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

Abstract

The battery cell according to the present invention comprises: an electrode assembly, wherein a first electrode, a second electrode, and a separator interposed between the first electrode and the second electrode are wound around a winding axis; a can housing having an open end such that the electrode assembly can be inserted into the can housing; a cell terminal electrically connected to the first electrode and disposed on a closure portion of the can housing located opposite the open end; an electrode current collector electrically connected to the second electrode and contacting the inner surface of the open end; and a can lid interconnected with the open end to seal the can housing, wherein the can lid includes a cover side portion forming its outer periphery, and the cover side portion can be fitted and connected to the inner surface of the open end, wherein the electrode current collector end portion forming the outermost edge of the electrode current collector is inserted between the cover side portion and the inner surface of the open end.

Description

Technical Field

[0001] This disclosure relates to a battery cell, a battery pack including the battery cell, and a vehicle, and more specifically, to a battery cell having an improved assembly structure between a can housing and a can lid, and a battery pack including the battery cell and a vehicle.

[0002] This application is based on and claims priority to Korean Patent Application No. 10-2024-0091321 filed with the Korean Intellectual Property Office on July 10, 2024, and Korean Patent Application No. 10-2025-0083248 filed on June 24, 2025, the disclosures of which are incorporated herein by reference in their entirety. Background Technology

[0003] Rechargeable batteries offer high applicability across various product categories and possess electrical characteristics such as high energy density. They are widely used not only in portable devices but also in electric vehicles (EVs) and hybrid electric vehicles (HEVs) powered by electric sources.

[0004] This type of secondary battery is attracting attention not only because of its major advantage of significantly reducing the use of fossil fuels, but also because it does not produce byproducts from energy use, making it a new energy source that enhances environmental sustainability and energy efficiency.

[0005] Currently widely used rechargeable batteries include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. These cell units typically operate at voltages between approximately 2.5V and 4.5V. Therefore, when a higher output voltage is required, multiple battery cells can be connected in series to form a battery pack. Furthermore, depending on the required charge / discharge capacity of the battery pack, multiple battery cells can be connected in parallel to form a battery pack. The number of battery cells included in a battery pack and their electrical connections can be configured in various ways according to the required output voltage or charge / discharge capacity.

[0006] Meanwhile, secondary batteries can be classified according to their shape into cylindrical battery cells, prismatic battery cells, and pouch battery cells. For example... Figure 1 As shown, a conventional cylindrical battery cell includes a beading portion 1 and a crimping portion 2. The beading portion 1 can be configured to be pressed inward in the region between an opening formed on one side of the can housing 3 and a receiving portion configured to accommodate an electrode assembly 4. Furthermore, the crimping portion 2 is configured to extend and bend to surround the edge of a battery cap 5 located on the beading portion 1. The crimping portion 2 can also secure a sealing gasket 6 and the battery cap 5. A cylindrical battery cell with the beading portion 1 and the crimping portion 2 has the advantage of easily securing the negative electrode current collector 7 and ensuring excellent airtightness between the can housing 3 and the battery cap 5.

[0007] However, forming the rolled edge 1 and the crimped portion 2 requires precise processing, which is not a simple process. This can lead to frequent product defects during the rolling or crimping process, potentially reducing yield. Furthermore, it has been noted that cylindrical battery cells with rolled edge 1 and crimped portion 2 are disadvantageous in terms of energy density. Therefore, it is necessary to improve the sealing structure by removing the rolled edge 1 and crimped portion 2 from the can housing 5 and simplifying the sealing structure. Summary of the Invention

[0008] Technical issues

[0009] This disclosure was designed to address the problems in the related technologies, and therefore aims to provide a cylindrical battery cell with high energy density, and to improve and simplify the assembly structure between the can housing and the can lid by omitting the rolled edge or crimped portion.

[0010] Furthermore, this disclosure also aims to provide a cylindrical battery cell in which the can cover and the electrode current collector can be integrally fixed to the can cover when the can housing and the can cover are assembled.

[0011] Furthermore, this disclosure is also intended to prevent changes in the outer diameter of the tank shell during the assembly of the tank shell and the tank cover.

[0012] The technical problems to be solved by this disclosure are not limited to those described above. Those skilled in the art will clearly understand from the following description of the invention other problems not mentioned above.

[0013] Technical solution

[0014] In one aspect of this disclosure, a battery cell is provided, the battery cell comprising: an electrode assembly configured with a first electrode, a second electrode wound around a winding axis, and a separator inserted between the first electrode and the second electrode; a can housing having an open end, the electrode assembly being inserted into the can housing through the open end; a cell terminal electrically connected to the first electrode and disposed in a closed portion of the can housing opposite to 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 lid side forming its outer periphery, and wherein the lid side can be fitted to the inner surface of the open end, wherein an end portion of the electrode current collector forming the outermost edge of the electrode current collector is inserted between the lid side and the inner surface of the open end.

