Aligner for welding battery cell, and method for aligning battery cell with welding device

Abstract

Provided is an aligner comprising: an imaging unit (75) which images a battery cell (90) so as to obtain an image (I) of the battery cell (90); a position correction unit (71) for correcting the position of at least one portion of the battery cell (90) with respect to a welding device (60); and a control unit (77) for detecting, in the image (I), one or more parts to be aligned (45, 47, 48) by using first information mathematically expressing a form that corresponds to or can correspond to at least one portion of the one or more parts to be aligned (45, 47, 48) of the battery cell (90), calculating, for each of the detected one or more parts to be aligned (45, 47, 48), an offset, which is the difference between an alignment reference position and the detected position, and controlling the position correction unit (71) such that that the offset is reduced.

Description

Alignment device for battery cell welding and method for aligning battery cells and welding device

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2024-0095983, dated July 19, 2024, and Korean Patent Application No. 10-2025-0090209, dated July 4, 2025, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to an alignment device for battery cell welding and a method for aligning a battery cell and a welding device, and more specifically, to a method for aligning a battery cell and a welding device, which can prevent defects by performing welding after checking whether a welding part is aligned, and an alignment device for battery cell welding to which such a method can be applied.

[0003] Cylindrical battery cells house jelly-roll-shaped electrode assemblies within a cylindrical metal can, making them more shock- and temperature-resistant than pouch-type batteries. Consequently, demand for can-type cells in vehicle battery packs is growing.

[0004] Conventional can-shaped battery cells electrically connect the electrodes and the can or terminals by bonding a separate tab member to the current collector of the electrode assembly and bonding the tab member to the can or terminal. However, in battery cells with this structure, the structure for electrically connecting the electrodes and terminals takes up a significant amount of internal space within the can. Furthermore, this electrical connection structure has limitations in reducing internal resistance because the current path is limited to the tab member. An electrical connection structure that makes it difficult to reduce internal resistance is unsuitable for application to large-capacity battery cells that carry high currents.

[0005] To increase energy density, cylindrical battery cells are being developed with increasing volume. Furthermore, technological development is being focused on maximizing the internal space of cylindrical battery cells, maximizing the volume of the electrode assembly within the space. Furthermore, active technological development is underway to reduce the internal resistance between the electrodes and terminals or cans of the electrode assembly.

[0006] Accordingly, a structure has recently been developed in which a non-coated portion of the current collector is exposed to the axial end of the electrode assembly, folded in a radial direction so that the folded non-coated portion forms a flat surface facing the axial direction, a current collector plate is welded to the surface, and the current collector plate is again joined to a can or terminal. According to this structure, the current path between the electrode and the can or terminal is widened to lower the internal resistance, while the space inside the can occupied by the electrical connection structure between the electrode and the can or terminal is minimized, thereby further increasing the energy density of the battery cell.

[0007] However, in these recent battery cell structures, if the welding positions of the current collector and the can are not precisely aligned when welding, the welding may be incomplete or weak, which may cause the current path to become narrower or the internal resistance to increase.

[0008] The present invention has been devised to solve the above-described problem, and provides an alignment method capable of accurately aligning a welding position of a battery cell with respect to a welding device for a welding process, and an alignment device capable of implementing the alignment method.

[0009] In addition, the present invention aims to provide an alignment method capable of accurately checking the alignment state of a battery cell with respect to a welding device immediately before welding of the battery cell, thereby preventing the occurrence of defects such as weak welding or no welding due to welding position alignment errors, and an alignment device capable of implementing such alignment method.

[0010] The technical objectives of the present invention are not limited to the aforementioned purposes. Other unmentioned objectives and advantages of the present invention can be understood through the following description and will be more clearly understood through the embodiments of the present invention. Furthermore, it will be readily apparent that the objectives and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims.

[0011] In order to solve the above-described problem, the present invention provides an alignment device including a photographing unit (75), a position correction unit (71), and a control unit (77).

[0012] The above-mentioned photographing unit (75) can photograph the battery cell (90) to obtain an image (I) of the battery cell (90).

[0013] The above position correction unit (71) can correct the position of at least a portion of the battery cell (90) with respect to the welding device (60).

[0014] The above control unit (77) can detect at least one alignment target portion (45, 47, 48) of the battery cell (90) in the image (I) using the first information.

[0015] The above first information may be information that mathematically expresses a shape (form) that corresponds or can correspond to at least a part of at least one of the alignment target portions (45, 47, 48).

[0016] The above control unit (77) can calculate an offset amount, which is the difference between the alignment reference position and the detection position, for each of at least one of the detected alignment target parts (45, 47, 48).

[0017] The above control unit (77) can control the position correction unit (71) so that the offset amount is reduced.

[0018] In one embodiment, the photographing unit (75) may include a coaxial light and a vision camera.

[0019] The above coaxial lighting can irradiate light to the battery cell (90) in a direction parallel to the axial direction of the battery cell (90).

[0020] The above vision camera can photograph the battery cell (90) in a direction parallel to the axial direction of the battery cell (90).

[0021] In one embodiment, the position correction unit (71) may include a motor.

[0022] The above motor may be capable of controlling the rotation angle about the rotation center axis.

[0023] The above rotation center axis and the center within the battery cell (90) can be aligned.

[0024] In one embodiment, the first information may include vector information.

[0025] The above vector information may be information that expresses the shape as a vector or can be expressed as a vector.

[0026] The above control unit (77) can detect at least one alignment target portion (45, 47, 48) using the above vector information.

[0027] In one embodiment, the photographing unit (75) can photograph the battery cell (90) to obtain the image (I) including the current collector (40) accommodated in the can (10) of the battery cell (90).

[0028] Each of the above alignment target portions (45, 47, 48) can be provided on the above current collector plate (40).

[0029] In one embodiment, each of the alignment target portions (45, 47, 48) may include a first portion (47), a second portion (48), and an extension portion (45).

[0030] The above first portion (47) and second portion (48) can be provided in the battery cell (90).

[0031] The first part (47) and the second part (48) can be spaced apart from each other.

[0032] The above extension portion (45) can be extended between the first portion (47) and the second portion (48) to connect the first portion (47) and the second portion (48).

[0033] In one embodiment, each of the extension portions (45) may extend radially with respect to the center (O) within the battery cell (90), or may extend obliquely with respect to the axial direction of the battery cell (90).

[0034] In one embodiment, the first information may include information mathematically representing a shape corresponding or capable of corresponding to a pair of first edges (V1).

[0035] The above pair of first edges (V1) can be defined by both ends in the width direction of the extension portion (45) of at least one of the alignment target portions (45, 47, 48).

[0036] The above width direction may intersect with the extension direction of the above extension portion (45).

[0037] The above control unit (77) can detect at least one alignment target portion (45, 47, 48) by detecting the pair of first edges (V1) in the image (I) using the above first information.

[0038] In one embodiment, the pair of first edges (V1) may be substantially parallel to the radial direction with respect to the center (O) within the battery cell (90).

[0039] In one embodiment, the first information may include information mathematically representing a shape corresponding or capable of corresponding to a pair of second edges (V2).

[0040] The above pair of second edges (V2) can be defined by the first portion (47) and the second portion (48) of at least one of the alignment target portions (45, 47, 48).

[0041] The above control unit (77) can detect at least one alignment target portion (45, 47, 48) by detecting the pair of second edges (V2) in the image (I) using the above first information.

[0042] In one embodiment, the pair of second edges (V2) may be substantially perpendicular to a radial direction with respect to a center (O) within the battery cell (90) or substantially parallel to a circumferential direction with respect to the center (O).

[0043] In one embodiment, the normal direction of the surface of the extended portion (45) may intersect with the normal direction of the surface of the battery cell (90) outside the extended portion (45) with the first portion (47) as the boundary, or may intersect with the normal direction of the surface of the battery cell (90) outside the extended portion (45) with the second portion (48) as the boundary.

[0044] In one embodiment, each of the alignment target portions (45, 47, 48) may be provided on a current collector plate (40) accommodated in a can (10) of the battery cell (90).

[0045] The above current collector (40) may be provided with one or more electrode contacts (42), one or more can contacts (44), and a current-carrying portion (46).

[0046] The above one or more electrode joints (42) can be joined to the tab (27) of the electrode (22) of the electrode assembly (20) accommodated in the can (10).

