Secondary battery electrode current collector and cylindrical secondary battery using the same

Abstract

An electrode current collector structure and a secondary battery using the electrode current collector are disclosed. The electrode current collector structure does not affect the electrode assembly even when deformed due to compression. The current collector includes: a main body; a can connecting portion disposed further outward in both axial and radial directions of the main body; and a bridging portion extending radially and connecting the main body and the can connecting portion. The bridging portion includes an inner bend, an inner bridging portion, a bridging bend, an outer bridging portion, and an outer bend.

Description

Technical Field

[0001] This application claims priority based on Korean Patent Application No. 10-2023-0152816 filed on November 7, 2023 and Korean Patent Application No. 10-2024-0139347 filed on October 14, 2024, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to an electrode current collector for a secondary battery and a cylindrical secondary battery using the electrode current collector, wherein the electrode current collector does not affect the electrode assembly even when deformed due to crimping. Background Technology

[0003] The process of manufacturing battery cells using cylindrical cans includes the following steps: deep drawing and stretching a metal sheet to form a circular bottom and a circular tube sidewall connected thereto; accommodating an electrode assembly therein; and then covering the open end of the sidewall with a cap.

[0004] Typical methods for covering the open end of a sidewall with a cap include: forming a rolled edge on the sidewall, inserting a cap washer on the axial outer surface of the rolled edge, and forming a crimping portion to press the edge of the cap.

[0005] In addition, in order to improve the energy density of the can and extend the current path, one structure currently in use is that a portion of the electrode foil is exposed in the axial direction at the axial end of the electrode assembly, and then radially bent to form an electrode tab, and a current collector electrically connects the electrode tab to the can.

[0006] For a current collector manufactured as a metal plate, its body is stacked axially on the electrode tabs of the electrode assembly to engage and be electrically connected to the electrode tabs of the electrode assembly, and its radial edge contacts and is electrically connected to the can or cap.

[0007] Here, in the structure where the rolled edge and the crimped part are processed and the opening end of the can is sealed with a cap, the edge of the manifold can be inserted and pressed between the axial outer surface of the rolled edge and the inwardly bent part of the crimped part, so that the edge of the manifold contacts the can or the cap.

[0008] Because the crimping involves plastically shaping the sidewall of the can to crimp the edge of the cap and the cap gasket therebetween, a large external force is applied to crimp the cap and cap gasket.

[0009] However, when external forces applied during the crimping process are transmitted to the manifold, which is relatively weaker than the sidewalls, the manifold may deform in an unexpected direction, thereby damaging the electrode assembly. Alternatively, external forces applied during the crimping process may be transmitted directly to the electrode assembly, resulting in damage to the electrode assembly. Summary of the Invention

[0010] Technical issues

[0011] To address the aforementioned problems, one object of the present invention is to provide a current collector structure and a secondary battery structure employing the current collector, which can be guided to deform in a direction that does not damage the electrode assembly even when subjected to external force during the crimping process.

[0012] Furthermore, an object of the present invention is to provide a current collector structure and a secondary battery structure employing the current collector, which can minimize the impact of the force applied for processing the sidewalls on the electrode assembly even when the current collector deforms in an unintended direction.

[0013] The technical problem to be solved by the present invention is not limited to the above-described objectives, and other objectives and advantages of the present invention not described herein may be understood through the following description, and will be more clearly understood through examples of the present invention. Furthermore, it is apparent that the objectives and advantages of the present invention may be embodied by the means set forth in the claims and combinations thereof.

[0014] Technical solution

[0015] To address the aforementioned problems, the present invention can be applied to a battery cell comprising: an electrode assembly; a current collector electrically connected to the electrode assembly; and a can housing the electrode assembly and the current collector.

[0016] The tank may include: a sidewall extending in an axial direction; and an open end disposed at one axial end of the sidewall.

[0017] A battery cell may include a cap that covers the open end.

[0018] The first end wall is connected to the opposite axial end of the side wall, thereby forming a closed end at the opposite axial end of the side wall.

[0019] The electrode assembly can be in the form of a core wound around a predetermined axis.

[0020] The electrode tabs are located at one of the two axial ends of the electrode assembly corresponding to the open end, and the current collector can be electrically connected to the electrode tabs.

[0021] The manifold can be electrically connected to the tank or cap.

[0022] The cap can be secured to the side wall of the can by pressing the edge of the cap against the rolled edge and crimping part provided at the opening end of the can.

[0023] The cap gasket can be inserted between the edge and the sidewall of the cap.

[0024] The edge of the cap can be pressed against the rolled edge and the crimped part by inserting a cap washer between them, thereby sealing the connection between the cap and the can.

[0025] The current collector includes a body that is in contact with and electrically connected to the electrode tabs.

[0026] The body may include an extension that engages with an electrode tab.

[0027] The body may also include an inner ring connected to the extension radially inside the extension. The inner ring may also be engaged with an electrode tab.

[0028] The connection between the body and the electrode tab can be achieved by welding, brazing, or soldering. Preferably, the connection can be achieved by laser welding in which a laser irradiates the surface of the extension.

[0029] The manifold includes a tank connection that is connected to at least one of the sidewall and the cap.

[0030] The can connection can be electrically connected to the main body.

[0031] The tank connection can be located on the radially outer side of the main body.

[0032] The tank connection can be located on the outer side of the main body along its axis.

[0033] The manifold includes a bridging portion that extends radially and has a radially inner end connected to the body and a radially outer end connected to the tank connection portion.

[0034] The bridging portion includes an inner bend, an inner bridging portion, a bridging bend, an outer bridging portion, and an outer bend, from the radially inner side to the radially outer side.

[0035] The present invention provides a current collector that can be used in the above-mentioned cylindrical secondary battery.

[0036] The diameter of the manifold can be equal to or greater than 35 mm and equal to or less than 46 mm.

[0037] The current collector includes a body that is in contact with and electrically connected to the electrode tabs.

[0038] The manifold includes: a tank connection portion disposed on the axial and radial exterior of the body, and configured to contact and be electrically connected to at least one of a tank accommodating an electrode assembly and a cap covering the open end of the tank.

[0039] The manifold includes a bridging portion that extends radially and has a radially inner end connected to the body and a radially outer end connected to the tank connection portion.

[0040] The bridging portion includes an inner bridging portion, which is connected to the main body by an inner bend portion that bends axially outward from the radial outer end of the main body at a first angle, the inner bridging portion extending radially outward and axially outward from the inner bend portion.

[0041] The bridging portion includes: an outer bridging portion, which is connected to the inner bridging portion by a bridging bend that bends radially outward from the radially outer end of the inner bridging portion at a second angle, and extends radially outward from the bridging bend.

