Secondary battery

Abstract

Provided is a secondary battery, the secondary battery including: a case having a cylindrical shape; an electrode assembly accommodated in the case and including a first tab protruding in a first direction and a second tab protruding in the first direction; a first current collector plate accommodated in the case and connected to the first tab; a second current collector plate configured to connect the second tab to the case; a crimp terminal connected to the first current collector plate and passing through the case; and an insulating member in contact with an outer periphery of each of the electrode assembly, the first current collector plate, and the second current collector plate.

Description

[0001] This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0082636 filed on June 27, 2023, in the Korean Intellectual Property Office, and Korean Patent Application No. 10-2023-0172088 filed on December 1, 2023, in the Korean Intellectual Property Office, the disclosure of each of which is incorporated herein by reference in its entirety. Technical Field

[0002] The present disclosure relates to a secondary battery. Background Art

[0003] Unlike primary batteries that cannot be recharged, secondary batteries are batteries that can be charged and discharged. Low-capacity batteries in which one battery cell is packaged in the form of a group can be used in small portable electronic devices such as smart phones and digital cameras, and large-capacity batteries in the form of a module in which dozens or hundreds of battery packs are connected can be used as a power source for driving motors in hybrid vehicles, electric vehicles, or drones, or as energy storage devices.

[0004] A rechargeable secondary battery may include an electrode assembly with a separator between positive and negative electrode plates, a current collector plate electrically connected to the electrode assembly, a terminal electrically connected to the current collector plate, and a case accommodating the electrode assembly and the current collector plate and to which the terminal is coupled.

[0005] The above information disclosed in the art serving as background art of the present disclosure is merely for improving understanding of the background art of the present disclosure and thus may include information that does not constitute related art. Summary of the invention

[0006] The present disclosure provides a secondary battery having low resistance and a short current path by arranging a first tab (e.g., a positive electrode tab) and a second tab (e.g., a negative electrode tab) of an electrode assembly in the same direction so as to be electrically connected to a first terminal (e.g., a riveted terminal) and a second terminal (e.g., a case), respectively.

[0007] The present disclosure also provides a secondary battery configured to accommodate a relatively large electrode assembly inside a case by having a first current collector plate (e.g., a positive electrode current collector plate) and a second current collector plate (e.g., a negative electrode current collector plate) that are three-dimensionally combined and arranged in the same area to occupy a small volume in the internal space of the case.

[0008] The present disclosure also provides a secondary battery, in which a conductive ring plate is disposed on the second terminal so that a flat surface is provided between a first terminal (eg, a riveted terminal) and a second terminal (eg, a housing).

[0009] A secondary battery according to one or more embodiments of the present disclosure may include: a shell having a cylindrical shape; an electrode assembly accommodated in the shell and including a first terminal tab protruding in a first direction and a second terminal tab protruding in the first direction; a first collector plate accommodated in the shell and connected to the first terminal tab; a second collector plate configured to connect the second terminal tab to the shell; a riveted terminal connected to the first collector plate and passing through the shell; and an insulating member contacting an outer periphery of each of the electrode assembly, the first collector plate, and the second collector plate.

[0010] In one or more embodiments, each of the first tabs may have a planar circular sector shape or a rectangular planar shape having a center, an outer arc, and an inner arc.

[0011] In one or more embodiments, an inner angle of each of the first tabs may be less than 180°.

[0012] In one or more embodiments, the second terminal tab may be spaced apart from and face the first terminal tab, and may have a planar circular sector shape or a rectangular planar shape having a center, an outer arc, and an inner arc.

[0013] In one or more embodiments, an inner angle of each of the second tabs may be less than 180°.

[0014] In one or more embodiments, the first collector plate may include: a first collector plate first connection region connected to the first terminal tab; a first collector plate connection region extending from the first collector plate first connection region in a first direction; and a first collector plate second connection region extending from the first collector plate connection region and configured to be connected to a riveted terminal.

[0015] In one or more embodiments, the first current collector plate first connection region may have a planar circular sector shape having a center, an outer arc, and an inner arc, and the first current collector plate second connection region may have a disc shape having a center.

