) and is welded to the first non-woven part (11). At this time, a welded portion may be provided between the first non-woven part joining portion (41) and the first non-woven part (11).

[0091] In one aspect of the present invention, referring to FIG. 5, the first non-woven portion connecting portions (41) may be configured to be spaced apart at a constant interval along the circumferential direction. The first non-woven portion connecting portions (41), that is, the first non-woven portion connecting portions (41), may be freely provided within a ring-shaped region having a predetermined thickness. For example, in the embodiment of FIG. 5, a plurality of first non-woven portion connecting portions (41) having a substantially rectangular shape are arranged at an interval of about 45 degrees.

[0092] In another embodiment of the present invention, referring to FIG. 6, the first non-conductive bonding portion (41) may form a ring-shaped region having a predetermined thickness. For example, when the current collector (40) is configured in an approximately circular shape, the first non-conductive bonding portion (41) may be configured in an approximately donut-shaped shape. In this case, welding may be continuously performed in the region having the donut shape.

[0093] Preferably, the area of ​​the first non-conductive bonding portion (41) may be configured to be about 60 to 80% of the total area of ​​the current collector (40). More preferably, the area of ​​the first non-conductive bonding portion (41) may be configured to be about 75% of the total area of ​​the current collector (40).

[0094] With the above configuration, a welding area can be secured above a certain level. Accordingly, the welding quality between the first non-conductive portion (11) and the current collector (40) can be effectively improved. Accordingly, the internal resistance of the battery cell (1) can be effectively reduced. In other words, with the above configuration of the present invention, a low-resistance battery cell (1) can be realized.

[0095]

[0096] In another aspect of the present invention, the terminal coupling portion (42) may be positioned spaced apart from the first non-coated portion coupling portion (41). Specifically, the terminal coupling portion (42) may be positioned spaced apart from the first non-coated portion coupling portion (41) in the radial direction. Preferably, the terminal coupling portion (42) may be positioned inside the first non-coated portion coupling portion (41). The terminal coupling portion (42) may be joined to the cell terminal (30) by welding. In order to secure a welding area for joining with the flat portion formed on the bottom surface of the cell terminal (30), the terminal coupling portion (42) may have a diameter substantially the same as or larger than the diameter of the flat portion formed on the bottom surface of the cell terminal (30). For example, the terminal coupling portion (42) may form a circular area centered on the center of the current collector (40) and having a predetermined radius.

[0097]

[0098] In another aspect of the present invention, the current collector (40) may include a connection area (43) provided between the first non-conductive coupling portion (41) and the terminal coupling portion (42).

[0099] Referring to Fig. 6, the connection area (43) may form a ring-shaped area having a predetermined thickness. In the case where the current collector (40) is configured in a substantially circular shape, the connection area (43) may be configured in a shape having a substantially donut shape. In this case, the connection area (43) may be provided in a region radially inner than the first non-conductive portion coupling portion (41). At the same time, a terminal coupling portion (42) may be provided in the region radially inner of the connection area (43).

[0100] The first non-conductive portion coupling portion (41) and the terminal coupling portion (42) can be electrically connected by the connection area (43). For example, the first non-conductive portion coupling portion (41) and the terminal coupling portion (42) can be indirectly connected by the connection area (43). Accordingly, the first non-conductive portion (11) can be electrically connected to the cell terminal (30) through the current collector (40).

[0101] In one aspect of the present invention, the connection region (43) may include a plurality of slits (S) spaced at a predetermined interval in the circumferential direction. For example, the connection region (43) may include at least two to four or more slits (S). In this case, the plurality of slits (S) may be arranged point-symmetrically around the center of the current collector (40).

[0102] In another aspect of the present invention, the slit (S) may be configured to have a curved shape. Preferably, the slit (S) may be configured to have a convex shape toward the radially inward direction. The slit (S) may be configured to extend continuously from one end to the other end, and may be configured as a curved shape convex toward the radially inward direction. For example, referring to FIG. 5, the slit (S) may be configured as a curve having an approximately S-shape.

