Battery cell, and battery pack and vehicle including same

Abstract

A battery cell according to the present disclosure may include: an electrode assembly configured with a first electrode, a second electrode, and a separator interposed therebetween, which are wound around a winding axis; a can housing having an open end through which the electrode assembly is inserted therein; a cell terminal electrically connected to the first electrode and provided on a closed portion of the can housing opposite the open end; an electrode current collector electrically connected to the second electrode and configured to contact an inner surface of the open end; and a can lid coupled to the open end to seal the can housing, wherein the can lid may include a lateral lid portion forming its outer perimeter, and wherein the lateral lid portion may be fitted into the inner surface of the open end with the end portion of the electrode current collector, which forms an outermost edge of the electrode current collector, interposed therebetween.

Description

Battery cells, battery packs containing the same, and vehicles

[0001] The present invention relates to a battery cell, a battery pack including the same, and a vehicle, and more particularly, to a battery cell having an improved assembly structure between a can housing and a can lead in a battery cell, and a battery pack including the same and a vehicle.

[0002] This application claims priority to Korean Patent Application No. 10-2024-0091321, filed on July 10, 2024, and Korean Patent Application No. 10-2025-0083248, filed on June 24, 2025, the entire contents of which are disclosed in the specification and drawings of the aforementioned applications are incorporated herein by reference.

[0003] Secondary batteries, which have high applicability according to product group and electrical characteristics such as high energy density, are widely used not only in portable devices but also in electric vehicles (EVs) and hybrid electric vehicles (HEVs) driven by electrical power sources.

[0004] These secondary batteries are attracting attention as a new energy source for environmental friendliness and energy efficiency because they not only have the primary advantage of drastically reducing the use of fossil fuels, but also have the advantage of producing no byproducts from energy use.

[0005] 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 batteries is approximately 2.5 V to 4.5 V. Therefore, if a higher output voltage is required, multiple batteries are connected in series to form a battery pack. Furthermore, depending on the required charge / discharge capacity of the battery pack, a number of battery cells are connected in parallel to form a battery pack. The number of battery cells included in the battery pack and the electrical connection type can be set in various ways depending on the required output voltage and / or charge / discharge capacity.

[0006] Meanwhile, secondary batteries can be classified into cylindrical, square, and pouch-shaped battery cells according to their shapes. Among these, as illustrated in FIG. 1, a conventional cylindrical battery cell includes a beading portion (1) and a crimping portion (2). The beading portion (1) may have a shape that is pressed inward in a region between an opening formed on one side of a can housing (3) and a receiving portion that receives an electrode assembly (4). In addition, the crimping portion (2) has a shape that is extended and bent so as to surround the edge of a battery cap (5) arranged above the beading portion (1). In addition to the battery cap (5), the crimping portion (2) can fix a sealing gasket (6). A cylindrical battery cell having the beading portion (1) and the crimping portion (2) has the advantages of easy securing of a negative electrode current collector (7) and excellent airtightness between the can housing (3) and the battery cap (5).

[0007] However, the process for forming the beading portion (1) and the crimping portion (2) is not a simple process as it requires precision. This may result in frequent product defects during the beading or crimping process, which may reduce production yield. Furthermore, it has been pointed out that the cylindrical battery cell having the beading portion (1) and the crimping portion (2) is disadvantageous in terms of energy density. Therefore, it is necessary to eliminate the beading portion (1) and the crimping portion (2) from the can housing (5) and to improve the sealing structure to be simpler.

[0008] The present invention was created in consideration of the above-described problems, and has as its primary purpose a cylindrical battery cell having a high energy density and an improved assembly structure between a can housing and a can lead by not having a beading portion and a crimping portion.

[0009] In addition, the present invention aims to provide a cylindrical battery cell in which a can lead and an electrode collector plate can be integrally fixed to a can housing during the process of assembling the can housing and the can lead.

[0010] In addition, the present invention aims to prevent changes in the outer diameter of the can housing when assembling the can housing and the can lid.

[0011] The technical problems to be solved by the present invention are not limited to the problems described above, and other problems not mentioned will be clearly understood by those skilled in the art from the description of the invention described below.

[0012] According to the present invention, a battery cell can be provided, including: an electrode assembly in which a first electrode and a second electrode and a separator interposed therebetween are wound around a winding axis; a can housing having an open end so that the electrode assembly can be inserted therein; a cell terminal electrically connected to the first electrode and provided in a closing portion of the can housing located opposite the open end; an electrode current collector plate electrically connected to the second electrode and configured to contact an inner surface of the open end; and a can lid that seals the can housing by being coupled to the open end, wherein the can lid includes a lead side portion forming an outer circumference thereof, and the lead side portion is fitted onto an inner surface of the open end with an end portion of the electrode current collector plate forming an outermost edge of the electrode current collector plate interposed therebetween.

