Cap assembly and secondary battery

Abstract

Disclosed herein is a cover assembly and a secondary battery. The cover assembly includes a cover plate, an electrode terminal, a lower insulating plate, a rivet, and a current collector. The cover plate has a through-hole. The electrode terminal has a terminal hole coaxially formed with the through-hole, and has a locking step portion formed on an inner peripheral surface of an upper end portion of the electrode terminal. The lower insulating plate is formed below the cover plate. The rivet is inserted into the through-hole and the terminal hole, and has an upper end portion positioned above the locking step portion and a lower end portion positioned below the lower insulating plate. The rivet includes a first alignment structure formed on a lower surface of the lower end portion of the rivet. The current collector is electrically connected to the electrode terminal by the rivet, and includes a second alignment structure in contact with the first alignment structure.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to Korean Patent Application No. 10-2025-0001010, filed on January 3, 2025, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] This disclosure relates to a cover assembly and a secondary battery including the cover assembly, which improves assemblability during the assembly of the current collector and the riveting by aligning the upper end position of the current collector and the upper end position of the riveting and ensuring concentricity between the current collector and the riveting. Background Technology

[0004] Recently, with the rapid increase in demand for portable electronic devices and the more active development of electric vehicles, energy storage batteries, robots, satellites, etc., in-depth research has been conducted on high-performance rechargeable and rechargeable batteries.

[0005] Secondary batteries can be classified into can-type and pouch-type secondary batteries based on the shape of their casing. In can-type secondary batteries, the electrode assembly is embedded in a metal can, while in pouch-type secondary batteries, the electrode assembly is embedded in a pouch formed of aluminum laminates. Can-type secondary batteries can also be classified into cylindrical and prismatic secondary batteries based on the shape of their metal can.

[0006] In a prismatic secondary battery, the electrode assembly is housed in a casing made of metallic material, and the cover assembly is connected to the open end.

[0007] Figure 1 The diagram shows a cross-sectional view of the cover assembly according to the relevant technology. Figure 2 This is a view used to illustrate problems with the cover component according to the relevant technology.

[0008] like Figure 1 As shown, the cover assembly according to the related technology is manufactured by inserting the collecting protrusion 13 of the collector 12 into the hollow portion of the rivet 11, and then welding the upper end 11a of the rivet 11 and the upper end 13a of the collecting protrusion 13.

[0009] Due to the design dimensional tolerances of the current collecting protrusion 13, the upper end portion 13a of the current collecting protrusion 13 and the upper end portion 11a of the riveting member 11 are not aligned, as indicated by reference numeral G1 in the attached drawing, resulting in a deterioration of the welding effect.

[0010] Furthermore, due to the design dimensional tolerances of the manifold protrusion 13, a gap G2 may occur between the inner circumferential surface 11b of the rivet 11 and the outer circumferential surface 13b of the manifold protrusion 13. Due to this gap G2, such as... Figure 2As shown, the center of the manifold protrusion 13 moves from C1, which is the center of the hollow portion of the riveting member 11, to C2, resulting in misalignment between the center of the riveting member 11 and the center of the manifold protrusion 13. Furthermore, due to the gap G2, welding defects such as cracks may occur during the welding of the riveting member 11 and the manifold protrusion 13.

[0011] The misalignment between i) the upper end 13a of the current collector protrusion 13 and the upper end 11a of the rivet 11, and ii) the misalignment between the center of the current collector protrusion 13 and the center of the hollow portion of the rivet 11 (C1≠C2) reduces the assemblability of the cover assembly and leads to a problem of reduced overall secondary battery yield. Summary of the Invention

[0012] This disclosure aims to provide a cover assembly and a secondary battery including the cover assembly, which improves assemblability during the assembly of the current collector and the riveting by aligning the upper end position of the current collector and the upper end position of the riveting and ensuring concentricity between the current collector and the riveting.

[0013] The cover assembly according to embodiments of the present disclosure may include a cover plate, electrode terminals, a lower insulating plate, a riveting member, and a current collector. The cover plate may have a through hole. The electrode terminal may have a terminal hole coaxially formed with the through hole and may include a locking step formed on the inner circumferential surface of the upper end portion of the electrode terminal. The lower insulating plate may be formed below the cover plate. The riveting member may be inserted into the through hole and the terminal hole, and may have an upper end portion positioned above the locking step portion of the electrode terminal and a lower end portion positioned below the lower insulating plate. The riveting member may include a first alignment structure formed at a predetermined position on the lower surface of the lower end portion of the riveting member. The current collector may be electrically connected to the electrode terminal through the riveting member and may include a second alignment structure formed at a position corresponding to and connected to the first alignment structure.

[0014] In the cover assembly according to embodiments of the present disclosure, the first alignment structure may include a first alignment groove formed by recessing a portion of the lower surface of the riveting member upwards. The second alignment structure may include a first alignment protrusion formed by protruding a portion of the upper surface of the current collector upwards. The first alignment groove may be formed in a trapezoidal shape having a narrower upper portion and a wider lower portion, or it may be formed in a rectangular shape. The first alignment protrusion may be formed in a trapezoidal shape having a narrower upper portion and a wider lower portion and corresponding to the first alignment groove, or it may be formed in a rectangular shape.

[0015] In a cover assembly according to an embodiment of the present disclosure, a first alignment structure may include a chamfered surface formed on the peripheral edge of the lower surface of the rivet. A second alignment structure may include an alignment step formed by protruding a portion of the upper surface of the current collector to engage and contact the chamfered surface.

[0016] In a cover assembly according to an embodiment of the present disclosure, a first alignment structure may include a retaining shoulder having a stepped shape and formed on the peripheral edge of the lower surface of the rivet. A second alignment structure may include an alignment shoulder protruding in a stepped shape to engage and contact the retaining shoulder.