[0015] The opening end can be configured to have an inclined portion on the inner surface of the opening end, such that the thickness of the opening end gradually decreases toward the end of the opening end.

[0016] The end portion of the electrode current collector can be pressed and fixed between the cover side portion and the inclined portion.

[0017] The end portion of the electrode current collector can extend along the height direction to be located at a height corresponding to the inclined portion.

[0018] The cover side portion may include: a first cover side portion, which is inclined parallel to the inclined portion; and a second cover side portion, which is configured to overlap with the end of the opening end in the height direction.

[0019] The first cover side portion can be forcibly fitted to the inclined portion of the opening end, wherein the end portion of the electrode current collector is inserted between the first cover side portion and the inclined portion of the opening end, and the second cover side portion can be configured such that its horizontal surface contacts the end portion of the opening end, and its vertical surface is parallel to the outer surface of the opening end.

[0020] The end portion of the electrode current collector can be press-fitted between the first cover side portion and the inclined portion.

[0021] The second cover side and the end of the opening can be welded from the side along the circumferential direction of the tank shell.

[0022] The battery cell may also include a welding target portion, which is formed to be recessed from the outside of the can shell at the position where the second cover side and the opening end are in contact with each other vertically, and a weld may be formed in the welding target portion.

[0023] The welding target portion may be constructed in a chamfered form in at least one of the outer corner regions of the second cover side facing each other and the outer corner region of the opening end.

[0024] The welding target portion can be continuously formed along the circumferential direction of the tank shell.

[0025] The weld can be formed by thermally melting the second cover side, the opening end, and the end portion of the electrode current collector.

[0026] The electrode current collector may include: a disk portion disposed on the winding surface of the electrode assembly and welded to the second electrode; a bent portion bent from the edge of the disk portion to contact the inner surface of the opening end; and an end portion of the electrode current collector forming the outermost edge and press-fitted between the cover side portion and the inner surface of the opening end.

[0027] According to another aspect of this disclosure, a battery pack is provided that includes the aforementioned battery cells.

[0028] According to another aspect of this disclosure, a vehicle including the battery pack is provided.

[0029] Beneficial effects

[0030] According to this disclosure, a cylindrical battery cell with high energy density can be provided, and an improved and simplified assembly structure between the can housing and the can lid is provided by excluding the crimped portion or the crimped portion.

[0031] Furthermore, according to this disclosure, when assembling the tank shell and the tank cover, the tank cover and the electrode current collector can be integrally fixed to the tank shell.

[0032] Furthermore, according to this disclosure, changes in the outer diameter of the tank shell can be prevented during the assembly of the tank shell and the tank cover.

[0033] Furthermore, according to this disclosure, the contact, fixation, and assemblability between the tank shell, the tank cover, and the electrode current collector can be improved.

[0034] The effects that can be obtained from this disclosure are not limited to those described above, and other effects not mentioned above will be clearly understood by those skilled in the art based on the description of the invention below. Attached Figure Description

[0035] Figure 1 This is a schematic partial cross-sectional view of a conventional cylindrical battery cell.

[0036] Figure 2 This is a schematic perspective view of a cylindrical battery cell according to an embodiment of the present disclosure.

[0037] Figure 3 This is a schematic cross-sectional view of a cylindrical battery cell according to an embodiment of the present disclosure.

[0038] Figure 4 This is an enlarged view of the closure portion of the tank shell according to an embodiment of the present disclosure.

[0039] Figure 5 This is an exploded perspective view of a cylindrical battery cell according to an embodiment of the present disclosure.

[0040] Figure 6 This is a diagram illustrating a can housing comprising an electrode assembly and a can lid that are separate from each other, according to an embodiment of the present disclosure.

[0041] Figure 7 yes Figure 6 A magnified view of a portion of the image.

[0042] Figure 8 It is shown Figure 6 A diagram showing an example of the can lid and electrode current collector being assembled into the open end of the can shell.

[0043] Figure 9 This is a diagram illustrating an example of a side weld between a tank shell and a tank cover according to an embodiment of the present disclosure.

[0044] Figure 10 This is a partial cross-sectional view of a tank shell and a tank cover with welded target portions applied, according to another embodiment of this disclosure.

[0045] Figure 11 This is a diagram illustrating an example of a triple-welded tank shell, tank cover, and electrode current collector according to another embodiment of this disclosure.

[0046] Figure 12 This is a schematic diagram illustrating a battery pack including battery cells according to embodiments of the present disclosure.