[0013] The above open end may be configured to have a sloped portion on the inner surface of the open end with the thickness gradually decreasing toward the end.

[0014] The end portion of the above electrode collector plate may be configured to be pressed and fixed between the lead side portion and the inclined portion.

[0015] The end portion of the above electrode collector plate may be configured to extend in the height direction so as to be positioned at a height corresponding to the inclined portion.

[0016] The above lead side portion may include a first lead side portion inclined parallel to the inclined portion; and a second lead side portion overlapping the end of the open end portion in the height direction.

[0017] The first lead side portion may be forcibly fitted into the inclined portion of the open end portion with the end portion of the electrode collector plate interposed therebetween, and the second lead side portion may have its horizontal surface in contact with the end portion of the open end portion and its vertical surface parallel to the outer surface of the open end portion.

[0018] The end portion of the electrode collector plate can be pressed and fixed between the first lead side portion and the inclined portion.

[0019] The end of the second lead side portion and the end of the open end portion can be side-welded along the circumferential direction of the can housing.

[0020] A welding target portion is formed recessed from the outside to the inside of the can housing at a portion where the second lead side portion and the open end are in vertical contact, and a welding bead can be formed in the welding target portion.

[0021] The above welding target portion may be provided in a chamfered form at least in one of the outer corner area of ​​the second lead side portion facing each other and the outer corner area of ​​the open end.

[0022] The above welding target portion can be provided continuously along the circumferential direction of the can housing.

[0023] The above welding bead can be formed by heat melting the second lead side portion, the open end portion, and the end portion of the electrode current collector plate.

[0024] The electrode current collector may include a disc portion that is mounted on a winding surface of the electrode assembly and welded to the second electrode; a bent portion that is bent at an edge of the disc portion and contacts the inner surface of the open end; and an end portion of the electrode current collector portion that forms an outermost edge and is press-fixed between the lead side portion and the inner surface of the open end.

[0025] According to another aspect of the present invention, a battery pack including the above-described battery cell can be provided.

[0026] According to another aspect of the present invention, a vehicle including the battery pack can be provided.

[0027] According to the present invention, a cylindrical battery cell can be provided that has a high energy density and a simplified assembly structure between a can housing and a can lead by not having a beading portion and a crimping portion.

[0028] In addition, according to the present invention, in the process of assembling the can housing and the can lid, the can lid and the electrode collector plate can be fixed integrally to the can housing.

[0029] In addition, according to the present invention, it is possible to prevent changes in the outer diameter of the can housing when assembling the can housing and the can lid.

[0030] In addition, according to the present invention, the contact, fixation, and ease of assembly between the can housing, the can lid, and the electrode collector plate can be improved.

[0031] 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 will be clearly understood by those skilled in the art from the description of the invention described below.

[0032] Figure 1 is a schematic cross-sectional view of a portion of a conventional cylindrical battery cell.

[0033] FIG. 2 is a schematic perspective view of a cylindrical battery cell according to one embodiment of the present invention.

[0034] FIG. 3 is a schematic cross-sectional view of a cylindrical battery cell according to one embodiment of the present invention.

[0035] Figure 4 is an enlarged view of a closure portion of a can housing according to one embodiment of the present invention.

[0036] FIG. 5 is an exploded perspective view of a cylindrical battery cell according to one embodiment of the present invention.

[0037] FIG. 6 is a drawing showing a can housing and a can lead that accommodate an electrode assembly according to one embodiment of the present invention separated.

[0038] Figure 7 is an enlarged view of a portion of Figure 6.

[0039] Fig. 8 is a drawing showing an example in which the can lead and electrode collector plate of Fig. 6 are fitted and connected to the open end of the can housing.

[0040] FIG. 9 is a drawing showing an example of side welding of a can housing and a can lid according to one embodiment of the present invention.

[0041] FIG. 10 is a cross-sectional view of a portion of a can housing and a can lid to which a welding target portion is applied, as another embodiment of the present invention.

[0042] FIG. 11 is a drawing showing another embodiment of the present invention, in which a can housing, a can lid, and an electrode collector plate are triple-welded.

[0043] FIG. 12 is a schematic drawing of a battery pack including a battery cell according to one embodiment of the present invention.

[0044] FIG. 13 is a schematic drawing of a vehicle including the battery pack of FIG. 12.

[0045] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms or words used in this specification and claims should not be interpreted as limited to their typical or dictionary meanings, but 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 a term to best explain his or her 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 be substituted for them at the time of filing this application. Throughout the specification, unless specifically stated otherwise, each component may be singular or plural.

