Secondary battery

Abstract

The present invention relates to a secondary battery in which the total resistance of the secondary battery is reduced and the space utilization is improved, and in which an electrolyte can be easily injected. The secondary battery according to an embodiment of the present invention includes a cover assembly for sealing an opening of a case into which an electrode assembly has been inserted. The cover assembly includes a cover plate, an insulating plate, an upper gasket, and an electrode terminal. A through-hole is formed in the cover plate. The insulating plate is disposed below the cover plate, and the upper gasket is disposed above the cover plate. The electrode terminal is inserted into the through-hole. An upper end portion of the electrode terminal is bent to an upper portion of the upper gasket, and a lower end portion of the electrode terminal is bent to a lower portion of the insulating plate, so that the upper gasket and the insulating plate are fixed to the cover plate.

Description

Technical Field

[0001] This disclosure relates to secondary batteries. Background Technology

[0002] Secondary batteries, which are highly adaptable to different product groups and have electrical characteristics such as high energy density, are typically used not only in portable devices, but also in electric vehicles (EVs) and hybrid electric vehicles (HEVs) powered by electric drive sources.

[0003] Such secondary batteries not only have the major advantage of significantly reducing the use of fossil fuels, but also the advantage of not producing byproducts from the use of energy. Therefore, such secondary batteries are attracting attention as a new energy source for improving environmental friendliness and energy efficiency.

[0004] Currently, widely used types of secondary batteries include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. The operating voltage of these single-cell secondary batteries ranges from approximately 2.5 V to 4.5 V.

[0005] 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 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.

[0006] In a prismatic secondary battery, the electrode assembly is housed in a box made of metal, and a cover is attached to the open end.

[0007] In related technologies, the cover component uses rivets to connect the electrode terminals and the cover plate, which increases the number of components and thus the total resistance of the secondary battery, and also leads to a reduction in space utilization due to the rivets.

[0008] In addition, in the case of prismatic batteries, an electrolyte injection port is provided, and when the electrolyte injection port is blocked by foreign objects or internal components, problems such as reduced electrolyte injection rate or electrolyte backflow may occur. Summary of the Invention Technical issues

[0009] The present disclosure aims to provide a secondary battery that can reduce the total resistance of the secondary battery, improve space utilization, and facilitate the injection of electrolyte. Technical solution

[0010] A secondary battery according to an embodiment of the present disclosure may include a cover assembly configured to seal an opening in a housing into which an electrode assembly is inserted. The cover assembly may include a cover plate, an insulating plate, an upper gasket, and electrode terminals. A through-hole may be formed in the cover plate. The insulating plate may be disposed below the cover plate, and the upper gasket may be disposed on the cover plate. The electrode terminals may be inserted into the through-hole. The upper end of the electrode terminal may be bent onto the upper portion of the upper gasket, and the lower end of the electrode terminal may be bent onto the lower portion of the insulating plate, thereby securing the upper gasket and the insulating plate to the cover plate.

[0011] A secondary battery according to an embodiment of the present disclosure may include a current collector comprising a current collector plate electrically connected to an electrode assembly and a current collector protrusion projecting from the current collector plate. The current collector protrusion may be inserted into an insertion hole formed in an electrode terminal, and the current collector protrusion may be welded to the upper end of the electrode terminal.

[0012] In a secondary battery according to an embodiment of the present disclosure, the electrode terminals may include a body portion, a first bent portion, and a second bent portion. The body portion can be inserted into a through hole and has an insertion hole at the center of the body portion into which a current-collecting protrusion is inserted. The first bent portion can be bent from the upper end of the body portion to the upper portion of the upper liner. The second bent portion can be bent from the lower end of the body portion to the lower portion of the insulating plate.

[0013] In a secondary battery according to an embodiment of the present disclosure, the first bending portion may include: a lower surface formed in the lower portion of the first bending portion; an outer stepped surface formed on the outer side of the lower surface; and an outer surface formed in a vertical direction at the end of the outer stepped surface.

[0014] In a secondary battery according to an embodiment of the present disclosure, the upper liner may be placed between the cover plate and the first bent portion.

[0015] In a secondary battery according to an embodiment of the present disclosure, the cover plate may include: a seating surface formed around a through hole; and a stepped surface formed to protrude from the outer side of the seating surface. The upper liner may include a first horizontal surface, a second horizontal surface, and a vertical surface. The first horizontal surface may have a first thickness and is formed to contact the seating surface of the cover plate. The second horizontal surface may have a second thickness greater than the first thickness and is formed to contact the seating surface and the stepped surface. The vertical surface may extend vertically from the outer end of the second horizontal surface and surround the outer surface of the first bent portion.

[0016] The secondary battery according to embodiments of the present disclosure may include a sealing gasket disposed between a through-hole and a body portion, and the sealing gasket is configured to insulate the cover plate from the electrode terminals and prevent electrolyte or gas inside the casing from leaking to the outside.

[0017] In a secondary battery according to an embodiment of the present disclosure, a first alignment protrusion extending from the through hole may be formed on the lower surface of the cover plate adjacent to the through hole. A first alignment groove may be formed in the sealing gasket at a position corresponding to the first alignment protrusion.

[0018] In the secondary battery according to the embodiments of the present disclosure, a second alignment protrusion may be formed on the upper surface of the second bent portion, and a second alignment groove may be formed on the lower surface of the sealing gasket at a position corresponding to the second alignment protrusion.

[0019] In the secondary battery according to the embodiments of the present disclosure, a fitting groove can be formed on the inner peripheral surface of the insertion hole. The fitting groove has an inclined shape with a narrower upper side and a wider lower side. A fitting protrusion can be formed on the outer peripheral surface of the current collecting protrusion, and the fitting protrusion is fitted into the fitting groove.

[0020] In the secondary battery according to an embodiment of the present disclosure, an undercut may be formed on the lower end of the body portion, and an inclined surface may be formed on the lower end of the current collecting protrusion, the inclined surface having a shape corresponding to the undercut.

[0021] In a secondary battery according to an embodiment of the present disclosure, a current collector protrusion may be formed at the center of the upper surface of the current collector plate, and an adhesive layer including a thermal fusion layer may be formed on opposite sides of the upper surface of the current collector plate.

[0022] The secondary battery according to embodiments of the present disclosure may include an insulator disposed between a cover plate and an electrode assembly and having an insulating plate provided thereon. The insulator may include: a guide hole positioned below an electrolyte injection hole formed in the cover plate; and a guide portion projecting downward from the guide hole and configured to guide the movement of the electrolyte.

[0023] In a secondary battery according to an embodiment of the present disclosure, the guiding portion may include: a support rod positioned in the lower portion of the guiding hole and configured to partially block the guiding hole; and an internal hole formed in the support rod and allowing fluid to move through the internal hole.

[0024] In a secondary battery according to an embodiment of the present disclosure, the internal hole may face the electrolyte injection hole and may be positioned at the center in the longitudinal direction of the guide portion.

[0025] In a secondary battery according to an embodiment of the present disclosure, the guiding portion may include a guiding edge and a support rod. The guiding edge may surround the lower portion of the guiding hole, the support rod may be fixed to the guiding edge, and a first opening and a second opening may be formed between the side edge of the support rod and the inner wall of the guiding edge.

[0026] In the secondary battery according to an embodiment of the present disclosure, an exhaust portion configured for venting gas can be formed in the cover plate. Here, the insulator may include the exhaust portion, which protrudes toward the bottom of the casing and has multiple exhaust openings. The exhaust portion may be positioned below the exhaust portion.

[0027] In a secondary battery according to an embodiment of the present disclosure, the electrode assembly may include an electrode portion and a plurality of foil tabs formed on the electrode portion. The plurality of foil tabs may be formed in one direction of the electrode assembly.

[0028] In a secondary battery according to an embodiment of the present disclosure, the electrode assembly may include an electrode portion and a plurality of foil tabs formed on the electrode portion. The plurality of foil tabs may be formed in opposite directions of the electrode assembly.