[0047] Figure 13 It is schematically shown that includes Figure 12 A diagram of a vehicle with a battery pack. Detailed Implementation

[0048] The preferred embodiments of this disclosure will now be described in detail with reference to the accompanying drawings. Before the description, it should be understood that the terminology used in the specification and appended claims should not be construed as limited to its general and dictionary meaning, but rather should be interpreted according to the meaning and concept corresponding to the technical aspects of this disclosure, based on the principle that allows the inventor to appropriately define terms for best interpretation. Therefore, the description presented herein is merely a preferred example for illustrative purposes and does not represent the entire scope of this disclosure; thus, it should be understood that other equivalents and modifications may be made to these examples without departing from the scope of this disclosure at the time of filing. Throughout the specification, unless otherwise stated, corresponding elements may include one or more elements.

[0049] For ease of explanation, in this specification, the longitudinal direction of the winding axis of the electrode assembly 100 wound in the form of a core will be referred to as the axial direction. Furthermore, the direction around the winding axis will be referred to as the circumferential direction. Additionally, the direction approaching or away from the winding axis will be referred to as the radial direction. The direction approaching the winding axis is called the centripetal direction, while the direction away from the winding axis is called the centrifugal direction.

[0050] Figure 2 This is a schematic perspective view of a cylindrical battery cell according to an embodiment of the present disclosure, and Figure 3 This is a schematic cross-sectional view of a cylindrical battery cell according to an embodiment of the present disclosure.

[0051] refer to Figure 2 and Figure 3 According to embodiments of the present disclosure, the battery cell 10 includes an electrode assembly 100, a can housing 200, a cell terminal 300, an electrode current collector, and a can cap 400.

[0052] Electrode assembly 100 has a structure in which a first electrode, a second electrode, and a diaphragm inserted between the first and second electrodes are wound around a winding axis, thereby defining a core and an outer peripheral surface. Electrode assembly 100 may be a wound-core type electrode assembly 100. An additional diaphragm may be disposed on the outer peripheral surface of electrode assembly 100 to insulate it from can housing 200. Electrode assembly 100 may have, but is not limited to, winding structures known in the art. The first electrode refers to an electrode having one of positive and negative polarities, while the second electrode refers to an electrode having a polarity opposite to that of the first electrode.

[0053] The first electrode includes a first electrode current collector and a first electrode active material coated on one or both surfaces of the first electrode current collector. An uncoated portion, without the first electrode active material, is disposed on the first electrode along its width direction (parallel to...). Figure 3 The cylindrical battery cell 10 shown is located at one end in the height direction Z. That is, the first electrode includes an uncoated portion located at the end of the long side along the winding direction of the first electrode, on which the active material is not coated to expose the exterior of the separator. The uncoated portion serving as the first electrode tab will be referred to as the first uncoated portion 111. The first uncoated portion 111 is provided in the electrode assembly 100 housed within the can housing 200 (in the height direction Z). Figure 3 (As shown in the cylindrical battery cell 10). That is, the first electrode includes a first uncoated portion disposed at the long side end, on which no active material layer is coated to expose the outside of the separator, and at least a portion of the first uncoated portion 111 serves as the electrode tab itself. The first uncoated portion 111 may be, for example, a positive electrode tab.

[0054] At least a portion of the first uncoated portion 111 may include multiple segments divided along the winding direction of the electrode assembly 100. In this case, the multiple segments may be bent along the radial direction of the electrode assembly 100. The bent multiple segments may overlap each other in multiple layers. An electrode current collector may be disposed below the first uncoated portion 111. For example, the first uncoated portion 111 and the electrode current collector may be connected by welding. In this case, the electrode current collector has the same positive polarity as the first uncoated portion 111 and will be referred to hereinafter as the positive electrode current collector 510.

[0055] The second electrode includes a second electrode current collector and a second electrode active material coated on one or both surfaces of the second electrode current collector. An uncoated portion, without the second electrode active material, is provided at the other end of the second electrode current collector along its width direction (parallel to the Z-axis). This uncoated portion, serving as the second electrode tab, will be referred to hereinafter as the second uncoated portion 121. The second uncoated portion 121 may be provided on the upper part of the electrode assembly 100, which is housed within the can housing 200 (in...). Figure 3 (As shown in the cylindrical battery cell 10). That is, the second electrode current collector includes a second uncoated portion 121 disposed at its long side end, on which no active material layer is coated to expose the outside of the separator, and at least a portion of the second uncoated portion 121 serves as the electrode tab itself. The second uncoated portion 121 may be, for example, a negative electrode tab.