[0103] With this configuration, the current path between the first non-conductive portion joining portion (41) and the terminal joining portion (42) can be shortened. Accordingly, the internal resistance of the battery can be effectively reduced. That is, with the present invention, a low-resistance battery cell (1) can be configured. In addition, with the above configuration, even when the connection area (43) is relatively narrow, a plurality of slits (S) can be effectively arranged. Accordingly, the design freedom of the current collector (40) can be improved. At the same time, with the above configuration, the overall vertical fluidity of the current collector (40) can be effectively secured by the slits (S). Furthermore, with the above structure, the area of ​​the first non-conductive portion joining portion (41) can be expanded. Accordingly, the welding quality between the first non-conductive portion and the current collector (40) can be improved, and at the same time, the internal resistance can be further reduced.

[0104]

[0105] In another aspect of the present invention, referring to FIG. 6, the slit (S) may include a first line (L1) and a second line (L2). The first line (L1) may extend from one end toward the terminal coupling portion (42). The first line (L1) may be configured in a straight or curved shape. For example, the first line (L1) may be configured in a convex curved shape toward the radial inward direction.

[0106] The second line (L2) may extend from the first line (L1) in a direction toward the first non-coated joint (41). The second line (L2) may be configured in a straight or curved shape. For example, the second line (L2) may be configured in a convex curved shape toward the outside in the radial direction.

[0107] Preferably, the slit (S) may be configured so that its extension direction changes at a point where the first line (L1) and the second line (L2) meet. The slit (S) may be configured to bend at a point where the first line (L1) and the second line (L2) meet. Specifically, referring to Fig. 6, the slit (S) may be configured to have a convex shape radially inward at a point where the first line (L1) and the second line (L2) meet. That is, the slit (S) may have a shape in which the first line (L1) and the second line (L2) are combined, and the first line (L1) and the second line (L2) may have a shape in which they are combined at a predetermined angle to each other.

[0108]

[0109] In another aspect of the present invention, referring to FIG. 6, a virtual first concentric circle (C1) centered around the center of the current collector (40) can be defined. In addition, a virtual second concentric circle (C2) centered around the center of the current collector (40) and having a smaller radius than the first concentric circle (C1) can be defined. In addition, a virtual third concentric circle (C3) centered around the center of the current collector (40) and having a larger radius than the first concentric circle (C1) can be defined. In this case, the second concentric circle (C2) can be included in the connection area (43).

[0110] Referring again to FIG. 6, the first concentric circle (C1) may be configured to coincide with the boundary point between the terminal coupling portion (42) and the connection area (43). Alternatively, the first concentric circle (C1) may be configured to be included within the connection area (43). In another aspect of the present invention, the third concentric circle (C3) may be configured to coincide with the boundary point between the first non-conductive coupling portion (41) and the connection area (43). Alternatively, the third concentric circle (C3) may be configured to be included within the connection area (43).

[0111] Referring back to FIG. 6, one end of the slit (S) may be configured to pass through a virtual first concentric circle (C1) centered on the center of the current collector (40). At this time, one end of the slit (S) may be included within the range of the connection area (43). Meanwhile, the point where the first line (L1) and the second line (L2) meet may be configured to pass through a virtual second concentric circle (C2). At this time, the point where the first line (L1) and the second line (L2) meet may be included within the range of the connection area (43). Meanwhile, the other end of the slit (S) may be configured to pass through a virtual third concentric circle (C3). At this time, the other end of the slit (S) may be included within the range of the connection area (43).

[0112] According to the structure of the present invention as described above, even when the connection area (43) is relatively narrow, a plurality of slits (S) can be effectively arranged. Accordingly, the degree of freedom in the design of the current collector (40) can be improved. At the same time, according to the above configuration, the total flowability of the current collector (40) in the direction of the slits (S) can be effectively secured.

[0113]

[0114] In one aspect of the present invention, referring to FIG. 5, the connection area (43) may include a first slit (S1) and a second slit (S2) spaced apart from the first slit (S1) by a predetermined distance.