[0029] In the secondary battery according to an embodiment of the present disclosure, after the electrode assembly and the current collector are connected to each other, a first insulating tape can be attached to the current collector. After the outer surface of the electrode assembly is wrapped with a second insulating tape, the electrode assembly can be inserted into the housing. The outer surface of the housing with the inserted electrode assembly can be wrapped with a third insulating tape. Beneficial effects

[0030] According to this disclosure, electrode terminals with riveted structures can be provided, thereby reducing the number of components, thus lowering the total resistance of the secondary battery and improving space utilization. Sealing functionality can be enhanced, thereby preventing electrolyte leakage. Furthermore, a guide portion for injecting electrolyte can be formed around the electrolyte injection hole, thereby facilitating electrolyte injection. Attached Figure Description

[0031] Figure 1 This is a perspective view illustrating a secondary battery according to an embodiment of the present disclosure.

[0032] Figure 2 It is along Figure 1 The cross-sectional view taken from line AA.

[0033] Figure 3 This is an exploded perspective view of a secondary battery according to an embodiment of the present disclosure.

[0034] Figure 4This is a perspective view of an electrode assembly in a secondary battery according to an embodiment of the present disclosure, wherein a plurality of first foil tabs and a plurality of second foil tabs are formed on the electrode portion.

[0035] Figure 5a and Figure 5b This is a view illustrating the first electrode plate and the second electrode plate in a secondary battery according to an embodiment of the present disclosure.

[0036] Figure 6 This is an exploded perspective view of a secondary battery according to another embodiment of the present disclosure.

[0037] Figure 7 This is a perspective view of an electrode assembly in a secondary battery according to another embodiment of the present disclosure, in which a plurality of first foil tabs and a plurality of second foil tabs are formed on the electrode portion.

[0038] Figure 8a , Figure 8b , Figure 9a and Figure 9b This is a view illustrating the first electrode plate and the second electrode plate in a secondary battery according to an embodiment of the present disclosure.

[0039] Figure 10 This is a perspective view of a cover assembly according to a first embodiment of the present disclosure.

[0040] Figure 11 This is a cross-sectional view of a cover assembly according to a first embodiment of the present disclosure.

[0041] Figure 12 This is a cross-sectional view of the cover assembly according to the second embodiment of the present disclosure.

[0042] Figure 13 This is a cross-sectional view of the cover assembly according to the third embodiment of the present disclosure.

[0043] Figure 14 This is a cross-sectional view of the cover assembly according to the fourth embodiment of the present disclosure.

[0044] Figure 15 This is a view illustrating the process of forming electrode terminals in a cover assembly according to an embodiment of the present disclosure.

[0045] Figure 16 This is a top perspective view of the insulator of a secondary battery according to an embodiment of the present disclosure.

[0046] Figure 17 This is a bottom perspective view of the insulator of a secondary battery according to an embodiment of the present disclosure.

[0047] Figure 18This is a bottom view illustrating the insulator of a secondary battery according to an embodiment of the present disclosure.

[0048] Figure 19 The diagram shows a partial cross-sectional view of the cover plate and the insulator.

[0049] Figure 20 It is a cross-sectional perspective view of the guiding part of the insulator.

[0050] Figure 21 It is a cross-sectional view showing the discharge section of the insulator.

[0051] Figure 22 This is a view illustrating the process of connecting foil contacts and a current collector in a secondary battery according to an embodiment of the present disclosure.

[0052] Figure 23 This is a view illustrating the process of connecting the cover component and the current collector in a secondary battery according to an embodiment of the present disclosure.

[0053] Figure 24 This is a view illustrating the process of connecting a current collector and foil tabs in a secondary battery according to an embodiment of the present disclosure, where the foil tabs are formed in opposite directions.

[0054] Figure 25 This is a view illustrating the process of connecting the cover component to the collector.

[0055] Figure 26 This is a view illustrating the process of connecting foil contacts and a current collector in a secondary battery according to another embodiment of the present disclosure.

[0056] Figure 27 This is a view illustrating the process of connecting the cover component and the current collector in a secondary battery according to another embodiment of the present disclosure.

[0057] Figure 28 This is a view illustrating the process of connecting a current collector and foil tabs in a secondary battery according to another embodiment of the present disclosure, where the foil tabs are formed in opposite directions.

[0058] Figure 29 This is a view illustrating the process of connecting the cover component to the collector.

[0059] Figure 30 This is a view illustrating the process of attaching insulating tape to interconnected electrode assemblies and current collectors.

[0060] Figure 31 This is a view illustrating a secondary battery including two electrode portions according to another embodiment of the present disclosure.

[0061] Figure 32This is a view illustrating a configuration according to another embodiment of the present disclosure, in which foil tabs formed on two electrode portions are coupled to a current collector. Detailed Implementation

[0062] Because this disclosure can be modified in various forms and can have various implementations, specific implementations will be illustrated and described in detail with reference to the accompanying 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.

[0063] 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,” “having,” etc., as used in this specification, are intended to specify the presence of the stated features, integrals, steps, operations, elements, components, and / or combinations thereof, but do not preclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or combinations thereof.

[0064] In the following, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. It should be noted that throughout the accompanying drawings, the same reference numerals refer to the same elements. To avoid unnecessarily obscuring the spirit of the disclosure, details of well-known configurations and functions may be omitted. For the same reason, some elements in the accompanying drawings are enlarged, omitted, or depicted schematically.

[0065] Figure 1 This is a perspective view illustrating a secondary battery according to an embodiment of the present disclosure. Figure 2 It is along Figure 1 The cross-sectional view taken from line AA. Figure 3 This is an exploded perspective view of a secondary battery according to an embodiment of the present disclosure. Figure 4 This is a perspective view of an electrode assembly in a secondary battery according to an embodiment of the present disclosure, wherein a plurality of first foil tabs and a plurality of second foil tabs are formed on the electrode portion. Figure 5a and Figure 5b This is a view illustrating the first electrode plate and the second electrode plate in a secondary battery according to an embodiment of the present disclosure.

[0066] like Figures 1 to 5b As illustrated, the secondary battery 1000 according to an embodiment of the present disclosure includes a housing 1100, an electrode assembly 1200, a current collector 1300, a cover component 1400, and an insulator 1500.

[0067] The housing 1100 forms the external shape of the secondary battery 1000. The housing 1100 may define a space capable of housing the electrode assembly 1200 therein, and the housing 1100 may have an opening on one of its surfaces. In this embodiment, the housing 1100 has a cuboid shape, but is not limited thereto and can be modified in various ways. The housing 1100 may be made of a rigid material capable of protecting the electrode assembly 1200 housed within the housing 1100. For example, the housing 1100 may be made of a metal such as aluminum or stainless steel.

[0068] The electrolyte can be housed together with the electrode assembly 1200 in a cartridge 1100. The electrolyte may include lithium salts such as LiPF6 or LiBF4 in organic solvents such as ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), or dimethyl carbonate (DMC). The electrolyte may be a liquid phase, a solid phase, or a gel phase.

[0069] The electrode assembly 1200 is housed in the housing 1100. For example... Figure 4 As illustrated, the electrode assembly 1200 includes an electrode portion 1210, a plurality of first foil tabs 1220, and a plurality of second foil tabs 1230. The plurality of first foil tabs 1220 and the plurality of second foil tabs 1230 are disposed on one end of the electrode portion 1210. In another embodiment, the first foil tabs 1220 may be disposed on one side surface of the electrode portion 1210, and the second foil tabs 1230 may be disposed on the other side surface of the electrode portion 1210. The plurality of first foil tabs 1220 are aligned with each other in the first foil tabs 1220, and the plurality of second foil tabs 1230 are aligned with each other in the second foil tabs 1230.

[0070] The electrode portion 1210 includes a plurality of first electrode plates 1211, a plurality of second electrode plates 1212, and spacers 1213.