[0046] For convenience of explanation, the direction along the longitudinal direction of the winding axis of the electrode assembly (100) wound in the form of a jelly roll is referred to as the axial direction in this specification. 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 referred to as the centripetal direction, and the direction away from the winding axis is referred to as the centrifugal direction.

[0047] FIG. 2 is a schematic perspective view of a cylindrical battery cell according to one embodiment of the present invention, and FIG. 3 is a schematic cross-sectional view of a cylindrical battery cell according to one embodiment of the present invention.

[0048] Referring to FIGS. 2 and 3, a battery cell (10) according to one embodiment of the present invention includes an electrode assembly (100), a can housing (200), a cell terminal (300), an electrode collector plate, and a can lead (400).

[0049] The electrode assembly (100) has a structure 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 circumference. The electrode assembly (100) may be a jelly-roll type electrode assembly (100). An additional separator may be provided on the outer circumference of the electrode assembly (100) for insulation from the can housing (200). The electrode assembly (100) may have a winding structure well known in the art without limitation. The first electrode means an electrode having one of a positive and a negative polarity, and the second electrode means an electrode having a polarity opposite to the first electrode.

[0050] 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 (parallel to the height direction (Z) of the cylindrical battery cell (10) illustrated in FIG. 3), 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 (111). The first non-coated portion (111) is provided at the lower end of the electrode assembly (100) accommodated in the can housing (200) (in the cylindrical battery cell (10) illustrated in FIG. 3). That is, the first electrode includes a first non-coated portion that is not coated with an active material layer on a long end and is exposed to the outside of the separator, and at least a portion of the first non-coated portion (111) is used as an electrode tab in itself. The first non-coated portion (111) may be, for example, a positive electrode tab.

[0051] Meanwhile, at least a portion of the first non-coated portion (111) may include a plurality of segments divided along the winding direction of the electrode assembly (100). In this case, the plurality of segments may be bent along the radial direction of the electrode assembly (100). The plurality of bent segments may be overlapped in multiple layers. An electrode collector plate may be arranged below the first non-coated portion (111). For example, the first non-coated portion (111) and the electrode collector plate may be connected by welding. In this case, the electrode collector plate has the same positive polarity as the first non-coated portion (111), and thus is hereinafter referred to as a positive collector plate (510).

[0052] 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 current collector 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 (121). The second non-coated portion (121) is provided in the upper direction of the electrode assembly (100) accommodated in the can housing (200) (in the cylindrical battery cell (10) of FIG. 3). That is, the second electrode current collector includes a second non-coated portion (121) 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 (121) is used as an electrode tab in its own right. The second non-coated portion (121) may be, for example, a negative electrode tab.

[0053] Meanwhile, at least a portion of the second non-coated portion (121) may include a plurality of segments divided along the winding direction of the electrode assembly (100). In this case, the plurality of segments may be bent along the radial direction of the electrode assembly (100). The plurality of bent segments may be overlapped in multiple layers. An electrode collector plate may be arranged on the upper portion of the second non-coated portion (121). For example, the second non-coated portion (121) and the electrode collector plate may be connected by welding. In this case, the electrode collector plate has the same negative polarity as the second non-coated portion (121), and thus is hereinafter referred to as a negative collector plate (520).

[0054] As described above, the first non-conductive portion (111) and the second non-conductive portion (121) extend in opposite directions along the height direction (parallel to the Z-axis) of the cylindrical battery cell (10). The first non-conductive portion (111) faces the closing portion (220) of the can housing (200), and the second non-conductive portion (121) faces the opening (O) of the can housing (200) located in the opposite direction to the closing portion (220).

[0055] The can housing (200) is a roughly cylindrical container having an opening (O) formed at the top (see FIG. 5), and is made of a conductive material such as metal, for example. The material of the can housing (200) may be, for example, steel, stainless steel, or nickel-plated iron. Hereinafter, the upper edge of the can housing (200) forming the opening (O) is referred to as an open end (210). In addition, the lower side of the can housing (200) located opposite the opening (O) is referred to as a closed end (220). The side surface (outer circumference) of the can housing (200) and the closed end (220) (220) may be formed integrally. The lower surface (the surface parallel to the XY plane) of the can housing (200), that is, the surface of the closed end (220), has a roughly flat shape. This can housing (200) can accommodate an electrode assembly (100) through an opening (O) formed at the top.