[0016] In one or more embodiments, the second collector plate may include a second collector plate first connection region connected to the second terminal tab, a second collector plate connection region extending from the second collector plate first connection region in a first direction, and a second collector plate second connection region extending from the second collector plate connection region and configured to be connected to the housing.

[0017] In one or more embodiments, the second collector plate first connection region may have a planar circular sector shape having a center, an outer arc, and an inner arc, and the second collector plate second connection region may have a semicircular ring plate shape having a center.

[0018] In one or more embodiments, a portion of the insulating member may support the second connection region of the second current collector plate.

[0019] In one or more embodiments, the secondary battery may further include one or more insulating plates between the first current collector plate and the second current collector plate, and the one or more insulating plates may have a planar circular sector shape having a center, an outer arc, and an inner arc.

[0020] In one or more embodiments, the secondary battery may further include a conductive ring plate attached to a portion of the case extending around an outer circumference of the riveted terminal.

[0021] In one or more embodiments, the first collector plate may include: a first connection area of ​​the first collector plate, connected to the first terminal tab; a first collector plate connection area, extending from the first connection area of ​​the first collector plate in a first direction; and a second connection area of ​​the first collector plate, extending from the first collector plate connection area to connect to the riveted terminal, and the second collector plate may include: a first connection area of ​​the second collector plate, connected to the second terminal tab; a second collector plate connection area, extending from the first connection area of ​​the second collector plate in the first direction; and a second connection area of ​​the second collector plate, extending from the second collector plate connection area and configured to be connected to the shell.

[0022] In one or more embodiments, the first collector plate first connection region and the second collector plate first connection region may be located substantially on the same plane, and the first collector plate second connection region may be located closer to the electrode assembly than the second collector plate second connection region.

[0023] In one or more embodiments, the housing may include a riveted plate combined with the riveted terminal, a side wall welded to the riveted plate and extending in a second direction opposite to the first direction, and a termination plate integrally extending from the side wall. In one or more embodiments, the termination plate may include a safety vent.

[0024] In one or more embodiments, the housing may include a riveted plate combined with the riveted terminal, a side wall integrally extending from the riveted plate in a second direction opposite to the first direction, and a termination plate configured to close one end of the side wall. In one or more embodiments, the termination plate may include a safety vent.

[0025] In one or more embodiments, the termination plate may be secured to the side wall by a crimped portion and a crimped portion on the side wall.

[0026] In one or more embodiments, the termination plate may be secured to the sidewall by welding. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1A and Figure 1B 1 and 2 are a perspective view and a cross-sectional view respectively showing a secondary battery according to an embodiment of the present disclosure.

[0028] Figure 2A and Figure 2B 1 and 2 are a plan view and a perspective view respectively showing an electrode assembly of an exemplary secondary battery according to an embodiment of the present disclosure.

[0029] FIG. 3A to FIG. 3D is a plan view showing a unfolded state of an electrode assembly of an exemplary secondary battery according to an embodiment of the present disclosure.

[0030] FIG. 4A to FIG. 4C sectional view, plan view, and perspective view respectively illustrate a current collector plate assembly and an insulating member of a secondary battery according to an embodiment of the present disclosure.

[0031] Figure 4D is a perspective view illustrating a state in which a current collector plate assembly and an insulating member are coupled to an electrode assembly according to an embodiment of the present disclosure.

[0032] Figure 5 is a schematic diagram illustrating a laser welding method in a method of manufacturing a secondary battery according to an embodiment of the present disclosure.

[0033] Figure 6 is a cross-sectional view showing a secondary battery according to an embodiment of the present disclosure.

[0034] Figure 7 is a cross-sectional view showing a secondary battery according to another embodiment of the present disclosure.

[0035] Figure 8 is a cross-sectional view showing a secondary battery according to still another embodiment of the present disclosure. DETAILED DESCRIPTION

[0036] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0037] Embodiments are provided to more fully describe the present disclosure to those skilled in the art, and the following embodiments may be modified in many different forms, and the scope of the present disclosure is not limited to the following embodiments. On the contrary, these embodiments are provided so that the present disclosure will be thorough and complete, and will fully convey the spirit of the present disclosure to those skilled in the art.