[0047] The one or more can joints (44) can be welded to the can (10) by the welding device (60) that welds the current collector (40) to the can (10).

[0048] The above-mentioned conductive portion (46) can be extended to electrically connect the one or more electrode contact portions (42) and the one or more can contact portions (44).

[0049] Each of the above extension portions (45) can be provided in the above power supply portion (46).

[0050] In one embodiment, the collector plate (40) may include a plate portion (41), one or more pit portions (43), and one or more leg portions (45).

[0051] The above one or more pit portions (43) may be arranged radially outward and axially outward than the above plate portion (41).

[0052] The one or more leg portions (45) may be extended to connect the plate portion (41) and the one or more pit portions (43).

[0053] The above one or more electrode contact portions (42) may be provided on the plate portion (41).

[0054] The above one or more can joints (44) can be provided in the above one or more pit parts (43).

[0055] The above one or more leg portions (45) may constitute a part of the above conductive portion (46).

[0056] In one embodiment, each of the first portions (47) may substantially correspond to each of the first bend portions (47) provided at the connection portions of the plate portion (41) and each of the leg portions (45).

[0057] Each of the second portions (48) can substantially correspond to each of the second bend portions (48) provided at the connection portions of each of the pit portions (41) and each of the leg portions (45).

[0058] In one embodiment, the alignment reference position may correspond to the position of the center point (C) of at least a portion of the alignment target portion (45, 47, 48) aligned with respect to the welding device (60).

[0059] The above detection location may correspond to the location of the center point (C) of at least a portion of the alignment target area (45, 47, 48) detected in the image (I).

[0060] In one embodiment, the alignment reference position may include a first azimuth angle (K) of the alignment target portion (45, 47, 48) aligned with respect to the welding device (60) with respect to the center (O) within the battery cell (90).

[0061] The above detection location may include a second azimuth angle (K) of the alignment target portion (45, 47, 48) detected in the image (I) with respect to the center (O).

[0062] The above offset amount may include an offset angle which is the difference between the first azimuth angle (K) and the second azimuth angle (K).

[0063] In one embodiment, the first azimuth angle (K) may be the azimuth angle (K) of the center point (C) of at least a portion of the alignment target portion (45, 47, 48) aligned with respect to the welding device (60) with respect to the center (O).

[0064] The above second azimuth angle (K) may be the azimuth angle (K) of the center point (C) of at least a portion of the alignment target area (45, 47, 48) detected in the image (I) with respect to the center (O).

[0065] In one embodiment, the position of the center (O) can be calculated using a plurality of the alignment reference positions or a plurality of the detection positions.

[0066] In one embodiment, the offset amount may include an offset angle with respect to the rotation center axis of the position correction unit (71).

[0067] The above control unit (77) can control the position correction unit (71) to rotate at least a portion of the battery cell (90) so that the offset amount is reduced.

[0068] In order to solve the above-described problem, the present invention provides a welding system including a transport device (80) and the alignment device (70) of any one of claims 1 to 20.

[0069] The above transport device (80) can transport the battery cell (90) to the welding device (60).

[0070] The above alignment device (70) can align the position of the battery cell (90) with respect to the welding device (60).

[0071] In one embodiment, the photographing unit (75) of the alignment device (70) can photograph the battery cell (90) being transported toward the welding device (60) by the transport device (80).

[0072] In one embodiment, the position correction unit (71) of the alignment device (70) may be installed in the transport device (80).

[0073] To solve the above-described problem, the present invention provides an alignment method (S100) including a shooting step (S110), a detection step (S120), a calculation step (S130), and a correction step (S140).

[0074] In the above shooting step (S110), the battery cell (90) can be photographed to obtain an image (I) of the battery cell (90).

[0075] In the above detection step (S120), at least one alignment target portion (45, 47, 48) of the battery cell (90) can be detected in the image (I) using first information that mathematically expresses a shape (form) that corresponds or can correspond to at least a part of the alignment target portion (45, 47, 48).

[0076] In the above calculation step (S130), for each of at least one of the detected alignment target parts (45, 47, 48), an offset amount, which is the difference between the alignment reference position and the detection position, can be calculated.

[0077] In the above correction step (S140), the position of at least a portion of the battery cell (90) can be corrected so that the offset amount is reduced.

[0078] In one embodiment, in the photographing step (S110), light is irradiated to the battery cell (90) in a coaxial direction and the battery cell (90) is photographed in a photographing direction parallel to the coaxial direction to obtain an image (I) of the battery cell (90).

[0079] The coaxial direction may be parallel to the axial direction of the battery cell (90) or perpendicular to an imaginary plane substantially including the current collector (40) accommodated in the battery cell (90).

[0080] In one embodiment, the first information may include information mathematically expressing a shape corresponding or capable of corresponding to a pair of first edges (V1). The pair of first edges (V1) may be defined by both ends in the width direction intersecting the extension direction of at least one of the alignment target portions (45, 47, 48). In this case, the detection step (S120) may include a process of detecting the pair of first edges (V1) in the image (I) using the first information.

[0081] Alternatively, the first information may include information mathematically expressing a shape corresponding or capable of corresponding to a pair of second edges (V2). The pair of second edges (V2) may be defined by a first portion (47) and a second portion (48) at both ends of at least one of the alignment target portions (45, 47, 48) in the extension direction. In this case, the detection step (S120) may include a process of detecting the pair of second edges (V2) in the image (I) using the first information.

[0082] In one embodiment, the alignment reference position may include a first azimuth angle (K) of the alignment target portion (45, 47, 48) aligned with respect to the welding device (60) with respect to the center (O) within the battery cell (90).

[0083] The above detection location may include a second azimuth angle (K) of the alignment target portion (45, 47, 48) detected in the image (I) with respect to the center (O).

[0084] The above offset amount may include an offset angle.

[0085] The above calculation step (S130) may include a process of calculating the offset angle from the difference between the first azimuth angle (K) and the second azimuth angle (K).

[0086] In one embodiment, the correction step (S140) may align the position of the battery cell (90) with respect to the welding device (60) by rotating at least a portion of the battery cell (90) so that the offset amount is reduced.

[0087] According to the present invention, while the battery cell is being transported to the welding device by the transport device, an image of the battery cell is acquired and analyzed to align the transported battery cell with respect to the welding device, so that it can be applied to the transfer of battery cells in a production line.

[0088] According to the present invention, since the battery cell transferred to the welding device arrives in a state aligned with respect to the welding device, welding can be performed accurately at the welding location of the battery cell without a process of aligning the welding device with respect to the battery cell, that is, even when the welding device is fixed.

[0089] According to the present invention, it is possible to completely manage the welding process of a battery cell so that no welding or weak welding occurs, thereby preventing defects from occurring in the welding process of a battery cell.

[0090] According to the present invention, since the alignment of the battery cell with respect to the welding device is performed immediately before the battery cell is transferred to the welding device, the alignment of the battery cell is not disturbed again during the transfer process, thereby ensuring welding quality.

[0091] In addition to the effects described above, specific effects of the present invention are described below while explaining specific details for carrying out the invention.

[0092] Figure 1 is an exploded perspective view of an electrode assembly of a battery cell to which a welding method of a battery cell according to an embodiment of the present invention can be applied.

[0093] Figure 2 is an exploded perspective view of the electrode assembly of Figure 1.

[0094] Figure 3 is a perspective view of an electrode assembly according to an embodiment of the present invention.

[0095] Fig. 4 is a perspective view showing a state in which a first collector plate is joined to the axial first end of the electrode assembly of Fig. 3.

[0096] Fig. 5 is a perspective view showing a state in which a second collector plate is joined to the axial second end of the electrode assembly of Fig. 3.

[0097] Figure 6 is a cross-sectional perspective view of the housing of the battery cell.

[0098] Fig. 7 is a cross-sectional view showing an electrode assembly inserted into the housing of Fig. 6.

[0099] Fig. 8 is a cross-sectional view showing a state in which the side wall near the opening of the housing of Fig. 7 has been beaded.

[0100] FIG. 9 is a perspective view schematically illustrating a welding system including a welding device, a transport device for transporting battery cells to the welding device, and an alignment device for the battery cells.

[0101] Figure 10 is a front view of Figure 9.

[0102] Figure 11 is a drawing showing an image taken by the photographing section of the alignment device of a battery cell being transported by a transport device.