[0056] The can housing (200) is electrically connected to the electrode assembly (100). The can housing (200) is, for example, electrically connected to the second non-conductive portion (121) of the electrode assembly (100). The can housing (200) may be configured to be in direct contact with the negative electrode collector (520) connected to the second non-conductive portion (121). In this case, the can housing (200) has the same negative polarity as the second non-conductive portion (121).

[0057] In this embodiment, the negative electrode collector plate (520), which is an electrode collector plate electrically connected to the second electrode, includes a circular plate portion (521), a bent portion (522), and an end portion (523) corresponding to an outermost edge, as illustrated in FIGS. 3 and 6. The circular plate portion (521) may be mounted on the winding surface of the electrode assembly (100) and may be welded to the second uncoated portion (121) of the second electrode. The bent portion (522) may be configured to be bent at the edge of the circular plate portion (521) and to come into contact with the inner surface of the open end (210). In addition, the end portion (523) may be configured to be pressed and fixed between the lid side portion (410) of the can lid (400) described below and the inner surface of the open end (210) of the can housing (200). The end portion (523) of the negative electrode collector (520) is pressed and fixed to the inclined portion (211) of the open end (210), and the bent portion (522) can be welded and fixed to the inner surface of the open end (210) from the lower side of the inclined portion (211). A more detailed description thereof will be provided later.

[0058] The cell terminal (300) is made of a conductive metal material. For example, aluminum (Al) can be used as the material of the cell terminal (300). When the material of the cell terminal (300) is aluminum, it is easy to process during the rivet processing described below, and 10 series aluminum with relatively low electrical resistance can be used. The cell terminal (300) is installed on the lower surface of the can housing (200), that is, on the closing portion (220) of the can housing (200). The cell terminal (300) is electrically connected to the first non-conductive portion (111) of the electrode assembly (100). In this case, the cell terminal (300) has a first polarity, that is, a positive polarity. Therefore, the cell terminal (300) can function as a positive terminal in the cylindrical battery cell (10) of the present invention. These cell terminals (300) are electrically insulated from the can housing (200) having a negative polarity. Electrical insulation between the cell terminals (300) and the can housing (200) can be achieved in various ways. For example, insulation can be achieved by interposing an insulator (600) between the positive current collector (510) and the closing portion (220) of the can housing (200), and interposing an insulating gasket (330) between the cell terminals (300) and the can housing (200).

[0059] Referring to FIG. 4, the cell terminal (300) includes a terminal exposure portion (310) and a terminal insertion portion (320). The terminal insertion portion (320) may include an electrical connection portion (321) and a flange portion (322). The terminal exposure portion (310) is exposed to the outside of the can housing (200). The terminal exposure portion (310) may be located approximately at the center of the closing portion (220) of the can housing (200). The maximum width of the terminal exposure portion (310) may be formed to be larger than the maximum width of a hole formed in the can housing (200) for insertion of the cell terminal (300). That is, the outer diameter of the cell terminal (300) exposed to the outside of the closure (220) may be larger than the inner diameter of the through hole formed in the closure (220) of the can housing (200) for exposing the cell terminal (300). Accordingly, the cross-section of the through hole formed in the closure (220) for exposing the cell terminal (300) may be included within the cross-section of the cell terminal (300) exposed to the outside of the closure (220). In addition, the portion where the cell terminal (300) is exposed to the outside of the closure (220) may cover at least a portion of the closure (220) of the can housing (200) in the axial direction. The terminal insertion portion (320) penetrates approximately the center of the closure (220) of the can housing (200), and the electrical connection portion (321) of the terminal insertion portion (320) may be electrically connected to the first non-conductive portion (111). The flange portion (322) of the terminal insertion portion (320) is formed around the electrical connection portion (321) and can be riveted onto the inner surface of the closure portion (220) of the can housing (200). That is, the flange portion (322) of the terminal insertion portion (320) can have a shape that is curved toward the inner surface of the closure portion (220) of the can housing (200). Accordingly, the maximum width of the terminal insertion portion (320) after the riveting process for fixing the cell terminal (300) is performed can be formed to be larger than the maximum width of the hole formed in the can housing (200) through which the terminal insertion portion (320) passes.

[0060] The electrical connection portion (321) of the terminal insertion portion (320) may be coupled with the positive electrode current collector (510). The electrical connection portion (321) of the terminal insertion portion (320) may have, for example, a substantially cylindrical shape. Of course, the shape of the electrical connection portion (321) of the terminal insertion portion (320) is not limited thereto. The electrical connection portion (321) of the terminal insertion portion (320) may have various shapes, such as, for example, a cylindrical shape having an oval cross-section, a square column shape, a hexagonal column shape, or an octagonal column shape. The bottom surface of the electrical connection portion (321) of the terminal insertion portion (320) may be formed to be at least partially substantially flat.

