Secondary battery

Abstract

Disclosed herein is a secondary battery capable of preventing relative rotation between components in a cover assembly. The secondary battery can include an electrode assembly, a current collector, a battery case, and a cover assembly. The cover assembly can include a base plate, an upper gasket, and a terminal. The secondary battery can prevent rotation of components while simplifying an assembly process of the cover assembly.

Description

Cross-references to related applications

[0001] This application claims priority and benefit to Korean Patent Application No. 10-2025-0052609, filed with the Korean Intellectual Property Office on April 22, 2025, and Korean Patent Application No. 10-2026-0070527, filed with the Korean Intellectual Property Office on April 20, 2026, the entire disclosure of which is incorporated herein by reference. Technical Field

[0002] This disclosure relates to a secondary battery, and more specifically to a secondary battery that can prevent relative rotation between components in a cover assembly. Background Technology

[0003] Recently, with the rapid increase in demand for portable electronic products and the more active development of electric vehicles, energy storage batteries, robots, satellites, etc., high-performance rechargeable and rechargeable batteries have been actively researched.

[0004] Secondary batteries can be classified according to the shape of their casing: can-type secondary batteries, in which the electrode assembly is embedded in a metal can; and pouch-type secondary batteries, in which the electrode assembly is embedded in a pouch-like component formed of aluminum laminates. Can-type secondary batteries can also be classified according to the shape of the metal can into cylindrical secondary batteries and prismatic secondary batteries.

[0005] The cover assembly of a secondary battery typically includes a base plate, insulating gaskets, and electrode terminals. The precise fit of these components not only determines the overall structural reliability of the battery but also affects its sealing performance and current conduction stability. During battery use, external vibrations, mechanical shocks, and other factors can cause the insulating gaskets and terminals within the cover assembly to rotate relative to the base plate. This rotation can create torsional loads at the welded joints between the current collector and the terminals, leading to weld cracking, detachment, increased internal resistance, and increased heat generation during charging and discharging, thus affecting the battery's cycle life and performance. Furthermore, rotation of the insulating gaskets can cause misalignment of the sealing surfaces between them and the base plate and terminals, damaging the battery's sealing structure and causing electrolyte leakage. This not only reduces the battery's electrochemical performance but also poses a risk of short circuits between the positive and negative electrodes within the battery.

[0006] In addition, in secondary batteries, the electrode contacts of the electrode assembly are connected to the current collector by welding. When welding the electrode contacts to the current collector, the electrode contacts are bent in the bending direction to increase the contact area between the electrode contacts and the current collector, with the current collector located on the upper side of the electrode contacts, and then welding is performed.

[0007] However, this configuration may damage the separator during the welding process of the current collector and the electrode contacts located below the current collector. Furthermore, as the capacity of secondary batteries increases, the number of electrode contacts welded at one time increases, resulting in contacts farther from the current collector not being adequately welded.

[0008] Therefore, there is a need to develop a secondary battery that can simplify the assembly process of the cover assembly while preventing the components from rotating.

[0009] Furthermore, a secondary battery needs to be developed that can stably weld a large number of electrode contacts to the current collector.

[0010] In addition, a secondary battery needs to be developed that can prevent the separator from being damaged when the electrode contacts are welded to the current collector. Summary of the Invention Technical issues

[0011] The purpose of this disclosure is to provide a secondary battery, as well as a battery module, battery pack, and vehicle including the secondary battery, which can simplify the assembly process of the cover assembly while preventing component rotation.

[0012] Another object of this disclosure is to provide a secondary battery and a battery module, battery pack and vehicle including the secondary battery, wherein the secondary battery can stably weld a large number of electrode contacts to the current collector when electrode contacts are welded to the current collector.

[0013] Another object of this disclosure is to provide a secondary battery and battery modules, battery packs and vehicles including the secondary battery, which can prevent the electrode assembly from being affected when electrode tabs are soldered to the current collector. Technical solution

[0014] A secondary battery according to an embodiment of the present disclosure may include an electrode assembly, a battery housing, and a cover assembly. The electrode assembly may include electrode portions and electrode contacts. The cover assembly may be coupled to the upper end of the battery housing. The cover assembly may include a base plate, an upper liner, and terminals. The base plate may include a seating portion and at least one locking portion, with an opening formed in the seating portion. The upper liner may be disposed in the seating portion of the base plate, and the upper liner may include: a bottom portion with an opening formed therein; a fixing portion disposed on at least one side of the bottom portion and coupled to the locking portion; and a rib formed along an edge of the upper surface of the bottom portion. Terminals may be disposed on the upper surface of the upper liner and have at least one groove formed in the lower surface of the terminal and an opening formed in the terminal.

[0015] The seated part can be quadrilateral or circular.

[0016] A welding area can be formed on the outer periphery of the lower surface of the support part.

[0017] The depth d1 of the seated portion can be 30% to 50% of the thickness t1 of the base plate.

[0018] The area of ​​the seated portion can be 8% to 20% of the area of ​​the base plate.

[0019] The area of ​​the opening in the base plate can be 5% to 20% of the area of ​​the seating portion.

[0020] Two locking parts can be provided, and these two locking parts are respectively located at opposite ends of the seating part.

[0021] The locking part can be quadrilateral or semi-circular in shape.

[0022] The total area of ​​the locked portions can be 1% to 10% of the area of ​​the seated portions.

[0023] The total area of ​​the locking parts can be set to a value in mm² corresponding to the calculation result of the following expression 1:

[0024] Expression 1

[0025]

[0026] Where A is the length of the base plate (mm), B is the ratio of the width of the opening of the sitting part to the width of the sitting part, C is the thickness of the base plate (mm), and N is the number of locking parts.

[0027] The length l of the locking part can be 10% to 80% of the length of the short side of the sitting part.

[0028] The width w of the locking part can be 3% to 10% of the length of the long side of the sitting part.

[0029] The fixing part can be convex towards the upper surface of the upper pad and concave towards the lower surface of the upper pad.

[0030] The height h1 of the rib can be 30% to 80% of the height h2 of the terminal.

[0031] The thickness t1 of the rib can be from 0.5 mm to 1.2 mm.

[0032] Multiple electrode tabs may be formed at one end of the electrode portion, and the secondary battery may also include a current collector welded to the multiple electrode tabs.

[0033] The plurality of electrode contacts include a plurality of first electrode contacts located at a first position and a plurality of second electrode contacts located at a second position. The plurality of first electrode contacts and the plurality of second electrode contacts have the same polarity and are spaced apart from each other in the width and length directions of the electrode assembly.

[0034] Multiple first electrode contacts and second electrode contacts are disposed on the upper side of the current collector.

[0035] A secondary battery according to embodiments of the present disclosure may include an electrode assembly, a current collector, a battery casing, and a cover assembly. The electrode assembly may include electrode portions and electrode contacts. The battery casing may have an open upper end and house the electrode assembly within the casing. The cover assembly may be coupled to the upper end of the battery casing. The cover assembly may be provided with a base plate, an upper gasket, and terminals. The base plate may include a seating portion having an opening formed in its upper surface. The upper gasket may be disposed in the seating portion of the base plate and may include: a lower surface portion having an opening formed therein; an upper surface portion extending outwardly around the outer periphery of the lower surface portion and projecting upward relative to the lower surface portion, thereby forming a step; and a rib formed along the edge of the upper surface portion. Terminals may be disposed on the upper gasket and may include a protrusion formed on the underside of the terminal and an opening formed in the terminal.

[0036] The terminal may also include a support portion connected to the upper side of the protrusion, the cross-sectional area of ​​which may be larger than that of the protrusion.

[0037] The lower surface portion can be configured to correspond to the shape and size of the seated portion to engage the seated portion, and the upper surface portion can be configured to engage the portion of the base plate located outside the seated portion.

[0038] The protruding portion can be configured to correspond to the shape and size of the lower surface portion to engage the lower surface portion, and the supporting portion can be configured such that its outer contour corresponds to the outer contour of the upper surface portion to engage the upper surface portion and the rib.

[0039] The seated portion can have a rectangular shape.

[0040] The depth d2 of the seated portion can be 30% to 50% of the thickness t2 of the base plate.

[0041] The area of ​​the opening in the base plate can be 5% to 20% of the area of ​​the seating portion.

[0042] The area of ​​the upper surface portion can be 50% to 80% of the area of ​​the lower surface portion.

[0043] The width of the upper surface portion can be from 2 mm to 4 mm.

[0044] The lower surface portion can have the same profile as the seated portion.

[0045] The height of the protruding part can be equal to the depth of the lower surface part.

[0046] A secondary battery according to embodiments of the present disclosure may include an electrode assembly, a current collector, a battery casing, and a cover assembly. The electrode assembly may include electrode portions and a plurality of electrode tabs. The battery casing may have an open upper end and house the electrode assembly within the casing. The cover assembly may be coupled to the upper end of the battery casing. The cover assembly may be provided with a base plate, an upper liner, and terminals. The base plate may include a seating portion and at least one protrusion, with an opening formed in the seating portion. The upper liner may be disposed in the seating portion of the base plate and may include: a bottom portion with an opening formed therein; at least one fixing portion disposed on the bottom portion and coupled to the protrusion; and a rib formed along an edge of the upper surface of the bottom portion. Terminals may be disposed on the upper surface of the upper liner and may have at least one groove formed in the lower surface of the terminal and an opening formed in the terminal.

[0047] The depth d3 of the seated portion can be 30% to 50% of the thickness t3 of the base plate.

[0048] The area of ​​the seated portion can be 8% to 20% of the area of ​​the base plate.

[0049] The area of ​​the opening in the base plate can be 5% to 20% of the area of ​​the seating portion.

[0050] The seated part can have a circular shape.

[0051] The seated portion can have a quadrilateral shape.

[0052] Two protrusions can be provided, and these two protrusions are respectively located on a diagonal line of the sitting part.

[0053] Four protrusions can be provided, and these four protrusions are respectively located at the corners of the seating part.

[0054] The total area of ​​multiple protrusions can be 2% to 10% of the area of ​​the seated portion.

[0055] The total area of ​​the protrusions can be set to a value in mm² corresponding to the calculation result of the following expression 2:

[0056] Expression 2

[0057]

[0058] Where A is the length of the base plate (mm), B is the ratio of the width of the opening of the sitting part to the width of the sitting part, C is the thickness of the base plate (mm), and N is the number of protrusions.

[0059] Each of the protrusions may have a shape selected from the group consisting of: cylindrical shape, elliptical cylindrical shape, and quadrangular prism shape.

[0060] The fixing part can be convex towards the upper surface of the upper pad and concave towards the lower surface of the upper pad.

[0061] The protrusions, fixing parts, and grooves are arranged in the same number.

[0062] The openings in the base plate, the upper gasket, and the terminal can be aligned to form a through hole.

[0063] The secondary battery may also include a current collector welded to the electrode tabs of the electrode assembly, and the current collector may also include a current collector protrusion inserted into a through hole.

[0064] At the end of the current collector protrusion, the current collector protrusion can be soldered to the terminal.

[0065] The secondary battery may also include: an annular gasket that is inserted into an opening in the base plate and contacts the upper gasket; and a rivet that passes through the annular gasket and is inserted into an opening in the terminal.