[0071] Active materials can be applied to multiple first electrode plates 1211 and multiple second electrode plates 1212. The multiple first electrode plates 1211 can each be formed by applying an active material, such as a transition metal oxide, to a metal plate, such as an aluminum plate. The multiple first electrode plates 1211 can be positive electrode plates. The multiple second electrode plates 1212 can each be formed by applying an active material, such as graphite or carbon, to a metal plate, such as a copper plate or a nickel plate. The multiple second electrode plates 1212 can be negative electrode plates.

[0072] Spacer 1213 is positioned between a plurality of first electrode plates 1211 and a plurality of second electrode plates 1212 to prevent short circuits between the plurality of first electrode plates 1211 and the plurality of second electrode plates 1212. Spacer 1213 may be made of polyethylene, polypropylene, or composite materials thereof.

[0073] The electrode portion 1210 can be formed by positioning the spacer 1213 between the first electrode plate 1211 and the second electrode plate 1212 arranged in sequence. In other words, in an embodiment, the electrode portion 1210 can be formed by stacking the first electrode plate 1211, the spacer 1213, the second electrode plate 1212 and the spacer 1213 in the listed order dozens to hundreds of times.

[0074] Although in this embodiment the electrode assembly 1200 includes a single electrode portion 1210, 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.

[0075] Unapplied foil tabs 1220 and 1230 are formed on one end of a plurality of first electrode plates 1211 and a plurality of second electrode plates 1212, respectively. In an embodiment, each of the electrode plates 1211 and 1212 and the corresponding foil tab 1220 or 1230 can be integrally formed by cutting a predetermined portion of a single metal plate using a laser or the like, such that the electrode plate 1211 or 1212 and the foil tab 1220 or 1230 are retained. The plurality of foil tabs 1220 and 1230 can be formed in a direction toward the cover member 1400.

[0076] When multiple first electrode plates 1211 and multiple second electrode plates 1212 are stacked, multiple first foil tabs 1220 overlap each other at a first position. Multiple second foil tabs 1230 overlap each other at a second position. In other words, multiple first foil tabs 1220 having the same polarity are grouped at the first position, and multiple second foil tabs 1230 are grouped at the second position. The first and second positions are spaced apart from each other on the electrode plates, and the grouped multiple first foil tabs 1220 and multiple second foil tabs 1230 can be spaced apart from each other in the longitudinal direction of the electrode assembly 1200.

[0077] Multiple foil tabs 1220 and 1230 overlapping at corresponding positions can be connected to the corresponding current collectors by ultrasonic welding, laser welding, etc., in order to promote the movement of current.

[0078] Each collector in collector 1300 includes a collector plate 1310 and a collector protrusion 1320.

[0079] Multiple foil tabs 1220 and 1230 are bent and welded to corresponding manifolds 1310. A manifold protrusion 1320 is formed on the central portion of the manifold 1310.

[0080] The current collector protrusion 1320 protrudes upward from the upper surface of the current collector plate 1310 and connects to the terminal hole 1421 of the corresponding electrode terminal 1420 to electrically connect the electrode assembly 1200a and the electrode terminal 1420.

[0081] The current collector 1300 can be made of the same material as the plurality of foil tabs 1220 and 1230. An insulating material can be disposed below the current collector 1300, and the insulating material can be an insulating film.

[0082] After multiple first foil tabs 1220 are welded together and multiple second foil tabs 1230 are welded together, current collectors 1300 are respectively disposed on the first foil tabs 1220 and the second foil tabs 1230.

[0083] After bending multiple first foil tabs 1220 and multiple second foil tabs 1230, the current collector 1300 is welded to the multiple first foil tabs 1220 and multiple second foil tabs 1230. Methods such as ultrasonic welding and laser welding can be used for welding.

[0084] The cover component 1400 may include a cover plate 1410, an electrode terminal 1420, an electrolyte injection port 1430, and an exhaust portion 1440.

[0085] The cover 1410 has a plate shape that covers the opening of the box 1100, and the cover 1410 includes at least one through hole 1410a. The shape of the cover 1410 may correspond to the shape of the opening of the box 1100. The cover 1410 may be made of the same material as the box 1100 and may be fixed to the box 1100 by a method such as laser welding.

[0086] Electrolyte injection port 1430 and venting portion 1440 can be formed in cover plate 1410.

[0087] Electrolyte can be injected into cartridge 1100 through electrolyte injection port 1430. Venting section 1440 opens when the internal pressure of cartridge 1100 exceeds a reference value.

[0088] Electrode terminal 1420 can be connected to cover plate 1410. Electrode terminal 1420 is electrically connected to foil tabs 1220 and 1230 via current collector 1300. Electrode terminal 1420 can each have a circular plate shape or a rectangular plate shape.

[0089] An insulator 1500 is disposed between the cover component 1400 and the electrode assembly 1200 to insulate the cover component 1400 from the electrode assembly 1200.

[0090] Figure 6 This is an exploded perspective view of a secondary battery according to another embodiment of the present disclosure. Figure 7This is a perspective view of an electrode assembly in a secondary battery according to another embodiment of the present disclosure, in which a plurality of first foil tabs and a plurality of second foil tabs are formed on the electrode portion. Figure 8a , Figure 8b , Figure 9a and Figure 9b This is a view illustrating the first electrode plate and the second electrode plate in a secondary battery according to an embodiment of the present disclosure.

[0091] like Figures 6 to 9b As illustrated, a secondary battery 1000a according to another embodiment of this disclosure includes a housing 1100, an electrode assembly 1200a, a current collector 1300a, a cover member 1400, and an insulator 1500. Compared with the secondary battery of the aforementioned embodiment, the configuration is substantially the same except for the structures of the electrode assembly 1200a and the current collector 1300a, and therefore their repeated description will be omitted.

[0092] like Figure 7 As illustrated, the electrode assembly 1200a includes an electrode portion 1210a, a plurality of first-1 foil tabs 1220a, a plurality of first-2 foil tabs 1220b, a plurality of second-1 foil tabs 1230a, and a plurality of second-2 foil tabs 1230b. The plurality of foil tabs 1220a to 1230b are disposed on one end of the electrode portion 1210a. The plurality of first-1 foil tabs 1220a are aligned with each other in the first-1 foil tabs 1220a, and the plurality of first-2 foil tabs 1220b are aligned with each other in the first-2 foil tabs 1220b. The plurality of second-1 foil tabs 1230a are aligned with each other in the second-1 foil tabs 1230a, and the plurality of second-2 foil tabs 1230b are aligned with each other in the second-2 foil tabs 1230b. The multiple foil tabs 1220a to 1230b, which are aligned respectively, are arranged so that they do not overlap in the width and longitudinal directions of the electrode assembly 1200a.

[0093] like Figure 8a , Figure 8b , Figure 9a and Figure 9b As illustrated, the electrode portion 1210a includes a plurality of first_1 electrode plates 1211a, a plurality of first_2 electrode plates 1211b, a plurality of second_1 electrode plates 1212a, a plurality of second_2 electrode plates 1212b, and a spacer 1213.

[0094] Active materials can be applied to multiple first-1 electrode plates 1211a, multiple first-2 electrode plates 1211b, multiple second-1 electrode plates 1212a, and multiple second-2 electrode plates 1212b. The multiple first-1 electrode plates 1211a and multiple first-2 electrode plates 1211b can each be formed by applying an active material, such as a transition metal oxide, to a metal plate, such as an aluminum plate. The multiple first-1 electrode plates 1211a and multiple first-2 electrode plates 1211b can have the same polarity and can be positive electrode plates. The multiple second-1 electrode plates 1212a and multiple second-2 electrode plates 1212b can each be formed by applying an active material, such as graphite or carbon, to a metal plate, such as a copper plate or a nickel plate. The multiple second-1 electrode plates 1212a and multiple second-2 electrode plates 1212b can have the same polarity and can be negative electrode plates.

[0095] Spacer 1213 is positioned between multiple electrode plates 1211a to 1212b to prevent short circuits between the multiple electrode plates 1211a to 1212b.

[0096] The electrode portion 1210a can be formed by positioning the spacer 1213 between the first _1 electrode plate 1211a and the second _1 electrode plate 1212a arranged in sequence, and between the first _2 electrode plate 1211b and the second _2 electrode plate 1212b arranged in sequence.