[0017] In the cover assembly according to embodiments of the present disclosure, the first alignment structure may include a second alignment protrusion formed by causing a portion of the lower surface of the riveting member to protrude downwards. The second alignment structure may include a second alignment groove formed by causing a portion of the upper surface of the current collector to be recessed downwards at a location corresponding to the second alignment protrusion. The second alignment protrusion may be formed in a trapezoidal shape having a wider upper portion and a narrower lower portion, or it may be formed in a rectangular shape. The second alignment groove may be formed in a trapezoidal shape having a wider upper portion and a narrower lower portion and corresponding to the second alignment protrusion, or it may be formed in a rectangular shape.

[0018] In the cover assembly according to embodiments of the present disclosure, the first alignment structure may include a third alignment protrusion formed by causing the peripheral edge of the lower surface of the rivet to protrude downwards. The second alignment structure may include a third alignment groove formed by causing a portion of the upper surface of the current collector to be recessed downwards at a location corresponding to the third alignment protrusion. The third alignment protrusion may be formed in a trapezoidal shape or in a rectangular shape. The third alignment groove may be formed in a trapezoidal shape corresponding to the third alignment protrusion or in a rectangular shape.

[0019] In the cover assembly according to embodiments of the present disclosure, the rivet may have a hollow structure, and the current collector may include a current collector protrusion inserted into the hollow structure.

[0020] In the cover assembly according to an embodiment of the present disclosure, the flow-collecting protrusion may be formed in a conical shape having a diameter that decreases from the lower portion toward the upper portion.

[0021] In the cover assembly according to an embodiment of the present disclosure, the hollow structure of the rivet can be formed as a conical shape corresponding to the shape of the flow-collecting protrusion and having a diameter that decreases from the lower portion toward the upper portion.

[0022] A secondary battery according to embodiments of the present disclosure may include a housing, an electrode assembly, and a cover assembly. The housing may include an opening. The electrode assembly can be inserted into the housing through the opening and may include electrode portions and a plurality of foil tabs formed on the electrode portions. The cover assembly may seal the opening of the housing into which the electrode assembly is inserted. The cover assembly may include a cover plate, electrode terminals, a lower insulating plate, a riveting member, and a current collector. The cover plate may have a through hole. The electrode terminals may have terminal holes coaxially formed with the through hole and may include a locking step formed on the inner peripheral surface of the upper end portion of the electrode terminal. The lower insulating plate may be formed below the cover plate. The riveting member may have a hollow structure. The riveting member can be inserted into the through hole and the terminal hole and may have an upper end portion positioned above the locking step portion of the electrode terminal and a lower end portion positioned below the lower insulating plate. The riveting member may include a first alignment structure formed at a predetermined position on the lower surface of the lower end portion of the riveting member. The current collector can be coupled to the electrode assembly for electrical connection with the foil tab, and the current collector can be electrically connected to the electrode terminal via a riveting member. It may also include a second alignment structure formed at a position corresponding to and connected to the first alignment structure. The current collector may include a current collection protrusion inserted into the hollow structure.

[0023] In a secondary battery according to an embodiment of the present disclosure, a plurality of foil tabs may be formed in one direction of the electrode assembly.

[0024] In a secondary battery according to an embodiment of the present disclosure, a plurality of foil tabs may be formed in two opposite directions of the electrode assembly.

[0025] In the secondary battery according to embodiments of the present disclosure, after the electrode assembly and the current collector are connected to each other, a first insulator can be attached to the current collector. After the outer surface of the electrode assembly is covered with a second insulator, the electrode assembly can be inserted into the housing. The outer surface of the housing in which the electrode assembly is inserted can be covered with a third insulator.

[0026] In a secondary battery according to an embodiment of the present disclosure, each of the first to third insulators may include an insulating strip. Attached Figure Description

[0027] Figure 1 The diagram shows a cross-sectional view of the cover assembly according to the relevant technology.

[0028] Figure 2 This is a view used to illustrate problems with the cover component according to the relevant technology.

[0029] Figure 3 This is a perspective view illustrating a secondary battery according to an embodiment of the present disclosure.

[0030] Figure 4The illustration shows an exploded perspective view of the cover assembly in a secondary battery according to an embodiment of the present disclosure.

[0031] Figure 5 This is a perspective view of an electrode assembly in a secondary battery according to an embodiment of the present disclosure, wherein a plurality of first foil tabs and second foil tabs are formed on the electrode portion.

[0032] Figure 6 This is a view illustrating the first electrode plate and the second electrode plate in a secondary battery according to an embodiment of the present disclosure.

[0033] Figure 7 This is a view illustrating the third and fourth electrode plates in a secondary battery according to an embodiment of the present disclosure.

[0034] Figure 8 This is a cross-sectional view of a cover assembly according to a first embodiment of the present disclosure.

[0035] Figure 9 This is a cross-sectional view of the cover assembly according to the second embodiment of the present disclosure.

[0036] Figure 10 This is a cross-sectional view of the cover assembly according to the third embodiment of the present disclosure.

[0037] Figure 11 This is a cross-sectional view of the cover assembly according to the fourth embodiment of the present disclosure.

[0038] Figure 12 This is a cross-sectional view of the cover assembly according to the fifth embodiment of the present disclosure.

[0039] Figure 13 This is a cross-sectional view of the cover assembly according to the sixth embodiment of the present disclosure.

[0040] Figure 14 This is a plan view illustrating the connection between the electrode terminals and the current collector protrusion in the cover assembly according to an embodiment of the present disclosure.

[0041] Figure 15 This is a cross-sectional view illustrating the process of welding electrode terminals and current collector protrusions in a cover assembly according to an embodiment of the present disclosure.

[0042] Figure 16 This is a view illustrating the process of connecting foil contacts and current collectors in a secondary battery according to an embodiment of the present disclosure.

[0043] Figure 17 This is a view illustrating the process of connecting the cover assembly and the current collector in a secondary battery according to an embodiment of the present disclosure.

[0044] Figure 18 This is a view illustrating the process of connecting a current collector and a foil in a secondary battery according to an embodiment of the present disclosure, where the foil is formed in opposite directions.