[0042] The tank connection is connected to the outer bridging part through an outer bend provided at the radial outer end of the outer bridging part.

[0043] The can connection part can have a shape with a width greater than the width of the outward bend.

[0044] In one embodiment, the first angle of the current collector, which is set before the cylindrical secondary battery is assembled, can be equal to or greater than 60 degrees and equal to or less than 75 degrees.

[0045] Preferably, the third slope, calculated as the ratio of the axial outer side to the radial outer side of the tank connection, can be equal to or greater than 20 degrees and equal to or less than 35 degrees.

[0046] Preferably, the can connection portion can be bent radially outward at the radially outer end of the outer bridging portion by a third angle through the outer bending portion of the current collector plate provided before assembling the cylindrical secondary battery.

[0047] Preferably, the third angle can be equal to or greater than 5 degrees and equal to or less than 20 degrees.

[0048] Preferably, the second angle of the current collector set before assembling the cylindrical secondary battery can be equal to or greater than 25 degrees and equal to or less than 40 degrees.

[0049] Preferably, the first extension length of the inner bridging portion can be equal to or greater than 0.5 times the second extension length of the outer bridging portion and equal to or less than 2 times the second extension length.

[0050] In another embodiment, the cross-sectional second moment of the outer bridging portion viewed along the extension direction of the outer bridging portion can be greater than the cross-sectional second moment of the inner bridging portion viewed along the extension direction of the inner bridging portion.

[0051] Preferably, a reinforcing portion can be provided at the width-direction edge of the outer bridging portion, and the width-direction end of the outer bridging portion can be axially bent inward at the reinforcing portion.

[0052] Preferably, the body may include an extension that extends radially outward from the radially outer end of the body.

[0053] The bridging portion can be arranged between the extension portions in the circumferential direction.

[0054] The expansion section and the bridging section can each be set to four.

[0055] The first width of the connection between the extension and the main body can be 1.5 to 2.5 times the second width of the connection between the bridging part and the main body.

[0056] The present invention provides a cylindrical secondary battery using the above-described current collector.

[0057] The cylindrical secondary battery includes: an electrode assembly with electrode tabs at its axial end; a can housing the electrode assembly; a cap covering the open end of the can; and a current collector.

[0058] The can is provided with a rolled edge, at which the sidewall of the can is radially recessed inward between the electrode assembly and the cap in the axial direction.

[0059] The tank connection of the manifold contacts the axial outer surface of the rolled edge.

[0060] The edge of the cap is pressed together by the rolled edge and crimped part of the side wall, and the cap gasket is inserted between the side wall and the cap.

[0061] The can connector is inserted between the cap washer and the rolled edge.

[0062] When the current collector is assembled in a cylindrical secondary battery, the can connection can be bent axially outward from the radial outer end of the outer bridge part by the outer bending part.

[0063] When the current collector is assembled in a cylindrical secondary battery, the outer bridging portion may have a second slope that extends radially outward from the bridging bend while extending axially inward.

[0064] The third angle of the current collector set before assembling the cylindrical secondary battery can be opposite to the third angle of the current collector assembled in the cylindrical secondary battery.

[0065] When the current collector is assembled in a cylindrical secondary battery, the second angle of the current collector can be greater than the second angle of the current collector set before assembling the cylindrical secondary battery.

[0066] When the current collector is assembled in a cylindrical secondary battery, the first angle of the current collector can be greater than the first angle of the current collector set before assembling the cylindrical secondary battery.

[0067] Beneficial effects

[0068] According to the present invention, even when external force is transmitted along the extension direction of the bridging portion during can pressing and / or shaping processes, the first angle and / or the second angle are set such that the external force causes bending of the inner bend and / or the bridging bend. Therefore, the external force applied to the manifold during the pressing process increases the bending angle of the inner bend and the bridging bend. Thus, even when the manifold deforms, the deformation will not damage the electrode assembly.

[0069] According to the present invention, even when external forces are transmitted along the extension direction of the bridging portion during can pressing and / or shaping processes, the bending stiffness of the outer bridging portion is ensured to be greater than that of other portions, thereby causing bending of the inner bending portion and / or the bridging bending portion by external forces. Therefore, even when the manifold deforms, the deformation will not damage the electrode assembly.

[0070] According to the present invention, even when external forces are transmitted along the extension direction of the bridging portion during the can-rolling and / or shaping processes, the bending stiffness of the outer bridging portion is ensured to be greater than that of other portions, thereby causing the outer bending portion to reverse through the external force. Therefore, the external force applied to the manifold during the pressing process significantly increases the bending angle of the inner bending portion and the bridging bending portion. Thus, even when the manifold deforms, the deformation will not damage the electrode assembly.

[0071] According to the present invention, by reducing the width of the bridging portion while minimizing the increase in internal resistance, the warping resistance of the bridging portion is reduced to the point that external forces acting in the extension direction of the bridging portion are not transmitted to the main body. Therefore, even if deformation of the bridging portion and / or the can connection portion occurs during the processing of the manifold before assembly, causing the manifold to deform in an unintended direction during can pressing and / or shaping processes, damage to the electrode assembly can be minimized.

[0072] In addition to the aforementioned beneficial effects, the specific effects of the present invention will be further described while describing the specific details of the invention. Attached Figure Description

[0073] Figure 1 It is an exploded perspective view of the electrodes and diaphragm of the electrode assembly housed in the can before winding.

[0074] Figure 2 Before winding Figure 1 A perspective view of the laminated electrodes and diaphragm of the electrode assembly.

[0075] Figure 3 This diagram schematically illustrates the process of winding the electrodes and separator around the core.

[0076] Figure 4 Through such Figure 3 The ground is wound as shown Figure 2 A perspective view of a cylindrical wound electrode assembly assembled from laminated electrodes and diaphragms.

[0077] Figure 5 It is folded radially inward. Figure 4 A perspective view of the electrode tabs of the electrode assembly.

[0078] Figure 6It is a perspective view of a first current collector plate attached to a first electrode tab, which is disposed at a first axial end of the electrode assembly facing the first end wall of the tank.

[0079] Figure 7 It is a perspective view showing a second current collector plate engaged with a second electrode tab, which is disposed at the second axial end of the electrode assembly facing the second end wall of the tank.

[0080] Figure 8 This is a perspective view showing a cylindrical battery cell.

[0081] Figure 9 It is shown Figure 15 A front cross-sectional view of a cylindrical battery cell.

[0082] Figure 10 This is a plan view and a side view showing a current collector applied to a cylindrical battery cell according to a comparative example.