[0056] At least a portion of the second uncoated portion 121 may include multiple segments divided along the winding direction of the electrode assembly 100. In this case, the multiple segments may be bent in the radial direction of the electrode assembly 100. The bent multiple segments may overlap each other in multiple layers. An electrode current collector may be disposed on top of the second uncoated portion 121. For example, the second uncoated portion 121 and the electrode current collector may be connected by welding. In this case, the electrode current collector has the same negative polarity as the second uncoated portion 121 and will be referred to hereinafter as the negative electrode current collector 520.

[0057] As described above, the first uncoated portion 111 and the second uncoated portion 121 extend in opposite directions along the height direction (parallel to the Z-axis) of the cylindrical battery cell 10. The first uncoated portion 111 faces the closed portion 220 of the can housing 200, and the second uncoated portion 121 faces the opening O of the can housing 200 that is positioned opposite to the closed portion 220.

[0058] The can shell 200 is a generally cylindrical container with an opening O formed at the top (see...). Figure 5The can housing 200 is made of a conductive material such as metal. It can be made of, for example, steel, stainless steel, or nickel-plated steel. In the following text, the upper edge of the can housing 200 forming the opening O will be referred to as the opening end 210. The lower portion of the can housing 200, positioned opposite the opening O, will be referred to as the closing portion 220. The side portion (outer peripheral surface) of the can housing 200 and the closing portion 220 can be integrally formed. The lower surface of the can housing 200 (parallel to the XY plane), i.e., the surface of the closing portion 220, can be configured to be substantially flat. The can housing 200 can receive the electrode assembly 100 through the opening O formed at the top.

[0059] The can housing 200 is electrically connected to the electrode assembly 100. The can housing 200 is also electrically connected to, for example, a second uncoated portion 121 of the electrode assembly 100. The can housing 200 can be configured to directly contact a negative current collector 520 connected to the second uncoated portion 121. In this case, the can housing 200 has the same negative polarity as the second uncoated portion 121.

[0060] In this embodiment, the negative electrode current collector 520, which is an electrode current collector electrically connected to the second electrode, includes a disk portion 521, a bent portion 522, and an end portion 523 corresponding to the outermost edge, such as... Figure 3 and Figure 6 As shown. The disc portion 521 can be disposed on the winding surface of the electrode assembly 100 and welded to the second uncoated portion 121 of the second electrode. The bent portion 522 can be configured to bend from the edge of the disc portion 521 and contact the inner surface of the opening end 210. In addition, the end portion 523 can be configured to be pressed and fixed between the cap side portion 410 of the can lid 400 (described later) and the inner surface of the opening end 210 of the can housing 200. The end portion 523 of the negative electrode current collector 520 can be pressed and fixed to the inclined portion 211 of the opening end 210, and the bent portion 522 can be welded to the inner surface of the opening end 210 from below the inclined portion 211. This will be described in more detail later.

[0061] The cell terminal 300 is made of a conductive metallic material. For example, aluminum (Al) can be used as the material for the cell terminal 300. When the cell terminal 300 is made of aluminum, 10-series aluminum with relatively low resistance can be applied to facilitate the riveting process, as described later. The cell terminal 300 is mounted on the lower surface of the can housing 200, i.e., on the closure portion 220 of the can housing 200. The cell terminal 300 is electrically connected to the first uncoated portion 111 of the electrode assembly 100. In this case, the cell terminal 300 has a first polarity, i.e., a positive polarity. Therefore, the cell terminal 300 can be used as the positive terminal in the cylindrical battery cell 10 of this disclosure. The cell terminal 300 is electrically insulated from the can housing 200, which has a negative polarity. The electrical insulation between the cell terminal 300 and the can housing 200 can be achieved in various ways. For example, the insulator 600 can be inserted between the positive current collector 510 and the closed portion 220 of the can housing 200, and the insulating washer 330 can be inserted between the cell terminal 300 and the can housing 200 to achieve insulation.

[0062] Reference Figure 4 The battery 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 322. The terminal exposure portion 310 is exposed to the outside of the can housing 200. The terminal exposure portion 310 may be positioned approximately at the center of the closure portion 220 of the can housing 200. The maximum width of the terminal exposure portion 310 may be configured to be greater than the maximum width of the hole formed in the can housing 200 for inserting the battery cell terminal 300. That is, the outer diameter of the battery cell terminal 300 exposed to the outside of the closure portion 220 may be greater than the inner diameter of the through hole formed in the closure portion 220 of the can housing 200 to expose the battery cell terminal 300. Therefore, the cross-section of the through hole formed in the closure portion 220 to expose the battery cell terminal 300 may be included in the cross-section of the battery cell terminal 300 exposed to the outside of the closure portion 220. Furthermore, the portion of the cell terminal 300 exposed outside the closure 220 can cover at least a portion of the closure 220 of the can housing 200 in the axial direction. The terminal insertion portion 320 can pass substantially through the center of the closure 220 of the can housing 200, and the electrical connection portion 321 of the terminal insertion portion 320 can be electrically connected to the first uncoated portion 111. The flange 322 of the terminal insertion portion 320 can be formed on the periphery of the electrical connection portion 321 and can be riveted to the inner surface of the closure 220 of the can housing 200. That is, the flange 322 of the terminal insertion portion 320 can have a shape that bends toward the inner surface of the closure 220 of the can housing 200. Therefore, the maximum width of the terminal insertion portion 320 after performing the riveting process for fixing the cell terminal 300 can be configured to be greater than the maximum width of the hole formed in the can housing 200 through which the terminal insertion portion 320 passes.