[0103] FIG. 12 is a drawing showing a state in which a pair of first edges and a pair of second edges are detected using the first information in the image of FIG. 11, and an alignment target area is detected through these.

[0104] Fig. 13 is a drawing showing a state in which the center within the battery cell is selected through the center points of the alignment target portion of Fig. 12.

[0105] Fig. 14 is a drawing showing a state in which the azimuth of the alignment target portion relative to the center within the battery cell of Fig. 13 is calculated.

[0106] Figure 15 is a front view showing the process of aligning the battery cell to the welding device using an alignment device.

[0107] Fig. 16 is a flowchart showing a method of aligning battery cells for a welding device performed by the alignment device of the present invention.

[0108] Figure 17 is a cross-sectional view showing the process of welding battery cells aligned by an alignment device by a welding device.

[0109] Figure 18 is a perspective view of a battery cell after the welding process has been completed by a welding device.

[0110] Figure 19 is a cross-sectional view showing the state in which the opening of a completed battery cell in the welding process is covered with a cap.

[0111] Figure 20 is a cross-sectional view showing the edge of the cap covering the opening being pressed with a crimping portion.

[0112] Figure 21 is a cross-sectional view of a completed battery cell.

[0113] Figure 22 is a flowchart of a method for aligning battery cells according to one embodiment of the present invention.

[0114] [Explanation of symbols]

[0115] 10: Can (Housing)

[0116] 11: Side wall

[0117] 12: End wall (first end wall)

[0118] 13: Bidding Department

[0119] 14: Crimping section

[0120] 15: Rivet terminal (first electrode terminal)

[0121] 16: Terminal gasket

[0122] 19: Insulator

[0123] 20: Electrode assembly

[0124] 21: First electrode (anode)

[0125] 22: Second electrode (cathode)

[0126] 23: Whole body (metal foil)

[0127] 24: Active material

[0128] 25: Maintenance Department

[0129] 26: Ministry of Immigration

[0130] 27: Electrode tab (notching tab)

[0131] 28: Membrane

[0132] 30: Positive collector plate (first collector plate)

[0133] 31: Periphery

[0134] 32: Electrode connection

[0135] 33: Central

[0136] 34: Terminal connection

[0137] 35: Bridge

[0138] 36: Challenge Department

[0139] 40: Negative collector plate (second collector plate)

[0140] 41: Plate section

[0141] 42: Electrode junction

[0142] 43: Pitbu

[0143] 44: Can joint (area to be welded)

[0144] 45: Leg (alignment target area)

[0145] 46: Ministry of Unification

[0146] 47: Part 1 (First bend)

[0147] 48: Second section (second bend)

[0148] 50: Cap (second end wall)

[0149] 55: Gasket

[0150] 60: Welding device

[0151] 61: Welding mask

[0152] 62: Pressurized surface

[0153] 63: Outer circumference

[0154] 64: Passing hole

[0155] 65: If it's chamfered

[0156] 66: Gas flow reactor

[0157] 68: Welding heating unit (laser generator)

[0158] L: Laser

[0159] 70: Alignment device

[0160] 71: Position compensation unit (motor, lifting unit, pressurizing unit)

[0161] 75: Camera (Vision Camera)

[0162] 77: Control Unit

[0163] C: Center point

[0164] O: Center

[0165] K: Azimuth

[0166] 80: Transport device

[0167] 81: Rotary Table

[0168] 82: Rotation axis

[0169] 83: Cell receiving area

[0170] 90: Battery cells

[0171] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0172] The present invention is not limited to the embodiments disclosed below, but can be implemented in various forms and with various modifications. However, these embodiments are provided to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention. Therefore, the present invention is not limited to the embodiments disclosed below, but should be understood to include all modifications, equivalents, and substitutes included within the technical spirit and scope of the present invention, as well as substitutions or additions of the components of one embodiment with those of another embodiment.

[0173] The attached drawings are merely intended to facilitate understanding of the embodiments disclosed in this specification, and should not be construed as limiting the technical ideas disclosed in this specification, but should be understood to encompass all modifications, equivalents, and substitutes included within the spirit and technical scope of the present invention. In the drawings, the components may be expressed in exaggerated sizes or thicknesses for ease of understanding, but the scope of protection of the present invention should not be construed as being limited thereby.

[0174] The terminology used in this specification is only used to describe specific implementations or examples and is not intended to limit the present invention. In addition, the singular expression includes the plural expression unless the context clearly indicates otherwise. In the specification, terms such as "comprises" and "consists of" are intended to indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification. In other words, it should be understood that terms such as "comprises" and "consists of" in the specification do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0175] While terms including ordinal numbers, such as "first" and "second," may be used to describe various components, these components are not limited by these terms. These terms are used solely to distinguish one component from another. Therefore, unless otherwise stated, a "first" component may also be a "second" component.

[0176] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components intervening. Conversely, when a component is referred to as being "directly connected" or "connected" to another component, it should be understood that there are no other components intervening.

[0177] When a component is referred to as being "above" or "below" another component, it should be understood that it is not only positioned directly above that other component, but that there may also be other components intervening there.

[0178] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0179] In describing the embodiments, the term "axial direction" refers to the direction in which the axis forming the winding center of the jelly-roll-shaped electrode assembly, i.e., the core axis, extends. This can be understood as a concept encompassing both directions in which the axis extends. Therefore, in the specification, when the term "axial direction" is used without any specific configuration limitation, it can be understood as the direction in which the core axis extends.

[0180] In describing the embodiments, the term "radial direction" or "radial direction" refers to a direction approaching or moving away from the axis. This can be understood as a concept that includes both directions approaching or moving away from the axis.

[0181] In describing the embodiments, the circumferential direction or the circumferential direction refers to the direction surrounding the axis.

[0182] Based on the description of these directions, the width direction of the electrode assembly in the unfolded state corresponds to the axial direction of the jelly roll. The length direction of the electrode assembly in the unfolded state corresponds to the circumferential direction of the jelly roll. And the normal direction to the electrode surface in the unfolded state of the electrode assembly corresponds to the radial direction of the jelly roll.

[0183] Referring to FIGS. 1 to 6 below, the manufacturing process and structure of an embodiment of a cylindrical battery cell manufactured using a welding system according to the present invention will be described.

[0184] Referring to FIG. 6, the battery cell (90) of the embodiment may include a housing (10) having a side wall (11) extending in the axial direction, an end wall (12) connected to an axial first end of the side wall (11), and an open end or opening provided at an axial second end of the side wall (11). The housing (10) may be a can (10) made of metal.

[0185] The battery cell (90) may have a jelly-roll-shaped electrode assembly (20) accommodated in a can (10).

[0186] The electrode assembly (20) can be manufactured in the form of a jelly-roll as shown in FIG. 3 by preparing a first electrode (21), a second electrode (22), and a separator (28) that extend in the longitudinal direction with a predetermined width as shown in FIG. 1, and forming a laminate by stacking the first electrode (21), the separator (28), the second electrode (22), and the separator (28) in that order as shown in FIG. 2 and winding it around a core shaft.

[0187] The first electrode (21) may be an anode, and the second electrode (22) may be a cathode. Of course, the opposite may also be the case.

[0188] The first electrode (21) and the second electrode (22) can be manufactured in the form of a roll sheet that extends in the longitudinal direction with a predetermined width. The electrodes (21, 22) can be manufactured in the form of forming an active material layer by applying an active material (24) to the surface of a metal foil constituting a current collector (23) and rolling it. The electrodes (21, 22) can have a holding portion (25) region where the active material (24) is applied, and a non-conductive portion (26) region where the active material (24) is not applied. The first electrode (21) can have a non-conductive portion (26) region at a first end of the current collector (23) in the width direction, and the second electrode (22) can have a non-conductive portion (26) region at a second end of the current collector (23) opposite the first end in the width direction.

[0189] Referring to FIGS. 1 and 2, the first electrode (21) and the second electrode (22) can be laminated such that their uncoated portions (26) extend further outward in the width direction than the separator (28) at the first and second ends in the width direction of the electrode assembly (20), respectively. Referring to FIG. 3, the uncoated portion (26) of the first electrode (21) can protrude from the axial first end of the rolled jelly-roll, and the uncoated portion (26) of the second electrode (21) can protrude from the axial second end of the jelly-roll. The uncoated portion (26) itself can function as at least one electrode tab (27).