[0097] Although electrode assembly 1200a includes a single electrode portion 1210a, in another embodiment, electrode assembly 1200a may include multiple electrode portions 1210a. The multiple electrode portions 1210a may be electrically connected to each other.

[0098] Unapplied foil tabs 1220a, 1220b, 1230a, and 1230b are formed on one end of a plurality of electrode plates 1211a to 1212b. In an embodiment, each of the electrode plates 1211a to 1212b and the corresponding foil tab 1220a, 1220b, 1230a, or 1230b can be integrally formed by cutting a predetermined portion of a single metal plate using a laser or the like, such that the electrode plates 1211a to 1212b and the foil tabs 1220a, 1220b, 1230a, and 1230b are retained. The plurality of foil tabs 1220a, 1220b, 1230a, and 1230b can be formed in a direction toward the cover member 1400.

[0099] First 1 foil tabs 1220a are formed at a first position in each first 1 electrode plate 1211a. First 2 foil tabs 1220b are formed at a second position in each first 2 electrode plate 1211b. Similarly, second 1 foil tabs 1230a are formed at a third position in each second 1 electrode plate 1212a, and second 2 foil tabs 1230b may be formed at a fourth position in each second 2 electrode plate 1212b.

[0100] Multiple first electrode plates 1211a and multiple second electrode plates 1212a can be stacked alternately with a spacer 1213 placed between the multiple first electrode plates 1211a and the multiple second electrode plates 1212a. The stack of multiple first electrode plates 1211a and multiple second electrode plates 1212a forms half of the electrode portion 1210a.

[0101] Multiple first-second electrode plates 1211b and multiple second-second electrode plates 1212b can be stacked alternately with spacers 1213 placed between them. The stack of multiple first-second electrode plates 1211b and multiple second-second electrode plates 1212b forms the remaining half of electrode portion 1210a.

[0102] Stacks of multiple first-1 electrode plates 1211a and multiple second-1 electrode plates 1212a, as well as stacks of multiple first-2 electrode plates 1211b and multiple second-2 electrode plates 1212b, are connected in the width direction of the electrode portion 1210a. When forming the electrode assembly 1200a, after the multiple first-1 electrode plates 1211a and multiple second-1 electrode plates 1212a are stacked, the multiple first-2 electrode plates 1211b and multiple second-2 electrode plates 1212b can be stacked.

[0103] When multiple electrode plates 1211a to 1212b are stacked, multiple first-1 foil tabs 1220a overlap each other at a first position. Multiple first-2 foil tabs 1220b overlap each other at a second position. In other words, among the multiple first-1 foil tabs 1220a and multiple first-2 foil tabs 1220b having the same polarity, the multiple first-1 foil tabs 1220a are grouped at the first position and the multiple first-2 foil tabs 1220b are grouped at the second position. The first position and the second position are spaced apart from each other on the electrode plates. The grouped multiple first-1 foil tabs 1220a and multiple first-2 foil tabs 1220b may be spaced apart from each other in the width direction and the longitudinal direction of the electrode assembly 1200a.

[0104] To enable stable soldering of a large number of foil tabs, foil tabs of the same polarity are divided into two groups that are spaced apart and aligned, and each group is soldered onto a corresponding current collector. In other words, although a single foil tab is formed on each electrode plate, by changing the position of the foil tabs formed on the respective electrode plates, two groups of foil tabs with the same polarity but different positions are formed after stacking the electrode plates. In another embodiment, two or more foil tabs can be formed at different positions on the same polarity side.

[0105] When multiple electrode plates 1211a to 1212b are stacked, multiple second-1 foil tabs 1230a overlap each other at a third position, and multiple second-2 foil tabs 1230b overlap each other at a fourth position. In other words, multiple second-1 foil tabs 1230a are grouped at the third position, and multiple second-2 foil tabs 1230b are grouped at the fourth position. The third and fourth positions are spaced apart from each other on the electrode plates, and the grouped multiple second-1 foil tabs 1230a and multiple second-2 foil tabs 1230b can be spaced apart from each other in the width and longitudinal directions of the electrode assembly 1200a.

[0106] The plurality of second_1 foil tabs 1230a and the plurality of second_2 foil tabs 1230b are foil tabs having the same polarity.

[0107] Multiple foil tabs 1220a, 1220b, 1230a and 1230b overlapping at corresponding positions can be connected to the current collector by ultrasonic welding, laser welding or other methods to facilitate the movement of current.

[0108] Each collector in collector 1300a includes a collector plate 1310a and a collector protrusion 1320.

[0109] The current collector 1310a includes a first current collection area 1311, a second current collection area 1312, and a connection area 1313.

[0110] Multiple first-1 foil tabs 1220a are bent and soldered to a first current collection area 1311. Multiple first-2 foil tabs 1220b are soldered to a second current collection area 1312. A connection area 1313 is located between the first current collection area 1311 and the second current collection area 1312, and is provided with a current collection protrusion 1320.

[0111] The first current collection region 1311 and the second current collection region 1312 are spaced apart in the longitudinal direction by a connecting region 1313. Since the first current collection region 1311 and the second current collection region 1312 are spaced apart from each other, the plurality of first_1 foil tabs 1220a and the plurality of first_2 foil tabs 1220b will not interfere with each other when they are soldered to the first current collection region 1311 and the second current collection region 1312.

[0112] The current collector protrusion 1320 protrudes upward from the upper surface of the connection area 1313 and connects to the terminal hole 1421 of the corresponding electrode terminal 1420 to electrically connect the electrode assembly 1200a and the electrode terminal 1420.

[0113] After multiple first-1 foil tabs 1220a are soldered to each other and multiple first-2 foil tabs 1220b are soldered to each other, a corresponding current collector 1310a can be disposed in the space between the first-1 foil tabs 1220a and the first-2 foil tabs 1220b. Here, the current collector 1310a is disposed on some of the first-1 foil tabs 1220a and some of the first-2 foil tabs 1220b.

[0114] After the current collector 1310a is disposed on the upper portion of the electrode portion 1210a, a plurality of first-1 foil tabs 1220a are bent toward the first current collection region 1311, and a plurality of first-2 foil tabs 1220b are bent toward the second current collection region 1312. In other words, the plurality of first-1 foil tabs 1220a and the plurality of first-2 foil tabs 1220b are bent in opposite directions to each other.

[0115] After bending multiple first-1 foil tabs 1220a and multiple first-2 foil tabs 1220b, welding is performed on the multiple first-1 foil tabs 1220a and multiple first-2 foil tabs 1220b. Methods such as ultrasonic welding and laser welding can be used for welding.

[0116] During welding, welding can be performed from multiple first-1 foil tabs 1220a toward the first current collection area 1311 of the current collector plate 1310a, and welding can be performed from multiple first-2 foil tabs 1220b toward the second current collection area 1312 of the current collector plate. To facilitate the fixing and welding of the foil tabs, multiple fine grooves or fine protrusions can be formed on the upper surface of the current collector plate 1310a.

[0117] exist Figure 1 In the secondary battery according to the embodiment of the present disclosure illustrated in FIG. 9, the current collector 1300, the cover component 1400, and the insulator 1500 can be combined to form a cover assembly (see FIG. 9). Figure 2 (The attached figure is labeled CA).

[0118] Figure 10 This is a perspective view of a cover assembly according to a first embodiment of the present disclosure. Figure 11 This is a cross-sectional view of a cover assembly according to a first embodiment of the present disclosure.

[0119] like Figure 10 and Figure 11 As illustrated, the cover assembly CA1 according to the first embodiment of the present disclosure may include a cover plate 1410, an electrode terminal 1420, an insulating plate 1510, a sealing gasket 1450, and an upper gasket 1460.

[0120] The cover 1410 has a plate shape that covers the opening of the box 1100, and the cover 1410 includes at least one through hole 1410a. The cover 1410 may have a shape corresponding to the shape of the opening of the box 1100, and the cover 1410 may be made of the same material as the box 1100.

