Current collector, battery cell, battery module, battery pack and vehicle comprising same

Abstract

A battery cell according to one 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 such that a core and an outer circumferential surface are defined, the first electrode including an active material part that coated with an active material layer in a winding direction and a first uncoated part that is not coated with the active material layer, and at least a part of the first uncoated part itself being used as an electrode tab; a battery housing for accommodating the electrode assembly through an opening part formed at one side thereof; and a current collector including a tab coupling part, which is coupled to the first uncoated part, and a housing coupling part, which extends from the tab coupling part and is electrically coupled to the inner surface of the battery housing, the housing coupling part having at least one notched part.

Description

Battery packs, battery cells, battery modules, battery packs and vehicles including the same

[0001] The present invention relates to a current collector, a battery cell, a battery module, a battery pack, and a vehicle including the same. This application claims priority to Korean Patent Application No. 10-2023-0191777, filed December 26, 2023, Korean Patent Application No. 10-2024-0025957, filed February 22, 2024, and Korean Patent Application No. 10-2024-0067268, filed May 23, 2024, all of which are incorporated herein by reference in their entirety.

[0002] Secondary batteries, which boast high electrical properties such as high energy density and high applicability across a wide range of product categories, 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 batteries are attracting attention as a new energy source for environmental friendliness and energy efficiency, not only because they can dramatically reduce fossil fuel use, but also because they produce no byproducts from energy use.

[0003] 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, multiple battery cells are connected in series to form a battery pack. Furthermore, depending on the charge / discharge capacity required for the battery pack, a number of battery cells are connected in parallel to form a 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.

[0004] Meanwhile, the current collector included in the conventional battery cell is designed with a four-way blade and is welded to the CBD flat part. Accordingly, when welding, there is concern about the inflow of welding debris (spatter), which is one of the main welding management items in the worst case scenario. There was a problem of debris inflow when welding was applied to the raised part between the upper bending position of the bead neck and the current collector due to the tolerance of the thickness of the can raw material wall, the tolerance of the flat part of the upper part of the bead neck, and the welding alignment tolerance.

[0005] Accordingly, the present invention aims to reduce the size of a laser injection unit by forming a notch in the contact portion of a current collector included inside a battery cell so that welding can be performed in a local area.

[0006] In addition, another object of the present invention is to improve welding performance while reducing the power of a laser beam.

[0007] Furthermore, another object of the present invention is to reduce the inflow of debris during the process.

[0008] In addition, the present invention aims to reduce welding back beads.

[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 is provided, which comprises an electrode assembly in which a core and an outer circumferential surface are defined by winding a first electrode, a second electrode, and a separator interposed therebetween around a winding axis, wherein the first electrode includes an active material portion coated with an active material layer along a winding direction, and a first uncoated portion not coated with an active material layer, wherein at least a portion of the first uncoated portion is used as an electrode tab in itself; a battery housing that receives the electrode assembly through an opening formed on one side thereof; and a current collector including a tab coupling portion coupled to the first uncoated portion and a housing coupling portion extending from the tab coupling portion and electrically coupled to an inner surface of the battery housing, wherein the housing coupling portion includes at least one notch portion.

[0011] The above battery housing may have a beaded portion formed at an end adjacent to the opening and recessed inward.

[0012] In one aspect of the present invention, the housing coupling portion may include a contact portion coupled to the bead portion of the battery housing; and a connecting portion connecting between the tab coupling portion and the contact portion.

[0013] Here, the notch portion may be provided on the contact portion.

[0014] In another aspect of the present invention, the notch portion may be configured to be irradiated with a laser beam.

[0015] The width of the above notch portion can be configured to be 10 to 90% of the width of the laser beam.

[0016] In another aspect of the present invention, the notch portion may extend in a direction perpendicular to the radial direction of the battery cell.

[0017] In another aspect of the present invention, a plurality of notches may be provided within one contact portion.

[0018] For example, the notches may be arranged spaced apart from each other at a predetermined interval in the radial direction of the battery cell.

[0019] In another aspect of the present invention, the notch portion may be configured to be included in plurality within the width of the laser beam.

[0020] In one aspect of the present invention, the notch portion may be positioned on a flat upper surface of the beading portion.

[0021] In another aspect of the present invention, the contact portion may be provided with a welding bead formed by irradiation with a laser beam.

[0022] The above notch portion may be formed by notching a predetermined portion of the housing joint portion to partially reduce the thickness of the housing joint portion.

[0023] The above notch portion may be positioned on the flat upper surface of the beading portion, and the center of the welding bead may be positioned toward the inside with respect to the center of the flat upper surface of the beading portion.

[0024] In another aspect of the present invention, the width of the welding bead can be configured to be 10 to 35% of the press-in depth of the beading portion.

[0025] Meanwhile, the present invention provides a battery pack comprising at least one battery cell according to the present invention.

[0026] In addition, the present invention provides a vehicle comprising at least one battery pack according to the present invention.

[0027] According to the present invention, by providing a notch portion in the contact portion of the current collector included in the cylindrical battery cell, smooth welding is possible even in a local area.

[0028] Additionally, according to the present invention, the size of the laser beam can be reduced.

[0029] In addition, according to the present invention, welding performance can be improved while reducing the power of the laser beam.

[0030] Furthermore, according to the present invention, the inflow of debris during the process can be reduced.

[0031] In addition, according to the present invention, welding back beads can be reduced.

[0032] 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.

[0033] 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.

[0034] FIG. 1 is a drawing for explaining a battery cell according to one embodiment of the present invention.

[0035] Figure 2 is a cross-sectional perspective view of the battery cell of Figure 1.

[0036] Figure 3 is a cross-sectional view of the battery cell of Figure 1.

[0037] Figure 4 is a plan view illustrating a whole body according to one embodiment of the present invention.

[0038] Figure 5 is a drawing for explaining a state in which the entire body of Figure 4 is mounted on a beading portion.

[0039] Fig. 6 is an enlarged drawing of the contact portion of the collector of Fig. 4.

[0040] Fig. 7 is an enlarged view of the notch portion and welding bead of the contact portion of Fig. 6.

[0041] Fig. 8 is a drawing for explaining the relationship between the notch portion provided in the entire body of Fig. 4 and the laser beam.

[0042] Fig. 9 is a cross-sectional view illustrating a state in which the entire body of Fig. 4 is mounted on the beading portion.

[0043] Figure 10 is a drawing for explaining a comparative example of the present invention.

[0044] Fig. 11 is a drawing for explaining the formation position of a welding bead provided in a collector according to one embodiment of the present invention.