[0190] Notches may be formed at a predetermined interval in the non-conductive portion (26) to form flag-shaped notched tabs (27).

[0191] In the jelly-roll type electrode assembly (20), the notching tab (27) can be folded and flattened radially as shown in FIG. 3. The notching tab (27) can be folded radially inward or outward.

[0192] The notching tabs (27) of the first electrode (21) and the notching tabs (27) of the second electrode (22), which are bent in the radial direction and overlapped in multiple numbers in the axial direction, can provide a plane that is substantially perpendicular to the axial direction at the axially opposite ends of the electrode assembly (20).

[0193] The first collector plate (30) and the second collector plate (40) can be joined to a substantially flat surface provided by bending the notched tabs (27) exposed at both axial ends of the electrode assembly (20), as shown in FIGS. 4 and 5.

[0194] The first collector plate (30) may include a central portion (33) provided at a position corresponding to the core hollow portion of the electrode assembly (20), a peripheral portion (31) surrounding the central portion (33), and a bridge (35) extending radially to connect the central portion (33) and the peripheral portion (31). The bridge (35) may function as a conductive portion (36) that electrically connects the peripheral portion (31) and the central portion (33). An electrode connection portion (32) welded to a notched tab (27) of the first electrode (21) may be provided in the peripheral portion (31).

[0195] The second collector plate (40) may include a plate portion (41) laminated on the flat surface of the notched tabs (27) provided at the axial second end of the electrode assembly (20). The plate portion (41) may be an annular flat plate having a center hole corresponding to the core hollow portion of the electrode assembly (20). The surface of the plate portion (41) may form one or more electrode bonding portions (42) that are penetratedly welded to the electrode tabs (27) of the second electrode (22) by a laser.

[0196] In addition, the second collector plate (40) may include one or more legs (45) that extend obliquely axially outward from the edge of the plate portion (41) toward the radial outer side. For example, four of the one or more legs (45) are provided at 90-degree intervals along the circumferential direction. However, the number of legs (45) is not limited thereto.

[0197] One or more feet (43) may be connected to the radially outer end of one or more leg portions (45). Each foot portion (43) has an arc shape extending in the circumferential direction and may be connected to each leg portion (45) at the center of the arc shape. The one or more feet (43) are arranged at a position offset axially outwardly with respect to the plate portion (41) and may be arranged radially further outward than the plate portion (41). It is exemplified that the one or more feet (43) are provided four at 90-degree intervals along the circumferential direction so as to correspond to the four leg portions (45), respectively. However, the number of feet (43) is not limited thereto, and the number of feet (43) does not necessarily have to follow the number of legs (45).

[0198] In the embodiment, the first collector plate (30) is exemplified as a positive collector plate and the second collector plate (40) is a negative collector plate. Of course, the opposite may also be true.

[0199] The electrode assembly (20) can be accommodated inside the can (10) through the opening of the can (10), as illustrated in FIGS. 6 and 7. Prior to inserting the electrode assembly (20) into the can (10), an insulator (19) can be laminated on the inner surface of the end wall (12). The insulator (19) can electrically insulate the first collector plate (30) from the end wall (12).

[0200] The end wall (12) of the can (10) may have a disc shape with a hole formed in the center, and the side wall (11) may have a circular tube shape surrounding the internal volume of the can (10).

[0201] A first electrode terminal (15) can be fitted into the hole. The first electrode terminal (15) can be fixed to the end wall (12) with a terminal gasket (16) interposed therebetween. The terminal gasket (16) is interposed between the first electrode terminal (15) and the end wall (12), sealing the inside and outside of the can (10) to prevent leakage of the electrolyte and electrically insulating the first electrode terminal (15) from the end wall (12).

[0202] The first electrode terminal (15) may have a first polarity, and the can (10) may have a second polarity. That is, the end wall (12) of the can (10) and the side wall (11) connected thereto may both have a second polarity.

[0203] The electrode assembly (20) can be accommodated in the can (10) in a state where the first collector plate (30) is aligned so as to face the end wall (12) of the can (10). At this time, an insulator (19) can be interposed between the first collector plate (30) and the end wall (12) of the can (10) to electrically insulate the first collector plate (30) from the end wall (12).

[0204] In addition, the central portion (33) of the first collector plate (30) can be joined to the first electrode terminal (15) fixed to the can (10) by resistance welding, ultrasonic welding, laser welding, or the like to define a terminal connection portion (34).

[0205] In a state where the electrode assembly (20) is accommodated inside the can (10), the electrode tab (27) of the second electrode (22) and the second collector plate (40) can be positioned to face the open end of the side wall (11), i.e., the opening of the housing (10).

[0206] After accommodating the electrode assembly (20) in the can (10), as illustrated in FIG. 8, the side wall (11) may be concavely formed radially inwardly from the axial outer side of the electrode assembly (20) by plastic processing to form a beading portion (13). The beading portion (13) supports the electrode assembly (20) accommodated in the can (10) in the axial direction, and may also support the inner surface of the edge of the cap (50) that covers the open end of the can (10) in the axial direction.

[0207] In a state where the beading portion (13) is formed, one or more pit portions (43) of the second collector plate (40) can be positioned approximately above the beading portion (13). In addition, one or more pit portions (43) and the plate portion (41) arranged so as to have a height difference can be connected by one or more leg portions (45) that extend obliquely in the radial outward direction and the axial outward direction from the plate portion (41).

[0208] In order to connect the plate portion (41) with such a step and each pit portion (43), a first bend portion (47) may be provided at the connection portion between the plate portion (41) and each leg portion (45), and a second bend portion (48) may be provided at the connection portion between each pit portion (43) and each leg portion (45). The normal of the virtual plane including the plate portion (41) may be substantially parallel to the axial direction. In addition, the normal of the virtual plane including each pit portion (43) may be substantially parallel to the axial direction. On the other hand, the normal of the virtual plane including each leg portion (45) may extend in a direction inclined with respect to the axial direction.

[0209] Each pit portion (43) can be in contact with the axial upper surface of the bead portion (13). The battery cell (90) on which the beading process has been completed is provided to a welding system described below, so that each pit portion (43) is welded to the bead portion (13) by a welding device (60), and the welded portion can form each can joint portion (44).

[0210] Meanwhile, the second collector plate (40) may be provided with a conductive portion (46) that electrically connects one or more electrode contact portions (42) and one or more can contact portions (44). According to an embodiment, each leg portion (45) may form a part of the conductive portion (46). In addition, one or more alignment target portions (45, 47, 48) described below may be provided on the second collector plate (40).

[0211] Referring to FIGS. 9 and 10, a welding system according to one embodiment of the present invention may include a transport device (80), a welding device (60), and an alignment device (70). Each component will be described in detail below.

[0212] A transport device (80) can transport a battery cell (90) to a welding device (60). The transport device (80) can include a rotary table (81), a rotary shaft (82), and one or more cell receiving portions (83). A battery cell (90) having a beaded portion (13) formed thereon can be transported by a rotary table (81) rotating around a rotary shaft (82) while being received in one or more cell receiving portions (83) provided along the periphery of the rotary table (81).

[0213] The transport device (80) may include an elevating member (71). The elevating member (71) is provided below the cell receiving member (83) of the rotary table (81) and can elevate a battery cell (90) seated in the cell receiving member (83) toward a welding mask (61) described later or lower it from the welding mask (61).

[0214] The lifting member (71) can raise the battery cell (90) relative to the welding mask (61) while supporting the bottom surface of the end wall (12) placed at the bottom of the battery cell (90), thereby bringing the battery cell (90) into close contact with the welding mask (61).

[0215] A welding device (60) may be provided on top of a rotary table (81) at a predetermined process position in the circumferential direction of the rotary table (81). The welding device (60) may include a welding heating unit (68) and a welding mask (61). The welding device (60) may weld a battery cell (90). For example, the welding device (60) may weld a second collector plate (40) to a can (10).

[0216] The welding heating unit (68) may be positioned above the rotary table (81) at the above process location. The welding heating unit (68) may include a generator (68) that irradiates a laser to the battery cell (90). For example, the generator (68) may irradiate a laser to the welding area (44) of the second current collector (40) and the beading unit (13).

[0217] The welding heating unit (68) can be installed independently of the rotary table (81). That is, the welding heating unit (68) can be placed at a predetermined position independently of the rotation of the rotary table (81).