[0063] The electrical connection portion 321 of the terminal insertion portion 320 can be connected to the positive current collector 510. The electrical connection portion 321 of the terminal insertion portion 320 can have, for example, an approximately cylindrical shape. The shape of the electrical connection portion 321 of the terminal insertion portion 320 is not limited to this. The electrical connection portion 321 of the terminal insertion portion 320 can have various shapes, such as a cylindrical shape with an elliptical cross-section, a square prism shape, a hexagonal prism shape, or an octagonal prism shape. The bottom surface of the electrical connection portion 321 of the terminal insertion portion 320 can be substantially formed to be at least partially flat.

[0064] The connection between the bottom surface of the central region of the terminal insertion portion 320 and the positive current collector 510 can be achieved, for example, by laser welding, spot welding or ultrasonic welding.

[0065] Welding can be performed by irradiating a laser beam through a hole formed in the winding center of the electrode assembly 100, or by inserting a tool for ultrasonic welding or spot welding to form a weld on a surface of the positive current collector 510 (the surface facing the hole formed in the winding center of the electrode assembly 100). A guide tube (not shown) for welding can be inserted into the hole formed in the winding center. When welding is performed with the guide tube inserted, the risk of damage to the diaphragm on the inner wall of the hole formed in the winding center can be reduced.

[0066] The can lid 400 is configured to seal the opening O of the can housing 200. The can lid 400 may be configured as a disc capable of covering the opening O, so as to be press-fitted into the open end 210 of the can housing 200.

[0067] The can lid 400 according to this embodiment may include a venting cut 420 configured to rupture when the pressure within the can housing 200 exceeds a threshold. For example, the venting cut 420 may be formed on both sides of the can lid 400 and may be formed on the surface of the can lid 400 in at least one of a continuous circular pattern, a discontinuous circular pattern, and a linear pattern. Furthermore, the venting cut 420 may be formed in various other patterns.

[0068] refer to Figure 5 The can lid 400 may include an electrolyte injection hole 430 at its center. The electrolyte injection hole 430 may be configured to face a hollow space formed at the center of the core of the electrode assembly 100. The negative electrode current collector 520 may have a central hole at its center, which faces the electrolyte injection hole 430.

[0069] For example, after the can lid 400 is attached to the open end 210 of the can housing 200, 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 cap 450 provided in the form of a metal disc. As an alternative to this embodiment, a ball (not shown) can be squeezed and inserted into the electrolyte injection hole 430 to seal 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 this embodiment, the electrolyte injection process can also be performed by drilling a hole in the cell terminal 300 provided in the closed portion 220 of the can housing 200, injecting electrolyte, and then sealing the hole. In this case, the can lid 400 may not include the cap 450 and the electrolyte injection hole 430.

[0070] The can lid 400 may include a lid side 410 forming its outer periphery, and the lid side 410 may be configured to fit onto the inner surface of the opening end 210 of the can housing 200, wherein a portion of the negative electrode current collector 520 is inserted between the lid side 410 and the inner surface of the opening end 210. Preferably, as Figures 6 to 8 As shown, the lid side 410 of the can lid 400 can be configured to be fitted to the inner surface of the opening end 210 of the can housing 200, wherein the end portion 523 of the negative current collector 520 is inserted between the lid side and the inner surface of the opening end 210.

[0071] In this embodiment, the opening end 210 of the can shell 200 has an inclined portion 211 on its inner surface, the inclined portion having a thickness that gradually decreases towards the end. The angle of the inclined portion 211 can be approximately 15° to 25°, and the length of the inclined portion 211 can be 0.2 mm to 2 mm. The opening end 210 has a shape that tapers in the height direction. In addition, the opening end 210 has an inclined portion 211 on its inner surface, and its outer surface extends straight in the height direction. Therefore, when viewed from the outside, the can shell 200 does not have a diameter change in the height direction.