[0045] FIG. 12 is a drawing for explaining a battery pack including a battery cell according to one embodiment of the present invention.

[0046] FIG. 13 is a drawing for explaining a vehicle including the battery pack of FIG. 12.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] Throughout the specification, unless otherwise specifically stated, each element may be singular or plural.

[0052] 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.

[0053] 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.

[0054] 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 to D", this means C or more and D or less, unless otherwise stated.

[0055] For convenience of explanation, in this specification, the direction along the longitudinal direction of the winding axis of the electrode assembly 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 circumferential 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.

[0056]

[0057] FIG. 1 is a drawing for explaining a battery cell according to one embodiment of the present invention, and FIG. 2 is a longitudinal cross-sectional perspective view of the battery cell of FIG. 1. FIG. 3 is a longitudinal cross-sectional view of the battery cell of FIG. 1.

[0058] Referring to FIGS. 1 to 3, a battery cell (1) according to one embodiment of the present invention includes an electrode assembly (10), a battery housing (20), and a current collector (30). The battery cell (1) may further include a housing cover (40) and / or a terminal (50) and / or a sealing gasket (G1) and / or a second current collector (60) and / or an insulator (70). The present invention is not limited by the shape of the battery, and is applicable to batteries of other shapes, such as square batteries.

[0059] The electrode assembly (10) includes a first non-coated portion (11) and a second non-coated portion (12). More specifically, the electrode assembly (10) has a structure in which the first electrode and the second electrode and the separator interposed therebetween are wound around a winding axis (which has a direction parallel to the Z-axis direction) to define a core and an outer circumference, with a separator interposed therebetween. That is, the electrode assembly (10) applied to the present invention may be a jelly-roll type electrode assembly (10). In this case, an additional separator may be provided on the outer circumference of the electrode assembly (10) for insulation from the battery housing (20). The electrode assembly (10) may have, without limitation, a winding structure well known in the art.

[0060] In the electrode assembly (10), the first uncoated portion (11) and the second uncoated portion (12) are arranged in opposite directions. In addition, the first uncoated portion (11) and the second uncoated portion (12) are exposed to the outside of the separator. In this electrode assembly (10), only a portion of the first uncoated portion (11) and the second uncoated portion (12) can be defined as electrode tabs and used.

[0061] The first electrode includes a first electrode current collector and a first electrode active material applied on one or both surfaces of the first electrode current collector. At one end of the first electrode in the width direction (the direction parallel to the height direction of the battery cell (1) illustrated in FIG. 1, the Z-axis direction), there is a non-coated portion on which the first electrode active material is not applied. That is, the first electrode includes a non-coated portion that is not coated with an active material at a long end along the winding direction and is exposed to the outside of the separator. The non-coated portion that functions as a first electrode tab is hereinafter referred to as a first non-coated portion (11). The first non-coated portion (11) is provided above the height direction (the direction parallel to the height direction of the battery cell (1) illustrated in FIG. 1) of the electrode assembly (10) accommodated in the battery housing (20). That is, the first electrode includes a first non-coated portion (11) that is not coated with an active material layer on the long end and is exposed to the outside of the separator, and at least a portion of the first non-coated portion (11) is used as an electrode tab in itself. The first non-coated portion (11) may be, for example, a negative electrode tab. In this case, the first electrode is a negative electrode plate.

[0062] Meanwhile, at least a portion of the first non-woven portion (11) may include a plurality of segments divided along the winding direction of the electrode assembly (10). In this case, the plurality of segments may be bent along the radial direction of the electrode assembly (10) (a direction perpendicular to the Z-axis direction, for example, the X-axis direction).

[0063] Referring to FIGS. 2 and 3, the plurality of segments of the first non-woven portion (11) that are banded can be overlapped in multiple layers to form a folded surface. In this case, the tab-connecting portion (32) of the current collector (30) to be described later can be coupled on the folded surface. The tab-connecting portion (32) can be coupled to an area where the plurality of segments are overlapped in multiple layers. In this case, welding can be performed on a certain area while the tab-connecting portion (32) is seated on the folded surface of the first non-woven portion (11). That is, the tab-connecting portion (32) can be coupled to an area where the plurality of segments of the first non-woven portion (11) are overlapped in multiple layers. For example, as can be seen in FIG. 5, the tab-connecting portion (32) can have at least one welded portion welded on a certain area while seated on the folded surface of the first non-woven portion (11).

[0064] The second electrode includes a second electrode current collector and a second electrode active material applied on one or both surfaces of the second electrode current collector. At the other end of the second electrode in the width direction (parallel to the height direction of the battery cell (1) illustrated in FIG. 1), there is a non-coated portion on which the second electrode active material is not applied. That is, the second electrode includes a non-coated portion on a long side along the winding direction that is not coated with an active material and is exposed to the outside of the separator. The non-coated portion that functions 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 a lower portion in the height direction of the electrode assembly (10) accommodated in the battery housing (20). That is, the second electrode includes a second non-coated portion (12) on a long side that is not coated with an active material layer and 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 and of itself. The second non-conductive portion (12) may be, for example, a positive electrode tab. In this case, the second electrode is a positive electrode plate.

[0065] Meanwhile, in the present invention, the positive active material coated on the positive electrode plate and the negative active material coated on the negative electrode plate can be used without limitation as long as they are active materials known in the art. Preferably, the battery cell (1) can be, for example, a cylindrical secondary battery having a form factor ratio (ratio of diameter to height) of greater than about 0.4. Preferably, the diameter of the cylindrical secondary battery can be 40 mm to 50 mm, and the height can be 60 mm to 130 mm. The form factor of the battery cell (1) can be, for example, 46110, 4875, 48110, 4880, or 4680.

[0066] Referring to FIGS. 1 to 3, the battery housing (20) is a roughly cylindrical container with an opening formed on one side, and is made of a conductive metal material. In one example, the battery housing (20) may be made of iron, nickel-plated iron, or stainless steel (SUS), and may be a battery can, but the present invention is not limited thereto. The side surface of the battery housing (20) and the lower surface located opposite the opening are typically formed as one piece. That is, the battery housing (20) typically has an open upper surface in the height direction (Z-axis direction) and a closed lower surface. The lower surface of the battery housing (20) may have a roughly flat shape. The battery housing (20) accommodates an electrode assembly (10) through an opening formed on one side in the height direction. The battery housing (20) may also accommodate an electrolyte through the opening.