[0083] Figure 11 Show Figure 10 A plan view of a portion of the manifold.

[0084] Figure 12 It is shown schematically. Figure 10 An enlarged side view of a portion of the manifold.

[0085] Figures 13 to 17 It schematically shows that Figure 12 The process of assembling the manifold into the tank.

[0086] Figure 18 This is a cross-sectional photograph showing the damage to the electrode assembly caused by abnormal deformation of the current collector according to the comparative example.

[0087] Figure 19 This is a plan view and a side view showing a current collector applied to a cylindrical battery cell according to a first embodiment.

[0088] Figure 20 These are a plan view and a side view of a current collector applied to a cylindrical battery cell according to the second embodiment.

[0089] Figure 21 It is shown Figure 20 Enlarged perspective view of the bridging section and tank connection section of the manifold.

[0090] Figure 22 This is a plan view showing a portion of the manifold according to an embodiment.

[0091] Figures 23 to 27 The process of assembling a manifold into a tank according to an embodiment is illustrated schematically.

[0092] [Explanation of reference numerals in the attached figures]

[0093] 10: Can (shell); 11: Side wall; 116: Crimped edge; 1161: Axial outer surface; 117: Press-fit part; 1171: Inward bending part; 12: First end wall (second electrode terminal); 14: First electrode terminal; 15: Terminal gasket; 16: Second end wall; 161: Shrink ring; 162: Cap body; 163: Weak part; 17: Cap gasket; 19: Insulator; 20: Electrode assembly; 21: First electrode; 22: Second electrode; 23: Current collector; 24: Active material; 25: Coated part; 26: Uncoated part; 27: Electrode tab (notched tab); 28: Diaphragm; 29: Core cavity; 290: Mandrel; 31: First current collector (anode current collector); 311 312: Terminal connection area; 313: Interconnection part; 32: Second current collector (cathode current collector); 320: Main body; 321: Inner ring; 322: Hole; 323: Extension part; W1: First width; 324: Tank connection part; b3: Third slope; 33: Bridging part; W2: Second width; 331: Inner bend; a1: First angle; 332: Outer bend; a3: Third angle; 333: Inner bridging part; b1: First slope; L1: First extension length; 334: Bridging bend; a2: Second angle; 335: Outer bridging part; b2: Second slope; L2: Second extension length; 336: Reinforcing part; 39: Welding part; 70: Battery cell Detailed Implementation

[0094] The above-described objects, features, and advantages will be described in detail below with reference to the accompanying drawings, enabling those skilled in the art to implement the technical concept of the present invention. In describing the invention, detailed descriptions of prior art related to the invention will be omitted where it is determined that such detailed descriptions unnecessarily obscure the essential points of the invention. Preferred embodiments according to the invention will be described in detail below with reference to the accompanying drawings. In the drawings, the same reference numerals are used to denote the same or similar components.

[0095] Although terms such as "first" and "second" are used to describe various elements, these elements are certainly not limited by these terms. These terms are only used to distinguish one element from another, and unless otherwise specified, the first element can also be the second element.

[0096] Throughout this specification, unless otherwise stated, each element may be singular or plural.

[0097] In the following text, "arranging an element on top of (or below) an element" or "arranging an element on the top of (or bottom) of an element" means not only "arranging an element to contact the upper (or lower) surface," but also "arranging an element above the upper (or lower) surface of another element, with the other element inserted in between."

[0098] Furthermore, when an element is described as being “connected,” “linked,” or “in contact” with another element, it should be understood that the element may be “directly connected,” “directly linked,” or “directly in contact” with the other element, or that the element may be “connected,” “linked,” or “in contact” with the other element by means of inserting another element between them or by means of another element.

[0099] Unless the context clearly specifies otherwise, the singular form used herein includes the plural form. Terms such as “consisting of” or “comprising” as used herein should not be construed as including all elements or steps described in the specification, but should be construed as excluding some elements or steps, or including additional elements or steps.

[0100] Throughout this specification, unless otherwise specified, “A and / or B” means A, B, or both A and B, and unless otherwise specified, “C to D” means from equal to or higher than C to equal to or lower than D.

[0101] In the description of the implementation, "axial direction" refers to "the direction in which the axis forming the winding center of the wound electrode assembly extends", "radial direction" refers to "the direction toward (centripetal) or away from (centrifugal) the axis", and "circumferential direction" refers to "the direction around the axis".

[0102] The battery cell employing the current collector according to the embodiment can, for example, be a cylindrical battery cell with a shape factor ratio greater than about 0.4. Here, the shape factor refers to a value representing the diameter and height of the cylindrical battery cell. The shape factor ratio can be defined as the value obtained by dividing the diameter of the cylindrical battery cell by its height, i.e., the ratio of diameter Φ to height H.

[0103] Cylindrical battery cells can be, for example, 46110 cells, 48750 cells, 48110 cells, 48800 cells, or 46800 cells. In the form factor value, the first two digits represent the diameter of the cell, the next two digits represent the height of the cell, and the last digit 0 indicates that the cross-section of the cell is circular.

[0104] The battery cell can be an approximately cylindrical cell with a diameter of about 46 mm, a height of about 110 mm, and a shape factor of 0.418.

[0105] According to another embodiment, the battery cell can be an approximately cylindrical cell with a diameter of about 48 mm, a height of about 75 mm, and a shape factor of 0.640.

[0106] According to another embodiment, the battery cell can be an approximately cylindrical cell with a diameter of about 48 mm, a height of about 110 mm, and a shape factor of 0.418.

[0107] According to another embodiment, the battery cell can be an approximately cylindrical cell with a diameter of about 48 mm, a height of about 80 mm, and a shape factor of 0.600.

[0108] According to another embodiment, the battery cell can be an approximately cylindrical cell with a diameter of about 46 mm, a height of about 80 mm, and a shape factor of 0.575.

[0109] This invention can obviously be applied to battery cells with a form factor ratio of approximately 0.4 or less (e.g., 18650 cells, 21700 cells, etc.). For an 18650 cell, its diameter is approximately 18 mm, its height is approximately 65 mm, and its form factor ratio is 0.277. For a 21700 cell, its diameter is approximately 21 mm, its height is approximately 70 mm, and its form factor ratio is 0.300.

[0110] Cylindrical battery cells

[0111] Reference Figures 1 to 9 The cylindrical battery cell 70 according to the first embodiment includes: an electrode assembly 20; current collectors 31 and 32 electrically connected to the electrode assembly 20; and a housing 10 for accommodating the electrode assembly 20 and the current collectors 31 and 32.