[0218] The welding mask (61) can pressurize the welding portion (44) of the battery cell (90). For example, the welding mask (61) can bring the bead portion (13) of the battery cell (90) and one or more pit portions (43) of the second current collector (40) into close contact with each other.

[0219] The welding mask (61) can be positioned above the rotary table (81). Although the drawing shows one welding mask (61) at the process position, a plurality of welding masks (61) can be installed along the circumference to correspond to the number of battery cells (90) transported by the rotary table (81), i.e., the number of cell receiving portions (83) of the rotary table (81), and can rotate together with the rotary table (81).

[0220] An alignment device (70) may be placed adjacent to a welding device (60). The alignment device (70) may include a photographing unit (75), a position correction unit (71), and a control unit (77). The alignment device (70) may align the position of the battery cell (90) with respect to the welding device (60).

[0221] The photographing unit (75) can photograph the battery cell (90) to obtain an image of the battery cell (90) (e.g., including the second collector plate (40)). The photographing unit (75) can photograph the battery cell (90) being transported toward the welding device (60).

[0222] The photographing unit (75) may include a coaxial light (not shown) that irradiates light to the battery cell (90) (e.g., the second collector plate) in a direction parallel to the axial direction of the battery cell (90), and a vision camera (75) that photographs the battery cell (90) (e.g., the second collector plate) in a direction parallel to the axial direction of the battery cell (90). The embodiment exemplifies that the photographing direction of the photographing unit (75) is parallel to the axial direction of the battery cell (90). However, the photographing direction is not necessarily limited thereto.

[0223] The photographing unit (75) can be installed independently of the rotary table (81). That is, the photographing unit (75) can be positioned at a predetermined position independently of the rotation of the rotary table (81). The photographing unit (75) can be installed immediately before the welding process position in the transport path of the transport device (80).

[0224] The photographing unit (75) can photograph the battery cell (90) being transported along the transport path of the transport device (80). Referring to FIG. 11, in the image (I) captured by the photographing unit (75), one or more leg portions (45) of the second current collector (40) may be expressed as darker than other portions of the second current collector (40), i.e., the plate portion (41) and one or more pit portions (43). This may be due to the fact that among the reflected light reflected from the coaxial lighting, light reflected by one or more leg portions (45) does not enter the vision camera (75).

[0225] The captured image (I) may include a reference image. In the reference image, the battery cell (90) (e.g., the second collector plate) may be aligned with respect to the welding device (60). That is, in the reference image, each alignment target portion (45, 47, 48) of the battery cell (90) (e.g., the second collector plate) may be located at each alignment reference position.

[0226] The captured image (I) may include a target image. In the target image, a battery cell (90) (e.g., a second collector plate) may be misaligned with respect to the welding device (60). That is, in the target image, at least one alignment target portion (45, 47, 48) of the battery cell (90) (e.g., a second collector plate) may be positioned off from at least one alignment reference position.

[0227] The captured image (I) can be transmitted to the control unit (77).

[0228] The control unit (77) can detect at least one alignment target portion (45, 47, 48) of the battery cell (90) (e.g., the second collector plate) in the image (I) using the first information.

[0229] Here, the first information may be information that mathematically (e.g., vector or geometric) expresses a shape (form) that corresponds or can correspond to at least a portion (e.g., a one-dimensional line or a two-dimensional shape) of at least one alignment target portion (45, 47, 48) of the battery cell (90) (e.g., the second current collector). For example, the first information may include vector information that expresses the shape as a vector or can be expressed as a vector. The first information may include geometric information that geometrically expresses the shape.

[0230] In one embodiment, the vector information may include information that can express the shape as a vector. This vector information may be identical to the geometric information. If the shape is a square, the vector information and the geometric information may include, for example, the positions of the four corners of the square. If the shape is a circle, the vector information and the geometric information may include, for example, the position of the center point and the radius of the circle. If the shape is one or more connected or separated straight lines or curves, the vector information and the geometric information may include the positions and curvatures of the two endpoints of each straight line or each curve.

[0231] In another embodiment, the vector information may include information expressing the shape as a vector. This vector information may be different from the geometric information. For example, if the shape is a) a square, b) a circle, or c) a line, the vector information may include a') four vectors corresponding to the four sides of the square, b') a vector equation of the circle, or c') a vector or vector equation corresponding to each line.

[0232] Below, we will examine the first, second, and third embodiments according to the subject of the first information.

[0233] In the first embodiment, the first information may be information about a reference shape. That is, the first information may be information that mathematically expresses a reference shape (e.g., within an image) corresponding to at least a portion of at least one alignment target portion (45, 47, 48) of a battery cell (90) (e.g., a second current collector). The first information about the reference shape may be input by a user or automatically extracted from an image (e.g., a reference image). In relation to the latter, for example, the control unit (77) may automatically extract the first information about the reference shape by detecting a set of edges or contours in the reference image and detecting a shape (e.g., a square or a straight line) formed by at least some of the edges or contours. The method for detecting edges or contours, the method for detecting a shape formed by the edges or contours, and the method for extracting the first information from the detected shape may follow or be derived from known techniques.

[0234] In the first embodiment, the control unit (77) can detect at least one alignment target portion (45, 47, 48) by finding at least some edges or contours in the target image that are similar to the reference shape (e.g., similar in aspect ratio to the rectangle or similar in length and direction to the straight line) by using first information about a reference shape (e.g., a square or a straight line) after detecting a set of edges or contours in the target image. For example, the control unit (77) can find at least some edges or contours in the target image that are similar to the reference shape by rotating or deforming the reference shape within a predetermined range or adjusting its size through a mathematical operation (e.g., a vector operation or a matrix operation) by using first information about the reference shape (e.g., vector information or geometric information).

[0235] In the second embodiment, the first information may be information about a candidate shape. That is, the first information may be information that mathematically expresses a candidate shape in a target image, which may correspond to at least a portion of at least one alignment target portion (45, 47, 48) of at least one battery cell (90) (e.g., a second current collector). There may be one or more candidate shapes. Each first information about each candidate shape may be automatically extracted from the target image. For example, the control unit (77) may automatically extract each first information about each candidate shape by detecting a set of edges or outlines in the target image and detecting each shape (e.g., a square or a straight line) formed by at least some of the edges or outlines.

[0236] In the second embodiment, the control unit (77) can detect at least one alignment target portion (45, 47, 48) in the target image by finding a candidate shape that is similar to a reference shape (e.g., a square or a straight line) (e.g., similar in aspect ratio to the square or similar in length and direction to the straight line) using the respective first information for each candidate shape. For example, the control unit (77) can find a candidate shape that is similar to the reference shape by rotating or deforming each candidate shape within a predetermined range or adjusting its size through a mathematical operation (e.g., vector operation or matrix operation) using the respective first information (e.g., vector information or geometric information) for each candidate shape.

[0237] In the third embodiment, the first information may be information about the reference shape and the candidate shape. That is, the first information may be information that mathematically expresses the reference shape and information that mathematically expresses the candidate shape. There may be one or more candidate shapes. The control unit (77) can detect at least one alignment target portion (45, 47, 48) in the target image by finding a candidate shape similar to the reference shape using the first information about the reference shape and each first piece of information about each candidate shape. For example, the control unit (77) can find a candidate shape similar to the reference shape by rotating or transforming the reference shape and each candidate shape within a predetermined range or adjusting the size using a mathematical operation (e.g., a vector operation or a matrix operation) using the first information about the reference shape and each first piece of information (e.g., vector information or geometric information) about each candidate shape.

[0238] In this way, since the control unit (77) uses the first information, even if, in the target image, i) the alignment target area (45, 47, 48) is partially omitted, distorted, or unclear, ii) the alignment target area (45, 47, 48) is rotated, deformed, or scaled, or iii) the brightness is not uniform, the control unit (77) can accurately detect the alignment target area (45, 47, 48).

[0239] Each of the alignment target portions (45, 47, 48) may include a first portion (47) and a second portion (48) spaced apart from each other on the battery cell (90) (e.g., the second current collector plate), and an extended portion (45) extending between the first portion (47) and the second portion (48) to connect the first portion (47) and the second portion (48). According to an embodiment, each of the extended portions (45) is exemplified as a respective leg portion (45). According to an embodiment, each of the first portions (47) may be a respective first bent portion (47) provided at a connection portion between the plate portion (41) and the respective leg portion (45), and each of the second portions (48) may be a respective second bent portion (48) provided at a connection portion between the respective pit portion (43) and the respective leg portion (45). However, each extension portion (45) does not necessarily have to be limited to each leg portion (45), and each first portion (47) and second portion (48) does not necessarily have to be limited to each first bend portion (47) and second bend portion (48).