[0066] The secondary battery may also include a current collector welded to the electrode tabs of the electrode assembly, the current collector including current collector protrusions inserted into through holes and inserted into rivets.

[0067] At the end of the current collector protrusion, the current collector protrusion can be soldered to the terminal.

[0068] The battery module according to embodiments of this disclosure may include a secondary battery.

[0069] A battery pack according to an embodiment of this disclosure may include a battery module.

[0070] The vehicle according to embodiments of this disclosure may include a battery pack. Beneficial effects

[0071] The secondary battery according to this disclosure can prevent component rotation while simplifying the assembly process of the cover assembly. In particular, by the shape fit between the locking part and the fixing part, and the further shape fit between the fixing part and the groove, the various parts of the cover assembly can be easily and conveniently assembled into one piece, and these mutually fitting designs form a multi-level anti-rotation structure that can effectively disperse and resist torsional loads caused by external vibration or impact, thereby reliably preventing the rotation of the upper gasket and terminals relative to the base plate.

[0072] Furthermore, in a preferred embodiment, the secondary battery according to this disclosure can significantly improve terminal conductivity and reduce current conduction resistance without increasing the overall battery volume.

[0073] According to this disclosure, the secondary battery can stably weld a large number of electrode contacts to the current collector when welding the electrode contacts to the current collector.

[0074] Furthermore, the secondary battery according to this disclosure can prevent the electrode assembly from being affected when the electrode tabs are welded to the current collector. Attached Figure Description

[0075] The above and other objects, features and advantages of this disclosure will become clearer from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0076] Figure 1 This is a view illustrating a secondary battery according to one embodiment of the present disclosure;

[0077] Figure 2 This is a view illustrating a secondary battery according to one embodiment of the present disclosure;

[0078] Figure 3 This is a view illustrating an electrode assembly in a secondary battery according to one embodiment of the present disclosure, in which a plurality of first electrode contacts and a plurality of second electrode contacts are formed on an electrode portion.

[0079] Figure 4A and Figure 4B This is a view illustrating a first electrode component and a second electrode component in a secondary battery according to one embodiment of the present disclosure;

[0080] Figure 5A and Figure 5B This is a view illustrating the third electrode component and the fourth electrode component in a secondary battery according to one embodiment of the present disclosure;

[0081] Figure 6 This is a view illustrating a secondary battery according to a modified embodiment of the present disclosure.

[0082] Figure 7 This is a view of a secondary battery according to a modified embodiment of the present disclosure, wherein a plurality of first electrode contacts to a plurality of fourth electrode contacts are formed at one end of the electrode assembly.

[0083] Figure 8 This is a view illustrating a current collector in a secondary battery according to one embodiment of the present disclosure;

[0084] Figure 9This is a view illustrating a current collector in a secondary battery according to one embodiment of the present disclosure;

[0085] Figure 10A and Figure 10B This is a cross-sectional view of a cover assembly according to a first embodiment of the present disclosure.

[0086] Figure 11 This is a view illustrating a cover assembly according to a first embodiment of the present disclosure;

[0087] Figure 12 This is a view illustrating the base plate according to the first embodiment of the present disclosure;

[0088] Figure 13 This is a view illustrating an alternative base plate according to the present disclosure;

[0089] Figure 14 This is a view illustrating the upper liner according to a first embodiment of the present disclosure;

[0090] Figure 15 This is a view illustrating the base plate and upper liner of a cover assembly according to a modified embodiment of the first embodiment of the present disclosure.

[0091] Figure 16A and Figure 16B This is a view illustrating the base plate and upper liner of a cover assembly according to a modified embodiment of the first embodiment of the present disclosure.

[0092] Figure 17 This is a view illustrating the base plate and upper liner of a cover assembly according to a modified embodiment of the first embodiment of the present disclosure.

[0093] Figure 18A and Figure 18B It is a cross-sectional view illustrating the cover assembly and current collector assembly state according to the first embodiment and modified embodiments of the present disclosure.

[0094] Figure 19 It is a plan view illustrating the assembled state of the cover assembly and the current collector according to the first embodiment of the present disclosure;

[0095] Figure 20 This is a view illustrating a cover assembly according to a second embodiment of the present disclosure;

[0096] Figure 21A and Figure 21B This is a cross-sectional view illustrating the assembled state of the cover assembly and the current collector according to the second embodiment and its variations of the present disclosure.

[0097] Figure 22 This is a view illustrating a cover assembly according to a third embodiment of the present disclosure;

[0098] Figure 23 This is a view illustrating a cover assembly according to a modified embodiment of the third embodiment of the present disclosure;

[0099] Figure 24 This is a view illustrating a cover assembly according to a modified embodiment of the third embodiment of the present disclosure;

[0100] Figure 25 This is a view illustrating a cover assembly according to a modified embodiment of the third embodiment of the present disclosure;

[0101] Figure 26A and Figure 26B The illustration shows a cross-sectional view of the cover assembly and collector assembled according to the third embodiment and variations thereof of this disclosure.

[0102] Figure 27 This is a diagram illustrating a secondary battery including a cover assembly according to a modified embodiment of the first embodiment of the present disclosure.

[0103] Figure 28 This is a diagram illustrating a cover assembly according to a modified embodiment of the first embodiment of the present disclosure;

[0104] Figure 29A and Figure 29B It is a diagram illustrating the assembly state of the cover assembly and the current collector, including a modified embodiment of the first embodiment according to the present disclosure;

[0105] Figure 30 This is a flowchart illustrating a method for manufacturing a secondary battery according to one embodiment of the present disclosure;

[0106] Figure 31 This is a view illustrating the state in which a plurality of first electrode contacts and a plurality of second electrode contacts are respectively grouped in a secondary battery according to an embodiment of the present disclosure;

[0107] Figure 32 This is a view illustrating the state in which a current collector is disposed between a plurality of first electrode contacts and a plurality of second electrode contacts in a secondary battery according to one embodiment of the present disclosure.

[0108] Figure 33 This is a view illustrating the state in which the current collector is welded to the first electrode tab and the second electrode tab in a secondary battery according to one embodiment of the present disclosure; and

[0109] Figure 34 This is a view illustrating the state in which the cover assembly is connected to the electrode assembly in a secondary battery according to one embodiment of the present disclosure. Detailed Implementation

[0110] Because this disclosure can be modified in various forms and has various implementations, specific implementations will be illustrated 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.

[0111] 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 exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or combinations thereof.

[0112] In the following, preferred 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. Details of well-known configurations and functions may be omitted to avoid unnecessarily obscuring the essential points of the present disclosure. For the same reason, some elements in the drawings are enlarged, omitted, or depicted schematically.

[0113] The secondary battery according to embodiments of the present disclosure will be described below.

[0114] Figure 1 This is a view illustrating a secondary battery according to one embodiment of the present disclosure, and Figure 2 This is a view illustrating a secondary battery according to one embodiment of the present disclosure. Figure 3 This illustration shows a view of an electrode assembly in a secondary battery according to one embodiment of the present disclosure, in which a plurality of first electrode contacts and a plurality of second electrode contacts are formed on an electrode portion. Figure 4A and Figure 4B This is a view illustrating a first electrode component and a second electrode component in a secondary battery according to an embodiment of the present disclosure, and Figure 5A and Figure 5B Figure 6 and Figure 7 are views illustrating the third and fourth electrode components in a secondary battery according to one embodiment of the present disclosure. Figures 7 and 8 are views showing the current collector in a secondary battery according to one embodiment of the present disclosure.

[0115] like Figure 1 and Figure 2As shown, a secondary battery 1000 according to one embodiment of the present disclosure includes a housing 1100, an electrode assembly 1200, a current collector 1300, and a cover assembly 1400.

[0116] The housing 1100 forms the exterior of the secondary battery 1000. The housing 1100 has an internal space configured to accommodate the electrode assembly 1200, wherein an opening is formed on one surface of the housing 1100. In this embodiment, the housing 1100 has a cuboid shape, but the shape of the housing 1100 can be varied and is not limited thereto. The housing 1100 can be made of a rigid material that can protect the electrode assembly 1200 housed within the housing 1100. For example, the housing 1100 can be made of a metal such as aluminum or stainless steel.

[0117] 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 EC, PC, DEC, EMC, or DMC. The electrolyte may be in a liquid, solid, or gel state.

[0118] The electrode assembly 1200 is housed within the housing 1100. For example... Figure 3 As illustrated, the electrode assembly 1200 includes an electrode portion 1210, a plurality of first electrode contacts 1220, and a plurality of second electrode contacts 1230. The plurality of first electrode contacts 1220 and the plurality of second electrode contacts 1230 are disposed at one end of the electrode portion 1210. The plurality of first electrode contacts 1220 are aligned with each other, and the plurality of second electrode contacts 1230 are aligned with each other. The aligned plurality of first electrode contacts 1220 and the aligned plurality of second electrode contacts 1230 are arranged in the width direction of the electrode assembly 1200 (i.e., Figure 3 The Y-axis direction and the length direction (i.e., Figure 3 They do not overlap in the Z-axis direction.

[0119] Specifically, the electrode portion 1210 includes a plurality of first electrode components 1211, a plurality of second electrode components 1212, a plurality of third electrode components 1213, a plurality of fourth electrode components 1214, and a separator.

[0120] The active material can be applied to multiple first electrode components 1211, multiple second electrode components 1212, multiple third electrode components 1213, and multiple fourth electrode components 1214. In the multiple first electrode components 1211 and multiple second electrode components 1212, the active material, such as a transition metal oxide, can be applied to a metal plate, such as aluminum. The multiple first electrode components 1211 and multiple second electrode components 1212 can have the same polarity and can be positive electrode plates. In the multiple third electrode components 1213 and multiple fourth electrode components 1214, the active material, such as graphite or carbon, can be applied to a metal plate, such as copper or nickel. The multiple third electrode components 1213 and multiple fourth electrode components 1214 can have the same polarity and can be negative electrode plates.

[0121] A separator is positioned between a plurality of first electrode members to a plurality of fourth electrode members 1211, 1212, 1213 and 1214 to prevent short circuits between the plurality of first electrode members to the plurality of fourth electrode members 1211, 1212, 1213 and 1214. The separator may be made of polyethylene, polypropylene or a composite thereof.

[0122] The electrode portion 1210 can be formed by disposing spacers between the first electrode member 1211 and the third electrode member 1213 arranged sequentially, and between the second electrode member 1212 and the fourth electrode member 1214 arranged sequentially. That is, in one embodiment, the electrode portion 1210 is formed such that one side of the electrode portion 1210 is formed by stacking the first electrode member 1211, the spacer, the third electrode member 1213, and the spacer in this sequential order dozens to hundreds of times, and the other side of the electrode portion 1210 is formed by stacking the second electrode member 1212, the spacer, the fourth electrode member 1214, and the spacer in this sequential order dozens to hundreds of times. In another embodiment, the electrode portion 1210 can be formed by stacking the first electrode member 1211, the spacer, the third electrode member 1213, the spacer, the second electrode member 1212, the spacer, the fourth electrode member 1214, and the spacer in this sequential order, and then winding the stacked structure.