[0112] <Electrode Assembly>

[0113] like Figure 1 The first electrode 21, the second electrode 22, and the diaphragm 28, having predetermined widths and extending along the length direction, are fabricated as shown. Figure 2 The first electrode 21, the diaphragm 28, the second electrode 22, and the diaphragm 28 are stacked sequentially as shown, and as... Figure 4 The stacked structure is wound into a core shape around the mandrel 290 as shown to manufacture the electrode assembly 20.

[0114] One of the first electrode 21 and the second electrode 22 can be an anode, and the other can be a cathode. In this embodiment, the first electrode 21 is implemented as an anode, and the second electrode 22 is implemented as a cathode.

[0115] The first electrode 21 and the second electrode 22 are manufactured into sheets having a predetermined width and extending along the length direction. The electrodes are manufactured by coating the current collector 23 with an active material 24.

[0116] The current collector 23 can be made of metal foil. One of the current collector 23 of the first electrode 21 and the current collector 23 of the second electrode 22 can be made of aluminum, and the other can be made of copper. In this embodiment, the current collector 23 of the first electrode 21 is made of aluminum foil, and the current collector 23 of the second electrode 22 is made of copper foil.

[0117] The electrode may include not only the area of ​​the current collector 23 coated with the active material 24, but also the area of ​​the current collector 23 not coated with the active material 24. For ease of description, within the two-dimensional region defined by the sheet-like current collector 23, the area coated with the active material 24 and capable of inducing a battery reaction is referred to as the coated portion 25 of the electrode, and the area not coated with the active material 24 and therefore not inducing a battery reaction is referred to as the uncoated portion 26 of the electrode.

[0118] The uncoated portion 26 of the electrode can be used for functions or operations other than battery reactions. For example, the uncoated portion 26 can provide electrode tabs 27 for electrically connecting the electrode to the electrode terminals. Specifically, the current collector 23 of the uncoated portion 26 can itself be used as the electrode tab 27, or a separate tab member can be attached to the current collector 23 of the uncoated portion 26 to provide the electrode tab.

[0119] According to this embodiment, the first electrode 21 has an uncoated portion 26 disposed at a first end in its width direction, and the second electrode 22 has an uncoated portion 26 disposed at a second end in its width direction.

[0120] Reference Figure 2 and Figure 4 The uncoated portion 26 protrudes from the electrode laminate or core along the width direction or toward the axial direction. The uncoated portion 26 itself serves as the electrode tab 27. In the width direction or axial direction, the inner end of the uncoated portion 26 is positioned further inward than the outer end of the diaphragm 28, and the outer end of the uncoated portion 26 is positioned further outward than the outer end of the diaphragm 28.

[0121] Reference Figure 1 and Figure 2 The uncoated portion 26 may be provided with cutting lines at predetermined intervals to provide a plurality of flag-shaped electrode tabs 27 arranged along the length direction.

[0122] In this embodiment, an electrode tab 27 having an isosceles trapezoidal shape is illustrated. Alternatively, the electrode tab 27 may have various shapes (e.g., semicircular, semi-elliptical, triangular, rectangular, parallelogram, etc.).

[0123] In this embodiment, electrode tabs 27 having the same width (length dimension) and arranged along the length direction are illustrated. However, the width of the electrode tabs can gradually or progressively increase from the core toward the outer periphery.

[0124] Furthermore, in this embodiment, an electrode tab 27 is shown with its height (axial dimension) gradually increasing from the core towards the outer periphery. However, the height of the electrode tab may be constant or may gradually decrease.

[0125] Furthermore, in the embodiment, a structure is illustrated in which the electrode tabs 27 are removed from predetermined sections at the centripetal and centrifugal ends of the uncoated portion 26. However, it is obvious that the electrode tabs are not removed from the centripetal end of the uncoated portion, the electrode tabs are not removed from the centrifugal end of the uncoated portion, and neither the centripetal nor the centrifugal end of the uncoated portion is removed.

[0126] like Figure 5 As shown, in the wound electrode assembly 20, the electrode tab 27 can be bent and flattened in the radial direction. The electrode tab 27 can be bent radially inward or radially outward. In this embodiment, a structure in which the electrode tab 27 is bent radially inward is illustrated.

[0127] like Figure 3 As shown, during the process of forming the wound electrode assembly 20 by winding the laminate, the electrode tabs 27 can be bent one by one. Alternatively, as Figure 4 As shown, after forming a core-type electrode assembly by winding the laminated material, the electrode tab 27 can be bent in one go.

[0128] The electrode tabs 27 of the first electrode 21 and the second electrode 22, which are folded and overlapped in the radial direction, can provide a first plane and a second plane that are substantially perpendicular to the axial direction at the two axial ends of the electrode assembly 20, respectively.

[0129] <Collider>

[0130] like Figure 6 and Figure 7 As shown, the first current collector 31 and the second current collector 32 can be respectively coupled to a generally flat first surface and a second surface provided by electrode tabs 27 exposed at the two axial ends of the electrode assembly 20.

[0131] One of the first current collector 31 and the second current collector 32 can be an anode current collector, and the other can be a cathode current collector. In this embodiment, the first current collector 31 is implemented as an anode current collector, and the second current collector 32 is implemented as a cathode current collector.

[0132] The first current collector 31 and the second current collector 32 may be made of aluminum or copper. In one embodiment, the first current collector 31 is made of aluminum, and the second current collector 32 is made of copper.

[0133] The manifolds 31 and 32 can be manufactured by stamping, trimming, piercing and bending the metal sheets.

[0134] Reference Figure 6 The first current collector 31 includes: a terminal connection region 311 disposed in a portion corresponding to the core cavity 29 of the electrode assembly 20; and an electrode connection region 312 disposed around the terminal connection region 311. The terminal connection region 311 is located at the center of the first current collector 31 and is configured to cover at least a portion of the core cavity 29 of the electrode assembly 20 in the axial direction. The electrode connection region 312 is configured to surround the terminal connection region 311 and is spaced apart from the terminal connection region 311 in the radial direction.

[0135] Terminal connection area 311 and electrode connection area 312 are physically and electrically connected to each other via interconnection portion 313. Interconnection portion 313 extends radially, connecting to terminal connection area 311 on the radially inner side and to electrode connection area 312 on the radially outer side.

[0136] In this embodiment, the interconnect portion 313 may extend radially relative to the terminal connection region 311, and a plurality of interconnect portions 313 may be arranged in a circumferential direction. The interconnect portion 313 may have a radial length greater than its circumferential width.

[0137] The electrode connection area 312 can be engaged with and electrically connected to the first electrode tab 27-1 disposed at the first electrode 21 of the electrode assembly 20. The terminal connection area 311 can be engaged with and electrically connected to the first electrode terminal 14, which will be described later.