[0121] Additionally, the cover plate 1410 includes a seating surface 1411 and a stepped surface 1412. The seating surface 1411 is formed around the through hole 1410a. The stepped surface 1412 is formed to protrude from the outer side of the seating surface 1411 by a predetermined height. A first horizontal surface 1461 and a second horizontal surface 1462 of the upper liner 1460 are disposed on the seating surface 1411. A vertical surface 1463 of the upper liner 1460 is disposed on the stepped surface 1412.

[0122] Additionally, on the lower surface of the cover plate 1410, adjacent to the through hole 1410a, a first alignment protrusion 1413 is formed, extending from the through hole 1410a. The first alignment protrusion 1413 is fitted into a first alignment groove 1451 formed in the sealing gasket 1450 to aid in the alignment between the cover plate 1410 and the sealing gasket 1450.

[0123] Electrode terminal 1420 can be inserted into and connected to the through hole 1410a of cover plate 1410. Electrode terminal 1420 is electrically connected to foil tab 1220 or 1230 through corresponding current collector 1300. Electrode terminal 1420 can have a circular plate shape or a rectangular plate shape.

[0124] An insertion hole 1420a is formed at the center of the electrode terminal 1420. The upper end of the electrode terminal 1420 is bent onto the upper portion of the upper liner 1460, and the lower end of the electrode terminal 1420 is bent onto the lower portion of the insulating plate 1510, thereby serving as a riveting member to fix the upper liner 1460, the cover plate 1410 and the insulating plate 1510 in place.

[0125] Specifically, the electrode terminal 1420 includes a body portion 1421, a first bent portion 1422, and a second bent portion 1423.

[0126] The body portion 1421 is the part that is inserted into the through hole 1410a, and is formed along the height direction (z direction), and an insertion hole 1420a is formed at the center of the body portion 1421. The current collecting protrusion 1320 is inserted into the insertion hole 1420a.

[0127] The first bending portion 1422 bends horizontally (xy direction) from the upper end of the body portion 1421 to the upper portion of the upper pad 1460. The first bending portion 1422 includes: a lower surface 1422a formed at the lower side of the first bending portion 1422; an outer stepped surface 1422b formed on the outer side of the lower surface 1422a; and an outer surface 1422c formed vertically at the end of the outer stepped surface 1422b. The lower surface 1422a contacts the first horizontal surface 1461 of the upper pad 1460, the outer stepped surface 1422b contacts the second horizontal surface 1462, and the outer surface 1422c is surrounded by the vertical surface 1462.

[0128] The second bent portion 1423 bends horizontally (xy direction) from the lower end of the body portion 1421 onto the lower portion of the insulating plate 1510. A second alignment protrusion 1423a is formed on the upper surface of the second bent portion 1423. The second alignment protrusion 1423a fits into a second alignment groove 1452 formed on the lower surface of the sealing gasket 1450 to aid in the alignment between the second bent portion 1423 and the sealing gasket 1450.

[0129] The first bend 1422 has a larger longitudinal (y-direction) dimension and a larger height (z-direction) dimension than the second bend 1423.

[0130] An insulating plate 1510 is disposed below the cover plate 1410 and above the second bent portion 1423 to insulate the cover plate 1410 from the electrode terminal 1420.

[0131] A sealing gasket 1450 is positioned between the through-hole 1410a and the body portion 1421 to insulate the cover plate 1410 from the electrode terminal 1420, thereby preventing electrolyte or gas leakage from the casing 1100 to the outside and preventing moisture or air from the outside from penetrating into the interior of the casing 1100. Here, the upper end of the sealing gasket 1450 extends to contact the first horizontal surface 1461 of the upper gasket 1460, and the lower end of the sealing gasket 1450 extends horizontally while contacting the upper surface of the first bent portion 1423. Additionally, a first alignment groove 1451 is formed in the sealing gasket 1450 at a position corresponding to the first alignment protrusion 1413, and a second alignment groove 1452 is formed in the lower surface of the sealing gasket 1450 at a position corresponding to the second alignment protrusion 1423a.

[0132] The upper liner 1460 is placed between the cover plate 1410 and the first bent portion 1422 to prevent electrolytes or gases inside the box 1100 from leaking to the outside and to prevent moisture or air from the outside from penetrating into the inside of the box 1100.

[0133] The upper gasket 1460 includes a first horizontal surface 1461, a second horizontal surface 1462, and a vertical surface 1463. The first horizontal surface 1461 has a first thickness and forms a seating surface 1411 that contacts the cover plate 1410 and the upper end of the sealing gasket 1450. The second horizontal surface 1462 has a second thickness greater than the first thickness and forms a contact seating surface 1411 and a stepped surface 1412. The vertical surface 1463 extends vertically from the outer end of the second horizontal surface 1462 to surround the outer surface of the first bent portion 1422.

[0134] The upper surface of the current collector protrusion 1320 inserted into the insertion hole 1420a and the upper surface of the electrode terminal 1420 can be connected to each other by welding.

[0135] The cover assembly CA1 according to the first embodiment of the present disclosure, having the above configuration, includes electrode terminals 1420 with a riveted structure, thereby reducing the number of parts and thus reducing the total resistance of the secondary battery and improving space utilization, and enhancing the sealing function to prevent electrolyte leakage.

[0136] Figure 12 This is a cross-sectional view of the cover assembly according to the second embodiment of the present disclosure.

[0137] like Figure 12As illustrated, the cover assembly CA2 according to the second embodiment of this disclosure may include a cover plate 1410, electrode terminals 1420, an insulating plate 1510, a sealing gasket 1450, and an upper gasket 1460. Except for the shape of the body portion 1421 of the electrode terminals and the shape of the current collecting protrusion 1320, the remaining configuration is substantially the same as that of the first embodiment described above, and therefore its repeated description will be omitted.

[0138] In the second embodiment, a fitting groove 1421a is formed in the inner peripheral surface of the insertion hole 1420a formed at the center of the body portion 1421, and a fitting protrusion 1321 to be fitted into the fitting groove 1421a can be formed on the outer peripheral surface of the collecting protrusion 1320.

[0139] The mounting groove 1421a can be formed in an inclined shape, with a narrower upper portion and a wider lower portion, such that its width decreases from the lower portion of the body portion 1421 toward its upper portion. Additionally, the mounting protrusion 1321 can be formed in a shape corresponding to the mounting groove 1421a.

[0140] After the current collector protrusion 1320 of the current collector 1300 is inserted into the insertion hole 1420a, welding can be performed on the upper surface of the electrode terminal 1420 to connect the electrode terminal 1420 and the current collector protrusion 1320.

[0141] Here, since the welding is performed with the mounting protrusion 1321 of the current collector protrusion 1320 fastened to the mounting groove 1421a of the body portion 1421 in a mounting manner, the connection force between the current collector 1300 and the electrode terminal 1420 can be improved.

[0142] In addition, since the fitting protrusion 1321 and the fitting groove 1421a are formed into an inclined shape with a narrower upper side and a wider lower side, when the collecting protrusion 1320 is fitted into the insertion hole 1420a, the friction caused by the fitting protrusion 1321 with the insertion hole 1420a can be minimized, and the fitting operation can be facilitated.

[0143] Figure 13 This is a cross-sectional view of the cover assembly according to the third embodiment of the present disclosure.

[0144] like Figure 13 As illustrated, the cover assembly CA3 according to the third embodiment of this disclosure may include a cover plate 1410, electrode terminals 1420, an insulating plate 1510, a sealing gasket 1450, and an upper gasket 1460. Except for the shape of the body portion 1421 of the electrode terminals and the shape of the current collecting protrusion 1320, the remaining configuration is substantially the same as that of the first embodiment described above, and therefore its repeated description will be omitted.

[0145] In the third embodiment, an undercut 1421b with a triangular cross-section is formed on the lower end of the body portion 1421. An inclined surface 1322 may be formed on the lower end of the flow collecting protrusion 1320, and the inclined surface 1322 has a shape corresponding to the undercut 1421b.