[0240] That is, the alignment target area (45, 47, 48) can be selected in various ways depending on the shape of the battery cell (90) (e.g., the second collector plate) as long as it is an area that is easy to distinguish from other areas in the captured image (I) and can serve as a reference for alignment.

[0241] In the embodiment, the four extension portions (45), i.e., the four leg portions (45), may extend radially at 90-degree intervals with respect to the center (O) within the battery cell (90) (e.g., the center of the battery cell or the second current collector (40)) and may extend obliquely with respect to the axial direction of the battery cell (90).

[0242] In the embodiment, the normal direction of the surface of the extension portion (45) may intersect with the normal direction of the surface of the battery cell (90) outside the extension portion (45) with the first portion (47) as the boundary (e.g., the surface of the plate portion), or may intersect with the normal direction of the surface of the battery cell (90) outside the extension portion (45) with the second portion (48) as the boundary (e.g., the surface of the pit portion).

[0243] Referring to FIG. 12, the control unit (77) can detect a pair of first edges (V1) defined by both ends in the width direction of an extension portion (45) of at least one alignment target portion (45, 47, 48) in the image (I) using the first information. The width direction can intersect with the extension direction of the extension portion (45). At this time, the first information can include information that mathematically expresses a shape corresponding or capable of corresponding to a pair of first edges (V1) of at least one alignment target portion (45, 47, 48).

[0244] In addition, the control unit (77) can detect a pair of second edges (V2) defined by a first portion (47) and a second portion (48) located at both ends of an extension portion (45) of at least one alignment target portion (45, 47, 48) in the image (I) using the first information. At this time, the first information can include information that mathematically expresses a shape corresponding or capable of corresponding to a pair of second edges (V2) of at least one alignment target portion (45, 47, 48).

[0245] According to an embodiment, a pair of first edges (V1) may be detected as corner portions of both sides of the leg portion (45) in the circumferential direction of the battery cell (90), and a pair of second edges (V2) may be detected as portions of the first bent portion (47) and the second bent portion (48). That is, a pair of first edges (V1) may be parallel to the extension direction of an extension portion (45) extending between the first portion (47) and the second portion (48), and a pair of second edges (V2) may intersect the extension direction. That is, a pair of first edges (V1) may be substantially parallel to a radial direction with respect to a center (O) within the battery cell (90) (e.g., a center of the battery cell or the second current collector plate). For example, a pair of first edges (V1) may be parallel to a radial direction from the center of the second collector plate (40) toward the center of the alignment target portion (45, 47, 48). Additionally, a pair of second edges (V2) may be substantially perpendicular to a radial direction with respect to a center (O) within the battery cell (90) (e.g., a center of the battery cell or the second collector plate) or substantially parallel to a circumferential direction with respect to the center (O). For example, a pair of second edges (V2) may be perpendicular to a radial direction from the center of the second collector plate (40) toward the center of the alignment target portion (45, 47, 48).

[0246] The control unit (77) can recognize a portion forming an approximately square shape by a pair of first edges (V1) and a pair of second edges (V2) as an alignment target portion (45, 47, 48). According to an embodiment, four alignment target portions (45, 47, 48) can be recognized in the image (I).

[0247] As described below, when the alignment reference position and the detection position correspond to the position of the center point (C) of at least a portion of the alignment target portion (45, 47, 48), the control unit (77) can calculate the center point (C) of at least a portion of each alignment target portion (45, 47, 48) (Fig. 13).

[0248] As described below, if i) the alignment reference position and the detection position include a first azimuth angle (K) and a second azimuth angle (K), respectively, and ii) the first azimuth angle (K) and the second azimuth angle (K) are azimuth angles (K) of a center point (C) of at least a portion of an alignment target portion (45, 47, 48) with respect to a center (O) (e.g., a center of a battery cell or a second current collector) within a battery cell (90), the control unit (77) can calculate the center (O) using the positions of the center points (C) of at least a portion of a plurality of alignment target portions (45, 47, 48) as illustrated in FIG. 13. For example, the position of the first center (O) used in calculating the first azimuth angle (K) can be calculated using a plurality of alignment reference positions (center points) in the reference image. The location of the second center (O) used in calculating the second azimuth (K) can be calculated using multiple detection locations (center points) in the target image.

[0249] For example, when a plurality of alignment target portions (45, 47, 48) are arranged in the circumferential direction with the center portion of the second collector plate (40) as the center, the control unit (77) can obtain a plurality of straight lines that intersect each other by connecting the center points (C) of the alignment target portions (45, 47, 48) that face each other with the center portion of the second collector plate (40) in between (Fig. 13). The control unit (77) can calculate the position of one or more intersection points of the plurality of straight lines. The control unit (77) can set the position of the first center (O) or the second center (O) to the position of one intersection point or to a position adjacent to at least some of the intersection points (Fig. 13).

[0250] Thereafter, the control unit (77) can calculate the azimuth angle (K) formed by the center point (C) with respect to the center (O) within the battery cell (90), as shown in FIG. 14.

[0251] According to an embodiment, a plurality of alignment target portions (45, 47, 48) recognized in the image (I) are arranged at a plurality of spaced apart locations along the circumferential direction with respect to the center (O), and the edge of each alignment target portion (45, 47, 48) may include a portion extending in a direction parallel to the radial direction and a portion extending perpendicular to the radial direction or in the circumferential direction. In addition, the alignment of the battery cell (90) is performed by rotation about the center (O) within the battery cell (90), and the alignment factor of the battery cell (90) may also correspond to the rotation angle.

[0252] Therefore, when the alignment target areas (45, 47, 48) are recognized using the first information, the recognition accuracy for the edges of each alignment target area (45, 47, 48) can be further improved. In addition, since the average position based on the edges is calculated when calculating the center point (C) of at least a portion of each alignment target area (45, 47, 48), even if an error occurs in the recognition of a portion of the edge, the error can be reduced in the process of calculating the position of the center point (C). In addition, since the center (O) within the battery cell (90) is calculated based on the center points (C) of each alignment target area (45, 47, 48) with reduced errors in this way, even if there is an error in the position of some of the center points (C), the error can be further reduced in the process of calculating the center (O).

[0253] Therefore, by performing image detection using the first information with a small error occurrence in edge recognition, calculating the center point (C) of at least a part of the alignment target area (45, 47, 48) to reduce the error once, and calculating the center (O) within the battery cell (90) again from the center points (C) to reduce the error once more, the calculated azimuth angle (K) may have almost no error occurrence compared to the rotation angle that requires actual alignment.

[0254] Next, the control unit (77) can calculate an offset amount, which is a difference between an alignment reference position and a detection position, for each of at least one detected alignment target portion (45, 47, 48). Here, the alignment reference position may correspond to a position of the alignment target portion (45, 47, 48) aligned with respect to the welding device (60). The alignment reference position may be directly input by the user, calculated using information input by the user, or calculated from a reference image. The detection position may correspond to a position of the alignment target portion (45, 47, 48) detected in the target image.

[0255] In one embodiment, the alignment reference position may correspond to the position of the center point (C) of at least a portion of the alignment target portion (45, 47, 48) aligned with respect to the welding device (60). The detection position may correspond to the position of the center point (C) of at least a portion of the alignment target portion (45, 47, 48) detected in the image (I, target image).

[0256] In one embodiment, the alignment reference position may include a first azimuth angle (K) of an alignment target portion (45, 47, 48) aligned with respect to a welding device (60) with respect to a center (O) within a battery cell (60). The detection position may include a second azimuth angle (K) of an alignment target portion (45, 47, 48) detected in an image (I, target image) with respect to the center (O). In this case, the offset amount may include an offset angle which is a difference between the first azimuth angle (K) and the second azimuth angle (K). The offset angle may be an angle with respect to a rotation center axis of a position correction unit (71) described later.

[0257] Here, the first azimuth angle (K) may be the azimuth angle (K) of the center point (C) of at least a portion of the alignment target portions (45, 47, 48) aligned with respect to the welding device (60) with respect to the center (O). The second azimuth angle (K) may be the azimuth angle (K) of the center point (C) of at least a portion of the alignment target portions (45, 47, 48) detected in the image (I, target image) with respect to the center (O).