[0123] In one embodiment, the electrode assembly 1200 includes one electrode portion 1210, but 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.

[0124] Electrode tabs 1220, 1230, 1240, and 1250 without applied active material are formed at one end of a plurality of first electrode members to a plurality of fourth electrode members 1211, 1212, 1213, and 1214. In one embodiment, the electrode members 1211, 1212, 1213, and 1214, as well as the electrode tabs 1220, 1230, 1240, and 1250, can be integrally formed by cutting predetermined portions from a single metal plate using a laser or the like, leaving the electrode members 1211, 1212, 1213, and 1214, and the electrode tabs 1220, 1230, 1240, and 1250. The plurality of electrode tabs 1220, 1230, 1240, and 1250 can be formed in a direction toward the cover assembly 1400.

[0125] The first electrode contact 1220 is formed at a first position of the first electrode member 1211. The second electrode contact 1230 is formed at a second position of the second electrode member 1212. Figure 4A and Figure 4B Similarly, the third electrode contact 1240 can be formed at the third position of the third electrode member 1213, and the fourth electrode contact 1250 can be formed at the fourth position of the fourth electrode member 1214. Figure 5A and Figure 5B ) place.

[0126] Multiple first electrode components 1211 and multiple third electrode components 1213 may be stacked alternately, with spacers placed between the multiple first electrode components 1211 and the multiple third electrode components 1213. The stack of multiple first electrode components 1211 and multiple third electrode components 1213 forms one half of electrode portion 1210.

[0127] Multiple second electrode components 1212 and multiple fourth electrode components 1214 may be stacked alternately, with spacers placed between the multiple second electrode components 1212 and the multiple fourth electrode components 1214. The stack of multiple second electrode components 1212 and multiple fourth electrode components 1214 forms the remaining half of the electrode portion 1210.

[0128] Stacks of multiple first electrode components 1211 and multiple third electrode components 1213, as well as stacks of multiple second electrode components 1212 and multiple fourth electrode components 1214, are connected in the width direction of the electrode portion 1210. When forming the electrode assembly 1200, multiple first electrode components 1211 and multiple third electrode components 1213 may be stacked, and then multiple second electrode components 1212 and multiple fourth electrode components 1214 may be stacked.

[0129] When multiple first electrode components to multiple fourth electrode components 1211, 1212, 1213, and 1214 are stacked, multiple first electrode tabs 1220 overlap each other at a first position. Multiple second electrode tabs 1230 overlap each other at a second position. That is, multiple first electrode tabs 1220 are grouped at the first position, and multiple second electrode tabs 1230 are grouped at the second position. The first and second positions may be spaced apart from each other on the electrode components, and the groups of multiple first electrode tabs 1220 and groups of multiple second electrode tabs 1230 may be spaced apart from each other in the width and length directions of the electrode assembly 1200.

[0130] A group of multiple first electrode contacts 1220 are welded together in one step, and a group of multiple second electrode contacts 1230 are welded together in one step.

[0131] The plurality of first electrode tabs 1220 and the plurality of second electrode tabs 1230 are electrode tabs having the same polarity. To stably weld a large number of electrode tabs, the electrode tabs are spaced apart from each other in the width and length directions of the electrode assembly 1200 and welded once, and then welded a second time to the current collector. That is, one electrode tab is formed on one electrode member. However, by forming electrode tabs at different positions on corresponding electrode members, after stacking the electrode members, two groups of electrode tabs with different positions are formed on electrode members of the same polarity. In another embodiment, two or more groups of electrode tabs with different positions can be formed on electrode members of the same polarity.

[0132] When multiple first to fourth electrode components 1211, 1212, 1213, and 1214 are stacked, multiple third electrode tabs 1240 overlap each other at a third position, and multiple fourth electrode tabs 1250 overlap each other at a fourth position. That is, the multiple third electrode tabs 1240 are grouped at the third position, and the multiple fourth electrode tabs 1250 are grouped at the fourth position. The third and fourth positions are spaced apart from each other on the electrode components, and the groups of multiple third electrode tabs 1240 and groups of multiple fourth electrode tabs 1250 can be spaced apart from each other in both the width and length directions of the electrode assembly 1200.

[0133] The multiple third electrode contacts 1240 and the multiple fourth electrode contacts 1250 are electrode contacts with the same polarity.

[0134] Multiple electrode contacts 1220, 1230, 1240 and 1250 overlapping at corresponding positions can be connected to each other by ultrasonic welding, laser welding or other means to facilitate current flow.

[0135] In the above exemplary embodiments, electrode contacts of different polarities are formed at opposite ends of the electrode assembly, and multiple contacts of the same polarity are located at the same end. However, this disclosure is not limited thereto. In modified embodiments, multiple electrode contacts spaced apart from each other and of different polarities may also be formed at the same end of the electrode assembly.

[0136] like Figure 6 As shown, the secondary battery 1000 according to a modified embodiment of the present disclosure may have two terminals 1430, 1430' at one end. In this embodiment, a space for accommodating the electrode assembly 1200 is formed inside the housing 1100, and an opening may be formed at one end of the housing.

[0137] The electrode assembly 1200 can be housed inside the housing 1100. For example... Figure 7 As shown, the electrode assembly 1200 may include: an electrode portion 1210, a plurality of first electrode contacts 1220, a plurality of second electrode contacts 1230, a plurality of third electrode contacts 1240, and a plurality of fourth electrode contacts 1250. The plurality of first electrode contacts 1220, the plurality of second electrode contacts 1230, the plurality of third electrode contacts 1240, and the plurality of fourth electrode contacts 1250 may be disposed at the same end of the electrode portion 1210.

[0138] On one side of one end of the electrode assembly 1200 (i.e., Figure 7 (At the upper end in the Z direction and on the left side in the Y direction), multiple first electrode contacts 1220 can be aligned with each other, and multiple second electrode contacts 1230 can be aligned with each other. On the other side of one end of the electrode assembly 1200 (i.e., Figure 7 (At the upper end in the Z direction and on the right side in the Y direction), multiple third electrode contacts 1240 can be aligned with each other, and multiple fourth electrode contacts 1250 can be aligned with each other. The multiple first electrode contacts 1220, multiple second electrode contacts 1230, multiple third electrode contacts 1240, and multiple fourth electrode contacts 1250, which are aligned with each other, can be arranged without overlapping each other in the width direction (x direction) and length direction (y direction) of the electrode assembly 1200.

[0139] The grouped first electrode contacts 1220 can be welded to each other once, the grouped second electrode contacts 1230 can be welded to each other once, the grouped third electrode contacts 1240 can be welded to each other once, and the grouped fourth electrode contacts 1250 can be welded to each other once.

[0140] Multiple first electrode contacts 1220 and multiple second electrode contacts 1230 are electrode contacts of the same polarity. To stably weld a large number of electrode contacts, the multiple first electrode contacts 1220 and multiple second electrode contacts 1230 spaced apart along the width and length directions of the electrode assembly 1200 can be welded once each, and then welded a second time to the first current collector. Similarly, multiple third electrode contacts 1240 and multiple fourth electrode contacts 1250 are electrode contacts of the same polarity. The multiple third electrode contacts 1240 and multiple fourth electrode contacts 1250 spaced apart along the width and length directions of the electrode assembly 1200 can be welded once each, and then welded a second time to the second current collector. That is, an electrode contact is formed on an electrode component. By forming the electrode contacts of each electrode component at different positions, after the electrode components are stacked, two sets of electrode contacts of the same polarity located at different positions can be formed.

[0141] The polarities of the multiple first and second electrode contacts 1220, 1230 and the multiple third and fourth electrode contacts 1240, 1250 can be different from each other.

[0142] like Figure 8 As shown in the figure, the collector 1300 includes a first collector section 1310, a second collector section 1320, and a connection section 1330.

[0143] The current collector 1300 may have a rectangular shape extending along the length of the electrode assembly 1200. The current collector 1300 may have a first current collecting portion 1310, a connecting portion 1330, and a second current collecting portion 1320 arranged sequentially along the length of the rectangular shape.

[0144] The first current collector 1310 is soldered to a plurality of first electrode contacts 1220. The plurality of first electrode contacts 1220 can be bent onto the first current collector 1310 and soldered to the first current collector 1310. The second current collector 1320 is soldered to a plurality of second electrode contacts 1230. The plurality of second electrode contacts 1230 can be bent onto the second current collector 1320 and soldered to the second current collector 1320.

[0145] A connecting portion 1330 is disposed between the first current collector portion 1310 and the second current collector portion 1320. The first current collector portion 1310 and the second current collector portion 1320 are respectively connected to opposite sides of the connecting portion 1330. Since the first current collector portion 1310 and the second current collector portion 1320 are spaced apart from each other by the connecting portion 1330, the plurality of first electrode contacts 1220 and the plurality of second electrode contacts 1230 will not interfere with each other when they are respectively soldered to the first current collector portion 1310 and the second current collector portion 1320.

[0146] Two current collectors 1300 can be provided, and the material of the current collectors 1300 can be the same as the material of the first electrode contact 1220 and the second electrode contact 1230 or the third electrode contact 1240 and the fourth electrode contact 1250. That is, the current collectors 1300 can be formed of aluminum, or they can be formed of copper or nickel.

[0147] A current collector protrusion 1331 is provided on the connecting portion 1330. The current collector protrusion 1331 is electrically connected to the electrode terminal. The material of the current collector protrusion 1331 may be the same as or different from the material of the connecting portion 1330. For example, both the connecting portion 1330 and the current collector protrusion 1331 may be formed of aluminum. Alternatively, the connecting portion 1330 may be formed of copper, and the current collector protrusion 1331 may be formed of aluminum. When the material of the current collector protrusion 1331 is the same as the material of the connecting portion 1330, the connecting portion 1330 and the current collector protrusion 1331 may be integrally formed.

[0148] The thickness of the current collector 1300 can be from 0.5 mm to 3.0 mm. In this disclosure, the current collector 1300 is positioned on the electrode portion, and electrode contacts 1220 and 1230 are positioned on the current collector 1300 and welded from the upper side of the electrode contacts 1220 and 1230, thereby ensuring the thickness of the current collector 1300. Therefore, the durability of the secondary battery can also be improved.

[0149] The width of the current collector 1300 can be 0.5 to 0.8 times the width of the electrode assembly 1200.

[0150] According to this disclosure, since the electrode tabs are positioned on the current collector 1300 and welded from the upper side of the electrode tabs, there is no risk of damaging the separators provided in the electrode section.

[0151] In related technologies, welding is performed after the current collector is positioned above the electrode contacts, thus requiring a high laser output to transfer heat to the electrode contacts located below the current collector. However, according to this disclosure, since the electrode contacts are positioned above the current collector, welding can be performed with a lower output. Furthermore, since it is not necessary to melt the lower portion of the current collector, the thickness of the current collector can be increased to protect the separator, thereby improving the durability of the secondary battery.

[0152] like Figure 9 As illustrated, insulator 1340 can be disposed below current collector 1300. Insulator 1340 can be an insulating plate or an insulating film. Electrode contacts 1220 and 1230 and electrode portion 1210 can be further protected by insulator 1340.