[0045] Figure 19 This is a view illustrating the process of connecting each cover assembly to its corresponding current collector.

[0046] Figure 20 This is a view illustrating the process of attaching an insulator to an electrode assembly and a current collector that are connected to each other. Detailed Implementation

[0047] Because this disclosure can be modified in various forms and has various implementations, specific implementations will be shown in the accompanying drawings and described in detail with reference to the drawings. However, this is not intended to limit this disclosure to a particular mode of practice, and it should be understood that all variations, equivalents, and alternatives without departing from the spirit and scope of this disclosure are included in this disclosure.

[0048] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. In this disclosure, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. It will also be understood that the terms “comprising,” “including,” “having,” etc., as used in this specification, are intended to specify the presence of the stated features, integers, steps, operations, elements, components, and / or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or combinations thereof.

[0049] In the following, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. It should be noted that throughout the drawings, the same reference numerals refer to the same elements. To avoid unnecessarily obscuring the spirit of the disclosure, details of well-known configurations and functions may be omitted. For the same reason, some elements in the drawings are enlarged, omitted, or depicted schematically.

[0050] Figure 3 This is a perspective view illustrating a secondary battery according to an embodiment of the present disclosure. Figure 4 The illustration shows an exploded perspective view of the cover assembly in a secondary battery according to an embodiment of the present disclosure. Figure 5 This is a perspective view of an electrode assembly in a secondary battery according to an embodiment of the present disclosure, wherein a plurality of first foil tabs and second foil tabs are formed on the electrode portion. Figure 6 This is a view illustrating the first electrode plate and the second electrode plate in a secondary battery according to an embodiment of the present disclosure. Figure 7 This is a view illustrating the third and fourth electrode plates in a secondary battery according to an embodiment of the present disclosure.

[0051] like Figure 3 and Figure 4 As shown, the secondary battery 1000 according to an embodiment of the present disclosure includes a housing 1100, an electrode assembly 1200, and a cover assembly 1400, the cover assembly 1400 including a current collector 1300.

[0052] The housing 1100 forms the external shape of the secondary battery 1000. The housing 1100 may define a space capable of accommodating the electrode assembly 1200 therein, and may have an opening on one of its surfaces. In this embodiment, the housing 1100 has a cuboid shape, but is not limited thereto, and may be modified in various ways. The housing 1100 may be made of a rigid material capable of protecting the electrode assembly 1200 housed therein. For example, the housing 1100 may be made of metal, such as aluminum or stainless steel.

[0053] The electrolyte can be housed together with the electrode assembly 1200 in the housing 1100. The electrolyte may include lithium salts such as LiPF6 or LiBF4 in organic solvents such as ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), or dimethyl carbonate (DMC). The electrolyte may be in a liquid, solid, or gel phase.

[0054] The electrode assembly 1200 is housed within the housing 1100. For example... Figure 5 As shown, the electrode assembly 1200 includes an electrode portion 1210, a plurality of first foil tabs 1220, a plurality of second foil tabs 1230, a plurality of third foil tabs 1240, and a plurality of fourth foil tabs 1250. The plurality of first foil tabs 1220 to the plurality of fourth foil tabs 1250 are disposed at one end of the electrode portion 1210. The plurality of first foil tabs 1220 are grouped and aligned with each other, the plurality of second foil tabs 1230 are grouped and aligned with each other, the plurality of third foil tabs 1240 are grouped and aligned with each other, and the plurality of fourth foil tabs 1250 are grouped and aligned with each other. The plurality of first foil tabs 1220 to the plurality of fourth foil tabs 1250, which are respectively aligned with each other, are arranged so as not to overlap in the width and longitudinal directions of the electrode assembly 1200.

[0055] like Figure 6 and Figure 7 As shown, the electrode portion 1210 includes a plurality of first electrode plates 1211, a plurality of second electrode plates 1212, a plurality of third electrode plates 1213, a plurality of fourth electrode plates 1214, and a separator.

[0056] An active material can be applied to multiple first electrode plates 1211, multiple second electrode plates 1212, multiple third electrode plates 1213, and multiple fourth electrode plates 1214. The multiple first electrode plates 1211 and multiple second electrode plates 1212 can each be formed by applying an active material, such as a transition metal oxide, to a metal plate, such as an aluminum plate. The multiple first electrode plates 1211 and multiple second electrode plates 1212 can have the same polarity and can be positive electrode plates. The multiple third electrode plates 1213 and multiple fourth electrode plates 1214 can each be formed by applying an active material, such as graphite or carbon, to a metal plate, such as a copper or nickel plate. The multiple third electrode plates 1213 and multiple fourth electrode plates 1214 can have the same polarity and can be negative electrode plates.

[0057] The separator is positioned between a plurality of first electrode plates 1211, a plurality of second electrode plates 1212, a plurality of third electrode plates 1213, and a plurality of fourth electrode plates 1214 to prevent short circuits among the plurality of first electrode plates 1211, a plurality of second electrode plates 1212, a plurality of third electrode plates 1213, and a plurality of fourth electrode plates 1214. The separator may be made of polyethylene, polypropylene, or composite materials thereof.

[0058] Electrode portion 1210 can be formed by positioning spacers between alternately arranged first electrode plates 1211 and third electrode plates 1213 and alternately arranged second electrode plates 1212 and fourth electrode plates 1214. In other words, in an embodiment, electrode portion 1210 can be formed such that one side of electrode portion 1210 is formed by stacking the first electrode plate 1211, spacers, third electrode plate 1213, and spacers in a listed order dozens to hundreds of times, and the other side of electrode portion 1210 is formed by stacking the second electrode plate 1212, spacers, fourth electrode plate 1214, and spacers in a listed order dozens or hundreds of times. In another embodiment, electrode portion 1210 can be formed by sequentially stacking the first electrode plate 1211, spacers, third electrode plate 1213, spacers, second electrode plate 1212, spacers, fourth electrode plate 1214, and spacers in a listed order, and then winding the stacked structure.