[0115] At this time, the connection area (43) may include a bridge portion (43B) provided in an area between two adjacent slits (S). For example, it may include a bridge portion (43B) provided in an area between the first slit (S1) and the second slit (S2).

[0116] In another aspect of the present invention, the bridge portion (43B) may form a current path. Referring again to FIG. 5, current may flow from the terminal coupling portion (42) to the first non-conductive coupling portion (41) along the bridge portion (43B). That is, the bridge portion (43B) may be configured to connect the first non-conductive coupling portion (41) and the terminal coupling portion (42).

[0117] Preferably, the bridge portion (43B) may be provided in multiple numbers. For example, each of the multiple bridge portions (43B) may be positioned between the first slit (S1) and the second slit (S2) that are adjacent to each other. Referring to Fig. 5, the bridge portions (43B) may be positioned at intervals of approximately 180 degrees based on the center of the current collector (40). In this case, the bridge portions (43B) may be provided in two numbers. In this embodiment, the bridge portions (43B) may be configured to face each other.

[0118] In another embodiment of the present invention, as shown in FIG. 7, when the connection area (43) includes the first slit (S1) to the fourth slit (S4), the bridge portion (43B) may be provided between the first slit (S1) and the second slit (S2), between the second slit (S2) and the third slit (S3), between the third slit (S3) and the fourth slit (S4), and between the fourth slit (S4) and the first slit (S1).

[0119]

[0120] Referring to FIG. 6, the current collector (40) may include a first slit (S1), a second slit (S2) spaced apart from the first slit (S1) by a predetermined distance, and a third slit (S3) spaced apart from the second slit (S2) by a predetermined distance. In this case, the first slit (S1), the second slit (S2), and the third slit (S3) may be arranged at intervals of about 120 degrees along the circumferential direction based on the center of the current collector (40). That is, the first slit (S1), the second slit (S2), and the third slit (S3) may be arranged spaced apart from each other by the same distance in the circumferential direction. In this embodiment, three bridge portions (43B) may be provided.

[0121] Referring to FIG. 7, the current collector (40) may include a first slit (S1), a second slit (S2) spaced apart from the first slit (S1) by a predetermined distance, a third slit (S3) spaced apart from the second slit (S2) by a predetermined distance, and a fourth slit (S4) spaced apart from the third slit (S3) by a predetermined distance. In this case, the first slit (S1), the second slit (S2), the third slit (S3), and the fourth slit (S4) may be arranged at intervals of about 90 degrees along the circumferential direction based on the center of the current collector (40). That is, the first slit (S1), the second slit (S2), the third slit (S3), and the fourth slit (S4) may be spaced apart from each other by the same distance in the circumferential direction. In this embodiment, four bridge portions (43B) may be provided.

[0122] Although the embodiments of the present invention have been described through FIGS. 5 to 7 as described above, it is to be understood that the number of slits (S) or the number of bridge portions (43B) of the present invention are not limited thereto.

[0123]

[0124] FIG. 8 is a drawing for explaining the shape of a current collector (40) welded to an electrode assembly (10) according to one embodiment of the present invention.

[0125] In this regard, in the case of a conventional cylindrical battery, a gap may occur between the current collector (40) and the cell terminal (30) due to an axial height deviation of the electrode assembly (10). In this state where a gap occurs, when the current collector (40) and the cell terminal (30) are welded, the current collector (40) is pressed, causing stress in the welded portion. Ultimately, there is a risk of damage to the welded portion due to this stress.

[0126] However, according to the configuration in which a plurality of slits (S) are provided in the current collector (40) of the present invention as shown in FIG. 8, damage to the weld between the current collector (40) and the cell terminal (30) can be effectively prevented. Specifically, according to the configuration, even if a gap occurs between the current collector (40) and the cell terminal (30) due to an axial height deviation of the electrode assembly (10), the bridge portion (43B) provided between the slits (S) can be extended in the winding axial direction. More specifically, since the path from the terminal coupling portion (42) to the first non-coated portion coupling portion (41) has a horizontal direction, i.e., two "sleeve gaps" in X and Y, when the terminal coupling portion (42) moves in the total height direction, bending occurs in the bridge portion (43B) in two directions, thereby ensuring fluidity in the total height direction.