[0072] An inclined portion 211 provided on the inner surface of the opening end 210 is used to guide the force fit of the can lid 400 into the can housing 200. That is, when the can lid 400 is assembled into the can housing 200, the inclined portion 211 of the opening end 210 can guide the insertion of the can lid 400, thereby increasing the ease of assembly and airtightness between the opening end 210 of the can housing 200 and the lid side portion 410 of the can lid 400, and reducing alignment errors.

[0073] The lid side 410 of the can lid 400 may include a first lid side 411 inclined to the inclined portion 211 parallel to the opening end 210 and a second lid side 412 overlapping the end 213 of the opening end 210 in the height direction.

[0074] Furthermore, the negative electrode current collector 520 can be configured such that its end is positioned at a height corresponding to the inclined portion 211 of the opening end 210. That is, the negative electrode current collector 520 can be configured such 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... Figure 7 As shown, when the end portion 523 of the negative electrode current collector 520 is vertically arranged, the end portion 523 of the negative electrode current collector 520 can be configured to extend in the vertical direction, such that the end of the negative electrode current collector 520 is positioned on the same plane as the end portion 213 of the opening end 210.

[0075] Based on the construction of the can housing 200, can lid 400, and negative electrode current collector 520, when the can lid 400 is assembled into the open end 210 of the can housing 200, the end portion 523 of the negative electrode current collector 520 can be pressed by the first cover side portion 411 of the can lid 400 to bend towards the inclined portion 211 of the open end 210. That is, the first cover side portion 411 of the can lid 400 can be forcibly assembled into the inclined portion 211 of the open end 210 while pressing the negative electrode current collector 520 towards the inclined portion 211. In this case, the end portion 523 of the negative electrode current collector 520 can be fixed by being squeezed by the first cover side portion 411 of the can lid 400 and the inclined portion 211 of the open end 210. Therefore, welding between the negative electrode current collector 520 and the can housing 200 can be omitted. The negative electrode current collector 520 is electrically connected to the can lid 400 and the can housing 200.

[0076] Additionally, the second lid side 412 of the can lid 400 can be disposed on the end 213 (i.e., the upper end) of the opening end 210. The second lid side 412 is configured such that its horizontal surface contacts the end 213 of the opening end 210, and its vertical surface is parallel to the outer surface of the opening end 210.

[0077] When the second cap side portion 412 is positioned on the end 213 of the opening end 210, the first cap side portion 411 is no longer inserted below the inclined portion 211 within the can housing 200. As described above, by ensuring that the second cap side portion 412 is positioned on the upper end of the opening end 210 and limiting the insertion depth of the can cap 400, the first cap side portion 411 is not forcibly fitted below the inclined portion 412, thus preventing excessive pressure from the force-fit of the can cap 400 on the inner wall of the can housing 200. Therefore, changes in the outer diameter of the can housing 200 due to over- or incorrect assembly of the can cap 400 can be prevented.

[0078] refer to Figure 7 and Figure 8 The bent portion 522 of the negative electrode current collector 520 (which is not inserted between the first cover side portion 411 and the inclined portion 211) can be welded (see 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 current collector 520 and the inner surface of the open end 210 are welded to each other. In this case, the lower part of the end portion 523 of the negative electrode current collector 520 can be fixed. Then, during the process of inserting the can lid 400 into the can housing 200, when the end portion 523 of the negative electrode current collector 520 is pressed by the first cover side portion 411, the disc portion 521 of the negative electrode current collector 520 does not move at the weld fixing point, and only the end portion 523 of the negative electrode current collector 520 can be bent. Therefore, the force-fit assembly between the first cover side 411 of the can lid 400, the end portion 523 of the negative electrode current collector 520, and the opening end 210 of the can shell 200 can be easily performed without precise tolerance control.

[0079] refer to Figure 9 The first cover side 411 is press-fitted to the inclined portion of the opening end 210 (where the end portion 523 of the negative current collector 520 is inserted between the first cover side 411 and the inclined portion), and then the second cover side 412 and the end of the opening end 210 are welded from the side (see W2).

[0080] Laser welding can be performed at the contact interface between the second cover side 412 and the end of the opening 210. The second cover side 412 and the end 213 of the opening 210 can be welded laterally (W2) along the circumferential direction of the can housing 200. That is, the battery cell 10 according to this embodiment is configured such that the second cover side 412 of the can cover 400 is placed on the end 213 of the opening 210. Therefore, the can cover 400 and the can housing 200 can be fixed to each other by lateral welding (W2). The contact interface between the second cover side 412 and the end 213 of the opening 210 can be the welding target, and welding can be performed continuously along the circumferential direction of the cylindrical battery cell 10. According to this embodiment, even if the first cover side 411 of the can cover 400 is forcibly fitted to the inner surface of the opening 210, the pressure applied to the inner surface of the opening 210 can be dispersed. Therefore, the increase in the outer diameter of the can housing 200 due to the force fit of the can cover 400 can be suppressed.