[0059] Although the electrode assembly 1200 is shown as including a single electrode portion 1210 in this embodiment, in another embodiment, the electrode assembly 1200 may include multiple electrode portions 1210. The multiple electrode portions 1210 may be electrically connected to each other.

[0060] First foil tabs 1220, second foil tabs 1230, third foil tabs 1240, and fourth foil tabs 1250, without the application of active material, are respectively formed at the respective ends of a plurality of first electrode plates 1211, a plurality of second electrode plates 1212, a plurality of third electrode plates 1213, and a plurality of fourth electrode plates 1214. In an embodiment, each of the first electrode plates 1211, second electrode plates 1212, third electrode plates 1213, and fourth electrode plates 1214 and the corresponding first foil tab 1220, second foil tab 1230, third foil tab 1240, or fourth foil tab 1250 can be integrally formed by cutting a predetermined portion of a single metal plate using a laser or the like, such that the first electrode plates 1211, second electrode plates 1212, third electrode plates 1213, or fourth electrode plates 1214 and the first foil tabs 1220, second foil tab 1230, third foil tab 1240, or fourth foil tab 1250 are retained. Multiple first foil tabs 1220, multiple second foil tabs 1230, multiple third foil tabs 1240 and multiple fourth foil tabs 1250 may be formed in a direction toward the cover assembly 1400.

[0061] Each first foil patch 1220 can be formed at a first position on a corresponding first electrode plate 1211. Each second foil patch 1230 can be formed at a second position on a corresponding second electrode plate 1212. Similarly, each third foil patch 1240 can be formed at a third position on a corresponding third electrode plate 1213, and each fourth foil patch 1250 can be formed at a fourth position on a corresponding fourth electrode plate 1214.

[0062] Multiple first electrode plates 1211 and multiple third electrode plates 1213 can be stacked alternately, wherein corresponding spacers are inserted between adjacent electrode plates. The stack including multiple first electrode plates 1211 and multiple third electrode plates 1213 forms half of the electrode portion 1210.

[0063] Multiple second electrode plates 1212 and multiple fourth electrode plates 1214 can be stacked alternately, wherein corresponding spacers are inserted between adjacent electrode plates. The stack including multiple second electrode plates 1212 and multiple fourth electrode plates 1214 forms the remaining half of the electrode portion 1210.

[0064] A stack comprising a plurality of first electrode plates 1211 and a plurality of third electrode plates 1213 is connected to a stack comprising a plurality of second electrode plates 1212 and a plurality of fourth electrode plates 1214 in the width direction of the electrode portion 1210. During the formation of the electrode assembly 1200, the plurality of first electrode plates 1211 and the plurality of third electrode plates 1213 may be stacked before the plurality of second electrode plates 1212 and the plurality of fourth electrode plates 1214 are stacked.

[0065] When multiple first electrode plates 1211, multiple second electrode plates 1212, multiple third electrode plates 1213, and multiple fourth electrode plates 1214 are stacked, multiple first foil tabs 1220 overlap each other at a first position. Multiple second foil tabs 1230 overlap each other at a second position. In other words, among the multiple first foil tabs 1220 and multiple second foil tabs 1230 having the same polarity, the multiple first foil tabs 1220 are grouped at the first position, and the multiple second foil tabs 1230 are grouped at the second position. The first position and the second position are spaced apart from each other on the electrode plates. The grouped multiple first foil tabs 1220 and the grouped multiple second foil tabs 1230 may be spaced apart in the width direction and the longitudinal direction of the electrode assembly 1200.

[0066] To stably weld a large number of foil tabs, foil tabs with the same polarity are divided into two groups that are spaced apart and aligned, and each group is welded to a corresponding current collector. That is, although a single foil tab is formed on each electrode plate, by changing the position of the foil tabs formed on the respective electrode plates, two groups of foil tabs with the same polarity but different positions are formed after stacking the electrode plates. In another embodiment, two or more foil tabs can be formed at different positions on the same polarity side.

[0067] When multiple first electrode plates 1211, multiple second electrode plates 1212, multiple third electrode plates 1213, and multiple fourth electrode plates 1214 are stacked, multiple third foil tabs 1240 overlap each other at a third position, and multiple fourth foil tabs 1250 overlap each other at a fourth position. In other words, the multiple third foil tabs 1240 are grouped at the third position, and the multiple fourth foil tabs 1250 are grouped at the fourth position. The third and fourth positions are spaced apart from each other on the electrode plates. The grouped multiple third foil tabs 1240 and the grouped multiple fourth foil tabs 1250 may be spaced apart in the width and longitudinal directions of the electrode assembly 1200.

[0068] The multiple third foil tabs 1240 and the multiple fourth foil tabs 1250 are foil tabs with the same polarity.

[0069] Multiple first foil tabs 1220, multiple second foil tabs 1230, multiple third foil tabs 1240 and multiple fourth foil tabs 1250 overlapping in corresponding positions can be connected to the corresponding current collector by ultrasonic welding, laser welding or the like to promote current flow.

[0070] The current collector 1300 includes a first current collection region 1310, a second current collection region 1320, and a connecting region 1330.

[0071] Multiple first foil tabs 1220 are bent and welded to a first current collection region 1310. Multiple second foil tabs 1230 are bent and welded to a second current collection region 1320. A connection region 1330 is disposed between the first current collection region 1310 and the second current collection region 1320, and a current collection protrusion 1331 is formed in the connection region 1330.

[0072] The first current collection region 1310 and the second current collection region 1320 are spaced apart from each other in the longitudinal direction by a connecting region 1330. Since the first current collection region 1310 and the second current collection region 1320 are spaced apart from each other, when a plurality of first foil tabs 1220 and a plurality of second foil tabs 1230 are respectively soldered to the first current collection region 1310 and the second current collection region 1320, the plurality of first foil tabs 1220 and the plurality of second foil tabs 1230 will not interfere with each other.

[0073] The current collector protrusion 1331 protrudes upward from the upper surface of the connection area 1330 and connects to the terminal hole 1421 of the electrode terminal 1420 to electrically connect the electrode assembly 1200 and the electrode terminal 1420.