[0061] The connection between the bottom surface of the center area of ​​the terminal insertion portion (320) and the positive electrode collector plate (510) can be made by, for example, laser welding, spot welding or ultrasonic welding.

[0062] The above welding can be performed by forming a welding bead on one side of the positive electrode collector (510) (the side facing the hole formed at the center of the winding of the electrode assembly (100)) by irradiating a laser through a hole formed at the center of the winding of the electrode assembly (100) or by inserting a tool for ultrasonic welding or spot welding. A guide pipe (not shown) for welding can be inserted into the hole formed at the center of the winding. When the welding is performed with the guide pipe inserted, the risk of damage to the separator forming the inner wall surface of the hole formed at the center of the winding can be reduced.

[0063] The above can lid (400) is configured to seal the opening (O) of the can housing (200) and can be configured to be fitted into the inside of the open end (210) of the can housing (200) in a circular shape that can cover the opening (O).

[0064] The can lid (400) according to the present embodiment may be provided with a vent notch (420) configured to rupture when the pressure inside the can housing (200) exceeds a threshold. For example, the vent notch (420) may be formed on both sides of the can lid (400), and may be formed in at least one pattern among a continuous circular pattern, a discontinuous circular pattern, and a linear pattern on the surface of the can lid (400). In addition, the vent notch (420) may be formed in various other patterns.

[0065] In addition, referring to FIG. 5, the can lid (400) may have an electrolyte injection hole (430) at its center. The electrolyte injection hole (430) may be configured to face a hollow portion formed at the center of the core of the electrode assembly (100). In addition, the negative electrode collector plate (520) may have a center hole at its center facing the electrolyte injection hole (430).

[0066] For example, after the can lid (400) is coupled to the open end (210) of the can housing (200), the electrolyte can be injected into the interior of the can housing (200) through the electrolyte injection hole (430) and the center hole. The electrolyte injection hole (430) can be closed after the electrolyte injection is completed. The electrolyte injection hole (430) can be sealed with a lead hole cap (450) provided in the shape of a metal disc. As an alternative to the present embodiment, the electrolyte injection hole (430) can be sealed by pressing a ball (not shown) into the electrolyte injection hole (430). In this case, welding can be performed or an adhesive can be applied to the contact interface between the ball and the electrolyte injection hole (430). Unlike the present embodiment, the electrolyte injection can also be performed by making a hole in the cell terminal (300) provided in the closing part (220) of the can housing (200), injecting the electrolyte, and closing the hole. In this case, the can lead (400) may have the lead hole cap (450) and the electrolyte injection hole (430) omitted.

[0067] The can lid (400) includes a lid side portion (410) forming its outer perimeter, and the lid side portion (410) may be configured to be fitted to the inner surface of the open end (210) of the can housing (200) with a portion of the negative electrode collector plate (520) interposed therebetween. Preferably, as illustrated in FIGS. 6 to 8, the lid side portion (410) of the can lid (400) may be configured to be fitted to the inner surface of the open end (210) of the can housing (200) with an end portion (523) of the negative electrode collector plate (520) interposed therebetween.

[0068] In this embodiment, the open end (210) of the can housing (200) has a thickness that gradually decreases toward the end and has an inclined portion (211) on the inner surface. The angle of the inclined portion (211) is about 15° to 25°, and the length of the inclined portion (211) may be 0.2 mm to 2 mm. The open end (210) has a shape that tapers as it goes in the height direction. In addition, the open end (210) has an inclined portion (211) on the inner surface, and the outer surface extends straight in the height direction. Therefore, the can housing (200) does not have a diameter change in the height direction when viewed from the outside.

[0069] The inclined portion (211) provided on the inner surface of the open end (210) serves to guide the forced fitting of the can lid (400) into the can housing (200). That is, when assembling the can lid (400) into the can housing (200), the inclined portion (211) of the open end (210) guides the insertion of the can lid (400), thereby increasing the convenience and airtightness of assembly between the open end (210) of the can housing (200) and the lid side portion (410) of the can lid (400), and reducing the alignment error.

[0070] The lead side portion (410) of the can lead (400) may include a first lead side portion (411) that is inclined parallel to the inclined portion (211) of the open end portion (210) and a second lead side portion (412) that overlaps the end (213) of the open end portion (210) in the height direction.

[0071] And the negative electrode collector plate (520) may be provided so that its end is positioned at a height corresponding to the inclined portion (211) of the open end (210). In other words, the negative electrode collector plate (520) may be provided so that its end is positioned at a height corresponding to any point from the starting point to the ending point of the inclined portion (211). For example, as illustrated in FIG. 7, when the end portion (523) of the negative electrode collector plate (520) is vertically erected, the end portion (523) of the negative electrode collector plate (520) may be provided in a form that extends in the vertical direction so that the end portion of the negative electrode collector plate (520) is positioned on the same plane as the end portion (213) of the open end (210).