[0138] Reference Figure 7 The second collector plate 32 is provided with a body 320, which includes an inner ring 321 having a hole 322 at its center. The body 320 may also include an extension 323 extending radially outward from the inner ring 321. A plurality of extensions may be arranged to be spaced apart from each other in the circumferential direction.

[0139] The second manifold 32 is provided with a tank connection portion 324 that surrounds the main body 320 radially outward. The main body 320 and the tank connection portion 324 can be spaced apart from each other in the radial direction.

[0140] The second manifold 32 is provided with a bridging portion 33 connecting the main body 320 and the tank connection portion 324. Multiple bridging portions 33 extending radially can be arranged to be spaced apart from each other circumferentially. The bridging portions 33 can be arranged circumferentially between the extension portions 323.

[0141] The main body 320 can be engaged with and electrically connected to the second electrode tab 27-2 disposed at the second electrode 22 of the electrode assembly 20. The can connection portion 324 can be engaged with and electrically connected to the side wall 11 of the can 10, which will be described later.

[0142] <Battery casing>

[0143] like Figure 8 and Figure 9 As shown, the electrode assembly 20 can be inserted into the housing 10 and engage with the first current collector 31 and the second current collector 32.

[0144] Reference Figure 8 and Figure 9 The housing 10 may include a metal can. The can 10 includes: a sidewall 11 extending axially between a first end and a second end; and a first endwall 12 connected to the first end of the sidewall 11 and extending radially. The first endwall 12 may have a flat disk shape intersecting the axial direction, and the sidewall 11 may have a circular tube shape extending axially.

[0145] The nickel-plated metal sheet on the steel surface can be deep-drawn and stretched, and while the side wall 11 is fixed with a pressure plate, the second end of the side wall 11 is trimmed with a punch, thereby manufacturing the first end wall 12 and the side wall 11. Obviously, the material of the can 10 is not limited to this.

[0146] In this embodiment, a first end wall 12 and a side wall 11 are shown as integrally connected. However, the first end wall 12 and the side wall 11 can be manufactured as separate components and then connected by welding or other methods.

[0147] The first end wall 12 and side wall 11 of the tank 10 separate the internal space of the tank from the external space. A terminal hole is located at the center of the first end wall 12, into which the first electrode terminal 14 can be fitted and installed by penetrating the first end wall 12 through the terminal hole. The first electrode terminal 14 is plastically deformed by inserting a terminal washer 15 therebetween and is fixed to the first end wall 12. The terminal washer 15 is inserted between the first electrode terminal 14 and the first end wall 12 to seal the inside and outside of the first end wall 12, thereby preventing electrolyte leakage and electrically insulating the first electrode terminal 14 from the first end wall 12.

[0148] However, the connection method between the first electrode terminal 14 and the can 10 is not limited to this. For example, in addition to these plastic processing methods, various other fixing methods (e.g., bolt-nut connection schemes and glass sealing schemes) can be applied, as long as the structure can seal between the first electrode terminal 14 and the can 10 and electrically insulate the first electrode terminal 14 and the can 10.

[0149] The sidewall 11 surrounds the interior space of the can 10 and extends in the axial direction. Therefore, the inner surface of the sidewall 11 faces radially toward the outer periphery of the electrode assembly 20. The second end of the sidewall 11 is open, thereby defining an opening in the can 10.

[0150] <Battery Cell Assembly>

[0151] Reference Figure 11 The electrode assembly 20 is housed in the tank 10, and the first current collector 31 is aligned with the first end wall 12 of the tank 10. An insulator 19 is inserted between the first current collector 31 and the first end wall 12 to electrically insulate the first current collector 31 and the first end wall 12 from each other.

[0152] The terminal connection area 311 of the first current collector 31 is fixed to and electrically connected to the first electrode terminal 14. In an embodiment, the first electrode terminal 14, fixed to the can 10, is fixed to the surface of the terminal connection area 311 of the first current collector 31 by a thermal bonding method such as welding and is electrically connected thereto. After the electrode assembly 20 is inserted into the can 10, the first electrode terminal 14 of the can 10 and the terminal connection area 311 of the first current collector 31 can be connected.

[0153] Therefore, the first electrode terminal 14 can have a first polarity corresponding to the first electrode 21.

[0154] With the electrode assembly 20 housed in the tank 10, the second manifold 32 is positioned on the open side. After the electrode assembly 20 is housed in the tank 10, the area near the second end of the sidewall 11 is radially pressed inward and plastically processed to form a concave crimp 116. This crimping process can be performed to axially position the crimp 116 between the tank connection 324 of the second manifold 32 and the electrode assembly 20.

[0155] The can connection portion 324 of the second manifold 32 faces and contacts the axial outer surface of the rolled edge 116. To ensure a stable electrical connection between the second manifold 32 and the side wall 11, the can connection portion 324 and the rolled edge 116 can be welded.

[0156] Next, the electrolyte is injected into tank 10.

[0157] After the electrolyte is injected, the edge of the second end wall 16, which is in the form of a cap or lid, is placed on the rolled edge 116 of the tank connection 324 in which the second manifold is placed, thereby covering the opening of the tank 10. Specifically, a cap gasket 17 is inserted between the edge of the second end wall 16 and the side wall 11, and the second end of the side wall 11 is radially caulked to form a crimp 117. The cap gasket 17 is pressed together by the rolled edge 116 and the crimp 117, thereby sealing the radial outer periphery of the second end wall 16 to the second axial end of the side wall 11.

[0158] The can connection portion 324 of the second manifold 32 is electrically connected to the can 10 near the second axial end of the sidewall 11. Therefore, the sidewall 11 may have a second polarity corresponding to the second electrode 22.

[0159] The first end wall 12 is electrically connected to the side wall 11. Therefore, the first end wall 12 can also have a second polarity. The diameter of the head of the first electrode terminal 14 located outside the first end wall 12 can be about 1 / 3 of the diameter of the first end wall 12. That is, the outer surface of the first end wall 12 can have sufficient area to engage the busbar.

[0160] According to an embodiment, both the first electrode terminal 14 and the second electrode terminal 12 can be disposed at the first axial end of the battery cell. Therefore, both the busbar connected to the first electrode terminal 14 and the busbar connected to the second electrode terminal 12 can be disposed at the upper part of the battery cell. In this embodiment, the first electrode terminal 14 serves as the anode terminal, and the second electrode terminal 12 serves as the cathode terminal.

[0161] In addition, the aforementioned insulator 19 electrically insulates the second electrode terminal 12 from the first current collector 31 to prevent a short circuit between the second electrode terminal 12 and the first current collector 31.