[0074] The current collector 1300 can be made of the same material as the plurality of first foil tabs 1220 and the plurality of second foil tabs 1230, and can have a predetermined thickness, for example, ranging from 0.8 mm to 1.2 mm. The use of a current collector with a relatively large thickness improves insulation and prevents damage to the separator.

[0075] Insulating material can be placed below the current collector 1300. The insulating material can be an insulating board or an insulating film.

[0076] After a plurality of first foil tabs 1220 are soldered to each other and a plurality of second foil tabs 1230 are soldered to each other, a current collector 1300 can be disposed in the space between the first foil tabs 1220 and the second foil tabs 1230. Here, the current collector 1300 can be disposed on some of the first foil tabs 1220 and some of the second foil tabs 1230.

[0077] After the current collector 1300 is disposed above the electrode portion 1210, a plurality of first foil tabs 1220 are bent toward the first current collector region 1310, and a plurality of second foil tabs 1230 are bent toward the second current collector region 1320. That is, the plurality of first foil tabs 1220 and the plurality of second foil tabs 1230 are bent in opposite directions.

[0078] After bending multiple first foil tabs 1220 and multiple second foil tabs 1230, welding is performed on the multiple first foil tabs 1220 and multiple second foil tabs 1230. For example, ultrasonic welding, laser welding and other methods can be used for welding.

[0079] During welding, in the first collecting region 1310 of the current collector 1300, welding can be performed from multiple first foil tabs 1220 toward the first collecting region 1310, and in the second collecting region 1320 of the current collector 1300, welding can be performed from multiple second foil tabs 1230 toward the second collecting region 1320. To facilitate the fixing and welding of the foil tabs, multiple fine grooves or fine protrusions can be formed on the upper surface of the current collector 1300.

[0080] The cover assembly 1400 seals the opening of the housing 1100 that accommodates the electrode assembly 1200. In this disclosure, the cover assembly 1400 is configured such that the upper end of the current collector 1300 and the upper end of the riveting are aligned during assembly of the current collector 1300 and the riveting, and the center of the current collector 1300 and the center of the riveting are aligned to ensure concentricity, thereby improving assemblability during assembly of the current collector 1300 and the riveting. Various embodiments of the cover assembly 1400 will be described with reference to... Figures 8 to 12 Detailed description.

[0081] Figure 8 This is a cross-sectional view of a cover assembly according to a first embodiment of the present disclosure.

[0082] like Figure 8 As shown, the cover assembly 1400_1 according to the first embodiment of this disclosure includes a cover plate 1410, electrode terminals 1420, a lower insulating plate 1430, a gasket 1440, an upper insulating plate 1450, and a riveting member 1460. A current collector 1300 can be connected to the riveting member 1460 to form the cover assembly.

[0083] The cover plate 1410 may have a plate shape that covers the opening of the housing 1100 and may include at least one through hole 1410a. The cover plate 1410 may have a shape corresponding to the shape of the opening of the housing 1100. The cover plate 1410 may be formed of the same material as the housing 1100 and may be fixed to the housing 1100 by a method such as laser welding.

[0084] The cover plate 1410 may have an exhaust portion 1411 and an electrolyte injection port 1412, such as Figure 4As shown in the diagram, the venting section 1411 opens when the internal pressure of the housing 1100 exceeds a reference value. In this embodiment, the venting section 1411 is formed in the cover plate 1410; however, in other embodiments, the venting section 1411 may be formed in the housing 1100. Electrolyte can be injected into the housing 1100 through the electrolyte injection port 1412.

[0085] Electrode terminals 1420 may be formed above cover plate 1410. Electrode terminals 1420 may be electrically connected to corresponding foil tabs via current collector 1300. Electrode terminals 1420 may have a plate shape in the form of a circle or a rectangle.

[0086] Electrode terminal 1420 may have a disc-shaped form coaxial with through hole 1410a. Terminal hole 1421 may be formed at the center of electrode terminal 1420. Locking step portion 1422 may be formed on the inner peripheral surface of the upper end of electrode terminal 1420. Rivet 1460 may be inserted into terminal hole 1421. After rivet 1460 is inserted into terminal hole 1421, the mating surfaces of terminal hole 1421 and rivet 1460 may be welded.

[0087] The upper end of the rivet 1460 sits on the locking step 1422.

[0088] The lower insulating plate 1430 can be disposed below the cover plate 1410. The lower insulating plate 1430 electrically insulates the cover plate 1410 from the riveting member 1460.

[0089] The upper insulating plate 1450 can be disposed between the electrode terminal 1420 and the cover plate 1410. The upper insulating plate 1450 electrically insulates the electrode terminal 1420 from the cover plate 1410.

[0090] The riveting member 1460 can contact the current collector 1300 to electrically connect the electrode assembly 1200 and the electrode terminal 1420. The riveting member 1460 may include a body portion 1461 fitted into the through hole 1410a, a lower wing-shaped portion 1462 formed horizontally at the lower end of the body portion 1461, and an upper wing-shaped portion 1463 formed horizontally at the upper end of the body portion 1461.

[0091] The body portion 1461 can be inserted into the through hole 1410a of the cover plate 1410. For sealing, a gasket 1440 can be inserted between the body portion 1461 and the inner wall of the through hole 1410a. The body portion 1461 can be formed to have a hollow structure. The gasket 1440 prevents electrolyte or gas inside the housing 1100 from leaking to the outside and prevents moisture or air from entering the housing 1100 from the outside.

[0092] The upper wing-shaped portion 1463 can be formed into a disc shape coaxial with the body portion 1461. The upper wing-shaped portion 1463 sits on a locking step portion 1422 formed on the inner peripheral surface of the upper end of the electrode terminal 1420.