[0067] The battery housing (20) may have a beading portion (21) formed at an end adjacent to an opening provided at the top of the battery housing (20). The battery housing (20) may further have a crimping portion (22) formed on the beading portion (21). The beading portion (21) has a shape in which the outer peripheral surface of the battery housing (20) is recessed to a predetermined depth. More specifically, the beading portion (21) may have a shape in which it is recessed inward in a region between the opening formed at one side of the battery housing (20) and the receiving portion that receives the electrode assembly (10).

[0068] The above beading portion (21) is formed on the upper portion of the electrode assembly (10). The inner diameter of the battery housing (20) in the area where the beading portion (21) is formed is formed to be smaller than the diameter of the electrode assembly (10). At least one tab-joining portion (32) of the current collector (30) to be described later may be located lower than the beading portion (21).

[0069] The above beading portion (21) provides a support surface on which the housing cover (40) can be seated. In addition, the beading portion (21) can provide a support surface on which at least a portion of the edge perimeter of the current collector (30), which will be described later, can be seated and coupled. That is, at least a portion of the edge perimeter of the current collector (30) of the present invention and / or the edge perimeter of the housing cover (40) can be seated on the upper surface of the beading portion (21). In order to stably support at least a portion of the edge perimeter of the current collector (30) and / or the edge perimeter of the housing cover (40), the upper surface of the beading portion (21) can have a shape that extends along a direction substantially parallel to the lower surface of the battery housing (20), that is, along a direction substantially perpendicular to the side wall of the battery housing (20).

[0070] The above beading portion (21) may prevent the electrode assembly (10), which may have a size roughly corresponding to the inner diameter of the battery housing (20), from coming out through the opening formed at the top of the battery housing (20), and may function as a support portion on which the housing cover (40) is mounted. The upper beading portion (21) may function as a support portion for fixing not only the housing cover (40), but also the contact portion (33a) of the current collector (30), the sealing gasket (G1), etc.

[0071] The above-mentioned crimping portion (22) is formed on the upper portion of the beading portion (21). The crimping portion (22) has an extended and banded shape so as to wrap around the edge of the housing cover (40) positioned on the upper portion of the beading portion (21). Due to the shape of the crimping portion (22), the housing cover (40) is fixed on the beading portion (21).

[0072]

[0073] Next, with reference to FIGS. 1 to 11, the current collector (30) according to an embodiment of the present invention will be described in detail in comparison with a conventional current collector.

[0074] First, referring to FIGS. 1 to 3, a current collector (30) according to one embodiment of the present invention is accommodated inside a battery housing (20), is electrically connected to an electrode assembly (10), and is also electrically connected to the battery housing (20). That is, the current collector (30) electrically connects the electrode assembly (10) and the battery housing (20).

[0075] FIG. 4 is a drawing for explaining a collector according to one embodiment of the present invention, and FIG. 5 is a drawing for explaining a state in which the collector of FIG. 4 is mounted on a beading portion.

[0076] Referring to FIGS. 4 and 5, the current collector (30) includes a support portion (31) positioned on one side of the electrode assembly (10), a tab coupling portion (32) extending from the support portion (31) and coupled to the first non-conductive portion (11), and a housing coupling portion (33) extending from the support portion (31) and coupled to the inner surface of the battery housing (20).

[0077] The above tab joint (32) and housing joint (33) are indirectly connected via the support (31) and are not directly connected to each other. Therefore, when an external impact is applied to the battery cell (1) of the present invention, the possibility of damage occurring to the joint portion of the current collector (30) and the electrode assembly (10) and the joint portion of the current collector (30) and the battery housing (20) can be minimized.

[0078] Referring again to FIG. 4, the housing joint portion (33) is provided with at least one notch portion (N). A laser beam can be irradiated to the notch portion (N). Accordingly, the housing joint portion (33) and the inner surface of the battery housing (20) can be welded together.

[0079] As described above, according to the present invention, by providing at least one notch portion (N) in the housing joint portion (33) of the current collector (30), local welding of the housing joint portion (33) can be smoothly performed. That is, by providing the notch portion (N) in the present invention, the laser can be irradiated mainly to the notch portion (N), so the probability of welding defects can be significantly reduced. In addition, according to the above configuration, since the welding performance is improved, there is no need to set the power of the laser beam unnecessarily high. That is, according to the present invention, welding performance can be expected while reducing the size of the laser beam injection unit and the power of the laser beam.

[0080] For example, if the power of a welding laser is excessively high, impurities called back beads are generated on the back of the weld. However, according to the above-described configuration of the present invention, the power of the laser beam can be reduced, thereby preventing the occurrence of back beads.

[0081]

[0082] Referring to Fig. 4, at least one tab coupling portion (32) and / or housing coupling portion (33) may be provided. At least one tab coupling portion (32) and at least one housing coupling portion (33) may be arranged, for example, in a roughly radial, cross-shaped, or combination thereof shape based on the center of the current collector (30). In another aspect, each of the plurality of housing coupling portions (33) may be arranged between adjacent tab coupling portions (32).

[0083] Referring to FIG. 3, the support portion (31) and a plurality of tab-connecting portions (32) are arranged on the upper portion of the electrode assembly (10). The tab-connecting portions (32) are connected to the first non-coated portion (11) of the electrode assembly (10). The tab-connecting portions (32) may be connected to the first non-coated portion (11) by welding, for example, along the radial direction of the electrode assembly (10). The tab-connecting portions (32) may be connected to the first non-coated portion (11) by welding, for example, in a state approximately parallel to the lower surface of the battery housing (20). Meanwhile, not only the tab-connecting portions (32) but also the support portions (31) may be connected to the first non-coated portion (11).

[0084] The current collector (30) may be made of the same metal as the first electrode current collector, or may be made of a material that can be welded well with it. For example, it may be made of copper or a copper alloy, nickel or a nickel alloy, iron, SUS, or a composite material thereof.

[0085] The above support member (31) may be provided with a current collector hole (H2) formed at a position corresponding to a winding hole (H1) formed at approximately the center of the electrode assembly (10). The winding hole (H1) and the current collector hole (H2), which are connected to each other, may function as a passage for inserting a welding rod or irradiating a laser beam for welding between a terminal (50) and a second current collector (60) described later or welding between a terminal (50) and a lead tab (not shown). The current collector hole (H2) may have a diameter that is substantially the same as or larger than the winding hole (H1) formed in the core of the electrode assembly (10) so as not to obscure the winding hole (H1). If the diameter of the above-mentioned collector hole (H2) is excessively smaller than the diameter of the winding hole (H1), the hole formed in the winding hole (H1) may be covered, which may result in reduced liquidity, and it may also be difficult to secure sufficient space for insertion of a device for welding or laser irradiation.