[0153] The cover assembly 1400 seals the opening of the housing 1100 that houses the electrode assembly 1200. The cover assembly 1400 includes a base plate 1410, an upper gasket 1420, and terminals 1430.

[0154] In the following text, a secondary battery including a cover assembly according to a first embodiment of the present disclosure will be described.

[0155] like Figure 10A and 10B As shown, the cover assembly 1400 seals the opening of the housing 1100, which internally houses the electrode assembly 1200. (Refer to...) Figure 10A The cover assembly 1400 may include a base plate 1410, an upper gasket 1420, and a terminal 1430. (See reference...) Figure 10B The cover assembly 1400 may include a base plate 1410, an upper gasket 1420, a terminal 1430, an annular gasket 1440, and a rivet 1450. The lower end of the cover assembly may also be fitted with an insulating member (not shown).

[0156] The base plate 1410 may be plate-shaped, covering the opening of the housing 1100. The base plate 1410 may have a shape corresponding to the shape of the opening of the housing 1100. The base plate 1410 may be made of the same material as the housing 1100 and may be fixed to the opening of the housing 1100 by methods such as laser welding. The base plate 1410 may have an opening. The curvature of the corners of the base plate 1410 may be 1~4 mm.

[0157] On the other hand, the base plate 1410 may have a vent (not shown) and an electrolyte injection port (not shown). The vent opens when the internal pressure of the housing 1100 exceeds a reference value. In this embodiment, the vent may be formed on either the base plate 1410 or the housing 1100. Electrolyte can be injected into the housing 1100 through the electrolyte injection port.

[0158] The upper gasket 1420 is assembled to the upper surface of the base plate 1410. The lower surface of the upper gasket 1420 has a shape that matches the upper surface of the base plate 1410. The upper gasket 1420 is an insulating material, for example, it can be formed from a highly elastic polymer resin. The edges of the upper gasket 1420 may be formed with reinforcing ribs. The upper gasket 1420 may be formed with openings.

[0159] Terminal 1430 is assembled on upper pad 1420. The lower surface of terminal 1430 has a shape that matches the upper surface of upper pad 1420. Terminal 1430 is electrically connected to electrode contacts 1220, 1230, 1240, and 1250 via current collector 1300. Terminal 1430 can be a circular or square plate. Terminal 1430 is made of the same material as housing 1100, such as aluminum or stainless steel. Terminal 1430 may have an opening.

[0160] like Figure 10A As shown, when the base plate 1410, upper gasket 1420, and terminal 1430 are assembled in sequence, the openings of the base plate 1410, upper gasket 1420, and terminal 1430 can be aligned. The lower surface of the terminal 1430 can be located further below the upper surface of the base plate 1410. This further prevents rotation between the components of the cover assembly.

[0161] The current collection protrusion 1331 of the current collector 1300 can be inserted into the aligned opening. Thus, the cover assembly 1400 can be electrically connected to the electrode assembly 1200 through the current collector 1300.

[0162] In modified embodiments, such as Figure 10B As shown, the annular gasket 1440 can be introduced through the aligned opening. The upper part of the annular gasket 1440 can contact the upper gasket 1420.

[0163] Rivet 1450 can be inserted into the opening of annular washer 1440 for riveting. Figure 10B After the rivet 1450 secures the base plate 1410, the upper gasket 1420, and the terminal 1430, the current collecting protrusion 1331 of the current collector 1300 can be introduced into the rivet 1450. After the current collecting protrusion 1331 is introduced into the opening 1435, the outer peripheral surface of the end of the current collecting protrusion 1331 can be welded to the inner peripheral surface of the opening 1435 of the terminal 1430.

[0164] The base plate 1410 may include a seating portion 1411 and a locking portion 1412. The seating portion 1411 forms a flat surface recessed downward from the upper surface of the base plate 1410. The seating portion 1411 may have a quadrilateral shape or a circular shape. The upper surface of the seating portion 1411 contacts the lower surface of the upper liner 1420. (See reference...) Figure 11 The depth d1 of the seating portion 1411 can be 30% to 50% of the thickness t1 of the base plate 1410. When the depth d1 of the seating portion 1411 is greater than 50% of the thickness t1 of the base plate 1410, the strength of the base plate 1410 may be weakened. If the depth d1 of the seating portion 1411 is less than 30% of the thickness t1 of the base plate 1410, the bonding strength between the base plate 1410 and the upper gasket 1420 may be weakened.

[0165] When the seating portion 1411 is quadrilateral, the curvature of the corners of the seating portion 1411 can be 2~3mm, preferably 2.5mm. In order to increase the friction coefficient of the surface of the seating portion 1411, silicone or the like can be coated on the surface of the seating portion 1411, or the surface roughness can be improved by surface treatment.

[0166] Meanwhile, a seating portion 1411 may be 8% to 20%, preferably 11% to 14%, of the area of ​​the base plate 1410. In this embodiment, only one seating portion 1411 is formed on the base plate 1410; however, when two support portions are formed on the base plate 1410, the sum of the areas of the two support portions relative to the area of ​​the base plate 1410 may be 8% to 20%, preferably 11% to 14%.

[0167] An opening 1415 is formed at the center of the seating portion 1411. During the assembly of the cover assembly 1400, a current collector protrusion 1331 of the current collector 1300 is introduced through the opening 1415. The area of ​​the opening 1415 can be 5% to 20% of the area of ​​the seating portion 1411. By ensuring that the diameter of the current collector protrusion 1331 introduced through the opening 1415 is sufficiently large, the internal resistance can be reduced when the secondary battery outputs electricity, and thereby heat generation can be reduced.

[0168] The locking portion 1412 may be provided on one or the other side, or both sides, of the seating portion 1411. The locking portion 1412 is formed by extending the upper surface of the base plate 1410 toward the seating portion 1411. The locking portion 1412 may have a quadrilateral shape or a semi-circular shape. The locking portion 1412 forms a step relative to the upper surface of the seating portion 1411.

[0169] The shape of the seating portion 1411 and the shape and number of the locking portions 1412 can be selected as needed. For example, as Figure 11 As illustrated, the seating portion 1411 may have a rectangular shape. The locking portion 1412 may have, for example, a quadrilateral shape, and the two locking portions 1412 may be respectively provided on the short side of the seating portion 1411.

[0170] The sum of the areas of the two locking portions 1412 can be 1% to 10%, preferably 2.25%, of the area of ​​the seating portion 1411. The upper pad 1420 and the terminal 1430 are sequentially stacked on the seating portion 1411 of the base plate 1410. When the total area of ​​the locking portions 1412 exceeds 10%, the area of ​​the lower surface of the terminal 1430 may decrease, thereby increasing internal resistance. When the total area of ​​the locking portions 1412 is less than 1%, the effect of preventing component rotation may be reduced, which is undesirable. The area of ​​the locking portion 1412 refers to the cross-sectional area of ​​the locking portion 1412 relative to the horizontal direction, i.e., the direction parallel to the upper surface of the base plate 1410.

[0171] Furthermore, the total area of ​​the locking portion 1412 can be set to a value S in mm² corresponding to the calculation result of the following expression 1, which conforms to the proportional relationship determined by the dimensional parameters of the base plate, and this proportional relationship is expressed by the following expression 1:

[0172] [Expression 1]

[0173]

[0174] (A is the length of the base plate (mm), B is the ratio of the opening width to the width of the seating part, C is the thickness of the base plate (mm), and N is the number of locking parts.)

[0175] Expression 1 is a design expression for determining the appropriate area of ​​the locked section based on structural parameters, rather than a conventional geometric area calculation formula.

[0176] If the base plate 1410 is long or thin, the area of ​​the locking portion 1412 can be increased, thereby increasing the contact area between the base plate 1410 and the upper pad 1420 in the vertical direction. When the width of the opening 1415 is larger than the width of the sitting portion 1411, it is difficult to ensure that the sitting portion in contact with the upper pad 1420 has sufficient width. Therefore, the rotation of the upper pad 1420 can be prevented by increasing the area of ​​the locking portion 1412.

[0177] At the same time, refer to Figure 13 The length l of the locking portion 1412 can be 10% to 80%, preferably 20%, of the length of the short side of the seating portion 1411. When the length l of the locking portion 1412 exceeds 80% of the length of the short side of the seating portion 1411, the distance between the locking portion 1412 and the long side of the seating portion 1411 may decrease, making it difficult for the upper pad 1420 to be seated smoothly. When the length l of the locking portion 1412 is less than 10% of the length of the short side of the seating portion 1411, the effect of preventing the component from rotating may be reduced.

[0178] The width w of the locking portion 1412 can be 3% to 10%, preferably 5%, of the length of the long side portion of the sitting portion 1411. When the width w of the locking portion 1412 exceeds 10% of the length of the long side portion of the sitting portion 1411, the groove on the lower surface of the terminal 1430 increases accordingly, resulting in a decrease in the effective metal conductive volume of the terminal 1430, thereby increasing the internal resistance.

[0179] The upper pad 1420 sits on the sitting portion 1411 of the base plate 1410. For example... Figure 11As illustrated, the upper pad 1420 may include a bottom portion 1421, at least one fixing portion 1422, and a rib 1423. The bottom portion 1421 is a flat surface and has the same profile as the seating portion 1411 of the base plate 1410. The lower surface of the bottom portion 1421 may be configured to have the same shape and dimensions as the upper surface of the seating portion 1411, so as to correspond to the shape of the upper surface of the seating portion 1411. The difference in the length of the long side between the seating portion 1411 and the bottom portion 1421 may be within 0.05 mm.

[0180] At least one fixing portion 1422 is provided on at least one side of the bottom portion 1421. The fixing portion 1422 is connected to the locking portion 1412 of the base plate 1410. In order to be connected to the locking portion 1412 protruding from the seating portion 1411, the fixing portion 1422 may be recessed on the lower side of the upper pad 1420 and protruding on the upper side of the upper pad 1420 relative to the bottom portion 1421. The fixing portions 1422 may be formed in the same number as the locking portions 1412, and may have the same shape as the locking portions 1412. The depth d2 of the recessed space inside the fixing portion 1422 may be equal to or greater than the depth d1 of the seating portion 1411.

[0181] An opening 1425 is formed at the center of the bottom portion 1421. During the assembly of the cover assembly 1400 and the electrode assembly, the current collecting protrusion 1331 of the current collector 1300 is introduced through the opening 1425.

[0182] Rib 1423 is formed along the edge of the upper surface of the bottom portion 1421. Rib 1423 is in close contact with the sidewall of the seating portion 1411 to seal the base plate 1410. Upper gasket 1420 has a container shape defined by rib 1423 and bottom portion 1421 and is configured to seat terminal 1430. Rib 1423 is formed upward from bottom portion 1421 and has a height h1 greater than the depth d1 of seating portion 1411. Furthermore, the height h1 of rib 1423 can be 30% to 80%, preferably 50%, of terminal height h2. When the height h1 of rib 1423 is less than 30% of terminal height h2, it may be difficult to stably seal terminal 1430.

[0183] The thickness tl of rib 1423 can be from 0.5 mm to 1.2 mm. When the thickness tl of rib 1423 is less than 0.5 mm, the sealing effect may be reduced.