[0127] Accordingly, the gap between the current collector (40) and the cell terminal (30) can be compensated for. Therefore, according to the present invention, by dispersing the stress that may have occurred due to the pressing of the current collector (40) in the past, the stress occurring in the weld between the current collector (40) and the cell terminal (30) can be reduced. In addition, the tensile force generated by the gap can be effectively reduced. In addition, according to such a structure, breakage of the current collector (40) can be prevented during elongation without a separate structure. That is, the current collector (40) composed of a single plate can be effectively elongated without breakage. Furthermore, according to the present invention, the production cost can be lowered and the production process can be simplified in the process of producing the current collector (40).

[0128]

[0129] Meanwhile, referring again to FIG. 7, the insulator (50) can block the electrical connection between the first non-conductive portion (11) and the battery housing (20). The insulator (50) can be interposed between the inner surface of the battery housing (20) facing the current collector (40) and the current collector (40). For example, the insulator (50) can be provided between the current collector (40) coupled to one side of the electrode assembly (10) and the inner surface of the battery housing (20). Specifically, it can be provided between the current collector (40) coupled to one side of the electrode assembly (10) and the inner surface of the closing portion of the battery housing (20). The insulator (50) prevents contact between the current collector (40) and the battery housing (20). That is, the insulator (50) is accommodated inside the battery housing (20), covers at least a portion of the electrode assembly (10), and is configured to block electrical connection between the first non-conductive portion (11) and the battery housing (20). Therefore, the insulator (50) may be made of a material having insulating performance. For example, the insulator (50) may include an insulating polymer material.

[0130]

[0131] FIG. 9 is a drawing for explaining a battery pack including a battery cell (1) according to one embodiment of the present invention.

[0132] Referring to FIG. 9, a battery pack (3) according to an embodiment of the present invention includes a battery assembly in which a plurality of battery cells (1) according to an embodiment of the present invention are electrically connected, and a pack housing (2) accommodating the battery cells. In the drawing of the present invention, components such as a bus bar, a cooling unit, and a power terminal for electrical connection are omitted for convenience of illustration. In addition, the battery pack (3) may further include various components, such as components of a battery pack (3) known at the time of filing of the present invention, such as a BMS, a pack case, a relay, and a current sensor.

[0133]

[0134] Fig. 10 is a drawing for explaining a vehicle including the battery pack (3) of Fig. 9.

[0135] Referring to FIG. 10, a vehicle (5) according to an embodiment of the present invention may be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle, and includes a battery pack (3) according to an embodiment of the present invention. The vehicle (5) includes a four-wheeled vehicle and a two-wheeled vehicle. The vehicle (5) operates by receiving power from the battery pack (3) according to an embodiment of the present invention. In addition, the vehicle (5) according to the present invention may further include various other components included in the vehicle in addition to the battery cell (1) or the battery pack (3). For example, the vehicle (5) according to the present invention may further include a body, a motor, a control device such as an ECU (electronic control unit), etc. in addition to the battery cell (1) according to the present invention.

[0136]

[0137] Meanwhile, although terms indicating directions such as up and down are used in this specification, it is obvious to those skilled in the art that these terms are only for convenience of explanation and may vary depending on the location of the target object or the location of the observer.

[0138] Although the present invention has been described above with reference to 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 idea of ​​the present invention and the equivalent scope of the patent claims to be described below by a person having ordinary skill in the art to which the present invention pertains.