[0086] A plurality of tab coupling portions (32) may have a shape extending approximately radially from the support portion (31) of the current collector (30) toward the side wall of the battery housing (20). Each of the plurality of tab coupling portions (32) may be positioned spaced apart from each other along the periphery of the support portion (31).

[0087] A plurality of housing coupling portions (33) may have a shape extending approximately radially from the support portion (31) of the current collector (30) toward the side wall of the battery housing (20). Each of the plurality of housing coupling portions (33) may be positioned spaced apart from each other along the periphery of the support portion (31). At least one housing coupling portion (33) may be positioned between adjacent tab coupling portions (32).

[0088] Referring to Fig. 5, the housing coupling portion (33) may extend from the support portion (31) and be electrically coupled to the inner surface of the battery housing (20). For example, the housing coupling portion (33) may be coupled to, for example, a beading portion (21) on the inner surface of the battery housing (20). In particular, the housing coupling portion (33) may be coupled to the upper surface of the beading portion (21).

[0089] In the battery cell (1) of the present invention, the housing joining portion (33) can be seated on the beading portion (21) through a process of accommodating the electrode assembly (10) with the current collector (30) joined thereto within the battery housing (20). Therefore, the welding process of the battery housing (20) and the current collector (30) can be easily performed. For example, as can be seen in FIG. 5, at least one welding bead (BW) can be included between the beading portion (21) and the housing joining portion (33). That is, the current collector (30) can include at least one welding bead (BW) that is welded onto the inner surface of the battery housing (20). The welding for joining the battery housing (20) and the current collector (30) can be applied by, for example, laser welding, ultrasonic welding, or spot welding. In addition, the upper surface of the beading portion (21) is configured to have a shape extending along a direction approximately parallel to the lower surface of the battery housing (20), that is, a direction approximately perpendicular to the side wall of the battery housing (20), and the housing joining portion (33) is also configured to have a shape extending along the same direction, that is, along the radial direction and the circumferential direction, thereby allowing the housing joining portion (33) to stably contact the beading portion (21). In addition, as the housing joining portion (33) stably contacts the beading portion (21) in this way, welding between the two parts can be smoothly performed, thereby improving the bonding strength between the two parts and minimizing the increase in resistance at the joining site.

[0090]

[0091] Referring to FIGS. 4 and 5, the housing coupling portion (33) may include a contact portion (33a) coupled to the inner surface of the battery housing (20) and a connection portion (33b) connecting the support portion (31) and the contact portion (33a). In one aspect of the present invention, the first tab coupling portion (32) may have a width greater than the connection portion (33b). In another aspect of the present invention, the contact portion (33a) may have a width greater than the connection portion (33b). Here, 'width' refers to a dimension in a direction perpendicular to the radial direction.

[0092] The above contact portion (33a) is coupled to the inner surface of the battery housing (20). Preferably, the contact portion (33a) may be coupled to the beading portion (21) of the battery housing (20). In this case, for stable contact and coupling, both the beading portion (21) and the contact portion (33a) may have a shape extending in a direction approximately parallel to the lower surface of the battery housing (20), i.e., in a direction approximately perpendicular to the side wall of the battery housing (20).

[0093] The contact portion (33a) may have an arc shape that extends circumferentially along at least a portion of the beading portion (21) of the battery housing (20). Accordingly, the circumferential extension length (L_33a) of the contact portion (33a) may be formed longer than the width (L_33b) of the connecting portion (33b). In this case, in order to maximize the contact area, the current collector (30) may be configured such that the sum of the circumferential extension lengths of the contact portions (33a) of each of the plurality of housing coupling portions (33) is substantially equal to or slightly shorter than the inner circumference of the battery housing (20). In another aspect, the contact portion (33a) may have an arc shape that extends circumferentially in opposite directions from the intersection of the connecting portion (33b) and the contact portion (33a) on the beading portion (21).

[0094] Referring to Fig. 4, the current collector (30) of the present invention may be provided with at least one injection hole (H3). The injection hole (H3) may be provided, for example, in the tab coupling portion (32). In the case where the tab coupling portions (32) are provided in multiple numbers, the injection hole (H3) may be provided in at least one tab coupling portion (32). Referring to Figs. 3 and 4, in manufacturing a battery cell (1) according to an embodiment of the present invention, an assembly including an electrode assembly (10) and a current collector (30) may be accommodated in a battery housing (20) and then an electrolyte may be injected. At this time, the injection property may be improved due to the injection hole (H3). In one tab coupling portion (32), the injection hole (H3) may be provided in multiple numbers. The plurality of injection holes (H3) may be arranged to be approximately symmetrical left and right with respect to the center of the width direction of the tab coupling portion (32).

[0095] It is preferable that the welding for joining the battery housing (20) and the current collector (30) is performed by laser welding. By applying laser welding, it is advantageous not only in ensuring quality and performance by preventing deformation caused by contact pressure welding such as resistance welding, but also in increasing product yield. In addition, since there is no need to replace the welding rod or horn, it is advantageous in improving production efficiency, reducing production costs, and reducing manufacturing process time. Laser welding has a higher bonding strength than ultrasonic welding, and can also ensure uniformity in welding performance and quality compared to resistance welding. The laser beam directly reaches the surface of the contact portion (33a), which is the body to be welded, from the top to the bottom of the battery housing (20). The laser welding device may be configured to include a laser injection unit that may include optical components such as a collimator, a lens, and a mirror for focusing the laser from the laser light source to create a laser beam with a predetermined spot diameter and irradiating the laser beam onto the body to be welded, and a system for injecting a welding atmosphere gas and discharging byproducts. Spot diameter refers to the diameter at the exact focus position. While welding in air is acceptable, it may be desirable to partially introduce an inert gas, such as nitrogen gas (N2) or argon gas (Ar), and thus a welding atmosphere gas introduction system including an inert gas supply unit may be included. Furthermore, a byproduct exhaust system including a dust collection unit that suctions and removes welding fumes may be included to remove the welding fumes.

[0096] Fig. 6 is an enlarged view of the contact portion of the current collector of Fig. 4, and Fig. 7 is an enlarged view of the notch portion and the welding bead of the contact portion of Fig. 6. The lower figure in Fig. 7 shows the cross-section taken along line AA' of the upper figure. Fig. 8 is a drawing for explaining the relationship between the notch portion provided in the current collector of Fig. 4 and the laser beam.

[0097] Referring to FIGS. 4 to 6, the notch portion (N) may be provided on the contact portion (33a). A laser beam may be irradiated to the notch portion (N). Accordingly, the contact portion (33a) and the inner surface of the battery housing (20) may be welded together. More preferably, the contact portion (33a) and the beading portion (21) may be welded together. That is, a welding bead (BW) may be formed between the contact portion (33a) and the beading portion (21) by irradiation with a laser beam.