[0184] The upper gasket 1420 may be made of insulating material. The terminal 1430 and the base plate 1410 are insulated from each other by the upper gasket 1420.

[0185] At the same time, such as Figure 14As illustrated, two locking portions 1412 can be provided. The two rectangular locking portions 1412 can be positioned symmetrically about the opening 1415 on one edge and the other edge of the seating portion 1411. When the locking portions 1412 are formed in a symmetrical position, there is an advantage that the orientation of the components does not need to be individually aligned during assembly, thereby facilitating assembly.

[0186] In another embodiment, such as Figure 16A As shown, the seating portion 1411 can have a circular shape, and two rectangular locking portions 1412 can be respectively disposed on both sides of the seating portion 1411. Alternatively, as... Figure 16B As shown, four rectangular locking portions 1412 are distributed at equal angles around the seating portion 1411. In this case, the width w of the locking portion 1412 can be 3% to 15% of the length of the long side of the seating portion 1411, preferably 13%.

[0187] In another modified embodiment, such as Figure 17 As shown, the seating portion 1411 is square, and four rectangular locking portions 1412 can be respectively set at the center of each side of the seating portion 1411.

[0188] Reference Figure 10A and Figure 11 Terminal 1430 is connected to upper pad 1420. At least one groove 1432 is formed on the lower surface of terminal 1430. Groove 1432 is connected to fixing portion 1422 of upper pad 1420. The inner side of groove 1432 contacts upper surface of fixing portion 1422.

[0189] The cover assembly 1400 is assembled in such a manner that the locking portion 1412 of the base plate 1410 is connected to the lower surface of the fixing portion 1422 of the upper liner 1420, and the upper surface of the fixing portion 1422 of the upper liner 1420 is connected to the groove 1432 of the terminal 1430.

[0190] Terminal 1430 is electrically connected to electrode contacts 1220, 1230, 1240, and 1250 via current collector 1300. Terminal 1430 may have a plate shape, which may be circular or quadrilateral. Terminal 1430 may be made of the same material as housing 1100, which may be a metal such as aluminum or stainless steel.

[0191] An opening 1435 may be formed in the terminal 1430. During the assembly of the cover assembly 1400, after the base plate 1410, upper gasket 1420, and terminal 1430 are stacked in sequence, the openings of the base plate 1410, upper gasket 1420, and terminal 1430 can be aligned. The current collector protrusion 1331 of the current collector 1300 is introduced through the opening 1435. After the current collector protrusion 1331 is introduced into the opening 1435, the current collector protrusion 1331 is caulked, and the outer peripheral surface of the end of the current collector protrusion 1331 and the inner peripheral surface of the opening 1435 can be welded.

[0192] Specifically, after the upper gasket 1420 and the terminal 1430 are sequentially stacked on the base plate 1410, the current collector protrusion 1331 can pass through the space aligned with the openings of the base plate 1410, the upper gasket 1420, and the terminal 1430. (Refer to...) Figure 18A The current collector protrusion 1331 passing through the upper surface of the terminal 1430 can be crimped and soldered. Considering the width of the current collector protrusion 1331 being crimped around the opening, the diameter of the opening can be set to 70% or less of the length of the short side of the terminal 1430.

[0193] Terminal 1430 can be electrically connected to electrode contacts 1220, 1230, 1240, and 1250 via current collector 1300.

[0194] In the modified embodiment, refer to Figure 18B After the upper gasket 1420 and the terminal 1430 are sequentially assembled on the base plate 1410, the annular gasket 1440 can be inserted into the opening. The upper part of the annular gasket 1440 can contact the upper gasket 1420.

[0195] Rivet 1450 can be inserted into the opening of annular gasket 1440 and riveted to the upper part of terminal 1430. Current collector protrusion 1331 of current collector 1300 can be introduced into the opening formed by rivet 1450 and connected to terminal 1430. The outer peripheral surface of the end of current collector protrusion 1331 can be welded to the inner peripheral surface of rivet, thereby forming an electrical connection between current collector protrusion 1331 and terminal 1430 via rivet.

[0196] Terminal 1430 can be electrically connected to electrode contacts 1220, 1230, 1240, and 1250 via current collector 1300.

[0197] exist Figure 18B In the embodiment shown, the base plate, gasket, and terminals can be more firmly fixed to each other in the vertical direction, thereby significantly improving the overall assembly rigidity and structural stability of the device.

[0198] The secondary battery including the cover assembly according to the second embodiment of this disclosure will be described. Configurations identical to those of the first embodiment of this disclosure will be omitted or briefly described.

[0199] Figure 20 This is a view illustrating a cover assembly according to another embodiment of the present disclosure.

[0200] like Figure 20 As illustrated, the cover assembly 2400 may include a base plate 2410, an upper gasket 2420, and a terminal 2430.

[0201] The base plate 2410 includes a seating portion 2411 and an opening 2415. The seating portion 2411 forms a flat surface recessed downward from the upper surface of the base plate 2410. The seating portion 2411 may have a rectangular or elliptical shape. The upper surface of the seating portion 2411 contacts the lower surface of the upper liner 2420. The depth d2 of the seating portion 2411 may be 30% to 50% of the maximum thickness t2 of the base plate 2410. Meanwhile, the area of ​​a seating portion 2411 relative to the base plate 2410 may be 8% to 20%, preferably 11% to 14%.

[0202] In this embodiment, a seating portion 2411 is formed on the base plate 2410, but when two seating portions are formed on the base plate 2410, the sum of the areas of the two seating portions relative to the area of ​​the base plate 2410 can be 8% to 20%, preferably 11% to 14%.

[0203] When the seating portion 2411 is quadrilateral, the curvature of the corners of the seating portion 2411 can be 2 to 3 mm, preferably 2.5 mm. In order to increase the coefficient of friction of the surface of the seating portion 2411, silicone or the like can be coated on the surface of the seating portion 2411, or the surface roughness can be improved by surface treatment.

[0204] An opening 2415 is formed at the center of the seating portion 2411. During the assembly of the cover assembly 2400, a current collector protrusion 1331 of the current collector 1300 is introduced through the opening 2415. The area of ​​the opening 2415 can be 5% to 20% of the area of ​​the seating portion 2411. By ensuring that the current collector protrusion 1331 introduced through the opening 2415 has a sufficiently large diameter, the internal resistance can be reduced when the electricity generated in the secondary battery is output, thereby reducing heat generation.

[0205] The upper pad 2420 is seated on the seating portion 2411 of the base plate 2410. The upper pad 2420 may include a lower surface portion 2421, an upper surface portion 2422, and a rib 2423.

[0206] The lower surface portion 2421 is a flat surface and has the same profile as the seating portion 2411 of the base plate 2410. The lower surface of the lower surface portion 2421 can be configured to have the same shape and dimensions as the upper surface of the seating portion 2411, so as to conform to the shape of the upper surface of the seating portion 2411. The difference in the length of the long side between the seating portion 2411 and the lower surface portion 2421 can be within 0.05 mm.

[0207] An opening 2425 is formed at the center of the lower surface portion 2421. During the assembly of the cover assembly 2400 and the electrode assembly, the current collecting protrusion 1331 of the current collector 1300 is introduced through the opening 2425.

[0208] The upper surface portion 2422 is connected to the outer periphery of the lower surface portion 2421. The upper surface portion 2422 is connected by a sidewall extending upward from the outer periphery of the lower surface portion 2421, thereby forming a step with the lower surface portion 2421. The upper surface portion 2422 has a predetermined width and is disposed outside the lower surface portion 2421 along its edge. The lower surface of the upper surface portion 2422 contacts the upper surface of the base plate 2410.

[0209] The upper pad 2420 may be made of an insulating material. The lower surface portion 2421 is in close contact with the upper surface of the seat portion 2411, and the upper surface portion 2422 is in close contact with the upper surface of the base plate 2410, thereby insulating the terminal 2430 from the base plate 2410.

[0210] An opening 2425 is formed in the center of the lower surface portion 2421. When assembling the cover assembly 2400 and the electrode assembly, the current collection protrusion 1331 of the current collector 1300 can be inserted through the opening 2425, or an annular gasket, rivet and current collection protrusion can be inserted.

[0211] The area of ​​the upper surface portion 2422 can be 50% to 80% of the area of ​​the lower surface portion 2421. By making the upper surface portion 2422 have 50% or more of the area of ​​the lower surface portion 2421, the dimensions of the terminal 2430 can be ensured. However, when the area of ​​the upper surface portion 2422 exceeds 80% of the area of ​​the lower surface portion 2421, the area of ​​the lower surface portion 2421 may be relatively reduced, and therefore the effect of preventing component rotation may be reduced. The width of the upper surface portion 2422 can be 2 mm to 4 mm.

[0212] Rib 2423 is formed along the edge of upper surface portion 2422. Upper liner 2420 has a container shape defined by rib 2423 and upper surface portion 2422, and is configured to seat terminal 2430. Rib 2423 is formed upward from upper surface portion 2422. Rib 2423 can be in close contact with the sidewall of terminal 2430.

[0213] The thickness of rib 2423 can be from 0.5 mm to 1.2 mm. When the thickness of rib 2423 is less than 0.5 mm, the sealing effect may be reduced.

[0214] Terminal 2430 is connected to upper pad 2420. Terminal 2430 includes a protruding portion 2431 and a supporting portion 2432. The protruding portion 2431 forms the lower portion of terminal 2430. The protruding portion 2431 contacts the lower surface portion 2421 of upper pad 2420. The protrusion distance of the protruding portion 2431 may be equal to the depth of the lower surface portion 2421.

[0215] The support portion 2432 constitutes the upper portion of the terminal 2430. The support portion 2432 has a larger cross-sectional area compared to the protruding portion 2431, and its edge is supported by the upper surface portion 2422 of the upper gasket 2420 and the rib 2423. The protruding portion 2431 contacts the lower surface portion 2421 of the upper gasket 2420, and the support portion 2432 contacts the upper surface portion 2422, thereby insulating and sealing the terminal 2430. Here, the height of the rib 2423 can be 40% to 70% of the height of the support portion 2432 of the terminal. When the height of the rib 2423 is less than 40% of the height of the support portion 2432 of the terminal 2430, it is difficult to stably seal the terminal 2430.

[0216] The cover assembly 2400 is assembled in such a manner that the seating portion 2411 of the base plate 2410 is connected to the lower surface of the lower surface portion 2421 of the upper liner 2420, and the upper surface of the lower surface portion 2421 of the upper liner 2420 is connected to the protruding portion 2431 of the terminal 2430.

[0217] An opening 2435 can be formed through the protrusion 2431 and the support 2432. The current collecting protrusion 1331 is introduced through the opening 2435. After the current collecting protrusion 1331 is introduced into the opening 2435, the outer peripheral surface of the end of the current collecting protrusion 1331 and the inner peripheral surface of the opening 2435 can be welded.

[0218] Specifically, such as Figure 21AAs shown, after the upper gasket 2420 and the terminal 2430 are sequentially assembled on the base plate 2410, the current collector protrusion 1331 can pass through the space aligned by the openings of the base plate 2410, the upper gasket 2420, and the terminal 2430. The current collector protrusion 1331 passing through the upper surface of the terminal 2430 can be pressed and welded.