[0081] According to the battery cell 10 disclosed above, since the can cap 400 is press-fitted into the opening end 210 of the can housing 200 and welded from the side along the circumferential direction of the battery cell 10, the energy density per unit volume is higher than that of the cells with rolled edges and press-fitted portions (see [link to original text]). Figure 1The energy density of the traditional battery cell 10 is higher, and the assembly structure between the can shell 200 and the can cover 400 is simple.

[0082] Furthermore, according to the battery cell 10 of this disclosure, the can cover 400 and the negative electrode current collector 520 can be integrally fixed to the can housing 200 during the assembly process of the can housing 200 and the can cover 400, thereby providing excellent contact, fixation and assemblability of the can housing 200, the can cover 400 and the negative electrode current collector 520.

[0083] Next, we will refer to Figure 10 and Figure 11 Describes battery cells according to other embodiments of this disclosure.

[0084] The same reference numerals as in the previous figures indicate the same parts, and redundant descriptions of the same parts will be omitted, focusing instead on the differences from the previous embodiments.

[0085] The battery cell 10 according to another embodiment of this disclosure differs from the aforementioned embodiment in that the structure of the opening end 210 of the can housing 200 and the second cover side 412 of the can cover 400 (where lateral welding is performed) is different, but the rest of the configuration and structure are basically the same.

[0086] like Figure 10 As shown, a battery cell 10 according to another embodiment of the present disclosure includes a welding target portion WT, which is formed to be recessed inward from the outside of the can housing 200 at a position where the second cover side portion 412 of the can cover 400 and the opening end 210 of the can housing 200 are in direct vertical contact with each other. For example, the welding target portion WT may be provided in a chamfered form in at least one of the outer corner regions of the second cover side portion 412 and the outer corner regions of the opening end 210.

[0087] The welding target part WT can be set at a position corresponding to the contact interface between the tank shell 200 and the tank cover 400. The welding target part WT can be continuously set along the circumferential direction of the tank shell 200. This welding target part WT can be used as a welding guide line to guide the welding point when welding the tank shell 200 and the tank cover 400.

[0088] Furthermore, in the construction of the welding target portion WT according to another embodiment of this disclosure, an increase in the outer diameter due to the weld seam WB can be prevented when the contact interface between the tank shell 200 and the tank cover 400 is laterally welded in the circumferential direction. For example, when the welding target portion WT is irradiated with a laser beam, the first cover side portion 411 and the opening end 210 partially melt and then solidify to produce the weld seam WB. In this case, as Figure 11As shown, the internal space of the welding target part WT can be filled with the weld seam WB. In addition, the weld seam WB does not protrude beyond the outer surface of the tank shell 200 during lateral welding, making it easy to manage the outer diameter of the tank shell 200.

[0089] Furthermore, the end portion 523 of the negative electrode current collector 520 is configured to be positioned at the height corresponding to the contact interface between the open end 210 and the second cover side portion 412. At least the end of the end portion 523 of the negative electrode current collector 520 is configured to be positioned on the same plane as the welding target portion. In this case, the negative electrode current collector 520 can be welded simultaneously when the can housing 200 and the can cover 400 are welded from the side. That is, the battery cell 10 according to another embodiment of the present disclosure may include a weld WB formed by thermally melting the open end 210, the second cover side portion 412, and the end portion 523 of the negative electrode current collector 520.

[0090] Since the battery cell 10 according to another embodiment of this disclosure includes a welding target portion WT, the depth of the metal that must be melted by laser irradiation during laser welding can be reduced. Therefore, the second cover side portion 412, the opening end 210, and the end portion 523 of the negative electrode current collector 520 can be integrally melted and joined using a relatively low laser output. Furthermore, if the laser focus position is not precisely aligned with the metal surface during laser welding, it is difficult to produce a uniform weld seam WB. In the case of the battery cell 10 of this disclosure, the laser irradiation position can be accurately guided by the welding target portion WT, which is continuously arranged along the circumferential direction of the battery cell 10, which is beneficial for producing a uniform weld seam WB.

[0091] Furthermore, according to another embodiment of the present disclosure, the can housing 200, the can lid 400, and the negative electrode current collector 520 can be joined to each other by a single welding process. Moreover, according to the present disclosure, the process of welding the can housing 200 and the negative electrode current collector 520 to ensure that the can housing 200 has negative polarity and the process of welding the can lid 400 to the can housing 200 to seal the can housing 200 can be completed simultaneously. Therefore, the number of assembly processes for the battery cell 10 can be reduced, thereby improving process efficiency and shortening cycle time.