[0162] [Flush head]

[0163] Reference Figures 10 to 12 The manifold 32 includes: a main body 320 that contacts and is electrically connected to the electrode tab 27; a can connection portion 324 that contacts and is electrically connected to the can 10 on the radially outer side of the main body 320; and a bridging portion 33 that connects the can connection portion 324 and the main body 320 in a radial direction.

[0164] The main body 320 includes: an extension 323 which engages with an electrode tab 27; and an inner ring 321 which is connected to the extension 323 on the radially inner side and has a hole 322 disposed therein.

[0165] The tank connection 324 is provided on the radial and axial outer sides of the main body 320 via the bridging part 33.

[0166] The bridging portion 33 includes, from the radial inner side to the radial outer side, an inner bend portion 331, an inner bridging portion 333, a bridging bend portion 334, an outer bridging portion 335, and an outer bend portion 332.

[0167] The inner bridging portion 333 is connected to the main body 320 by an inner bending portion 331 that bends outward from the radial outer end of the main body 320 at a first angle a1, and extends radially outward and axially outward from the inner bending portion 331 for a first extension length L1.

[0168] Therefore, the inner bridging portion 333 extends radially outward and axially outward with a first slope b1.

[0169] The outer bridging portion 335 is connected to the inner bridging portion 333 by a bridging bend 334 that bends radially outward from the radial outer end of the inner bridging portion 333 at a second angle a2, and extends radially outward and axially outward from the bridging bend 334 by a second extension length L2.

[0170] Therefore, the outer bridging portion 335 extends radially outward with a second slope b2 and also extends axially outward.

[0171] The can connector 324 is connected to the outer bridging portion 335 via an outer bend 332 located at the radially outer end of the outer bridging portion 335. The can connector 324 is bent radially outward from the radially outer end of the outer bridging portion 335 by a third angle a3 via the outer bend 332.

[0172] Therefore, the can connection 324 extends radially outward with a third slope b3 and axially outward.

[0173] Reference Figure 13 When the main body 320 of the manifold 32 is joined to the electrode tab 27 of the electrode assembly 20, when the sidewall 11 is formed by pressing the sidewall 11 radially inward from the axial outside after the electrode assembly 20 and the manifold 32 are housed in the tank 10, an axial outer surface 1161 is formed on the sidewall 116.

[0174] In this state, when the can connector 324 is pressed along the axial direction to bring it into contact with the axial outer surface 1161, the inner bend 331 of the cantilevered bridge portion 33 undergoes primary deformation, and the can connector 324 contacts the axial outer surface 1161, as... Figure 14 As shown.

[0175] After that, as Figure 15 As shown, a weld portion 39 is formed to temporarily fix the can connection portion 324 to the crimp 116. The weld portion 39 can be easily formed by tab welding.

[0176] like Figure 9As shown, when the edge of the can 10 is pressed against the crimping portion 117 and the cap washer 17 is inserted therebetween, the force of the cap 16 and the cap washer 17, which are axially pressed inward by the crimping portion 117, acts as a distributed load f at the boundary between the bridging portion 33 and the can connection portion 324 spaced apart from the crimped edge 116. Figure 16 As shown.

[0177] However, as Figure 10 and Figure 11 As shown, the circumferential width of the tank connection 324 is greater than the circumferential width of the outer bridging part 335, causing the distributed load f to cause strong deformation of the outer bending part 332 and the adjacent outer bridging part 335.

[0178] As a result, Figure 17 As shown, the outer bridging portion 335 bends inward axially, so that the force F is transmitted to the inner bending portion 331 along the extension direction of the bridging portion 33, thereby pressing the inner bending portion 331 inward axially.

[0179] Due to this deformation behavior of the current collector 32, the radially outer end of the main body 320 deforms in such a way that the radially outer end is inserted into the electrode assembly 20 along the axial direction, as... Figure 18 As shown.

[0180] This deformation is caused by the distributed load f, which causes strong deformation of the outer bend 332 and the adjacent outer bridging portion 335. Furthermore, it can be confirmed that this deformation is caused by the failure of the bending angle of the bridging bend 334 to expand when the external force F acts along the extension direction of the bridging portion 33. Furthermore, it can be confirmed that this deformation is caused by the failure of the bending angle of the inner bend 331 to expand when the external force F acts along the extension direction of the bridging portion 33. Furthermore, it can be confirmed that the abnormal deformation is caused by the bridging portion 33 failing to warp sufficiently due to its high stiffness when the external force F acts along the extension direction of the bridging portion 33.

[0181] like Figure 19 and Figure 22 The first embodiment shown and Figures 20 to 22 As shown in the second embodiment, the present invention provides a structure for eliminating the causes of the above-mentioned abnormal deformation.

[0182] Reference Figure 19 and Figure 23 In the manifold 32 according to the first embodiment, the first angle a1 of the inner bend 331 is set to be equal to or greater than 60 degrees and equal to or less than 75 degrees. Compared with the comparative example above, even when the bridging portion 33 deforms to make the can connection portion 324 contact the rolled edge 116, the first slope b1 of the inner bend 331 can be sufficiently ensured, such as Figure 24 As shown.

[0183] As a result, even when the external force F acts in the extension direction of the bridging portion 33, the lever arm of the external force F transmitted to the inner bending portion 331 through the outer bridging portion 335 is long enough to guide the external force to act in the direction of widening the bending angle a1 of the inner bending portion 331, and at the same time guide the external force to act in the direction of widening the bending angle a2 of the bridging bending portion 334.

[0184] Furthermore, when the first angle a1 is less than 60 degrees, after the bridging portion 33 deforms to bring the can connection portion 324 into contact with the rolled edge 116, there is a risk that the first slope b1 cannot be sufficiently guaranteed, such as... Figure 23 As shown.

[0185] Furthermore, when the first angle a1 is greater than 75 degrees, the first extension length L1 of the inner bridge portion 333 may be insufficient due to axial space constraints, which may prevent the lever arm from being lengthened.

[0186] Reference Figure 19 and Figure 23 The third slope b3 of the can connector 324 is set to be equal to or greater than 20 degrees and equal to or less than 35 degrees. Therefore, even when the bridging portion 33 deforms to make the can connector 324 contact the rolled edge 116, the amount of deformation of the bridging portion 33 can be limited (e.g., Figure 24 As shown), this ensures that the first slope b1 of the inner bend 331 is adequately guaranteed.

[0187] When the third slope b3 is equal to or greater than 35 degrees, there is a risk that the deformation of the bridging portion 33 used to make the can connection portion 324 contact the rolled edge 116 is too large, so the first slope b1 may not be sufficiently guaranteed after the bridging portion 33 is deformed.