[0098] A weld bead is usually a deposited metal formed by a single welding pass (a single laser beam pass) and may also be called a weld spot. The size, shape, location, and degree of overlap of the weld bead may vary depending on the welding conditions. In this specification, the term weld bead (BW) is used to refer to a welded portion, including not only weld beads that are formed separately and thus distinct from each other, but also weld beads that partially overlap to form a single mass. The method of forming a weld bead (BW) may include wobble welding, spot welding, weaving (hatching) welding, and scan welding.

[0099] According to this structure, by providing at least one notch (N) in the contact portion (33a) of the current collector (30), welding can proceed smoothly even in a local area of ​​the contact portion (33a). That is, by providing the notch (N) in the present invention, the laser can be irradiated mainly to the notch (N), so the probability of welding defects can be significantly reduced. In addition, according to the above configuration, since the welding performance is improved, there is no need to set the power of the laser beam unnecessarily high. That is, according to the present invention, welding performance can be expected while reducing the size of the laser beam injection unit and the power of the laser beam.

[0100] Referring to FIGS. 7 and 8, the notch portion (N) may refer to a portion formed by notching a predetermined portion of the current collector (30), particularly the housing joint portion (33), particularly the contact portion (33a), thereby partially reducing the thickness of the contact portion (33a). However, the notch portion (N) here is not limited to a notch formed by notching in its dictionary sense, and may also refer to a space created by cutting or pressing the current collector (30) by other methods, and may be used in the sense that it may include a groove that is formed inherently in the current collector (30) by the casting shape when the current collector (30) is manufactured by casting. In addition to the notch, the notch portion (N) may refer to a groove or trench-shaped recessed portion that goes inward from the upper surface of the contact portion (33a) of the current collector (30). The depth (d_N) of the notch portion (N) is less than or equal to the thickness (d_33a) of the contact portion (33a). Preferably, the depth (d_N) of the notch portion (N) may have a size of 50% or less of the thickness (d_33a) of the contact portion (33a). The cross-sectional shape of the notch portion (N) may be a V-shaped triangle according to the dictionary meaning of notch, but may also include shapes such as a trapezoid, a square, a semi-ellipse, a semicircle, etc. In addition, the lower corner portions of the notch portion (N) may have a round shape to prevent stress from being concentrated on the corner portions during notching and cracks from occurring.

[0101] The length (L_BW) of the weld bead (BW) is a dimension in a direction approximately perpendicular to the radial direction of the battery cell (1), and may be formed along the irradiation direction of the laser beam and may be approximately 1-3 mm. The length (L_N) of the notch portion (N) is also a dimension in a direction approximately perpendicular to the radial direction of the battery cell (1), and may be less than or equal to the length (L_BW) of the weld bead (BW).

[0102] The width (B) of the weld bead (BW) is a dimension in the radial direction of the battery cell (1) and may be approximately 0.3-1 mm. The width (S) of the notch portion (N) is also a dimension in the radial direction of the battery cell (1) and is smaller than the width (B) of the weld bead (BW).

[0103] The weld bead (BW) may not be limited in size and shape as long as it can maintain the bonding strength. With regard to the bonding strength, the tensile strength of the joint between the current collector (30) and the battery housing (20) by the weld bead (BW) is preferably 2 kgf or more, preferably 3 kgf or more and 15 kgf or less, and more preferably 5 kgf or more and 15 kgf or less. The tensile strength is a force applied perpendicular to the bonding surface. It can be converted into tensile strength by multiplying the size of the surface on which the force acts. When the tensile strength is 2 kgf or more, preferably 3 kgf or more, when using the battery cell (1), the performance of the battery cell (1) is not affected, and the current collector (30) is not detached from the battery housing (20) due to vibration or pressure of the equipment generated during the process.

[0104] It is desirable to increase the tensile strength as much as possible within the allowable range by optimally selecting the welding method. Since the joint strength in terms of tensile strength is also related to the area and depth of the weld bead (BW) (D_BW in Fig. 11), the joint strength can be controlled by adjusting the area and depth of the weld bead (BW). The weld bead (BW) should not exist only on the surface as shown in the cross-section of Fig. 11, but should be formed at the contact surface of the two parts to be joined by welding, and has a three-dimensional shape with thickness. The depth of the weld bead (BW) can be controlled by the output of the laser beam, the irradiation time, etc. The deeper the laser beam output, the deeper the weld bead, and the longer the irradiation time, the deeper the weld bead. The output of the laser beam, the irradiation time, etc. can be controlled so that the weld bead (BW) is not formed deep enough to expose the outer surface of the beading portion (21) while maintaining an appropriate joint strength. In an actual process, since the thickness range of the current collector (30) and the battery housing (20) is fixed, the depth of the laser beam must be controlled at a level to prevent overwelding. In the present invention, by providing at least one notch (N) in the contact portion (33a) of the current collector (30), welding is performed on a local area of ​​the contact portion (33a), so that the depth of the laser beam can be made shallow. The shallow depth of the laser beam can be achieved by using a low-power laser beam, thereby reducing the manufacturing cost and the generation of welding debris. The shallow depth of the laser beam can also be achieved by shortening the irradiation time, thereby reducing the manufacturing time and increasing productivity.

[0105] In one aspect of the present invention, the width (S) of the notch portion (N) may be configured within a range of about 10 to 90% of the width (L) of the laser beam. Here, the width (L) of the laser beam may mean a spot diameter. The spot diameter of the laser beam may be 10 μm to 200 μm. When the spot diameter of the laser beam exceeds 200 μm, there is a disadvantage in that the influence on corrosion increases and the aspect ratio of the welding bead (BW) decreases, which may lower the welding efficiency. In addition, when the laser beam size is less than 10 μm, there is a disadvantage in that the area to be welded is small, and sufficient bonding strength cannot be secured with a single welding. Therefore, it is preferable that the spot diameter of the laser beam satisfies the above range. Preferably, the spot diameter of the laser beam may be about 50 μm.

[0106] For example, referring to FIG. 8, the width (S) of the notch portion (N) may be configured to be smaller than the width (L) of the laser beam. That is, if there is a structure in which the width (S) of the notch portion (N) can be included within the width (L) of the laser beam, it may be said to be included in the scope of the present invention. If the width (S) of the notch portion (N) becomes larger than the width (L) of the laser beam, it can no longer function as the notch portion (N). This is because the notch portion (N) functions as a guideline for irradiating the laser beam for welding, and in order to perform such a function, it must be smaller than the width (L) of the laser beam.