[0258] Here, the position of the center (O) can be calculated using a plurality of alignment reference positions or a plurality of detection positions. When the first azimuth angle (K) and the second azimuth angle (K) are azimuth angles (K) of the center point (C) of at least a portion of the alignment target portion (45, 47, 48), the method for calculating the center (O) is as described above.

[0259] For example, for one alignment target portion (45, 47, 48), if the first azimuth angle (K) included in the alignment reference position is 45 degrees and the second azimuth angle (K) included in the detection position is about 44 degrees, the control unit (77) can calculate an offset angle, which is a difference between the first azimuth angle (K) and the second azimuth angle (K), that is, 1 degree. If the absolute value of the allowable range of the offset angle is at most 2 degrees, the control unit (77) can determine that one alignment target portion (45, 47, 48) is at the alignment reference position. On the other hand, if the second azimuth angle (K) is 40 degrees, the control unit (77) can calculate an offset angle of 5 degrees and determine that the alignment target portion (45, 47, 48) is deviated from the alignment reference position.

[0260] The control unit (77) can control the position correction unit (71) described below to reduce the offset amount when the alignment target portion (45, 47, 48) is positioned outside the alignment reference position. When the offset amount includes an offset angle, the control unit (77) can control the position correction unit (71) to reduce the offset angle, thereby rotating at least a portion of the battery cell (90).

[0261] The position correction unit (71) can be positioned adjacent to the welding device (60). The position correction unit (71) can correct the position of at least a portion (e.g., the entire battery cell) of the battery cell (90) with respect to the welding device (60).

[0262] In an embodiment, the position compensation unit (71) may include a motor capable of controlling a rotation angle about a rotation center axis. The rotation center axis may be aligned with or correspond to a center (O) within the battery cell (90) (e.g., the center of the battery cell or the second current collector plate). According to an embodiment, as illustrated in FIGS. 15 and 16, the rotation angle of the motor, which is the position compensation unit (71), may be controlled by the control unit (77) so that the motor rotates about the rotation center axis by the offset angle.

[0263] In the embodiment, the position correction unit (71) can be installed on the transport device (80). The position correction unit (71) is exemplified as being installed together with the lifting unit (71). However, the installation position of the position correction unit (71) is not limited thereto. For example, the position correction unit (71) can be installed on the rotary table (81) separately from the lifting unit (71). That is, as long as the structure is capable of rotating the battery cell (90), the installation position and configuration of the position correction unit (71) can be configured in various ways using known means.

[0264] Referring to FIGS. 15 to 17, the battery cell (90) whose alignment with respect to the welding device (60) is completed through the alignment device (70) as described above is raised by the lifting unit (71), and accordingly, the welding portion (44) of the battery cell (90), that is, the contact portion between the pit portion (43) of the second collector plate (40) and the beading portion (13) of the can (10), can be brought into close contact by the lifting unit (71). In other words, the lifting unit (71) may be a pressing unit (71) that provides a pressing force to press the welding mask (61) to the second collector plate (40).

[0265] The welding mask (61) can pressurize the pit portion (43) of the second collector plate (40) to adhere to the axial outer surface of the bead portion (13) of the can (10). To this end, the edge portion of the bottom surface of the welding mask (61) can be in contact with the pit portion (43) of the second collector plate (40) and form a pressing surface (62) that presses the pit portion (43) downward.

[0266] The outer peripheral surface (63) of the welding mask (61) is in contact with the inner peripheral surface of the side wall (11) of the can (10) and can align the center of the battery cell (90) and the welding mask (61). In addition, a chamfered surface (65) can be provided at the corner where the outer peripheral surface (63) of the welding mask (61) and the pressure surface (62) meet so that the lower part of the welding mask (61) can be inserted into the inside of the side wall (11).

[0267] The welding mask (61) may be provided with a passing hole (64) that opens toward the pressure surface (62) in an area corresponding to the welding portion of the second collector plate (40), i.e., the can joint portion (44) of the pit portion (43). The passing holes (64) may be spaced apart from each other in multiples along the circumferential direction of the welding mask (61) so as to be arranged corresponding to the pit portion (43). In the embodiment, it is exemplified that four passing holes (64) are provided at 90-degree intervals.

[0268] The passing hole (64) may have a shape that penetrates the welding mask (61). The passing hole (64) may extend parallel to the direction in which the pressing surface (62) presses the second collector plate (40) so as to intersect with the pressing surface (62). The pressing direction may correspond to the axial direction of the electrode assembly (20).

[0269] The welding mask (61) may be equipped with a gas flow path (66) that supplies an inert gas and absorbs gas generated during welding to prevent byproducts generated during the welding process from entering the battery cell (90). The gas flow path (66) may extend to the vicinity of a passing hole (64) opened toward the pressurized surface (62).

[0270] The welding heating unit (68) may be a generator (68) that irradiates a laser (L) to a welding area (44). The laser (L) irradiated from the generator (68) may be irradiated to the welding area (44) through a passing hole (64).

[0271] When the pit portion (43) is welded to the bead portion (13) at the can joint portion (44) as shown in Fig. 18, the can (10) and the second collector plate (40) can be electrically connected.

[0272] After the first collector plate (30) and the first electrode terminal (15) are joined and the second collector plate (40) and the beading portion (13) are joined, an electrolyte can be injected into the can (10). After the electrolyte is injected, the open end of the side wall member (11) can be covered and sealed with a cap (50) as shown in FIGS. 19 and 20.

[0273] The battery cell (90) of the embodiment may be provided with a cap (50) forming an end wall covering the open end of the can (10). The cap (50) may be placed on the open end of the can (10) with a gasket (55) wrapped around its edge. Accordingly, the edge of the cap (50) may be placed on the beading portion (13) to which the pit portion (43) is welded.

[0274] And the axial end of the side wall (11) can be caulked from the axial outer side to the radial inner side of the cap (50) to form a crimping portion (14). The crimping portion (14) can press the edge of the outer surface of the cap (50) axially inward.

[0275] The gasket (55) surrounds the axial inner surface, the radial outer surface, and the axial outer surface of the edge of the cap (50) and is press-fitted between the cap (50) and the side wall (11), thereby allowing the can (10) to be sealed. The gasket (55) can seal the gap between the crimping portion (14) and the cap (50) and electrically insulate the cap (50) from the side wall (11).

[0276] The battery cell (90) assembled in this manner can be positioned so that both the end wall (12) of the can (10) and the first electrode terminal (15) are positioned on the upper surface with the cap (50) positioned on the bottom, as shown in Fig. 21. Accordingly, all bus bars electrically connecting the battery cells (90) can be connected to the upper portion of the battery cells (90).

[0277] [Sorting method]

[0278] Referring to FIG. 22, an alignment method (S100) according to one embodiment of the present invention may include a photographing step (S110), a detection step (S120), a calculation step (S130), and a correction step (S140).

[0279] In the shooting step (S110), the battery cell (90) can be shot to obtain an image (I) of the battery cell (90).

[0280] Here, light can be irradiated to the battery cell (90) in a coaxial direction. The coaxial direction can be a direction parallel to the axial direction of the battery cell (90) or a direction perpendicular to an imaginary plane that substantially includes the current collector (40) accommodated in the battery cell (90). In addition, the battery cell (90) can be photographed in a photographing direction parallel to the coaxial direction to obtain an image (I) of the battery cell (90).

[0281] In the detection step (S120), at least one alignment target portion (45, 47, 48) of the battery cell (90) can be detected in the image (I) using first information that mathematically expresses a shape (form) that corresponds or can correspond to at least a part of at least one alignment target portion (45, 47, 48).

[0282] The detection step (S120) may include a first step of detecting a pair of first edges (V1) in the image (I) using first information and / or a second step of detecting a pair of second edges (V2). When the detection step (S120) includes the first step, the first information may include information mathematically expressing a shape corresponding to or capable of corresponding to the pair of first edges (V1). When the detection step (S120) includes the second step, the first information may include information mathematically expressing a shape corresponding to or capable of corresponding to the pair of second edges (V2). Here, the pair of first edges (V1) and the pair of second edges (V2) are as described above.