[0188] Furthermore, when the third slope b3 is less than 20 degrees, sufficient axial space cannot be ensured between the tank connection 324 and the electrode assembly 20 (e.g., Figure 23 As shown in the figure, when processing the rolled edge 116, the can connection part 324 may interfere with the rolled edge 116.

[0189] Reference Figure 19 and Figure 23 The third angle a3 of the outer bending part 332 is set to be equal to or greater than 5 degrees and equal to or less than 20 degrees.

[0190] When the third angle a3 is less than 5 degrees, the bending angle is almost non-existent, so that even though the distributed load f is applied to the outer bending part 332, the effect of concentrating the bending deformation on the outer bending part 332 can be avoided. Therefore, the possibility that the outer bridging part 335 will experience bending deformation cannot be ruled out.

[0191] Furthermore, when the third angle a3 exceeds 20 degrees, sufficient axial space cannot be ensured between the tank connection 324 and the electrode assembly 20 (e.g., Figure 23 As shown in the figure, when processing the rolled edge 116, the can connection part 324 may interfere with the rolled edge 116.

[0192] Reference Figure 19 and Figure 23 In the current collector 32 according to the first embodiment, the second angle a2 of the bridging bend 334 is set to be equal to or greater than 25 degrees and equal to or less than 40 degrees. When the second angle a2 exceeds 25 degrees, even if the external force F acts in the extension direction of the bridging portion 33, the lever arm of the external force F transmitted to the inner bend 331 through the outer bridging portion 335 is long enough, so that the external force can be guided to act in the direction of widening the bending angle a1 of the inner bend 331, and at the same time, the external force can be guided to act in the direction of widening the bending angle a2 of the bridging bend 334.

[0193] Furthermore, when the second angle a2 exceeds 40 degrees, sufficient space in the axial direction cannot be ensured between the can connection 324 and the electrode assembly 20, which may cause interference between the can connection 324 and the crimp 116 when processing the crimp 116.

[0194] Next, refer to Figure 20 and Figure 21 According to the second embodiment, the current collector 32 is provided with a reinforcing portion 336, which is formed by bending the width-direction edge of the outer bridging portion 335 axially inward with the width-direction end of the outer bridging portion 335 facing the electrode assembly 20. That is, compared with the inner bridging portion 333, the outer bridging portion 335 also includes the reinforcing portion 336.

[0195] Therefore, the second moment of the cross section of the outer bridging portion 335, when viewed along the extension direction of the outer bridging portion 335, becomes greater than the second moment of the cross section of the inner bridging portion 333, when viewed along the extension direction of the inner bridging portion 333.

[0196] As a result, Figure 26 As shown, when the distributed load f applied during the processing of the crimping portion 117 causes deformation to concentrate in the outer bending portion 332 and the adjacent tank connection portion 324 with lower bending stiffness, the outer bending portion 332 is further axially lowered inward, and a reverse bending of the outer bending portion 332 is caused, as shown. Figure 27 As shown.

[0197] Preferably, the can connection portion 324 has a shape in which the width gradually increases as it extends from the outer bend portion 332, thereby further causing the aforementioned deformation.

[0198] Therefore, the lever arm of the external force F transmitted from the outer bridging portion 335 to the inner bending portion 331 is long enough to guide the external force to act in the direction of widening the bending angle a1 of the inner bending portion 331, and simultaneously in the direction of widening the bending angle a2 of the bridging bending portion 334. In particular, since the outer bridging portion 335 has high bending stiffness along its entire extension direction, the load is more concentrated on the bridging bending portion 334, thereby causing more reliable bending expansion.

[0199] To ensure the lever arm and facilitate bending of the bending portion, the first extension length L1 of the inner bridging portion 333 can be set to be equal to or greater than 0.5 times and equal to or less than 2 times the second extension length L2 of the outer bridging portion 335. That is, the extension lengths of the inner bridging portion 333 and the outer bridging portion 335 can be set such that the difference does not exceed twice.

[0200] In addition, the main body 320 of the manifold 32 also includes an extension 323, which is arranged in the circumferential direction between the bridging portions 33 and extends radially outward from the radial outer end of the main body 320.

[0201] According to the embodiment, the first width W1 of the connection between the extension portion 323 and the main body 320, measured along the circumferential direction, is set to be equal to or greater than 1.5 times the second width W2 of the connection between the bridging portion 33 and the main body 320, and the first width W1 is equal to or less than 2.5 times the second width W2. Therefore, within the limited circumferential dimensions of the manifold 32, the increase in the width of the connection between the bridging portion 33 and the main body 320 is restricted, thereby enhancing the deformation compliance of the inner bend portion 331.

[0202] Specifically, the diameter of the manifold 32 is equal to or greater than 35 mm and equal to or less than 46 mm, and it can be provided with four extension sections 323 and four bridging sections 33.

[0203] In the implementation, the first width W1 is approximately 8 mm to 9 mm, and the second width W2 is approximately 3.5 mm to 4.5 mm.

[0204] As a result, the warping resistance of the bridging portion 33 will decrease. Even if the manifold 32 does not deform along the design direction due to accidental deformation of the manifold 32 before assembly, the deformation caused by external force is concentrated in the bending or warping deformation of the bridging portion 33, thereby preventing the external force from being transmitted to the main body 320.

[0205] Reference Figures 23 to 27 This describes the assembly process of a cylindrical secondary battery using the current collector 32 of this embodiment. Even when the bridging portion 33 deforms to cause the can connection portion 324 to contact the rolled edge 116 (e.g.) Figure 23 As shown), the first slope b1 can also be sufficiently ensured (as shown). Figure 24(as shown), thereby fully ensuring the lever arm of the outer bridging portion 335 relative to the inner bending portion 331.

[0206] In addition, such as Figure 26 As shown, even when a distributed load f is applied near the outer bend 332 during the processing of the crimping portion 117, the outer bend 332 is sufficiently lowered and bends in the reverse direction, and the resulting bend can increase the first angle a1 and the second angle a2. Furthermore, as... Figure 27 As shown, the outer bridging portion 335 has a second slope b2 that extends radially outward from the bridging bend portion 334 while extending axially inward.

[0207] Therefore, the distributed load f will not axially compress the inner bend 331, and as a result, the deformation of the current collector 32 that may occur during the crimping process has no effect on the electrode assembly 20.

[0208] It should be understood that the described embodiments are illustrative in all respects and not limiting, and the scope of the invention should be indicated by the appended claims rather than the detailed description described herein. Furthermore, the meaning and scope of the claims described subsequently, as well as all variations and modifications derived from equivalent concepts, should be interpreted as being included within the scope of the invention.