[0146] During the manufacture of the secondary battery, when the current collector protrusion 1320 is inserted into the insertion hole 1420a, the undercut 1421b located at the lower end of the body portion 1421 ensures sufficient insertion margin, thereby facilitating the insertion process.

[0147] After insertion, while the undercut 1421b and the inclined surface 1322 remain in close contact with each other, welding can be performed on the upper surface of the electrode terminal 1420, thereby connecting the electrode terminal 1420 to the current collector protrusion 1320.

[0148] Figure 14 This is a cross-sectional view of the cover assembly according to the fourth embodiment of the present disclosure.

[0149] like Figure 14 As illustrated, the cover assembly CA4 according to the fourth embodiment of this disclosure may include a cover plate 1410, electrode terminals 1420, an insulating plate 1510, a sealing gasket 1450, and an upper gasket 1460. Except for the structure of the current collector 1300, the remaining configuration is substantially the same as that of the first embodiment described above, and therefore its repeated description will be omitted.

[0150] In the fourth embodiment, the collector 1300 includes a collector plate 1310, a collector protrusion 1320, and an adhesive layer 1330. The collector plate 1310 and the collector protrusion 1320 are substantially the same as those in the first embodiment described above, and therefore their repeated description will be omitted.

[0151] A current collector protrusion 1320 is formed at the center of the upper surface of the current collector plate 1310. An adhesive layer 1330 is formed on opposite sides of the upper surface of the current collector plate 1310. The adhesive layer 1330 includes a conductive layer 1331 and a heat-fused layer 1332 formed on the upper and lower surfaces of the conductive layer 1331.

[0152] The thermal fusion layer 1332 comprises a thermoplastic resin that melts by heat. The thermal fusion layer 1332 is formed on the upper and lower surfaces of the conductive layer 1331 and melts and solidifies by heat, such that the current collector 1310 and the second bent portion 1423 of the electrode terminal 1420 are bonded together by thermal fusion on the upper and lower surfaces of the conductive layer 1331.

[0153] Modified polyolefin resins can be used as the heat-fusion layer 1432, and preferably copolymers of ethylene or propylene with monomers having polar groups can be used. Examples include ethylene / acrylic acid copolymers, ethylene / methacrylic acid copolymers, ethylene / ethyl acrylate copolymers, ethylene / butyl acrylate copolymers, ethylene / vinyl acetate copolymers, ethylene / itaconic acid copolymers, ethylene / monomethyl maleate copolymers, ethylene / maleic acid copolymers, ethylene / acrylic acid / methyl methacrylate copolymers, ethylene / methacrylic acid / ethyl acrylate copolymers, ethylene / monomethyl maleate / ethyl acrylate copolymers, ethylene / methacrylic acid / vinyl acetate copolymers, ethylene / acrylic acid / vinyl alcohol copolymers, ethylene / propylene / acrylic acid copolymers, ethylene / styrene / acrylic acid copolymers, ethylene / methacrylic acid / acrylonitrile copolymers, ethylene / fumaric acid / vinyl methyl ether copolymers, ethylene / vinyl chloride / acrylic acid copolymers, ethylene / vinylidene chloride / acrylic acid copolymers, ethylene / trifluoroethylene chloride / methacrylic acid copolymers, ethylene / sodium methacrylate copolymers, ethylene / zinc acrylate copolymers, ethylene / sodium styrene sulfonate copolymers, and styrene-ethylene-propylene copolymers. Propylene / acrylic acid copolymer, propylene / methacrylic acid copolymer, propylene / vinyl acetate copolymer, propylene / butyl acrylate copolymer, propylene / vinyl acetate copolymer, propylene / itaconic acid copolymer, propylene / monomethyl maleic acid copolymer, propylene / maleic acid copolymer, propylene / acrylic acid / methyl methacrylate copolymer, propylene / methacrylic acid / ethyl acrylic acid copolymer, propylene / monomethyl maleate / ethyl acrylic acid copolymer, propylene / methacrylic acid / vinyl acetate copolymer, propylene / acrylic acid / vinyl alcohol copolymer, propylene / propylene / acrylic acid copolymer, propylene / styrene / acrylic acid copolymer, propylene / methacrylic acid / acrylonitrile copolymer, propylene / fumaric acid / vinyl methyl ether copolymer, propylene / vinyl chloride / acrylic acid copolymer, propylene / vinylidene chloride / acrylic acid copolymer, propylene / trifluoroethylene chloride / methacrylic acid copolymer, propylene / sodium methacrylate copolymer, propylene / zinc acrylate copolymer, propylene / sodium styrene sulfonate copolymer, and styrene-propylene-propylene copolymer. Other examples include substituted polyolefin resins, such as maleic anhydride-grafted polyethylene or polypropylene, such as maleic anhydride-grafted high-density polyethylene (m-HDPE), maleic anhydride-grafted polypropylene (m-PP), maleic anhydride-grafted polyethylene / propylene copolymer (m-cpp), chlorinated polyethylene, polypropylene (CM), and chlorosulfonated polyethylene or polypropylene (CSM).

[0154] During the manufacture of the secondary battery, after the current collector protrusion 1320 is inserted into the insertion hole 1420a, and before the electrode terminal 1420 and the current collector protrusion 1320 are joined by welding, heat can be applied to the cover assembly CA4 so that the current collector plate 1310 and the second bent portion 1423 are joined by thermal fusion, thereby improving the connection force between the current collector 1300 and the electrode terminal 1420.

[0155] Figure 15 This is a view illustrating the process of forming electrode terminals in a cover assembly according to an embodiment of the present disclosure.

[0156] First, after setting the cover plate 1410, insulating plate 1510, sealing gasket 1450, and upper gasket 1460, the electrode terminal 1420b with an µ-shaped hollow structure is inserted into the sealing gasket 1450. The lower horizontal portion of the electrode terminal 1420b forms a second bent portion 1423, and the hollow structure of the electrode terminal 1420b forms an insertion hole 1420a.

[0157] Next, the electrode terminal 1420b is pressed from above to bend it horizontally. The upper portion of the bent electrode terminal 1420b is placed on the upper portion of the upper pad 1460, thus forming the first bent portion 1422.

[0158] Figure 16 This is a top perspective view of the insulator of a secondary battery according to an embodiment of the present disclosure. Figure 17 This is a bottom perspective view of the insulator of a secondary battery according to an embodiment of the present disclosure. Figure 18 This is a bottom view illustrating the insulator of a secondary battery according to an embodiment of the present disclosure. Figure 19 The diagram shows a partial cross-sectional view of the cover plate and the insulator. Figure 20 It is a cross-sectional perspective view of the guiding part of the insulator.

[0159] like Figures 16 to 20 As illustrated, an insulator 1500 is disposed between the cover plate 1410 and the electrode assembly 1200 to insulate the cover plate 1410 from the electrode assembly 1200. The insulator 1500 can be formed to correspond to the shape of the cover plate 1410 and can be formed to be in the shape of an elongated rectangular plate. The upper insulator 1500 is configured to face the cover plate 1410 and can be configured to be parallel to the cover plate 1410.

[0160] The insulator 1500 may include an insulating plate 1510 in the shape of a rectangular plate and two support protrusions 1520 that protrude downward toward the box 1100 from opposite edges of the insulating plate 1510 in the longitudinal direction (y-axis direction).

[0161] An insertion hole 1530 may be formed in the insulating plate 1510, into which the body portion 1421 of the electrode terminal 1420 and the sealing gasket 1450 are inserted.

[0162] In addition, the insulator 1500 may include: a guide hole 1511 located below the electrolyte injection hole 1430; a guide portion 1540 protruding downward from the guide hole 1511; and a discharge portion 1550 located below the exhaust portion 1440.

[0163] The guiding portion 1540 may include: a guiding edge 1541 surrounding the lower portion of the guiding hole 1511; a support rod 1542 positioned below the guiding hole 1511 to partially block it; and an internal hole 1543 formed in the support rod 1542 to allow fluid movement. The guiding edge 1541 may be annular, and the support rod 1542 may be linear. The support rod 1542 may be fixed to the lower end of the guiding edge 1541 and may extend in the diametrical direction of the guiding hole 1511.