[0219] In modified embodiments, such as Figure 21B As shown, after the upper gasket 2420 and the terminal 2430 are sequentially assembled on the base plate 2410, the annular gasket can be inserted into the space aligned with the openings of the base plate 2410, the upper gasket 2420, and the terminal 2430. The upper part of the annular gasket 2440 can contact the upper gasket 2420.

[0220] Rivet 2450 can be inserted into the opening of annular gasket 2440 and riveted to the upper part of terminal 2430. Current collector protrusion 1331 can be inserted into the opening formed by rivet 2450 and connected to terminal 2430. The outer peripheral surface of the end of current collector protrusion 1331 can be welded to the inner peripheral surface of rivet, thereby forming an electrical connection with terminal 2430 via rivet.

[0221] Terminal 2430 is electrically connected to electrode contacts 1220, 1230, 1240 and 1250 via current collector 1300.

[0222] exist Figure 21B In the embodiment shown, the base plate, gasket, and terminals can be more firmly fixed to each other in the vertical direction, thereby significantly improving the overall assembly rigidity and structural stability of the device.

[0223] In the secondary battery according to the second embodiment of this disclosure, the upper liner 2420 of the cover assembly 2400 may include a lower surface portion 2421, an upper surface portion 2422, and a rib 2423. The lower surface portion 2421 may have an opening 2425. The upper surface portion 2422 may extend outward around the outer periphery of the lower surface portion 2421 and protrude upward relative to the lower surface portion 2421, thereby forming a step. The rib 2423 may extend upward around the outer periphery of the upper surface portion 2422.

[0224] The terminal 2430 of the cover assembly 2400 may include a lower protrusion 2431 and an upper support portion 2432. The support portion 2432 is connected to the protrusion 2431 on the upper side to form an integral terminal 2430. The terminal 2430 also has an opening 2435 extending through the protrusion 2431 and the support portion 2432.

[0225] When the cover assembly 2400 is assembled as a single unit, the lower surface portion 2421 of the upper gasket 2420 is configured to correspond in shape and size to the seating portion 2411 of the base plate 2410 to engage the seating portion 2411. The upper surface portion 2422 of the upper gasket 2420 is configured to engage the portion of the base plate 2410 located on the outer periphery of the seating portion 2411. Accordingly, the protruding portion 2431 of the terminal 2430 is configured to correspond in shape and size to the lower surface portion 2421 to engage the lower surface portion 2421, and the outer contour of the support portion 2432 corresponds to the outer contour of the upper surface portion 2422 to engage the upper surface portion 2422 and the rib 2423 extending around the outer periphery.

[0226] Therefore, in the secondary battery according to the second embodiment of the present disclosure, the upper pad 2420 is provided with an upper surface portion 2422 extending outward around the entire outer periphery of the lower surface portion, and the terminal 2430 is provided with an outer support portion 2432 that cooperates with the upper surface portion. Thus, the terminal 2430 includes not only the protruding portion 2431 located in the recessed seat portion 2411, but also the support portion 2432 located outside the seat portion 2411.

[0227] In this way, the secondary battery can significantly improve terminal conductivity and reduce current conduction resistance without increasing the overall battery volume. Specifically, the terminals of existing cover assemblies only include the portion confined within the recessed space of the base plate's mounting portion. The terminals are small in size due to the constraint of the mounting portion, resulting in high current conduction resistance. In contrast, in this application, the upper liner 2420 includes an upper surface portion 2422 that engages with the outer periphery of the mounting portion 2411 of the base plate, and the terminals include corresponding support portions 2432. This fully utilizes the unused space outside the mounting portion 2411 of the base plate. Without changing the overall dimensions of the base plate and battery casing, and without compressing the arrangement space of the internal electrode components of the battery, the conductive metal volume and effective conductive cross-sectional area of ​​the terminals are increased, effectively reducing the resistance during current conduction and improving the conductivity of the terminals, thereby enhancing the battery's charge / discharge capacity and output stability.

[0228] Furthermore, the terminals of this application include not only the protruding portion within the seating portion but also the supporting portion outside the seating portion. The protruding portion engages with the lower surface portion of the upper liner, and the supporting portion tightly engages with the upper surface portion and ribs of the upper liner, forming a large-area outer peripheral support surface. This increases the contact area and contact friction between the terminals and the upper liner, thereby further restricting the relative movement of the components of the cover assembly and effectively preventing the terminals and the upper liner from rotating relative to the base plate. Even under complex operating conditions of long-term vibration and impact, the terminals will not shift or loosen. This significantly enhances the structural stability, vibration resistance, and impact resistance of the cover assembly.

[0229] The secondary battery including the cover assembly according to the third embodiment of this disclosure will be described. Configurations identical to those in the first embodiment of this disclosure will be omitted or briefly described.

[0230] Reference Figure 22 The cover assembly 3400 includes a base plate 3410, an upper gasket 3420, and a terminal 3430.

[0231] The base plate 3410 includes a seating portion 3411 and at least one protrusion 3412. The seating portion 3411 forms a flat surface recessed downward from the upper surface of the base plate 3410. The seating portion 3411 may have a quadrilateral or circular shape. The upper surface of the seating portion 3411 contacts the lower surface of the upper pad 3420. The depth d3 of the seating portion 3411 may be 30% to 50% of the maximum thickness t3 of the base plate 3410. When the depth d3 of the seating portion 3411 is greater than 50% of the thickness t3 of the base plate 3410, the strength of the base plate 3410 may be weakened. When the depth d3 of the seating portion 3411 is less than 30% of the thickness t3 of the base plate 3410, the bonding strength with the upper pad 3420 may be weakened.

[0232] When the seating portion 3411 is quadrilateral, the curvature of the corners of the seating portion 3411 can be 2 to 3 mm, preferably 2.5 mm. In order to increase the coefficient of friction of the upper surface of the seating portion 3411, silicone or the like can be coated on the surface of the seating portion 3411, or the surface roughness can be improved by surface treatment.

[0233] Meanwhile, the area of ​​a seating portion 3411 relative to the base plate 3410 can be 8% to 20%, preferably 11% to 14%.

[0234] An opening 3415 is provided at the center of the seating portion 3411. During the assembly of the cover assembly 3400, the current collecting protrusion 1331 of the current collector 1300 is introduced through the opening 3415. The area of ​​the opening 3415 can be 5% to 20% of the area of ​​the seating portion 3411, preferably 14%. By ensuring that the current collecting protrusion 1331 introduced through the opening 3415 has a sufficiently large diameter, the internal resistance can be reduced when the electricity generated in the secondary battery is output, thereby reducing heat generation.

[0235] One or more protrusions 3412 may be provided on the seating portion 3411. The protrusions 3412 protrude from the upper surface of the seating portion 3411 at a predetermined height. The protrusions 3412 may have a circular shape, a polygonal shape, or a linear shape.

[0236] The shape of the seating portion 3411 and the shape and number of the protrusions 3412 can be selected as needed. For example, such as Figure 22As illustrated, the seating portion 3411 can have a rectangular shape. Additionally, four cylindrical protrusions 3412 can be positioned near the four corners of the seating portion 3411. When the positions of the multiple protrusions 3412 are set symmetrically about the opening 3415, there is an advantage that the orientation of the components does not need to be aligned during assembly, thus facilitating assembly.

[0237] When multiple protrusions 3412 are formed on the seating portion 3411, the total area of ​​the multiple protrusions can be 2% to 10% of the area of ​​the seating portion 3411. The upper gasket 3420 and the terminal 3430 are sequentially stacked on the seating portion 3411 of the base plate 3410. When the total area of ​​the protrusions 3412 exceeds 10%, the area of ​​the lower surface of the terminal 3430 may decrease, thereby increasing internal resistance. When the total area of ​​the protrusions 3412 is less than 2%, the effect of preventing component rotation may be reduced, which is undesirable. The area of ​​the protrusion 3412 refers to the cross-sectional area of ​​the protrusion 3412 relative to the horizontal direction, i.e., the direction parallel to the upper surface of the base plate 3410.

[0238] Furthermore, the total area of ​​the protrusion 3412 can be set to a value S in mm² corresponding to the calculation result of the following expression 2, which conforms to the proportional relationship determined by the dimensional parameters of the base plate, and this proportional relationship is expressed by the following expression 2:

[0239] [Expression 2]

[0240]

[0241] (A is the length of the base plate (mm), B is the ratio of the opening width to the width of the seating portion, C is the thickness of the base plate (mm), and N is the number of protrusions)

[0242] Expression 2 is a design expression for determining the appropriate area of ​​the protrusion based on structural parameters, rather than a conventional geometric area calculation formula.

[0243] If the base plate 3410 is long or thin, the contact area between the base plate 3410 and the upper pad 3420 in the vertical direction can be increased by increasing the area of ​​the protrusion 3412 or increasing the number of protrusions 3412. When the width of the opening 3415 is larger than the width of the sitting portion 3411, it is difficult to ensure that the sitting portion 3411 in contact with the upper pad 3420 has sufficient width. Therefore, rotation of the upper pad 3420 can be prevented by increasing the area of ​​the protrusion 3412 or increasing the number of protrusions 3412.

[0244] In another embodiment, the seating portion 3411 may have a rectangular shape, and the two protrusions 3412 may be arranged to be diagonally spaced apart from each other on the seating portion 3411. Figure 23 Alternatively, the seating portion 3411 may have a circular shape, and the two protrusions 3412 may be arranged to be spaced apart from each other on the seating portion 3411. Figure 24 Alternatively, the seating portion 3411 may have a rectangular shape, and the two linear protrusions 3412 may be arranged to be spaced apart from each other on the seating portion 3411. Figure 25 The protrusion can be one of the following shapes: cylindrical, elliptical, or quadrangular.

[0245] The upper pad 3420 sits on the sitting portion 3411 of the base plate 3410. The upper pad 3420 may include a bottom portion 3421, at least one fixing portion 3422, and a rib 3423. The bottom portion 3421 is a flat surface and has the same profile as the sitting portion 3411 of the base plate 3410. The lower surface of the bottom portion 3421 may be configured to have the same shape and size as the upper surface of the sitting portion 3411 so as to correspond to the shape of the upper surface of the sitting portion 3411.

[0246] An opening 3425 is formed at the center of the bottom portion 3421. During the assembly of the cover assembly 3400 and the electrode assembly, the current collecting protrusion 1331 of the current collector 1300 is introduced through the opening 3425.

[0247] At least one fixing portion 3422 is provided on the bottom portion 3421. The fixing portion 3422 is connected to the protrusion 3412 of the base plate 3410. In order to be connected to the protrusion 3412 protruding from the sitting portion 3411, the fixing portion 3422 is recessed towards the lower side and protrudes towards the upper side. The fixing portion 3422 may have the same shape as the protrusion 3412.

[0248] Rib 3423 is formed along the edge of the upper surface of the bottom portion 3421. Rib 3423 is in close contact with the sidewall of the seating portion 3411 to seal the base plate 3410. Upper gasket 3420 has a container shape defined by rib 3423 and bottom portion 3421 and is configured to seat terminal 3430. Rib 3423 is formed upward from bottom portion 3421 and has a height greater than the depth of seating portion 3411.