[0139]

[0140] [Explanation of symbols]

[0141] 5: Car

[0142] 3: Battery pack

[0143] 2: Pack housing

[0144] 1: Battery cell

[0145] 10: Electrode assembly

[0146] 11: 1st Military Department

[0147] 11a: Segmentation

[0148] 12: 2nd Military Department

[0149] C: Center of winding

[0150] 20: Battery housing

[0151] 20a: External surface

[0152] 30: Cell terminal

[0153] G2: Insulating gasket

[0154]

[0155] 40: Whole house

[0156] 41: First joint of the ignorant part

[0157] 42: Terminal joint

[0158] 43: Connection area

[0159] 43B: Bridge section

[0160] S: Slit

[0161] S1: First slit

[0162] S2: Second slit

[0163] S3: Third slit

[0164] L1: First line

[0165] L2: Second line

[0166] C1: First concentric circle

[0167] C2: Second concentric circle

[0168] C3: Third concentric circle

Claims

1. An electrode assembly in which a first electrode and a second electrode and a separator interposed therebetween are wound around a winding axis to define a core and an outer circumferential surface, wherein the first electrode is not coated with an active material layer on a long side end along the winding direction and includes a first uncoated portion exposed to the outside of the separator, and at least a portion of the first uncoated portion is used as an electrode tab in itself; A battery housing comprising an opening on one side and configured to receive the electrode assembly through the opening; a cell terminal configured to pass through a surface located opposite the opening of the battery housing; and A current collector including a first non-coated portion coupling portion arranged on one side of the electrode assembly and configured to be welded to the first non-coated portion, a terminal coupling portion positioned spaced apart from the first non-coated portion coupling portion and configured to be welded to the cell terminal, and a connection region provided between the first non-coated portion coupling portion and the terminal coupling portion, the connection region having a plurality of slits spaced at a predetermined interval in the circumferential direction and having a convex shape toward the radial inward direction. Battery cells containing .

2. In paragraph 1, A battery cell characterized in that the first non-conductive joints are arranged so as to be spaced apart at a constant interval along the circumferential direction.

3. In paragraph 1, A battery cell characterized in that the first non-conductive bonding portion forms a ring-shaped region having a predetermined thickness.

4. In paragraph 1, The above slit is, A first line extending from one end toward the terminal joint; and A second line extending from the first line in a direction toward the first non-conductive joint A battery cell characterized by including:

5. In paragraph 4, The above slit is, A battery cell characterized in that the extension direction is switched at the point where the first line and the second line meet.

6. In paragraph 4, The above slit is, A battery cell characterized in that it has a convex shape radially inward at a point where the first line and the second line meet.

7. In paragraph 4, One end of the above slit is, A battery cell characterized by passing through a virtual first concentric circle centered on the center of the above-mentioned collector.

8. In paragraph 7, The point where the first line and the second line meet is A battery cell characterized in that it passes through a virtual second concentric circle having a smaller radius than the first concentric circle and is centered on the center of the above-mentioned collector.

9. In paragraph 7, The other end of the above slit is, A battery cell characterized in that it passes through a virtual third concentric circle having a radius larger than the first concentric circle and is centered on the center of the above-mentioned collector.

10. In paragraph 7, The above first concentric circle is, A battery cell characterized in that it is configured to coincide with the boundary point of the terminal joint and the connection area.

11. In paragraph 9, The third concentric circle above is, A battery cell characterized in that it is configured to coincide with the boundary point of the first non-conductive joint and the connection area.

12. In paragraph 1, The above connection area is, It includes a first slit and a second slit spaced apart from the first slit by a predetermined distance, A battery cell characterized by including a bridge portion provided in an area between the first slit and the second slit.

13. A battery cell according to any one of claims 1 to 12; and A pack housing accommodating a plurality of the above battery cells; Battery pack containing.

14. A vehicle comprising a battery pack according to Article 13.

15. A current collector applied to a battery cell, comprising an electrode assembly having a first non-conductive portion and a second non-conductive portion, a battery housing that accommodates the electrode assembly through an opening formed on one side and is electrically connected to the second non-conductive portion, and a cell terminal that is electrically connected to the first non-conductive portion. A first non-conductive part joining part arranged on one side of the electrode assembly and configured to be welded to the first non-conductive part; a terminal joint located apart from the first non-conductive joint and configured to be welded to the cell terminal; and A connection area provided between the first non-conductive joint and the terminal joint, wherein a plurality of slits are provided at a certain interval in the circumferential direction and have a convex shape toward the radial inward direction. The entire house including.

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