[0093] The lower wing-shaped portion 1462 can be formed into a disc shape coaxial with the body portion 1461. Before assembly, the lower wing-shaped portion 1462 can have a shape extending along the longitudinal direction of the body portion 1461. After the body portion 1461 is inserted into the through hole 1410a, the lower wing-shaped portion 1462 can be unfolded outward by a fixing clamp, so that the electrode terminal 1420 can be fixed on the cover plate 1410.

[0094] The upper surface of the lower airfoil portion 1462 contacts the lower surface of the washer 1440 and the lower surface of the lower insulating plate 1430. The lower surface of the lower airfoil portion 1462 contacts the upper surface of the current collector 1300.

[0095] A first alignment structure may be formed at a predetermined position on the lower surface of the lower airfoil portion 1462. The first alignment structure may include a first alignment groove 1471 formed by recessing upward into a portion of the lower surface of the lower airfoil portion 1462.

[0096] The first alignment groove 1471 can be formed as a trapezoidal shape with a narrower upper portion and a wider lower portion, or it can be formed as a rectangular shape.

[0097] A second alignment structure, which connects to and contacts the first alignment structure, can be formed at a position on the upper surface of the current collector 1300 corresponding to the first alignment structure. The second alignment structure may include a first alignment protrusion 1341 protruding upward from the upper surface of the current collector 1300.

[0098] The first alignment protrusion 1341 can be formed as a trapezoidal shape with a narrower upper portion and a wider lower portion corresponding to the first alignment groove 1471, or it can be formed as a rectangular shape.

[0099] Reference Figures 9 to 13 The cover assembly 1400_2 to cover assembly 1400_6 according to the second to sixth embodiments of this disclosure are described.

[0100] Figure 9 This is a cross-sectional view of the cover assembly according to the second embodiment of the present disclosure. Figure 10 This is a cross-sectional view of the cover assembly according to the third embodiment of the present disclosure. Figure 11 This is a cross-sectional view of the cover assembly according to the fourth embodiment of the present disclosure. Figure 12 The illustration shows a cross-sectional view of the cover assembly according to the fifth embodiment of this disclosure, and Figure 13This is a cross-sectional view of the cover assembly according to the sixth embodiment of the present disclosure.

[0101] like Figures 9 to 13 As shown, the cover assemblies 1400_2 to 1400_6 according to the second to sixth embodiments of this disclosure may each include a cover plate 1410, an electrode terminal 1420, a lower insulating plate 1430, a gasket 1440, an upper insulating plate 1450, and a riveting member 1460. The current collector 1300 may be connected to the riveting member 1460 to form a cover assembly.

[0102] The cover assemblies 1400_2 to 1400_6 according to the second to sixth embodiments of this disclosure differ from the cover assembly 1400_1 according to the first embodiment only in the shape of the rivet 1460 and the shape of the current collector 1300 connected to the rivet 1460, and the rest of the configurations are substantially the same as those of the first embodiment; therefore, repeated descriptions thereof will be omitted.

[0103] In the cover assembly 1400_2 to cover assembly 1400_6 according to the second to sixth embodiments of the present disclosure, a first alignment structure is formed at a predetermined position on the lower surface of the lower wing portion 1462 constituting the rivet 1460, and a second alignment structure connected to and in contact with the first alignment structure is formed at a position corresponding to the first alignment structure on the upper surface of the current collector 1300.

[0104] exist Figure 9 In the second embodiment shown, the first alignment structure may be a chamfered surface 1472 formed on the peripheral edge of the lower surface of the lower airfoil portion 1462. The second alignment structure may be an alignment step portion 1342 formed by protruding a portion of the upper surface of the current collector 1300 to engage and contact with the chamfered surface 1472.

[0105] The chamfered surface 1472 can be formed by cutting the peripheral edge of the lower surface of the lower wing portion 1462 at a predetermined angle. The aligned step portion 1342 may include an inclined surface having the same angle as that formed by the chamfered surface 1472.

[0106] exist Figure 10 In the third embodiment shown, the first alignment structure may include a stepped retaining shoulder 1473 formed on the peripheral edge of the lower surface of the lower wing portion 1462. The second alignment structure may include a stepped alignment shoulder 1343 formed by protruding a portion of the upper surface of the current collector 1300 to engage and contact with the retaining shoulder 1473.

[0107] exist Figure 11In the fourth embodiment shown, the first alignment structure may include a second alignment protrusion 1474 formed by causing a portion of the lower surface of the lower wing portion 1462 to protrude downwards. The second alignment protrusion 1474 may be formed in a trapezoidal shape having a wider upper portion and a narrower lower portion, or it may be formed in a rectangular shape.

[0108] The second alignment structure may include a second alignment groove 1344 formed by recessing a portion of the upper surface of the current collector 1300 downward at a location corresponding to the second alignment protrusion 1474. The second alignment groove 1344 may be formed in a trapezoidal shape with a wider upper portion and a narrower lower portion corresponding to the second alignment protrusion 1474, or it may be formed in a rectangular shape.

[0109] exist Figure 12 In the fifth embodiment shown, the first alignment structure may include a third alignment protrusion 1475 formed by projecting the peripheral edge of the lower wing-shaped portion 1462 downwards. The third alignment protrusion 1475 may be formed in a trapezoidal shape or in a rectangular shape.

[0110] The second alignment structure may include a third alignment groove 1345 formed by recessing a portion of the upper surface of the current collector 1300 downward at a position corresponding to the third alignment protrusion 1475. The third alignment groove 1345 may be formed in a trapezoidal shape corresponding to the third alignment protrusion 1475, or it may be formed in a rectangular shape.

[0111] exist Figure 13 In the sixth embodiment shown, the first alignment structure and the second alignment structure may include the alignment structures described in the first to fifth embodiments. In the sixth embodiment, in addition to the alignment structures of the first to fifth embodiments, the concentricity between the current collector 1300 and the riveting member 1460 can be ensured by using the shapes of the current collector protrusion 1331 and the body portion 1461 of the riveting member 1460.