[0092] The aforementioned battery cell 10 can be housed within the battery pack casing of the battery pack P, such as... Figure 12 As shown. The battery pack P can be constructed using battery modules in an intermediate assembly form, or it can be constructed directly using battery cells 10 without battery modules, as shown. As disclosed in this embodiment, the battery pack P in which battery cells 10 are directly housed within the battery pack housing without battery modules can provide higher energy density.

[0093] A battery pack P with this high energy density can store the same amount of energy while reducing its size 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, such as... Figure 13 As shown, this can further increase the vehicle's range per unit of energy.

[0094] A vehicle V according to an embodiment of the present disclosure includes a battery pack P according to an embodiment of the present disclosure. The vehicle V can be configured to operate using power supplied from the battery pack P according to an embodiment of the present disclosure.

[0095] The previously disclosed embodiments should be considered as being intended to describe embodiments of this disclosure, and not to limit them. Therefore, the scope of this disclosure, as defined by the following claims rather than the detailed description above, should be interpreted as encompassing the claims and all modifications and variations derived from the equivalent concepts of this disclosure.

[0096] As described above, although this disclosure has been described with reference to limited embodiments and accompanying drawings, this disclosure is not limited thereto, and various modifications and alterations can be made by those skilled in the art without departing from the technical concept of this disclosure and the equivalent scope of the claims described below. Furthermore, although the operational effects of the configuration according to this disclosure are not explicitly described in the foregoing description of the embodiments, it is apparent that the predictable effects produced by the configuration should also be considered within the scope of this disclosure.

Claims

1. A battery cell, the battery cell comprising: An electrode assembly, the electrode assembly being configured with a first electrode, a second electrode wound around a winding axis, and a diaphragm inserted between the first electrode and the second electrode; A can housing with an open end, through which the electrode assembly is inserted into the can housing; A cell terminal, which is electrically connected to the first electrode and disposed in a closed portion of the can housing opposite the open end; An electrode current collector is electrically connected to the second electrode and configured to contact the inner surface of the opening end; as well as A can lid, which is attached to the open end to seal the can body. The can lid includes a lid side portion forming its outer periphery, and The cover side portion is fitted to the inner surface of the opening end, and the end portion of the electrode current collector forming the outermost edge of the electrode current collector is inserted between the cover side portion and the inner surface of the opening end.

2. The battery cell according to claim 1, in, The opening end is configured to have an inclined portion on the inner surface of the opening end, such that the thickness of the opening end gradually decreases toward the end of the opening end.

3. The battery cell according to claim 2, in, The end portion of the electrode current collector is press-fitted between the cover side portion and the inclined portion.

4. The battery cell according to claim 2, in, The end portion of the electrode current collector extends along the height direction to be located at a height corresponding to the inclined portion.

5. The battery cell according to claim 2, in, The cover side includes: A first cover side portion, the first cover side portion being inclined parallel to the inclined portion; and The second cover side is configured to overlap the end of the opening end in the height direction.

6. The battery cell according to claim 5, in, The first cover side is forcibly fitted to the inclined portion of the opening end, and the end portion of the electrode current collector is inserted between the first cover side and the inclined portion of the opening end. The second cover side is configured such that its horizontal surface contacts the end of the opening, and its vertical surface is parallel to the outer surface of the opening.

7. The battery cell according to claim 5, in, The end portion of the electrode current collector is pressed and fixed between the first cover side portion and the inclined portion.

8. The battery cell according to claim 5, in, The second cover side and the end of the opening are welded from the side along the circumferential direction of the tank shell.

9. The battery cell according to claim 5, The battery cell also includes a welding target portion, which is formed to be recessed from the outside of the can housing at the position where the second cover side and the opening end are in contact with each other vertically. in, A weld is formed in the target area of ​​the welding.

10. The battery cell according to claim 9, in, The welding target portion is constructed in a chamfered form in at least one of the outer corner regions of the second cover side facing each other and the outer corner region of the opening end.

11. The battery cell according to claim 9, in, The welding target portion is formed continuously along the circumferential direction of the tank shell.

12. The battery cell according to claim 9, in, The weld is formed by thermally melting the second cover side, the opening end, and the end portion of the electrode current collector.

13. The battery cell according to claim 1, in, The electrode current collector includes: A disk portion, which is disposed on the winding surface of the electrode assembly and welded to the second electrode; A curved portion, the curved portion bending from the edge of the disk portion to contact the inner surface of the opening end; and The electrode current collector is formed at the outermost edge and press-fitted at the end portion between the inner surface of the cover side and the opening end.

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

15. A vehicle comprising the battery pack according to claim 14.

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