[0107] On the other hand, if the width (S) of the notch (N) is smaller than about 10% of the width (L) of the laser beam, the size of the notch (N) becomes too small, making it difficult to detect the notch (N) for welding. On the other hand, if the width (S) of the notch (N) is larger than about 90% of the width (L) of the laser beam, the size of the notch (N) becomes too large, making it almost the same as the width (L) of the laser beam, making the positional deviation of the welding bead (BW) large. For example, the center of the laser beam may be located within the notch (N), but if the width of the notch (N) itself becomes too wide, the area where the center of the laser beam can be located becomes wider. As a result, the positional deviation of the welding bead (BW) to be welded becomes large, making it difficult to secure an accurate welding position. Therefore, it is preferable that the width (S) of the notch (N) be within a range of about 10 to 90% of the width (L) of the laser beam.

[0108]

[0109] In another aspect of the present invention, the notch portion (N) may be configured to extend in a direction approximately perpendicular to the radial direction of the battery cell (1). For example, referring to FIGS. 6 to 8, the notch portion (N) may be configured to have a straight shape extending in a direction approximately perpendicular to the radial direction of the battery cell (1). Accordingly, the welding bead (BW) may form a straight welding pattern having a length (L_BW) extending approximately along the circumferential direction on the bead portion (21). Alternatively, as another embodiment, the notch portion (N) may be configured to have an approximately arc shape approximately perpendicular to the radial direction of the cylindrical battery cell (1). Accordingly, at least one welding bead (BW) formed between the bead portion (21) and the contact portion (33a) may form an arc-shaped welding pattern extending approximately along the circumferential direction on the bead portion (21). The welding bead (BW) formed on the above contact portion (33a) may have a shape extending along the circumferential direction.

[0110] If the notch portion (N) extends in a direction approximately parallel to the radial direction of the battery cell (1), the welding length may become short and sufficient welding performance may not be secured. In addition, if the notch portion (N) extends in a direction approximately parallel to the radial direction of the battery cell (1), the number of welding operations required to secure the required welding strength increases. Ultimately, the efficiency of the process may be reduced. On the other hand, according to a structure in which the notch portion (N) extends in a direction approximately perpendicular to the radial direction of the battery cell (1), as in the present invention, the efficiency of the process may be improved.

[0111]

[0112] In another aspect of the present invention, the notch portion (N) may be provided in multiple numbers within one contact portion (33a). For example, two or more may be provided. For example, referring to FIGS. 6 to 8, the notch portion (N) may be provided in multiple numbers within one contact portion (33a) in a direction approximately perpendicular to the radial direction of the battery cell (1). Preferably, the notch portions (N) may be arranged spaced apart from each other at a predetermined interval in the radial direction of the battery cell (1). For example, referring to FIG. 7, the notch portions (N) may be provided in multiple numbers with a spacing pitch (P). Welding is applied to the notch portion (N), and a positional deviation may exist at each welding. At this time, when multiple notch portions (N) are provided, the positional deviation of the weld bead (BW) that is ultimately formed can be minimized compared to a structure in which a single notch portion (N) is provided.

[0113] For example, the notch portion (N) may be configured to be included in multiple portions within the width (L) of the laser beam. Accordingly, multiple welding points may be configured within one laser beam. To this end, the width (S) of the notch portion (N) must be smaller than the width (L) of the laser beam. As described above, it is preferable that the width (S) of the notch portion (N) be configured within a range of about 10 to 90% of the width (L) of the laser beam.

[0114] Since the welding area where welding is applied may have an alignment deviation, it is difficult to weld in the same area every time welding, and it must be managed within a certain level of tolerance. Since the welding will be centered on the notch (N) when the laser beam is irradiated, if multiple notches (N) are provided, the number of defects during welding may be reduced. For example, even if welding is performed at a location slightly off the notch (N) due to an alignment deviation, errors such as reduced weld strength and weak welding are reduced when multiple notches (N) are provided compared to when there is only one notch (N). Therefore, it may be desirable to provide multiple notches (N).

[0115] As described above, the structure of the present invention can significantly reduce the welding defect rate. In addition, since the structure having multiple notch portions (N) enables improvement in welding strength and prevents errors such as weak welding, it is preferable to have multiple notch portions (N).

[0116] And, the width (S) and the pitch (P) of the notch (N) can be determined by considering the number of notches (N) that fall within the width (B) of the weld bead (BW) and the width (L) of the laser beam. For example, when the number of notches (N) is n, n × S + (n-1) × P can be smaller than B, and S can be smaller than P. The width (S) and the pitch (P) of the notch (N) can be designed to prevent damage to the current collector (30) and to prevent cracks or deformation when forming a fine notch (N).

[0117] Fig. 9 is a cross-sectional side view for explaining a state in which the current collector of Fig. 4 is seated on a beading portion, and Fig. 10 is a drawing for explaining a comparative example of the present invention. Fig. 11 is a drawing for explaining the formation position of a welding bead provided on a current collector according to one embodiment of the present invention.

[0118]

[0119] In one aspect of the present invention, the contact portion (33a) may have a flat surface that is coupled with the upper surface of the beading portion (21) facing the open portion. Referring to FIGS. 9 to 11, the contact portion (33a) may be seated on the flat upper surface of the beading portion (21). At this time, the notch portion (N) may be positioned on the flat upper surface of the beading portion (21). At this time, since laser welding is applied to the notch portion (N), the contact portion (33a) may be welded to the flat upper surface of the beading portion (21) by a laser beam. More specifically, the contact portion (33a) may be provided with a welding bead (BW) formed by irradiation with a laser beam.

[0120] For example, referring to FIG. 10 corresponding to a comparative example of the present invention, a predetermined gap (G) may exist between the contact portion (33a) of the housing coupling portion (33) and the beading portion (21). More specifically, since the beading portion (21) has a shape in which the outer circumference of the battery housing (20) is recessed to a predetermined depth (D), the beading portion (21) has a flat section (21a) at a certain portion, and then, in a region near the innermost point of the beading portion (21), a curved area (21b) having a predetermined radius of curvature exists. That is, from the point where the curved area (21b) starts from the flat section (21a) of the beading portion (21), the vertical distance from the contact portion (33a) gradually increases as one goes inward in the radial direction. That is, as can be confirmed in Fig. 10, a microscopic space such as a gap (G) that gradually widens inward in the radial direction exists between the beading portion (21) of the contact portion (33a). At this time, when welding is performed in the area where the microscopic gap (G) is located as shown in Fig. 10 to form a weld bead (BW'), a problem of weld debris inflow occurs. Weld debris refers to various impurities (dross) generated during welding, and is a general term for particles that do not become weld metal from the molten metal during welding and stick to or fall off the surface of the base material. In this way, in the past, weld debris may inflow into the microscopic space, and this may act as a factor causing defects not only in the welding process but also in the post-welding process.