[0038] In addition, in the accompanying drawings, for the convenience and clarity of illustration, the thickness or size of each layer is exaggerated, and in the accompanying drawings, the same reference numerals represent the same elements. As used in this specification, the term "and / or" may include any combination and all combinations of one or more of the relevant listed items. In addition, in this specification, it will be understood that when component A is referred to as being "connected to" component B, component A may be directly connected to component B, or component C may be placed between component A and component B, so that component A is indirectly connected to component B.

[0039] The term used herein is for the purpose of describing a specific embodiment, and is not intended to limit the present disclosure. As used in this specification, unless a specific situation is clearly indicated according to the context, the singular form may include the plural form. In addition, when the term "comprise" or "comprising" and / or its variations are used in this specification, it is explained that there are stated features, quantities, steps, operations, components, elements and / or their groups, but it is not excluded that there are or add one or more other features, quantities, steps, operations, components, elements and / or their groups.

[0040] In this specification, although the terms "first", "second", etc. can be used to describe various components, components, regions, layers and / or parts, these components, components, regions, layers and / or parts will not be limited by these terms. These terms are used to distinguish one component, component, region, layer or part from another component, component, region, layer or part. Therefore, without departing from the teachings of the present disclosure, the first component, first component, first region, first layer or first part described below may also refer to the second component, second component, second region, second layer or second part.

[0041] In order to easily understand one element or feature and another element or feature(s) as shown in the accompanying drawings, spatially relative terms such as "bottom", "under", "below", "down", "above", and "on" may be used herein. These spatially relative terms are intended to facilitate the understanding of the present disclosure according to various process states or use states of the present disclosure, and are not intended to limit the present disclosure. For example, when the elements or features in the accompanying drawings are turned over, the elements or features described as "bottom", "under", or "below" may be changed to "above" or "on". Therefore, the terms "bottom" or "under" may cover the terms "above" or "on".

[0042] Figure 1A and Figure 1B 1 and 2 are perspective views and cross-sectional views respectively showing a secondary battery 100 according to one or more embodiments of the present disclosure. Figure 1A and Figure 1BAs shown in , a secondary battery 100 according to one or more embodiments of the present disclosure may include a case 110 , an electrode assembly 120 , a collector plate assembly 130 , a rivet terminal 140 , and an insulating member 150 .

[0043] The housing 110 may be provided in an approximately cylindrical shape. The housing 110 may include an approximately disc-shaped riveted plate 111 having a terminal hole 1111 at its center, a side wall 112 extending in a downward direction from the riveted plate 111, and a termination plate 113 configured to close the lower end of the side wall 112. The housing 110 may include or be referred to as a can, a shell, or an external material. The housing 110 may include steel, a steel alloy, nickel-plated steel, aluminum, an aluminum alloy, copper, or a copper alloy. The housing 110 may be manufactured by a deep drawing process, by an extrusion process, or by a bending and welding process, in which a metal plate is placed on a die having an opening and pressed by a punch to manufacture a cylindrical housing, in which a molten metal is placed in an extrusion die and extruded into a tubular housing, in which a thin metal plate is rolled into a cylindrical shape and bent and welded to manufacture a housing in a bending and welding process. The case 110 is configured to house the electrode assembly 120 , the current collector plate assembly 130 , and (optional) an electrolyte, and to isolate them from the external environment.

[0044] In one or more embodiments, the side wall 112 and the termination plate 113 may be integral. In one or more embodiments, the riveted plate 111 and the side wall 112 may be provided separately and then be combined with each other by laser welding. In one or more embodiments, the riveted plate 111 and the side wall 112 may be combined with each other by crimping / pressing, curling or seaming. In one or more embodiments, the riveted plate 111 and the side wall 112 may be integral. In one or more embodiments, the side wall 112 and the termination plate 113 may be provided separately and then be welded and combined with each other. In one or more embodiments, the side wall 112 and the termination plate 113 may be combined with each other by crimping / pressing, curling or seaming.