[0112] In the sixth embodiment, the flow-collecting protrusion 1331 can be formed into a conical shape with a trapezoidal cross-section, specifically a narrower upper portion and a wider lower portion. That is, the flow-collecting protrusion 1331 can be formed into a conical shape with a diameter decreasing from the lower portion to the upper portion. Furthermore, corresponding to the shape of the flow-collecting protrusion 1331, the hollow portion of the rivet 1460 can be formed into a conical shape with a diameter decreasing from the lower portion to the upper portion. In other words, the wall thickness of the body portion 1461 of the rivet can be formed to increase from the lower portion to the upper portion. With the above configuration, the flow-collecting protrusion 1331 can be easily inserted into the hollow portion of the rivet 1460.

[0113] As another example, the manifold protrusion 1331 can be formed into a cylindrical shape with a diameter decreasing from the lower portion to the upper portion, and the hollow portion of the rivet 1460 can be formed such that the upper and lower portions have the same diameter. In this case, the manifold protrusion 1331 can be inserted into the hollow portion of the rivet 1460 by press fit. With the above configuration, a connecting force can be generated between the manifold protrusion 1331 and the rivet 1460.

[0114] According to the cover assemblies 1400_1 to 1400_6 constructed as described above according to embodiments of the present disclosure, a first alignment structure (parts indicated by reference numerals 1471 to 1475) is formed on the lower surface of the riveting member 1460, and a second alignment structure (parts indicated by reference numerals 1341 to 1345) connected to and in contact with the first alignment structure is formed on the upper surface of the current collector 1300 at a position corresponding to the first alignment structure. Therefore, during the assembly of the current collector 1300 and the riveting member 1460, even when there are design dimensional tolerances in the current collector protrusion 1331, the first and second alignment structures are mechanically aligned, thereby allowing the center of the current collector protrusion 1331 and the center of the riveting member 1460 to be easily aligned with each other to ensure concentricity. Furthermore, the mismatch between the upper end of the current collector protrusion 1331 and the upper end of the riveting member 1460 can be resolved by adjusting the engagement depth between the first and second alignment structures.

[0115] Figure 14 This is a plan view illustrating the connection between the electrode terminals and the current collector protrusion in the cover assembly according to an embodiment of the present disclosure. Figure 15 This is a cross-sectional view illustrating the process of welding electrode terminals and current collector protrusions in a cover assembly according to an embodiment of the present disclosure.

[0116] like Figure 14 As shown, during the assembly of the manifold protrusion 1331 and the riveting member 1460, the manifold protrusion 1331 and the riveting member 1460 are mechanically aligned by a first alignment structure (1471 to 1475) and a second alignment structure (1341 to 1345), thereby ensuring concentricity. The upper ends of the manifold protrusion 1331 and the riveting member 1460 can be aligned with each other by adjusting the engagement depth between the first and second alignment structures. The adjustment of the engagement depth can be implemented by determining the engagement depth at which the upper ends of the manifold protrusion 1331 and the riveting member 1460 are aligned with each other through repeated experiments, and by manufacturing the first alignment structure (1471 to 1475) and the second alignment structure (1341 to 1345) to achieve the determined engagement depth.

[0117] After the connection as described above, such as Figure 15 As shown, the upper end of the current collector protrusion 1331 and the upper end of the riveting member 1460 are welded to each other. Because the riveting member 1460 and the electrode terminal 1420 are also in a welded state, the current collector protrusion 1331, the riveting member 1460 and the electrode terminal 1420 are connected to each other.

[0118] Figure 16 This is a view illustrating the process of connecting foil contacts and current collectors in a secondary battery according to an embodiment of the present disclosure. Figure 17 This is a view illustrating the process of connecting the cover assembly and the current collector in a secondary battery according to an embodiment of the present disclosure.

[0119] like Figure 16 and Figure 17 As shown, the first foil tab 1220 to the fourth foil tab 1250 are welded to the upper surface of the current collector 1300. In each current collector 1300, the corresponding foil tab extends onto the current collector 1300 from different directions around the current collector protrusion 1331. The first foil tab 1220 to the fourth foil tab 1250 can be positioned so as not to overlap with the riveting member 1460, thereby avoiding mutual interference. Therefore, the welding position of the first foil tab 1220 to the fourth foil tab 1250 can be located between the current collector 1300 and the insulator (lower insulating plate 1430) of the cover assembly 1400.

[0120] The current collector 1300 can be installed at either the positive or negative electrode. In this case, an insulator is provided below the current collector 1300, thereby electrically isolating the current collector 1300 from the electrode assembly.

[0121] Figure 18 This is a view illustrating the process of connecting a current collector and a foil in a secondary battery according to an embodiment of the present disclosure, where the foil is formed in opposite directions. Figure 19 This is a view illustrating the process of connecting each cover assembly to its corresponding current collector. Figure 20 This is a view illustrating the process of attaching an insulator to an electrode assembly and a current collector that are connected to each other.

[0122] exist Figure 16 and Figure 17 In this configuration, both the foil contacts on the positive electrode and the foil contacts on the negative electrode are formed in the same direction. However, as... Figure 18 and Figure 19 As shown, the electrode assembly can be configured such that the foil tabs on the positive electrode and the foil tabs on the negative electrode are formed in different directions. Accordingly, the current collector 1300 can also be connected to the opposite side surface of the electrode assembly 1200.

[0123] like Figure 20As shown, after the electrode assembly 1200 and the current collector 1300 are connected to each other, the first insulator I1 can be attached to the current collector 1300. Therefore, short circuits between the foil tab and the cover assembly 1400 can be prevented.

[0124] After the first insulator I1 is attached, the outer surface of the electrode assembly 1200 can be wrapped with the second insulator I2, and then the electrode assembly 1200 can be inserted into the housing 1100, and the current collector 1300 connected to the electrode assembly 1200 is connected to the rest of the cover assembly 1400 to seal the opening of the housing 1100.

[0125] Subsequently, the outer surface of the casing 1100 can be wrapped with a third insulator I3, thereby completing the manufacture of the secondary battery. Here, the first insulator I1 to the third insulator I3 can be formed from insulating tape or the like.