[0072] According to the configuration of the can housing (200), the can lid (400), and the negative electrode collector plate (520), when the can lid (400) is inserted into the open end (210) of the can housing (200), the end portion (523) of the negative electrode collector plate (520) can be bent toward the inclined portion (211) of the open end (210) by being pressed by the first lead side portion (411) of the can lid (400). That is, the first lead side portion (411) of the can lid (400) can be forcibly fitted into the inclined portion (211) of the open end (210) while pressing the negative electrode collector plate (520) toward the inclined portion (211). In this case, the end portion (523) of the negative electrode collector plate (520) can be pressed and fixed to the first lead side portion (411) of the can lid (400) and the inclined portion (211) of the open end (210). Therefore, welding between the negative electrode collector plate (520) and the can housing (200) can be omitted. The negative electrode collector plate (520) is electrically connected to the can lid (400) and the can housing (200).

[0073] Additionally, the second lead side portion (412) of the can lead (400) can be mounted on the end (213), i.e., the upper end, of the open end (210). The second lead side portion (412) is provided such that its horizontal surface contacts the end (213) of the open end (210) and its vertical surface is parallel to the outer surface of the open end (210).

[0074] When the second lid side portion (412) is seated at the end (213) of the open end (210), the first lid side portion (411) is not inserted below the inclined portion (211) from the inside of the can housing (200). In this way, by allowing the second lid side portion (412) to be seated at the upper end of the open end (210) and thereby limiting the insertion depth of the can lid (400), the first lid side portion (411) is not forcibly fitted below the inclined portion (412), so that the pressure due to the forcible fitting of the can lid (400) does not excessively act on the inner wall of the can housing (200). Accordingly, it is possible to prevent the outer diameter of the can housing (200) from changing due to over-assembly or incorrect assembly of the can lid (400).

[0075] Meanwhile, referring to FIGS. 7 and 8, the negative electrode collector plate (520) may have a bent portion (522) that is not interposed between the first lead side portion (411) and the inclined portion (211) welded (W1) to the inner surface of the open end (210). For example, before inserting the can lid (400) into the can housing (200), the bent portion (522) of the negative electrode collector plate (520) and the inner surface of the open end (210) are welded together. In this case, the lower part of the end portion (523) of the negative electrode collector plate (520) may be fixed. Then, when the end portion (523) of the negative electrode collector plate (520) is pressed by the first lead side portion (411) in the process of inserting the can lid (400) into the can housing (200), the circular portion (521) of the negative electrode collector plate (520) does not move based on the welded and fixed point, and only the end portion (523) of the negative electrode collector plate (520) can be bent. Therefore, a forced fit assembly between the first lead side portion (411) of the can lid (400), the end portion (523) of the negative electrode collector plate (520), and the open end (210) of the can housing (200) can be easily performed without tolerance.

[0076] Referring to Fig. 9, the first lead side portion (411) is forcefully fitted to the inclined portion of the open end portion (210) with the end portion (523) of the negative electrode collector (520) interposed therebetween, and then the end portion of the second lead side portion (412) and the open end portion (210) are side-welded (W2).

[0077] Laser welding can be accommodated at the contact interface between the second lead side portion (412) and the end of the open end (210). The second lead side portion (412) and the end (213) of the open end (210) can be side-welded (W2) along the circumferential direction of the can housing (200). That is, the battery cell (10) according to the present embodiment is configured such that the second lead side portion (412) of the can lid (400) is seated on the upper portion of the end (213) of the open end (210). Accordingly, the can lid (400) and the can housing (200) can be fixedly connected through the side welding (W2). The contact interface between the second lead side portion (412) and the end (213) of the open end (210) is a welding target, and welding can be continuously performed along the circumferential direction of the cylindrical battery cell (10). According to this implementation configuration, even if the first lead side portion (411) of the can lid (400) is forcefully fitted to the inner surface of the open end (210), the pressure applied to the inner surface of the open end (210) can be distributed. Therefore, it is possible to suppress an increase in the outer diameter of the can housing (200) due to the forceful fitting of the can lid (400).

[0078] According to the present invention described above, the battery cell (10) has a structure in which the can lead (400) is forcibly fitted into the open end (210) of the can housing (200) and is side-welded along the circumference of the battery cell (10), so that the energy density per unit volume is higher than that of a battery cell (10) to which a beading portion and a crimping portion (see FIG. 1) are applied in the prior art, and the assembly structure between the can housing (200) and the can lead (400) is simple.