[0121] In the present invention, since the notch portion (N) is provided, the power of the laser beam required to form the weld bead (BW') without the conventional notch portion can be reduced, or the size of the laser beam injection unit can be reduced to form the weld bead (BW). Therefore, the generation of weld debris can be reduced, and the problem of weld debris flowing in even when welding is performed in an area where the microscopic gap (G) is located can be significantly resolved. Furthermore, in the battery cell (1) according to one embodiment of the present invention, as can be confirmed in FIG. 11, the notch portion (N) can be positioned on the flat upper surface of the bead portion (21). That is, the notch portion (N) is positioned within the flat section (21a) of the bead portion (21), and accordingly, the contact portion (33a) can be welded and joined on the flat upper surface of the bead portion (21) by the laser beam. Preferably, the width (B) of the welding bead (BW) formed between the contact portion (33a) and the beading portion (21) can be formed to be smaller than the flat section (21a) of the beading portion (21).

[0122] Ultimately, according to this structure of the present invention, since the formation position of the welding bead (BW) is controlled so that welding is performed only in an area where there is no gap (G) between the contact portion (33a) and the beading portion (21), the inflow of debris during the process can be reduced.

[0123]

[0124] In another aspect of the present invention, the center of the welding bead (BW) may be provided on the inside with respect to the center of the flat upper surface of the beading portion (21).

[0125] For example, referring to FIG. 11, the center (C_BW) of the welding bead (BW) may be positioned toward the inside with respect to the center (C_21a) of the flat upper surface of the beading portion (21). That is, the welding bead (BW) may be provided closer to the inside than the outside in the radial direction within a flat section without a gap (G) between the contact portion (33a) and the beading portion (21).

[0126] According to this structure, since welding is performed only in an area without a gap between the contact portion (33a) and the beading portion (21), the inflow of debris during the process can be reduced, and at the same time, since the welding area is closer to the inner side in the radial direction, the welding strength between the beading portion (21) and the current collector (30) can be relatively improved. That is, according to the above structure, the current collector (30) can be maintained in a more stably bonded state on the beading portion (21).

[0127] Since the flat section (21a) of the beading portion (21) has a value determined according to the specifications of the battery cell (1), the position of the center (C_21a) of the flat upper surface of the beading portion (21) is a fixed value in the determined battery cell (1). In order to position the center (C_BW) of the weld bead (BW) inward from the center (C_21a) of the flat upper surface of the beading portion (21) while forming the weld bead (BW) in an area without a gap (G) between the contact portion (33a) and the beading portion (21), it is advantageous that the width (B) of the weld bead (BW) is small. According to the present invention, since a notch portion (N) is formed in the contact portion (33a) of the current collector (30) so that welding can be performed in a local area, there is an advantage in that the width (B) of the weld bead (BW) can be made smaller than the width of a conventional weld bead (BW'). In another aspect of the present invention, a welding bead (BW) is formed between the contact portion (33a) and the beading portion (21), and the width (B) of the welding bead (BW) may be configured to be smaller than the penetration depth (D) of the beading portion (21). The width (B) of the welding bead (BW) may be, for example, greater than or equal to the width (L) of the laser beam.

[0128] For example, referring to FIG. 11, the width (B) of the welding bead (BW) is smaller than the penetration depth (D) of the beading portion (21). Preferably, the width (B) of the welding bead (BW) may be configured to be about 10 to 35% of the penetration depth (D) of the beading portion (21). More preferably, the width (B) of the welding bead (BW) may be configured to be about 15 to 31.67% of the penetration depth (D) of the beading portion (21). According to the above configuration of the present invention, it is possible to secure sufficient welding strength while maximizing the efficiency of the welding process.

[0129] The depth (D_BW) of the weld bead (BW) can be 2-4 mm. If the power of the welding laser is excessively high, a back bead may occur on the back of the weld. In the present invention, since the power of the laser beam can be reduced by the configuration of the notch portion (N), the phenomenon of a back bead occurring when forming a weld bead (BW) with a small depth (D_BW) of 2-4 mm can be prevented.

[0130]

[0131] Referring again to FIGS. 1 to 3, the housing cover (40) covers the opening formed on one side of the battery housing (20). The housing cover (40) may be fixed by a crimping portion (22) formed on the upper end of the battery housing (20). In this case, a sealing gasket (G1) may be interposed between the battery housing (20) and the housing cover (40) and between the current collector (30) and the housing cover (40) to improve the fixing force and the sealing property of the battery housing (20). In this case, the contact portion (33a) and / or the second contact portion (33a) may be interposed between the beading portion (21) of the battery housing (20) and the sealing gasket (G1). In this way, the contact portion (33a) and / or the second contact portion (33a) interposed between the beading portion (21) and the sealing gasket (G1) can be fixed by bending the crimping portion (22) extending upward from the beading portion (21).

[0132]

[0133] Referring to FIG. 3, the terminal (50) is electrically connected to the second non-conductive portion (12) of the electrode assembly (10) by penetrating the battery housing (20) on the opposite side of the opening of the battery housing (20). The terminal (50) may penetrate approximately the center of the lower surface of the battery housing (20). The terminal (50) may be electrically connected to the electrode assembly (10) by, for example, being coupled to a second current collector (60) coupled to the second non-conductive portion (12) or being coupled to a lead tab (not shown) coupled to the second non-conductive portion (12). Accordingly, the terminal (50) has the same polarity as the second electrode of the electrode assembly (10) and may function as a second electrode terminal (T2). When the second non-conductive portion (12) is a positive electrode tab, the terminal (50) may function as a positive terminal.

[0134] Considering the polarity and function of the terminal (50), the terminal (50) must be insulated from the battery housing (20) having the opposite polarity. To this end, an insulating gasket may be applied between the terminal (50) and the battery housing (20). Alternatively, insulation may be achieved by coating a portion of the surface of the terminal (50) with an insulating material.

[0135] For the same reason, the second non-conductive portion (12) and / or the second current collector (60) must be kept insulated from the battery housing (20). To this end, an insulator (70) may be interposed between the second non-conductive portion (12) and the battery housing (20) and / or between the second current collector (60) and the battery housing (20). When the insulator (70) is applied, the terminal (50) may penetrate the insulator (70) for electrical connection with the second non-conductive portion (12).