[0126] According to this disclosure, the assemblability during the assembly of the current collector and the riveting member can be improved by aligning the upper end of the current collector and the upper end of the riveting member and ensuring the concentricity between the current collector and the riveting member.

[0127] Although this disclosure has been described with reference to specific embodiments, it will be apparent to those skilled in the art that various changes or modifications may be made to this disclosure by adding, altering, or deleting components without departing from the spirit of this disclosure as defined in the following claims. It should be noted that such changes or modifications also fall within the scope of this disclosure.

Claims

1. A cover assembly, comprising: Cover plate, the cover plate including through holes; The electrode terminal includes a terminal hole coaxially formed with the through hole, and includes a locking step portion formed on the inner circumferential surface of the upper end of the electrode terminal; A lower insulating plate is formed below the cover plate; A riveting member, which is inserted into the through hole and the terminal hole, and has an upper end portion positioned above the locking step portion of the electrode terminal and a lower end portion positioned below the lower insulating plate, the riveting member including a first alignment structure formed at a predetermined position on the lower surface of the lower end portion of the riveting member; as well as The current collector is electrically connected to the electrode terminal via the rivet and includes a second alignment structure formed at a position corresponding to the first alignment structure and connected to and in contact with the first alignment structure.

2. The cover assembly according to claim 1, in, The first alignment structure includes a first alignment groove formed by recessing a portion of the lower surface of the rivet upwards, and The second alignment structure includes a first alignment protrusion formed by causing a portion of the upper surface of the current collector to protrude upwards.

3. The cover assembly according to claim 2, in, The first alignment groove is formed in a trapezoidal shape with a narrower upper portion and a wider lower portion, or in a rectangular shape. The first alignment protrusion is formed as a trapezoidal shape having a narrower upper portion and a wider lower portion and corresponding to the first alignment groove, or it is formed as a rectangular shape.

4. The cover assembly according to claim 1, in, The first alignment structure includes a chamfered surface formed on the peripheral edge of the lower surface of the riveting member, and The second alignment structure includes an alignment step portion formed by protruding a portion of the upper surface of the current collector to connect and contact with the chamfered surface.

5. The cover assembly according to claim 1, in, The first alignment structure includes a retaining shoulder having a stepped shape and formed on the peripheral edge of the lower surface of the rivet, and The second alignment structure includes an alignment shoulder that protrudes in a stepped shape to maintain connection and contact with the shoulder.

6. The cover assembly according to claim 1, in, The first alignment structure includes a second alignment protrusion formed by causing a portion of the lower surface of the riveting member to project downwards, and The second alignment structure includes a second alignment groove formed by recessing a portion of the upper surface of the current collector downward at a position corresponding to the second alignment protrusion.

7. The cover assembly according to claim 6, in, The second alignment protrusion is formed in a trapezoidal shape with a wider upper portion and a narrower lower portion, or in a rectangular shape. The second alignment groove is formed as a trapezoidal shape having a wider upper portion and a narrower lower portion and corresponding to the second alignment protrusion, or it is formed as a rectangular shape.

8. The cover assembly according to claim 1, in, The first alignment structure includes a third alignment protrusion formed by causing the peripheral edge of the lower surface of the riveted member to project downwards, and The second alignment structure includes a third alignment groove formed by recessing a portion of the upper surface of the current collector downward at a position corresponding to the third alignment protrusion.

9. The cover assembly according to claim 8, in, The third alignment protrusion is formed in a trapezoidal shape or in a rectangular shape, and The third alignment groove is formed in a trapezoidal shape corresponding to the third alignment protrusion, or in a rectangular shape.

10. The cover assembly according to any one of claims 1-9, wherein, The rivet has a hollow structure, and the current collector includes a current collector protrusion inserted into the hollow structure.

11. The cover assembly according to claim 10, wherein, The flow-collecting protrusion is formed in a conical shape with a diameter that decreases from the lower part to the upper part.

12. The cover assembly according to claim 11, wherein, The hollow structure of the rivet is formed in a conical shape corresponding to the shape of the flow-collecting protrusion and having a diameter that decreases from the lower part to the upper part.

13. A secondary battery, comprising: A housing, the housing including an opening; An electrode assembly, which is inserted into the housing through the opening, and includes an electrode portion and a plurality of foil tabs formed on the electrode portion; as well as A cover assembly that seals the opening in the housing into which the electrode assembly is inserted. The cover assembly includes: Cover plate, the cover plate including through holes; The electrode terminal includes a terminal hole coaxially formed with the through hole, and includes a locking step portion formed on the inner circumferential surface of the upper end of the electrode terminal; A lower insulating plate is formed below the cover plate; A riveting member having a hollow structure and inserted into the through hole and the terminal hole, the riveting member having an upper end portion positioned above the locking step portion of the electrode terminal and a lower end portion positioned below the lower insulating plate, and the riveting member including a first alignment structure formed at a predetermined position on the lower surface of the lower end portion of the riveting member; and A current collector is connected to the electrode assembly for electrical connection with the foil tab, and the current collector is electrically connected to the electrode terminal via the riveting member. The current collector includes a second alignment structure and a current collection protrusion. The second alignment structure is formed at a position corresponding to the first alignment structure and is connected to and in contact with the first alignment structure. The current collection protrusion is inserted into the hollow structure.

14. The secondary battery according to claim 13, wherein, The plurality of foil tabs are formed in one direction of the electrode assembly.

15. The secondary battery according to claim 13, wherein, The plurality of foil tabs are formed in two opposite directions on the electrode assembly.

16. The secondary battery according to claim 13, in, After the electrode assembly and the current collector are connected to each other, the current collector is attached to a first insulator. After the outer surface of the electrode assembly is covered with a second insulator, the electrode assembly is inserted into the housing, and The outer surface of the housing into which the electrode assembly is inserted is covered with a third insulator.

17. The secondary battery according to claim 16, wherein, Each of the first to the third insulators includes an insulating strip.

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