[0079] In addition, the battery cell (10) according to the present invention can fix the can lead (400) and the negative electrode collector plate (520) to the can housing (200) as a single unit during the process of assembling the can housing (200) and the can lead (400), so that the contact, fixation, and ease of assembly between the can housing (200), the can lead (400), and the negative electrode collector plate (520) are excellent.

[0080] Next, with reference to FIGS. 10 and 11, battery cells according to other embodiments of the present invention will be described.

[0081] The same reference numerals as in the previous drawings indicate the same reference parts, and duplicate descriptions of the same reference parts will be omitted, and the differences from the previously described embodiment will be mainly explained.

[0082] A battery cell (10) according to another embodiment of the present invention, compared to the above-described embodiment, has a difference in the structure of the open end (210) of the can housing (200) where side welding is performed and the second lead side portion (412) of the can lead (400), and the remaining configuration and structure are substantially the same.

[0083] A battery cell (10) according to another embodiment of the present invention, as illustrated in FIG. 10, includes a welding target portion (WT) formed recessed from the outside to the inside of the can housing (200) at a portion where the second lead side portion (412) of the can lead (400) and the open end portion (210) of the can housing (200) vertically contact each other. For example, the welding target portion (WT) may be provided in a chamfered form at least one of the outer corner region of the second lead side portion (412) and the outer corner region of the open end (210) that face each other.

[0084] The above welding target portion (WT) may be provided at a position corresponding to the contact interface between the can housing (200) and the can lid (400). The welding target portion (WT) may be provided continuously along the circumferential direction of the can housing (200). This welding target portion (WT) may function as a welding guide line that guides the location where welding is to be performed when welding the can housing (200) and the can lid (400).

[0085] In addition, according to the configuration of the welding target portion (WT) according to another embodiment of the present invention, when side welding is performed along the circumferential direction at the contact interface between the can housing (200) and the can lid (400), an increase in the outer diameter due to the welding bead (WB) can be prevented. For example, when a laser is irradiated to the welding target portion (WT), the first lid side portion (411) and the open end (210) are locally melted and then solidified to generate a welding bead (WB). At this time, as shown in FIG. 11, the welding bead (WB) can fill the inner space of the welding target portion (WT). In this case, when side welding is performed, the welding bead (WB) does not protrude beyond the outer surface of the can housing (200), making it easy to manage the outer diameter of the can housing (200).

[0086] In addition, the end portion (523) of the negative electrode collector plate (520) is configured to be positioned at a height corresponding to the contact interface between the open end portion (210) and the second lead side portion (412). At least the end portion of the end portion (523) of the negative electrode collector plate (520) is configured to be positioned on the same plane as the welding target portion. In this case, when the can housing (200) and the can lid (400) are side-welded, the negative electrode collector plate (520) can be welded together at the same time. That is, the battery cell (10) according to another embodiment of the present invention may have a weld bead (WB) formed by heat melting the open end portion (210), the second lead side portion (412), and the end portion (523) of the negative electrode collector plate (520).

[0087] The battery cell (10) according to another embodiment of the present invention described above has a welding target portion (WT), so that the depth of the metal that must be melted by laser irradiation during laser welding is reduced. Therefore, the second lead side portion (412), the open end portion (210), and the end portion (523) of the negative electrode current collector (520) can be melted and joined as a single body with a relatively low laser output. In addition, laser welding makes it difficult to create a uniform weld bead (WB) if the laser focus position does not exactly match the metal surface. In the case of the battery cell (10) of the present invention, the laser irradiation position can be precisely guided by the welding target portion (WT) continuously provided along the circumferential direction of the battery cell (10), which is advantageous in creating a uniform weld bead (WB).

[0088] In addition, according to the configuration according to another embodiment of the present invention described above, the can housing (200), the can lid (400), and the negative electrode collector plate (520) can be fixedly joined to each other with a single welding process. In addition, according to the present invention, the work of welding the can housing (200) and the negative electrode collector plate (520) to make the can housing (200) have a negative polarity, and the work of welding the can lid (400) to the can housing (200) to seal the can housing (200) can be accomplished at once. Therefore, the number of assembly processes of the battery cell (10) is reduced, thereby improving process efficiency and shortening the cycle time.

[0089] Meanwhile, the battery cell (10) as described above can be accommodated in a pack case of a battery pack (P) as illustrated in FIG. 12. The battery pack (P) may be configured using a battery module, which is an intermediate form of assembly, or may be configured using the battery cell (10) directly without a battery module as illustrated. As in the present embodiment, a battery pack (P) in which the battery cell (10) is accommodated directly in the pack case of the battery pack (P) without configuring a battery module can be implemented with a higher energy density.