[0136] Meanwhile, in the present invention, the outer surface (20a) of the closed portion located opposite the open portion provided at the top of the battery housing (20) can function as a first electrode terminal (T1). When the first non-conductive portion (11) is a negative tab, the first electrode terminal (T1) can be a negative terminal. The battery cell (1) according to the present invention has a structure in which the terminal (50) exposed on the lower surface located opposite the open portion of the battery housing (20) can be used as a second electrode terminal (T2), and the remaining area of ​​the lower surface of the battery housing (20) excluding the area occupied by the terminal (50) (including the area where the insulating gasket is exposed when the insulating gasket is exposed to the outside of the terminal (50) on the outer surface (20a) of the closed portion can be used as the first electrode terminal (T1). Accordingly, the battery cell (1) according to the present invention can simplify the electrical connection structure by connecting both the positive and negative poles in one direction when electrically connecting a plurality of battery cells (1). In addition, the battery cell (1) according to the present invention has a structure in which most of the lower surface located opposite the opening of the battery housing (20) can be used as an electrode terminal, and thus has the advantage of securing a sufficient area for welding components for electrical connection.

[0137] Referring again to FIGS. 2 and 3, the second current collector (60) is coupled to the lower portion of the electrode assembly (10). The second current collector (60) is made of a conductive metal material and is electrically coupled to the second non-conductive portion (12).

[0138]

[0139] Referring to FIG. 12, a battery pack (3) according to one embodiment of the present invention includes a battery assembly in which a plurality of battery cells (1) according to one embodiment of the present invention are electrically connected, and a pack housing (2) accommodating the same. 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. The plurality of battery cells (1) are arranged in a predetermined number of rows, and the terminal (50) exposed on the lower surface of each battery cell (1) is used as a second electrode terminal (T2), and the remaining area of ​​the lower surface of the battery housing (20) is arranged so that it can be used as a first electrode terminal (T1). Therefore, when electrically connecting the plurality of battery cells (1), both positive and negative poles can be connected in one direction, thereby simplifying the electrical connection structure. Through this, the number of battery cells (1) that can be mounted in the same space can be increased, thereby improving energy density, and electrical wiring work can be easily performed. Therefore, the space efficiency is good and the electrical wiring efficiency is high, which has a significant work improvement effect in the assembly process of the electric vehicle and in the assembly and maintenance of the battery pack (3).

[0140] Referring to FIG. 13, a vehicle (5) according to one 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 one 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 one embodiment of the present invention.

[0141]

[0142] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and various modifications and variations are possible by those skilled in the art within the scope of the technical idea of ​​the present invention and the equivalent scope of the claims to be described below.

[0143] [Explanation of symbols]

[0144] 5: Car

[0145] 3: Battery pack

[0146] 2: Pack housing

[0147] 1: Battery cell

[0148]

[0149] 10: Electrode assembly

[0150] 11: 1st Military Department

[0151] 12: 2nd Military Department

[0152] H1: Winding hole

[0153]

[0154] 20: Battery housing

[0155] 20a: Outer surface of the closure

[0156] T1: First electrode terminal

[0157] 21: Bidding Department

[0158] 22: Crimping section

[0159]

[0160] 30: Whole house (1st whole house)

[0161] H2: Whole house hall

[0162] 31: Support

[0163] 32: Tab joint

[0164] H3: Liquid hole

[0165] 33: Housing joint

[0166] 33a: Contact

[0167] 33b: Connection

[0168] N notch

[0169] BW welding bead

[0170]

[0171] 40: Housing cover

[0172] 41: Benting Department

[0173] G1: Sealing gasket

[0174] 50: Terminal

[0175] T2: Second electrode terminal

[0176] 60: Second House

[0177] 70: Insulator

Claims

1. An electrode assembly in which a core and an outer peripheral surface are defined by winding a first electrode, a second electrode, and a separator interposed therebetween around a winding axis, wherein the first electrode includes an active material portion coated with an active material layer along a winding direction, and a first uncoated portion not coated with an active material layer, and at least a portion of the first uncoated portion is used as an electrode tab in itself; A battery housing for accommodating the electrode assembly through an opening formed on one side; and A current collector including a tab coupling portion coupled with the first non-conductive portion and a housing coupling portion extending from the tab coupling portion and electrically coupled to an inner surface of the battery housing, wherein the housing coupling portion has at least one notch portion. A battery cell comprising:

2. In paragraph 1, The above battery housing, A battery cell characterized by having a beaded portion formed at an end adjacent to the opening and directed inward.

3. In paragraph 2, The above housing joint is, a contact portion coupled to the bead portion of the battery housing; and A connecting portion connecting the above tab joint portion and the above contact portion A battery cell characterized by including a .

4. In paragraph 3, A battery cell characterized in that the notch portion is provided on the contact portion.

5. In paragraph 3, A battery cell characterized in that the notch portion is configured to be irradiated with a laser beam.

6. In paragraph 5, A battery cell characterized in that the width of the notch portion is 10 to 90% of the width of the laser beam.

7. In paragraph 1, A battery cell characterized in that the notch portion extends in a direction perpendicular to the radial direction of the battery cell.

8. In paragraph 3, A battery cell characterized in that a plurality of notches are provided within one contact portion.

9. In paragraph 1, A battery cell characterized in that the notches are arranged spaced apart from each other at a predetermined interval in the radial direction of the battery cell.

10. In paragraph 5, A battery cell characterized in that the notch portion is configured to be included in multiple numbers within the width of the laser beam.

11. In paragraph 2, A battery cell, characterized in that the notch portion is located on a flat upper surface of the beading portion.

12. In paragraph 5, A battery cell characterized in that the above contact portion is provided with a welding bead formed by irradiation with a laser beam.

13. In paragraph 1, A battery cell characterized in that the notch portion is formed by notching a predetermined portion of the housing joint portion to partially reduce the thickness of the housing joint portion.

14. In paragraph 12, The above notch portion is located on the flat upper surface of the beading portion, A battery cell characterized in that the center of the welding bead is positioned inward relative to the center of the flat upper surface of the beading portion.

15. A tab joint coupled to a bare portion of an electrode assembly of a battery cell; and a housing joint extending from the tab joint and electrically coupled to an inner surface of a battery housing of the battery cell. A current collector characterized in that the housing joint portion is provided with at least one notch portion, the notch portion is configured to be irradiated with a laser beam, and the width of the notch portion is 10 to 90% of the width of the laser beam.

16. A battery pack comprising at least one battery cell according to any one of claims 1 to 14.

17. A vehicle characterized by comprising at least one battery pack as described in paragraph 16.

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