[0164] The internal hole 1543 can be located at the center in the longitudinal direction of the support rod 1542 and can be formed facing the electrolyte injection hole 1430. The diameter D3 of the internal hole 1543 is smaller than the diameter D1 of the electrolyte injection hole 1430. The internal hole 1543 can be positioned inside the lower region corresponding to the electrolyte injection hole 1430.

[0165] The diameter D2 of the guide hole 1511 can be larger than the diameter D1 of the electrolyte injection hole 1430. The width W1 of the support rod 1542 can be 0.2 to 0.6 times the diameter D2 of the guide hole 1511. However, the width W1 of the support rod 1542 can be larger than the diameter D1 of the electrolyte injection hole 1430 and can be 1.1 to 1.5 times the diameter D1 of the electrolyte injection hole 1430.

[0166] A first opening 1544 and a second opening 1545 may be formed between the side edge of the support rod 1542 and the inner wall of the guide edge 1541. The first opening 1544 and the second opening 1545 may open downward and may be spaced apart from each other, wherein the support rod 1542 is positioned between the first opening 1544 and the second opening 1545.

[0167] The insulator 1500 is positioned below the cover plate 1410. With the cover plate 1410 connected to the housing 1100, electrolyte is injected through the electrolyte injection hole 1430. The presence of a guide hole 1511 and a guide portion 1540 with a guide edge 1541 and a support rod 1542 in the insulator 1500 prevents the electrolyte injection hole 1430 from being blocked by the lower structure and facilitates electrolyte injection.

[0168] In particular, since the internal hole 1543 is located directly below the electrolyte injection hole 1430, the electrolyte can move into the box 1100 through the internal hole 1543. This not only prevents electrolyte backflow, but also allows the electrolyte to be injected into the box 1100 through the first opening 1544 and the second opening 1545 formed on opposite sides of the support rod 1542 in the event that the internal hole 1543 is blocked or a large amount of electrolyte is supplied.

[0169] Figure 21 It is a cross-sectional view showing the discharge section of the insulator.

[0170] like Figure 16 and Figure 21 As illustrated, the exhaust portion 1550 is positioned below the exhaust portion 1440 and has multiple exhaust openings. The exhaust portion 1550 may include: a support frame 1512, which projects downward and is formed in a ring shape; and multiple partition rods 1554, which are fixed to the support frame 1512 and extend in the width direction (x-axis direction) of the insulator 1500. A first exhaust opening 1551 is formed at the center of the exhaust portion 1550. A second exhaust opening 1552 and a third exhaust opening 1553 may be formed on opposite sides of the first exhaust opening 1551. The first exhaust opening 1551 has a larger cross-sectional area than each of the second exhaust opening 1552 and the third exhaust opening 1553.

[0171] Therefore, with the discharge section 1550 formed in the insulator 1500, as the internal pressure of the box 1100 increases, the exhaust element 1441 can rupture under a preset pressure, thereby allowing the gas inside the box 1100 to be easily discharged.

[0172] Figure 22 This is a view illustrating the process of connecting foil contacts and a current collector in a secondary battery according to an embodiment of the present disclosure. Figure 23 This is a view illustrating the process of connecting the cover assembly and the current collector in a secondary battery according to an embodiment of the present disclosure.

[0173] like Figure 22 and Figure 23As illustrated, foil tabs 1220 and 1230 are soldered to current collector 1300. Foil tabs 1220 and 1230 can be soldered to the underside of current collector 1300. Current collector 1300 can be mounted on the positive and negative terminals, respectively. After foil tabs 1220 and 1230 are soldered to current collector 1300, current collector 1300 and cover component 1400 can be connected to each other.

[0174] Figure 24 This is a view illustrating the process of connecting a current collector and foil tabs in a secondary battery according to an embodiment of the present disclosure, where the foil tabs are formed in opposite directions. Figure 25 This is a view illustrating the process of connecting the cover assembly to the collector.

[0175] exist Figure 22 and Figure 23 In this configuration, both the foil contacts on the positive electrode and the foil contacts on the negative electrode are formed in the same direction. However, as... Figure 24 and Figure 25 As illustrated, the electrode assembly can be configured such that the foil tabs on the positive electrode and the foil tabs on the negative electrode are formed in different directions. Therefore, the current collector 1300 can also be connected to the opposite side surface of the electrode assembly 1200.

[0176] Figure 26 This is a view illustrating the process of connecting foil contacts and a current collector in a secondary battery according to another embodiment of the present disclosure. Figure 27 This is a view illustrating the process of connecting the cover component and the current collector in a secondary battery according to another embodiment of the present disclosure.

[0177] like Figure 26 and Figure 27 As illustrated, foil tabs 1220a, 1220b, 1230a, and 1230b are soldered to current collector 1300. Foil tabs 1220a and 1220b, or foil tabs 1230a and 1230b, are positioned from different directions on a corresponding current collector 1300 based on current collector protrusions 1320. Foil tabs 1220a, 1220b, 1230a, and 1230b can be positioned to avoid interference with each other. Current collector 1300 can be mounted on the positive and negative terminals respectively. Here, insulating material can be positioned below each current collector so that the current collectors are insulated from the electrode assemblies.

[0178] Figure 28 This is a view illustrating the process of connecting a current collector and foil tabs in a secondary battery according to another embodiment of the present disclosure, where the foil tabs are formed in opposite directions. Figure 29 This is a view illustrating the process of connecting the cover component to the collector. Figure 30This is a view illustrating the process of attaching insulating tape to interconnected electrode assemblies and current collectors.

[0179] exist Figure 26 and Figure 27 In this configuration, both the foil contacts on the positive electrode and the foil contacts on the negative electrode are formed in the same direction. However, as... Figure 28 and Figure 29 As illustrated, the electrode assembly can be configured such that the foil tabs on the positive electrode and the foil tabs on the negative electrode are formed in different directions. Therefore, the current collector 1300 can also be connected to opposite side surfaces of the electrode assembly 1200.

[0180] like Figure 30 As illustrated, after the electrode assembly 1200 and the current collector 1300 are connected to each other, the first insulating tape T1 can be attached to the current collector 1300. Therefore, a short circuit between the foil tab and the cover member 1400 can be prevented.

[0181] After the first insulating tape T1 is attached, the outer surface of the electrode assembly 1200 can be wrapped with the second insulating tape T2, and then the electrode assembly 1200 can be inserted into the housing 1100.

[0182] Subsequently, the outer surface of box 1100 can be wrapped with the third insulating tape T3, thereby completing the manufacturing of the secondary battery.

[0183] Figure 31 This is a view illustrating a secondary battery including two electrode portions according to another embodiment of the present disclosure. Figure 32 This is a view illustrating a configuration according to another embodiment of the present disclosure, in which foil tabs formed on two electrode portions are coupled to a current collector.

[0184] like Figure 31 and Figure 32 As illustrated, a secondary battery 1000 according to another embodiment of the present disclosure includes a housing 1100, an electrode assembly 1200, a current collector 1300, and a cover component 1400.

[0185] The electrode portion 1210 of the electrode assembly 1200 includes a first electrode portion 1210_1 and a second electrode portion 1210_2. A first foil tab 1220_1 and a second foil tab 1230_1 are formed on the first electrode portion 1210_1, and a first foil tab 1220_2 and a second foil tab 1230_2 are formed on the second electrode portion 1210_2. The first foil tab 1220_1 of the first electrode portion 1210_1 and the first foil tab 1220_2 of the second electrode portion 1210_2 are coupled to a single identical current collector 1300_1. The second foil tab 1230_1 of the first electrode portion 1210_1 and the second foil tab 1230_2 of the second electrode portion 1210_2 are coupled to a single identical current collector 1300_2.

[0186] In this embodiment, the first electrode portion 1210_1 and the second electrode portion 1210_2 are bonded together with a fourth insulating tape T4 and a fifth insulating tape T5. The fourth insulating tape T4 is attached to the height direction side surface of the electrode assembly 1200, and the fifth insulating tape T5 is attached to the length direction side surface of the electrode assembly 1200.