[0090] A battery pack (P) with such a high energy density can store the same amount of energy while reducing its volume and weight. Therefore, when a battery pack (P) equipped with such battery cells (10) is installed in a vehicle (V) that uses electricity as its energy source, as illustrated in Fig. 13, the vehicle's mileage relative to its energy consumption can be further increased.

[0091] A vehicle (V) according to one embodiment of the present invention includes a battery pack (P) according to one embodiment of the present invention. The vehicle (V) may be configured to operate by receiving power from the battery pack (P) according to one embodiment of the present invention.

[0092] It should be understood that the above-described embodiments are illustrative in all respects and not restrictive, and the scope of the present invention will be determined by the claims that follow, rather than by the detailed description set forth above. Furthermore, the meaning and scope of the claims that follow, as well as all possible modifications and variations derived from their equivalent concepts, should be construed as encompassing the scope of the present invention.

[0093] Although the present invention has been described with reference to the drawings exemplified above, it is to be understood that the present invention is not limited to the embodiments and drawings disclosed herein, and that various modifications may be made by those skilled in the art within the scope of the technical idea of ​​the present invention. Furthermore, even if the operational effects according to the configuration of the present invention have not been explicitly described while describing the embodiments of the present invention, it is natural that the effects predictable by the corresponding configuration should also be acknowledged.

Claims

1. An electrode assembly in which a first electrode, a second electrode, and a separator interposed therebetween are wound around a winding axis; A can housing having an open end so that the electrode assembly can be inserted therein; A cell terminal electrically connected to the first electrode and provided in the closed portion of the can housing located opposite the open end; An electrode collector plate electrically connected to the second electrode and configured to contact the inner surface of the open end; and A can lid is included that is mutually coupled with the open end to seal the can housing, A battery cell characterized in that the can lead includes a lead side portion forming its outer perimeter, and the lead side portion is fitted to the inner surface of the open end with the end portion of the electrode current collector forming the outermost edge of the electrode current collector being interposed therebetween.

2. In paragraph 1, A battery cell characterized in that the open end is configured to have a sloped portion on the inner surface of the open end so that the thickness gradually decreases toward the end.

3. In paragraph 2, A battery cell characterized in that the end portion of the electrode collector plate is pressed and fixed between the lead side portion and the inclined portion.

4. In paragraph 2, A battery cell characterized in that the end portion of the electrode collector plate is extended in the height direction so as to be positioned at a height corresponding to the inclined portion.

5. In paragraph 2, The above lead side part A first lead side portion inclined parallel to the above-mentioned slope; and A battery cell characterized by including a second lead side portion that overlaps the end of the open end portion in the height direction.

6. In paragraph 5, The first lead side portion is forcibly fitted into the inclined portion of the open end with the end portion of the electrode collector plate interposed therebetween, A battery cell characterized in that the second lead side portion has a horizontal surface that contacts the end of the open end and a vertical surface that is arranged parallel to the outer surface of the open end.

7. In paragraph 5, A battery cell characterized in that the end portion of the electrode collector plate is pressed and fixed between the first lead side portion and the inclined portion.

8. In paragraph 5, A battery cell characterized in that the second lead side portion and the end of the open end are side-welded along the circumferential direction of the can housing.

9. In paragraph 5, Including a welding target portion formed recessed inwardly from the outside of the can housing at a portion where the second lead side portion and the open end are in vertical contact, A battery cell characterized in that a welding bead is formed at the above welding target portion.

10. In paragraph 9, A battery cell characterized in that the welding target portion is provided in a chamfered shape at least in one of the outer corner area of ​​the second lead side portion facing each other and the outer corner area of ​​the open end.

11. In paragraph 9, A battery cell characterized in that the above welding target portion is continuously provided along the circumferential direction of the can housing.

12. In paragraph 9, A battery cell characterized in that the welding bead is formed by thermal melting of the second lead side portion, the open end portion, and the end portion of the electrode current collector plate.

13. In paragraph 1, The above electrode collector plate is, A circular portion that is mounted on the winding surface of the electrode assembly and welded to the second electrode; A bent portion that is bent at the edge of the above-mentioned disc portion and contacts the inner surface of the above-mentioned open end portion; and A battery cell characterized by including an end portion of the electrode current collector plate that forms an outermost rim and is pressed and fixed between the lead side portion and the inner surface of the open end portion.

14. A battery pack comprising a battery cell according to any one of claims 1 to 13.

15. A vehicle characterized by including a battery pack according to Article 14.