[0209] Although the invention has been described with reference to exemplary drawings, it should be understood that the invention is not limited to the embodiments and drawings disclosed in this specification, and those skilled in the art will understand that various modifications can be made without departing from the scope and concept of the invention. Furthermore, although the operational effects of the configuration according to the invention are not explicitly described in the description of embodiments of the invention, it should be understood that the configuration can also identify predictable effects.

Claims

1. A current collector (32) for a cylindrical secondary battery, the current collector comprising: The main body (320) is in contact with and electrically connected to the electrode tabs (27) of the electrode assembly (20); A can connection portion (324) is disposed on the axial and radial exterior of the body (320) and is configured to contact and be electrically connected to at least one of a can (10) accommodating the electrode assembly (20) and a cap (16) covering the open end of the can (10); and A bridging portion (33) extends radially and has a radially inner end connected to the body (320) and a radially outer end connected to the tank connection portion (324). The bridging portion (33) includes: an inner bridging portion (333) connected to the body (320) via an inner bend (331) that bends axially outward from the radially outer end of the body (320) by a first angle (a1), the inner bridging portion (333) extending radially outward and axially outward from the inner bend (331); and an outer bridging portion (335) connected to the inner bridging portion (333) via a bridging bend (334) that bends radially outward from the radially outer end of the inner bridging portion (333) by a second angle (a2), and extending radially outward from the bridging bend (334). The tank connection (324) is connected to the outer bridging portion (335) via an outer bend (332) provided at the radially outer end of the outer bridging portion (335), and The first angle (a1) is equal to or greater than 60 degrees and equal to or less than 75 degrees.

2. The collector plate (32) according to claim 1, wherein, The third slope (b3), calculated as the ratio of the axial outer side to the radial outer side of the tank connection (324), is equal to or greater than 20 degrees and equal to or less than 35 degrees.

3. The collector plate (32) according to claim 2, wherein, The tank connector (324) is bent radially outward at the radial outer end of the outer bridging portion (335) by a third angle (a3) ​​via the outer bending portion (332), and The third angle (a3) ​​is equal to or greater than 5 degrees and equal to or less than 20 degrees.

4. The collector plate (32) according to claim 1, wherein, The second angle (a2) is equal to or greater than 25 degrees and equal to or less than 40 degrees.

5. The collector plate (32) according to claim 1, wherein, The first extension length (L1) of the inner bridging portion (333) is equal to or greater than 0.5 times the second extension length (L2) of the outer bridging portion (335) and equal to or less than 2 times the second extension length (L2).

6. The collector plate (32) according to claim 1, wherein, The main body (320) includes an extension (323) disposed circumferentially between the bridging portions (33) and extending radially outward from the radially outer end of the main body (320). The first width (W1) of the connection between the extension (323) and the main body (320) is equal to or greater than 1.5 times the second width (W2) of the connection between the bridging part (33) and the main body (320), and the first width (W1) is equal to or less than 2.5 times the second width (W2).

7. The collector plate (32) according to claim 6, wherein, The extension section (323) and the bridging section (33) are each configured as four.

8. The collector plate (32) according to claim 7, wherein, The diameter of the collector plate (32) is equal to or greater than 35 mm and equal to or less than 46 mm.

9. The collector plate (32) according to claim 1, wherein, The can connection (324) has a shape in which the width gradually increases as it extends from the outer bend (332).

10. A current collector (32) for a cylindrical secondary battery, the current collector comprising: The main body (320) is in contact with and electrically connected to the electrode tabs (27) of the electrode assembly (20); A can connection portion (324) is disposed on the axial and radial exterior of the body (320) and is configured to contact and be electrically connected to at least one of a can (10) accommodating the electrode assembly (20) and a cap (16) covering the open end of the can (10); and A bridging portion (33) extends radially and has a radially inner end connected to the body (320) and a radially outer end connected to the tank connection portion (324). The bridging portion (33) includes: an inner bridging portion (333) connected to the body (320) via an inner bend (331) that bends axially outward from the radially outer end of the body (320) by a first angle (a1), the inner bridging portion (333) extending radially outward and axially outward from the inner bend (331); and an outer bridging portion (335) connected to the inner bridging portion (333) via a bridging bend (334) that bends radially outward from the radially outer end of the inner bridging portion (333) by a second angle (a2), and extending radially outward from the bridging bend (334). The tank connection (324) is connected to the outer bridging portion (335) via an outer bend (332) provided at the radially outer end of the outer bridging portion (335), and The second moment of the cross section of the outer bridging portion (335) when viewed along the extension direction of the outer bridging portion (335) is greater than the second moment of the cross section of the inner bridging portion (333) when viewed along the extension direction of the inner bridging portion (333).

11. The collector plate (32) according to claim 10, wherein, A reinforcing part (336) is provided at the width direction edge of the outer bridging part (335) to axially bend the width direction end of the outer bridging part (335) inward.

12. The collector plate (32) according to claim 1, wherein, The main body (320) includes an extension (323) disposed circumferentially between the bridging portions (33) and extending radially outward from the radially outer end of the main body (320). The first width (W1) of the connection between the extension (323) and the main body (320) is equal to or greater than 1.5 times the second width (W2) of the connection between the bridging part (33) and the main body (320), and the first width (W1) is equal to or less than 2.5 times the second width (W2).

13. A cylindrical secondary battery, the cylindrical secondary battery comprising: Electrode assembly (20), wherein an electrode tab (27) is provided at the axial end of the electrode assembly (20); A container (10) that houses the electrode assembly (20); A cap (16) covering the open end of the can (10); and The current collector (32) according to any one of claims 1 to 12 is electrically connected to the electrode tab (27). Wherein, the can (10) is provided with a radially inwardly recessed rolled edge (116) on the side wall (11) of the can (10) between the electrode assembly (20) and the cap (16) in the axial direction. The tank connection portion (324) of the manifold (32) contacts the axial outer surface (1161) of the rolled edge (116). The edge of the cap (16) is pressed together by the rolled edge (116) and the crimping portion (117) of the sidewall (11), and the cap washer (17) is inserted between the sidewall (11) and the cap (16). The can connector (324) is inserted between the cap gasket (17) and the rolled edge (116).

14. The cylindrical secondary battery according to claim 13, wherein, The tank connection (324) is bent outward from the radial outer end of the outer bridging part (335) via the outer bending part (332).

15. The cylindrical secondary battery according to claim 13, wherein, The outer bridging portion (335) has a second slope (b2) that extends radially outward from the bridging bend portion (334) while extending axially inward.

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