[0249] Additionally, the height of rib 3423 can be 30% to 80% of the terminal height, preferably 20%. When the height of rib 3423 is less than 30% of the terminal height, it is difficult to stably seal the terminal 3430. The thickness of rib 3423 can be 0.5 mm to 1.2 mm. When the thickness of rib 3423 is less than 0.5 mm, the sealing effect may be reduced.

[0250] The upper gasket 3420 may be made of insulating material. The terminal 3430 and the base plate 3410 are insulated from each other by the upper gasket 3420.

[0251] Terminal 3430 is connected to upper gasket 3420. At least one groove 3432 is formed on the lower surface 3431 of terminal 3430. Groove 3432 is connected to fixing portion 3422 of upper gasket 3420. The inner side of groove 3432 contacts upper surface of fixing portion 3422. Cover assembly 3400 is assembled by connecting protrusion 3412 of base plate 3410 to lower surface of fixing portion 3422 of upper gasket 3420, and connecting upper surface of fixing portion 3422 of upper gasket 3420 to groove 3432 of terminal 3430. Protrusion 3412, fixing portion 3422 and groove 3432 can be provided in the same number and can be provided in corresponding positions.

[0252] An opening 3435 may be formed in the terminal 3430. During the assembly of the cover assembly 3400, the current collector protrusion 1331 of the current collector 1300 is introduced through the opening 3435. After the current collector protrusion 1331 is introduced into the opening 3435, the outer peripheral surface of the end of the current collector protrusion 1331 and the inner peripheral surface of the opening 3435 may be welded.

[0253] Specifically, after the upper gasket 3420 and the terminal 3430 are sequentially stacked on the base plate 3410, the current collecting protrusion 1331 can pass through the space aligned with the openings of the base plate 3410, the upper gasket 3420, and the terminal 3430. (Refer to...) Figure 26A The current collection protrusion 1331 passing through the upper surface of terminal 3430 can be pressed and soldered.

[0254] In the modified embodiment, refer to Figure 26B After the upper gasket 3420 and the terminal 3430 are sequentially assembled on the base plate 3410, the annular gasket 3440 can be introduced into the space aligned by the openings of the base plate 3410, the upper gasket 3420, and the terminal 3430. The upper part of the annular gasket can contact the upper gasket 3420.

[0255] Rivet 3450 can be inserted into the opening of annular gasket 3440 and riveted to the upper part of terminal 3430. Current collector protrusion 1331 can be introduced into the opening formed by the rivet and connected to terminal 3430. The outer peripheral surface of the end of current collector protrusion 1331 can be welded to the inner peripheral surface of rivet 3450, thereby forming an electrical connection with terminal 3430 via rivet.

[0256] Terminal 3430 is electrically connected to electrode contacts 1220, 1230, 1240 and 1250 via current collector 1300.

[0257] In the embodiment shown in Figure 26B, the base plate, gasket, and terminals are more firmly fixed to each other in the vertical direction, thereby significantly improving the overall assembly rigidity and structural stability of the device.

[0258] Figure 27 This is a diagram illustrating a secondary battery including a cover assembly according to a modified embodiment of the first embodiment of the present disclosure. Figure 28 This is a diagram illustrating a cover assembly according to a modified embodiment of the first embodiment of the present disclosure. Figure 29A and Figure 29B This diagram illustrates the assembly state of the cover assembly and the current collector, including a modified embodiment of the first embodiment according to the present disclosure.

[0259] like Figure 27 and Figure 28 As shown, in one embodiment of the secondary battery according to this disclosure, a cover assembly 1400 having two electrode terminals 1430, 1430' can be disposed at one end of a housing 1100. The housing 1100 has an opening formed at one end, and a cover assembly 1400 is connected to the housing 1100 to seal the opening.

[0260] Two seating portions 1411 and 1411' formed on the base plate 1410 are respectively joined with upper gaskets 1420 and 1420' and terminals 1430 and 1430', thereby forming a cover assembly 1400. When the upper gaskets 1420 and terminals 1430 are sequentially joined to the seating portions 1411 of the base plate 1410, and the upper gaskets 1420' and terminals 1430' are sequentially joined to the seating portions 1411', the openings of the base plate 1410, upper gaskets 1420, and terminals 1430 can be aligned, and the openings of the base plate 1410, upper gaskets 1420, and terminals 1430' can also be aligned. The current collecting protrusion 1331 can pass through the space where the openings of the base plate 1410, upper gaskets 1420, and terminals 1430 are aligned.

[0261] like Figure 29AAs shown, the current collector protrusion 1331 that penetrates the opening can be riveted and welded to the upper surface of the terminal 1430. Considering the width of the current collector protrusion 1331 being riveted around the opening, the diameter of the opening can be set to less than 70% of the short side length of the terminal 1430.

[0262] In modified embodiments, such as Figure 29B As described above, after the upper gasket 1420 and the terminal 1430 are sequentially assembled on the base plate 1410, the annular gasket 1440 can be introduced into the space formed by the openings of the base plate 1410, the upper gasket 1420, and the terminal 1430. The upper part of the annular gasket 1440 can contact the upper gasket 1420.

[0263] Rivet 1450 can be inserted into the opening of annular gasket 1440 and riveted to the upper part of terminal 1430. Current collector protrusion 1331 can be introduced into the opening formed by rivet 1450 and connected to the terminal. The outer peripheral surface of the end of current collector protrusion 1331 can be welded to the inner peripheral surface of rivet, thereby forming an electrical connection with terminal 1430 via rivet.

[0264] Figure 30 This is a flowchart illustrating a method for manufacturing a secondary battery according to one embodiment of the present disclosure. Figure 31 This is a view illustrating a state in which a plurality of first electrode contacts and a plurality of second electrode contacts are respectively grouped in a secondary battery according to one embodiment of the present disclosure. Figure 32 This is a view illustrating the state in which a current collector is disposed between a plurality of first electrode contacts and a plurality of second electrode contacts in a secondary battery according to one embodiment of the present disclosure. Figure 33 This is a view illustrating the state in which the current collector is welded to the first electrode contact and the second electrode contact in a secondary battery according to one embodiment of the present disclosure, and Figure 34 This is a view illustrating the state in which the cover assembly is connected to the electrode assembly in a secondary battery according to one embodiment of the present disclosure.

[0265] like Figure 30 As illustrated, in order to manufacture a secondary battery according to one embodiment of the present disclosure, an electrode assembly is prepared (S5100). The electrode assembly 1200 includes an electrode portion 1210, a plurality of first electrode contacts 1220 and a plurality of second electrode contacts 1230 formed at one end of the electrode portion.

[0266] A plurality of first electrode tabs 1220 and a plurality of second electrode tabs 1230 are disposed at one end of the electrode portion 1210. When multiple electrode components forming the electrode portion are stacked, the plurality of first electrode tabs 1220 overlap each other at a first position, and the plurality of second electrode tabs 1230 overlap each other at a second position. That is, the plurality of first electrode tabs 1220 are grouped at the first position, and the plurality of second electrode tabs 1230 are grouped at the second position. The first and second positions are spaced apart from each other on the electrode components, and the grouped plurality of first electrode tabs 1220 and the grouped plurality of second electrode tabs 1230 may be spaced apart from each other in the width and length directions of the electrode assembly 1200. Figure 31 As illustrated, a group of multiple first electrode contacts 1220 can be disposed at one end in the width direction of the electrode assembly, and a group of multiple second electrode contacts 1230 can be disposed at the other end in the width direction of the electrode assembly 1200.

[0267] Next, a plurality of first electrode contacts 1220 are welded together, and a plurality of second electrode contacts 1230 are welded together (S5200). The plurality of first electrode contacts 1220 and the plurality of second electrode contacts 1230 are aligned to be spaced apart from each other in the length direction of the electrode assembly 1200. The grouped and aligned plurality of electrode contacts are welded together in one step, such that the first electrode contacts 1220 are welded together and the second electrode contacts 1230 are welded together.

[0268] After the current collector 1300 is positioned between a plurality of first electrode contacts 1220 and a plurality of second electrode contacts 1230 that are welded together in one step, the plurality of first electrode contacts 1220 and the plurality of second electrode contacts 1230 are welded to the current collector 1300 (S5300). In order to connect the plurality of electrode contacts 1220 and 1230 to the current collector 1300, in this embodiment, the electrode contacts 1220 and 1230 having the same polarity are divided into two groups and welded to the current collector 1300.

[0269] At one end of the electrode portion 1210, a space is formed between a plurality of first electrode contacts 1220 and a plurality of second electrode contacts 1230 that are welded together in one step. To facilitate the installation of the current collector 1300, the welded plurality of first electrode contacts 1220 and the welded plurality of second electrode contacts 1230 can be bent toward the outside of the electrode assembly 1200, respectively. The current collector 1300 is placed between the first electrode contacts 1220 and the second electrode contacts 1230, and the first electrode contacts 1220 and the second electrode contacts 1230 are bent toward the upper surface of the current collector 1300, respectively. The plurality of first electrode contacts 1220 are bent onto the upper surface of the first current collecting portion 1310 of the current collector 1300, and the plurality of second electrode contacts 1230 are bent onto the upper surface of the second current collecting portion 1320 of the current collector 1300. The plurality of first electrode contacts 1220 and the plurality of second electrode contacts 1230 are bent in opposite directions.

[0270] The current collector 1300 and the first electrode contact 1220 and the second electrode contact 1230 placed on the current collector 1300 are welded together. Figure 24 Multiple first electrode contacts 1220 are welded to a first current collector 1310, and multiple second electrode contacts 1230 are welded to a second current collector 1320. Welding can be performed on the upper portions of the multiple first electrode contacts 1220 and the multiple second electrode contacts 1230. Welding can be performed using methods such as ultrasonic welding or laser welding.

[0271] During welding, welding can be performed at the first current collection portion 1310 of the current collector 1300 from a plurality of first electrode contacts 1220 toward the first current collection portion 1310, and welding can be performed at the second current collection portion 1320 of the current collector 1300 from a plurality of second electrode contacts 1230 toward the second current collection portion 1320.

[0272] In this embodiment, multiple electrode contacts are welded together in one operation, such that the first electrode contacts 1220 are welded together and the second electrode contacts 1230 are welded together and then welded to the current collector 1300. However, in another embodiment, the multiple electrode contacts 1220 and 1230 can be directly bent and welded to the current collector 1300 without performing a single welding operation.

[0273] The electrode assembly 1200 to which the current collector 1300 is welded is housed in the housing 1100, and the cover assembly 1400 seals the opening of the housing 1100 to be assembled (S5400).

[0274] After inserting the current collecting protrusion 1331 into the opening 1435 of the terminal 1430 of the cover assembly 1400, the outer peripheral surface of the end of the current collecting protrusion 1331 and the inner peripheral surface of the end of the opening 1435 are welded together (S5500).