[0283] In the calculation step (S130), for each of at least one detected alignment target portion (45, 47, 48), an offset amount, which is the difference between the alignment reference position and the detection position, can be calculated.

[0284] When the alignment reference position includes a first azimuth angle (K) of an alignment target portion (45, 47, 48) aligned with respect to a welding device (60) with respect to a center (O) within a battery cell (90), and the detection position includes a second azimuth angle (K) of an alignment target portion (45, 47, 48) detected in an image (I) with respect to the center (O), and the offset amount includes an offset angle, the calculation step (S130) may include a process of calculating an offset angle from a difference between the first azimuth angle (K) and the second azimuth angle (K).

[0285] In the correction step (S140), the position of at least a portion of the battery cell (90) can be corrected so that the offset amount is reduced.

[0286] The correction step (S140) may align the position of the battery cell (90) with respect to the welding device (60) by rotating at least a portion of the battery cell (90) so that the offset amount (e.g., offset angle) is reduced.

[0287] Meanwhile, matters not mentioned in relation to the alignment method (S100) can be inferred from the alignment device (70) described above.

[0288] 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.

[0289] 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. A photographing unit (75) that photographs a battery cell (90) to obtain an image (I) of the battery cell (90); A position correction unit (71) for correcting the position of at least a part of the battery cell (90) relative to the welding device (60); and An alignment device comprising a control unit (77) for detecting at least one alignment target portion (45, 47, 48) in the image (I) using first information that mathematically expresses a shape corresponding to or capable of corresponding to at least a portion of at least one alignment target portion (45, 47, 48) of the battery cell (90), calculating an offset amount, which is a difference between an alignment reference position and a detection position, for each of the at least one detected alignment target portions (45, 47, 48), and controlling the position correction unit (71) to reduce the offset amount.

2. In claim 1, The above-mentioned photographing unit (75) is an alignment device including a coaxial light that irradiates light to the battery cell (90) in a direction parallel to the axial direction of the battery cell (90) and a vision camera that photographs the battery cell (90) in a direction parallel to the axial direction of the battery cell (90).

3. In claim 1 or claim 2, The above first information includes vector information that expresses the shape as a vector or can be expressed as a vector, The above control unit (77) is an alignment device that detects at least one alignment target portion (45, 47, 48) using the above vector information.

4. In any one of claims 1 to 3, An alignment device, wherein each of the alignment target portions (45, 47, 48) comprises a first portion (47) and a second portion (48) provided on the battery cell (90) and spaced apart from each other, and an extension portion (45) extended between the first portion (47) and the second portion (48) to connect the first portion (47) and the second portion (48).

5. In claim 4, Each of the above extension portions (45) is an alignment device that extends radially with respect to the center (O) within the battery cell (90) or obliquely with respect to the axial direction of the battery cell (90).

6. In claim 4 or claim 5, The above first information includes information mathematically expressing a shape corresponding or capable of corresponding to a pair of first edges (V1) defined by both ends in the width direction of the extension portion (45) of at least one of the alignment target portions (45, 47, 48), The above width direction intersects the extension direction of the above extension portion (45), An alignment device in which the control unit (77) detects at least one alignment target portion (45, 47, 48) by detecting the pair of first edges (V1) in the image (I) using the first information.

7. In claim 6, An alignment device wherein the first pair of edges (V1) are substantially parallel to the radial direction with respect to the center (O) within the battery cell (90).

8. In any one of claims 4 to 7, The above first information includes information mathematically expressing a shape corresponding or capable of corresponding to a pair of second edges (V2) defined by the first portion (47) and the second portion (48) of at least one of the alignment target portions (45, 47, 48), An alignment device in which the control unit (77) detects at least one alignment target portion (45, 47, 48) by detecting the pair of second edges (V2) in the image (I) using the first information.

9. In claim 8, An alignment device wherein the second pair of edges (V2) are substantially perpendicular to the radial direction with respect to the center (O) within the battery cell (90) or substantially parallel to the circumferential direction with respect to the center (O).

10. In any one of claims 4 to 9, An alignment device in which the normal direction of the surface of the above-mentioned extended portion (45) intersects with the normal direction of the surface of the battery cell (90) outside the extended portion (45) with the first portion (47) as the boundary, or intersects with the normal direction of the surface of the battery cell (90) outside the extended portion (45) with the second portion (48) as the boundary.

11. In any one of claims 4 to 10, Each of the above alignment target portions (45, 47, 48) is provided on a current collector plate (40) accommodated in a can (10) of the battery cell (90), The above current collector plate (40) has one or more electrode joints (42) joined to the tabs (27) of the electrodes (22) of the electrode assembly (20) accommodated in the can (10), one or more can joints (44) welded to the can (10) by the welding device (60) that welds the current collector plate (40) to the can (10), and a current-carrying portion (46) extending to electrically connect the one or more electrode joints (42) and the one or more can joints (44). Each of the above extension portions (45) is provided with an alignment device in the above power supply portion (46).

12. In any one of claims 1 to 11, The above alignment reference position corresponds to the position of the center point (C) of at least a part of the alignment target portion (45, 47, 48) aligned with respect to the welding device (60), An alignment device, wherein the detection position corresponds to the position of the center point (C) of at least a part of the alignment target area (45, 47, 48) detected in the image (I).

13. In any one of claims 1 to 12, The above alignment reference position includes the first azimuth angle (K) of the alignment target portion (45, 47, 48) aligned with respect to the welding device (60) with respect to the center (O) within the battery cell (90), The above detection location includes the second azimuth angle (K) of the alignment target area (45, 47, 48) detected in the image (I) with respect to the center (O), An alignment device in which the above offset amount includes an offset angle which is a difference between the first azimuth angle (K) and the second azimuth angle (K).

14. In claim 13, An alignment device in which the position of the center (O) is calculated using a plurality of alignment reference positions or a plurality of detection positions.

15. In any one of claims 1 to 14, The above offset amount includes an offset angle with respect to the rotation center axis of the position correction unit (71), The above control unit (77) controls the position correction unit (71) to reduce the offset amount, thereby rotating at least a portion of the battery cell (90), an alignment device.

16. Welding device (60) for welding battery cells (90); A transfer device (80) for transferring the battery cell (90) to the welding device (60); and A device comprising the alignment device (70) of any one of claims 1 to 20, which aligns the position of the battery cell (90) with respect to the welding device (60). Welding system.

17. In claim 16, The photographing unit (75) of the above alignment device (70) photographs the battery cell (90) being transported toward the welding device (60) by the transport device (80), or A welding system in which the position correction unit (71) of the above alignment device (70) is installed in the above transport device (80).

18. A photographing step (S110) of photographing a battery cell (90) to obtain an image (I) of the battery cell (90); A detection step (S120) of detecting at least one alignment target portion (45, 47, 48) in the image (I) using first information that mathematically expresses a shape (form) that corresponds or can correspond to at least a part of at least one alignment target portion (45, 47, 48) of the battery cell (90); For each of at least one of the detected alignment target parts (45, 47, 48), a calculation step (S130) for calculating an offset amount, which is the difference between the alignment reference position and the detection position; and An alignment method comprising a correction step (S140) of correcting the position of at least a portion of the battery cell (90) so as to reduce the offset amount.

19. In claim 18, The above first information includes information mathematically expressing a shape corresponding or capable of corresponding to a pair of first edges (V1) defined by both ends in the width direction intersecting the extension direction of at least one of the alignment target portions (45, 47, 48), The above detection step (S120) includes a process of detecting the pair of first edges (V1) in the image (I) using the first information, or The above first information includes information mathematically expressing a shape corresponding or capable of corresponding to a pair of second edges (V2) defined by the first portion (47) and the second portion (48) at both ends of the extension direction of at least one of the alignment target portions (45, 47, 48), The above detection step (S120) is an alignment method including a process of detecting a pair of second edges (V2) in the image (I) using the first information.

20. In claim 18 or claim 19, The above alignment reference position includes the first azimuth angle (K) of the alignment target portion (45, 47, 48) aligned with respect to the welding device (60) with respect to the center (O) within the battery cell (90), The above detection location includes the second azimuth angle (K) of the alignment target area (45, 47, 48) detected in the image (I) with respect to the center (O), The above offset amount includes the offset angle, The above calculation step (S130) is an alignment method including a process of calculating the offset angle from the difference between the first azimuth angle (K) and the second azimuth angle (K).

Images