[0187] When n pieces of fourth insulating tape T4 or fifth insulating tape T5 are attached to a surface, the fourth insulating tape T4 and the fifth insulating tape T5 can be attached at positions that divide the length of the surface to which the tape is attached into (n+1) parts. For example, as Figure 31 As shown, when a fourth insulating tape T4 is attached to a height-direction side surface, the fourth insulating tape T4 is attached at a location where the height-direction side surface of the electrode assembly 1200 is divided into two parts. When two fifth insulating tapes T5 are attached to a length-direction side surface, these fifth insulating tapes T5 are attached at two locations where the length-direction side surface of the electrode assembly 1200 is divided into three parts. In this embodiment, one fourth insulating tape T4 and two fifth insulating tapes T5 are provided, but this disclosure is not limited thereto. The fourth insulating tape T4 and the fifth insulating tapes T5 are used to bond the first electrode portion 1210_1 and the second electrode portion 1210_2 together and also provide an insulating effect.

[0188] After attaching the electrode assembly 1200 with the fourth insulating tape T4 or the fifth insulating tape T5, the sixth insulating tape T6 can be attached to the electrode assembly 1200 to wrap all surfaces of the electrode assembly 1200 except for the side surfaces where foil tabs 1220_1, 1220_2, 1230_1, and 1230_2 are formed, thereby ensuring insulation from the housing 1100. Thereafter, the electrode assembly 1200 is inserted into the housing 1100, and the cover member 1400 is attached to the opening of the housing 1100.

[0189] Although embodiments of this disclosure have been described, it will be apparent to those skilled in the art that various modifications or alterations can be made to this disclosure by adding, changing, or deleting components without departing from the spirit of this disclosure as defined in the appended claims. It should be noted that such modifications or alterations also fall within the scope of this disclosure.

[0190] [Description of reference numerals in the attached figures]

[0191] 1000: Secondary battery; 1100: Box

[0192] 1200: Electrode assembly; 1210: Electrode section

[0193] 1220, 1230: Foil splice; 1300: Current collector

[0194] 1310: Manifold plate; 1320: Manifold protrusion

[0195] 1400: Cover component

[0196] 1410: Cover plate; 1420: Electrode terminal

[0197] 1421: Main body 1422: First bend

[0198] 1423: Second bend section; 1430: Electrolyte injection port

[0199] 1440: Exhaust section; 1450: Sealing gasket

[0200] 1460: Upper padding

[0201] 1500: Insulator; 1510: Insulating board

[0202] 1520: Support protrusion; 1530: Insertion hole

[0203] 1540: Guidance section; 1550: Emission section

Claims

1. A secondary battery, the secondary battery comprising a cover assembly configured to seal an opening in a housing into which electrode assemblies are inserted. in, The cover assembly includes: A cover plate having a through hole formed therein; Upper gasket, the upper gasket being disposed on the cover plate; An insulating plate, the insulating plate being disposed below the cover plate; and An electrode terminal is inserted into the through hole and has an upper end and a lower end. The upper end of the electrode terminal is bent onto the upper portion of the upper pad and the lower end of the electrode terminal is bent onto the lower portion of the insulating plate, such that the upper pad and the insulating plate are fixed to the cover plate by the electrode terminal.

2. The secondary battery according to claim 1, comprising: The current collector includes a current collector plate electrically connected to the electrode assembly and a current collector protrusion projecting from the current collector plate. The current collector protrusion is inserted into an insertion hole formed in the electrode terminal, and the current collector protrusion is welded to the upper end of the electrode terminal.

3. The secondary battery according to claim 2, wherein the electrode terminals comprise: The body portion is inserted into the through hole and has the insertion hole formed at the center of the body portion. The first bending portion bends from the upper end of the body portion to the upper portion of the upper liner, and The second bending portion bends from the lower end of the body portion onto the lower portion of the insulating plate.

4. The secondary battery according to claim 3, wherein, The first bending portion includes: a lower surface; an outer stepped surface formed on the outer side of the lower surface; and an outer surface formed at the end of the outer stepped surface in a vertical direction.

5. The secondary battery according to claim 3, wherein, The upper liner is placed between the cover plate and the first bent portion.

6. The secondary battery according to claim 5, in, The cover plate includes: a seating surface formed around the through hole; and a stepped surface formed to protrude from the outer side of the seating surface. The upper pad includes: a first horizontal surface having a first thickness and being formed to contact the seating surface of the cover plate; a second horizontal surface having a second thickness greater than the first thickness and being formed to contact the seating surface and the stepped surface; and a vertical surface extending from the outer end of the second horizontal surface along the vertical direction and surrounding the outer surface of the first bent portion.

7. The secondary battery of claim 6, further comprising a sealing gasket disposed between the through-hole and the body portion, the sealing gasket being configured to insulate the cover from the electrode terminals and prevent electrolyte or gas inside the casing from leaking to the outside.

8. The secondary battery according to claim 7, in, On the lower surface of the cover plate, adjacent to the through hole, a first alignment protrusion is formed, extending from the through hole. A first alignment groove is formed in the sealing gasket at a position corresponding to the first alignment protrusion.

9. The secondary battery according to claim 7, wherein, A second alignment protrusion is formed on the upper surface of the second bent portion, and a second alignment groove is formed on the lower surface of the sealing gasket at a position corresponding to the second alignment protrusion.

10. The secondary battery according to claim 3, wherein, A fitting groove is formed on the inner peripheral surface of the insertion hole. The fitting groove has an inclined shape with a narrower upper side and a wider lower side. A fitting protrusion is formed on the outer peripheral surface of the collecting protrusion, and the fitting protrusion fits into the fitting groove.

11. The secondary battery according to claim 3, wherein, An undercut is formed on the lower end of the main body portion, and an inclined surface is formed on the lower end of the flow collecting protrusion, the inclined surface having a shape corresponding to the undercut.

12. The secondary battery according to claim 3, wherein, The flow collector protrusion is formed at the center of the upper surface of the flow collector plate, and an adhesive layer including a heat-fusion layer is formed on opposite sides of the upper surface of the flow collector plate.

13. The secondary battery according to claim 1, comprising an insulator, the insulator being disposed between the cover plate and the electrode assembly and having the insulating plate thereon. in, The insulator includes: a guide hole positioned below an electrolyte injection hole formed in the cover plate; and a guide portion projecting downward from the guide hole and configured to guide the movement of the electrolyte.

14. The secondary battery according to claim 13, wherein, The guiding portion includes: a support rod positioned in the lower portion of the guiding hole and configured to partially block the guiding hole; and an internal hole formed in the support rod and allowing fluid to move through the internal hole.

15. The secondary battery according to claim 14, wherein, The internal hole faces the electrolyte injection hole and is positioned at the center in the longitudinal direction of the guide portion.

16. The secondary battery according to claim 14, wherein, The guide portion includes a guide edge that surrounds the lower portion of the guide hole, the support rod is fixed to the guide edge, and a first opening and a second opening are formed between the side edge of the support rod and the inner wall of the guide edge.

17. The secondary battery according to claim 13, in, An exhaust section configured for discharging gases is formed in the cover plate. The insulator includes a discharge portion that protrudes toward the bottom of the housing and has multiple discharge openings. The emission section is located below the exhaust section.

18. The secondary battery according to claim 1, in, The electrode assembly includes an electrode portion and a plurality of foil tabs formed on the electrode portion, and The plurality of foil tabs are formed in one direction of the electrode assembly.

19. The secondary battery according to claim 1, in, The electrode assembly includes an electrode portion and a plurality of foil tabs formed on the electrode portion, and The plurality of foil tabs are formed in opposite directions on the electrode assembly.

20. The secondary battery according to claim 1, in, After the electrode assembly and the current collector are connected to each other, the current collector is attached with a first insulating tape. After the outer surface of the electrode assembly is wrapped with a second insulating tape, the electrode assembly is inserted into the box, and The outer surface of the box into which the electrode assembly is inserted is wrapped with a third insulating tape.

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