[0275] When the current collector is welded to the upper portion of the electrode tabs, the thickness of the current collector needs to be reduced to transfer heat to the electrode tabs located on the lower side, which leads to a deterioration in durability. However, according to this disclosure, bending and welding multiple electrode tabs to the current collector ensures the thickness of the current collector and allows the electrode tabs to be welded to the current collector more effectively.

[0276] Furthermore, according to this disclosure, multiple electrode contacts with the same polarity are divided into two groups and welded together, so that the electrode contacts can be stably welded without any unwelded portions.

[0277] According to this disclosure, since the electrode contacts are positioned on the current collector 1300 and welding is performed on the upper portion of the electrode contacts, the thickness of the current collector can be increased without worrying about damaging the separators provided in the electrode section. Therefore, the durability of the secondary battery can also be improved.

[0278] Furthermore, according to this embodiment, a battery module can be constructed by including multiple secondary batteries. Multiple secondary batteries can be connected to each other via busbars or the like to form a battery module. Additionally, a battery pack can be constructed by including multiple battery modules. A battery pack can be constructed by arranging multiple battery modules in an upper housing and a lower housing that constitute the pack housing. Moreover, the battery pack can provide a vehicle for moving luggage or people, or for performing work while moving. Such a vehicle can include bicycles, heavy equipment, agricultural and fishing equipment, automobiles, buses, and aircraft. Here, the automobile can be an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. The automobile can include a four-wheeled vehicle or a two-wheeled vehicle. The vehicle can be operated by power supplied by the battery pack.

[0279] According to one embodiment of this disclosure, a secondary battery, a battery module including the secondary battery, a battery pack, and a vehicle can prevent the electrode assembly from being affected when electrode tabs are soldered to the current collector.

[0280] Furthermore, according to one embodiment of this disclosure, a secondary battery, a battery module including the secondary battery, a battery pack, and a vehicle can stably weld a large number of electrode contacts to the current collector when welding electrode contacts to the current collector.

[0281] Furthermore, according to one embodiment of this disclosure, a secondary battery, a battery module including the secondary battery, a battery pack, and a vehicle can prevent component rotation while simplifying the assembly process of the cover assembly.

[0282] Although this disclosure has been described with respect 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 appended claims.

Claims

1. A secondary battery, comprising: An electrode assembly, comprising an electrode portion and an electrode contact; A battery housing having an open upper end and housing the electrode assembly within the battery housing; as well as A cover assembly, the cover assembly being coupled to the upper end of the battery housing. The cover assembly includes: A base plate, the base plate including a seating portion and at least one locking portion, wherein an opening is formed in the seating portion; An upper pad, disposed in the seating portion of the base plate, the upper pad comprising: a bottom portion having an opening formed therein; a fixing portion disposed on at least one side of the bottom portion and connected to the locking portion; and a rib formed along an edge of the upper surface of the bottom portion; and A terminal is disposed on the upper surface of the upper liner, the terminal having at least one groove formed in the lower surface of the terminal and having an opening formed in the terminal.

2. The secondary battery according to claim 1, wherein, The seated portion has a quadrilateral or circular shape.

3. The secondary battery according to claim 1, wherein, The depth of the seated portion is 30% to 50% of the thickness of the base plate.

4. The secondary battery according to claim 1, wherein, The area of ​​the opening in the base plate is 5% to 20% of the area of ​​the seating portion.

5. The secondary battery according to claim 1, wherein, The unit is provided with two locking parts, and the two locking parts are respectively located at opposite ends of the seated part.

6. The secondary battery according to claim 1, wherein, The locking portion has a quadrilateral or semi-circular shape.

7. The secondary battery according to claim 1, wherein, The total area of ​​the locking portions is 1% to 10% of the area of ​​the seating portions.

8. The secondary battery according to claim 1, wherein, The length of the locking portion is 10% to 80% of the length of the short side of the seating portion.

9. The secondary battery according to claim 1, wherein, The width of the locking portion is 3% to 10% of the length of the long side of the seating portion.

10. The secondary battery according to claim 1, characterized in that, The total area of ​​the locking parts is set to a value in mm² corresponding to the calculation result of the following expression 1: Expression 1 Wherein, A is the length of the base plate (mm), B is the ratio of the width of the opening of the seating portion to the width of the seating portion, C is the thickness of the base plate (mm), and N is the number of locking portions.

11. The secondary battery according to claim 1, wherein, The fixing part is convex on the upper surface of the upper pad and concave on the lower surface of the upper pad.

12. The secondary battery according to claim 1, wherein, The height of the rib is 30% to 80% of the height of the terminal.

13. The secondary battery according to claim 1, wherein, The thickness of the rib is 0.5 mm to 1.2 mm.

14. The secondary battery according to claim 1, wherein, The electrode assembly includes a plurality of electrode tabs formed at one end of the electrode portion, and the secondary battery also includes a current collector welded to the plurality of electrode tabs.

15. The secondary battery according to claim 14, wherein, The plurality of electrode contacts include a plurality of first electrode contacts located at a first position and a plurality of second electrode contacts located at a second position. The plurality of first electrode contacts and the plurality of second electrode contacts have the same polarity and are spaced apart from each other in the width and length directions of the electrode assembly.

16. The secondary battery according to claim 15, wherein, The plurality of first electrode contacts and second electrode contacts are disposed on the upper side of the current collector.

17. A secondary battery, comprising: An electrode assembly, the electrode assembly including an electrode portion and a plurality of electrode tabs formed at one end of the electrode portion; A battery housing having an open upper end and housing the electrode assembly within the battery housing; as well as A cover assembly, the cover assembly being coupled to the upper end of the battery housing. The cover assembly includes: A base plate, the base plate including a seating portion having an opening formed therein; Upper pad, the upper pad being disposed in the seating portion of the base plate, the upper pad comprising: a lower surface portion having an opening formed therein; an upper surface portion extending outwardly around the outer periphery of the lower surface portion and projecting upward relative to the lower surface portion, thereby forming a step; and a rib formed along the edge of the upper surface portion; and A terminal, wherein the terminal is disposed on the upper liner, the terminal including a protrusion formed on the underside of the terminal and having an opening formed in the terminal.

18. The secondary battery according to claim 17, wherein, The terminal also includes a support portion connected to the protruding portion on the upper side of the protruding portion, the cross-sectional area of ​​the support portion being larger than the cross-sectional area of ​​the protruding portion.

19. The secondary battery according to claim 18, wherein, The lower surface portion is configured to correspond to the shape and size of the seat portion to engage the seat portion, and the upper surface portion is configured to engage the portion of the base plate located on the outer periphery of the seat portion.

20. The secondary battery according to claim 19, wherein, The protruding portion is configured to correspond to the shape and size of the lower surface portion to engage the lower surface portion, and the outer contour of the support portion corresponds to the outer contour of the upper surface portion to engage the upper surface portion and the rib.

21. The secondary battery according to claim 17, wherein, The seated portion has a rectangular or elliptical shape.

22. The secondary battery according to claim 17, wherein, The depth of the seated portion is 30% to 50% of the thickness of the base plate.

23. The secondary battery according to claim 17, wherein, The area of ​​the opening in the base plate is 5% to 20% of the area of ​​the seating portion.

24. The secondary battery according to claim 17, wherein, The area of ​​the upper surface portion is 50% to 80% of the area of ​​the lower surface portion.

25. The secondary battery according to claim 17, wherein, The width of the upper surface portion is 2 mm to 4 mm.

26. The secondary battery according to claim 17, wherein, The lower surface portion has the same contour as the seated portion.

27. The secondary battery according to claim 17, wherein, The height of the protruding portion is equal to the depth of the lower surface portion.

28. A secondary battery, comprising: An electrode assembly, comprising an electrode portion and an electrode contact; A battery housing having an open upper end and housing the electrode assembly within the battery housing; as well as A cover assembly, the cover assembly being coupled to the upper end of the battery housing. The cover assembly includes: A base plate, the base plate including a sitting portion and at least one protrusion, wherein an opening is formed in the sitting portion; An upper pad, disposed in the seating portion of the base plate, the upper pad comprising: a bottom portion having an opening formed therein; at least one fixing portion disposed on the bottom portion and connected to the protrusion; and a rib formed along an edge of the upper surface of the bottom portion; and A terminal is disposed on the upper surface of the upper liner, the terminal having at least one groove formed in the lower surface of the terminal and having an opening formed in the terminal.

29. The secondary battery according to claim 28, wherein, The depth of the seated portion is 30% to 50% of the thickness of the base plate.

30. The secondary battery according to claim 28, wherein, The area of ​​the opening in the base plate is 5% to 20% of the area of ​​the seating portion.

31. The secondary battery according to claim 28, wherein, The seated portion has a circular shape.

32. The secondary battery according to claim 28, wherein, The seated portion has a quadrilateral shape.

33. The secondary battery according to claim 32, wherein, The seat portion has two protrusions, and each of the two protrusions is located on a diagonal line of the seat portion.

34. The secondary battery according to claim 32, wherein, The unit is provided with four protrusions, and the four protrusions are respectively located at the corners of the seat portion.

35. The secondary battery according to claim 32, wherein, The sum of the areas of the plurality of protrusions is 2% to 10% of the area of ​​the seated portion.

36. The secondary battery according to claim 28, characterized in that, The total area of ​​the protrusions is set to a value in mm² corresponding to the calculation result of the following expression 2: Expression 2 Wherein, A is the length of the base plate (mm), B is the ratio of the width of the opening of the sitting portion to the width of the sitting portion, C is the thickness of the base plate (mm), and N is the number of protrusions.

37. The secondary battery according to claim 32, wherein, Each of the protrusions has a shape selected from the group consisting of: cylindrical shape, elliptical cylindrical shape, and quadrangular prism shape.

38. The secondary battery according to claim 28, wherein, The fixing part is convex on the upper surface of the upper pad and concave on the lower surface of the upper pad.

39. The secondary battery according to claim 32, wherein, The protrusions, the fixing portions, and the grooves are arranged in the same number.

40. The secondary battery according to any one of claims 1, 17, and 28, wherein, The area of ​​the seating portion is 8% to 20% of the area of ​​the base plate.

41. The secondary battery according to any one of claims 1, 17, and 28, wherein, The openings of the base plate, the upper gasket, and the terminal are aligned to form a through hole.

42. The secondary battery according to claim 41, wherein, The secondary battery also includes a current collector, which is welded to the electrode tabs of the electrode assembly. The current collector includes a current collecting protrusion, which is inserted into the through hole.

43. The secondary battery according to claim 42, wherein, At the end of the current collector protrusion, the current collector protrusion is welded to the terminal.

44. The secondary battery according to claim 41, wherein, The cover assembly further includes: an annular gasket inserted into an opening in the base plate and in contact with the upper gasket; and a rivet passing through the annular gasket and inserted into an opening in the terminal.

45. The secondary battery according to claim 44, wherein, The secondary battery also includes a current collector, which is welded to the electrode tabs of the electrode assembly. The current collector includes a current collecting protrusion, which is inserted into the through hole and the current collecting protrusion is inserted into the rivet.

46. ​​The secondary battery according to claim 45, wherein, At the end of the current collector protrusion, the current collector protrusion is welded to the rivet, thereby forming an electrical connection between the current collector protrusion and the terminal via the rivet.

Images