[0045] In one or more embodiments, the termination plate 113 may include a vent recess 1134 disposed in an upper surface thereof, so that the termination plate 113 is relatively thin at the vent recess 1134. The vent recess 1134 may include a safety vent, or may be referred to as a safety vent. The vent recess 1134 is configured to rupture to release internal gas when the internal pressure of the secondary battery is higher than a reference pressure.

[0046] The electrode assembly 120 may be provided in a substantially cylindrical shape. The electrode assembly 120 may be wound into a cylindrical shape and then coupled to the housing 110. The electrode assembly 120 may include or be referred to as an electrode group or a core. The electrode assembly 120 may include a first electrode plate 121 (e.g., a positive electrode plate), a second electrode plate 122 (e.g., a negative electrode plate), and a separator 123 between the first electrode plate 121 and the second electrode plate 122. In one or more embodiments, the first electrode plate 121 (e.g., a positive electrode plate), the separator 123, and the second electrode plate 122 (e.g., a negative electrode plate) may be wound into an approximately cylindrical shape while being stacked. The first electrode plate 121 may include a plurality of first tabs 1211 extending in an upward direction. The second electrode plate 122 may include a plurality of second tabs 1221 extending in an upward direction. In one or more embodiments, the upward direction may be defined as a first direction, and a downward direction opposite to the upward direction may be defined as a second direction.

[0047] In one or more embodiments, the first electrode plate 121 may be provided by applying a first active material 1213 such as a transition metal oxide onto a first current collector 1212 formed of a metal foil such as aluminum, and may include a first tab 1211 extending and protruding in an upward direction of the first current collector 1212 (e.g., a region where the first active material 1213 is not coated). The extended and protruding first tab 1211 may be referred to as a first uncoated tab or a first substrate tab, and the first tabs 1211 may be aligned at the same or similar positions to form a plurality of tabs by a winding process, a substrate stamping process, or a substrate slotting process of the electrode assembly 120. In one or more embodiments, the first tab 1211 may include a lead tab that is separately provided and welded to the first current collector 1212.

[0048] In one or more embodiments, a compound capable of reversibly inserting and extracting lithium (lithiated inserting compound) may be used as the first active material. In one or more embodiments, at least one of a composite oxide of lithium and a metal selected from cobalt, manganese, nickel, iron, and a combination thereof may be used.

[0049] The composite oxide may be a lithium transition metal composite oxide, and embodiments thereof may include lithium nickel-based oxides, lithium cobalt-based oxides, lithium manganese-based oxides, lithium iron phosphate-based compounds, cobalt-free nickel manganese-based oxides, or combinations thereof.

[0050] In an embodiment, a compound represented by any one of the following chemical formulas may be used: Li a A 1-b X b O 2- c D c(where 0.90≤a≤1.8, 0≤b≤0.5, and 0≤c≤0.05); Li a Mn 2-b X b O 4-c D c (where 0.90≤a≤1.8, 0≤b≤0.5, and 0≤c≤0.05); Li a Ni 1-b-c Co b X c O 2-α D α (where 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, and 0<α<2); Li a Ni 1-b-c Mn b X c O 2-α D α (where 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, and 0<α<2); Li a Ni b Co c L 1 d G e O2 (where 0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, and 0≤e≤0.1); Li a NeG b O2 (where 0.90≤a≤1.8 and 0.001≤b≤0.1); Li a CoG b O2 (where 0.90≤a≤1.8 and 0.001≤b≤0.1); Li a Mn 1-b G b O2 (where 0.90≤a≤1.8 and 0.001≤b≤0.1); Li a Mn b O4 (where 0.90≤a≤1.8 and 0.001≤b≤0.1); Li a Mn 1-g G g PO4 (where 0.90≤a≤1.8 and 0≤g≤0.5); Li (3-f) Fe2(PO4)3 (0≤f≤2); and Li a FePO4 (where 0.90≤a≤1.8).

[0051] In the above chemical formula, A is Ni, Co, Mn or a combination thereof; X is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element or a combination thereof; D is O, F, S, P or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V or a combination thereof; and L 1 It is Mn, Al or a combination thereof.

[0052] In one or more embodiments, a positive electrode for a lithium secondary battery may include a current collector (e.g., a first current collector) and a positive electrode active material layer (e.g., a first active material layer) formed on the current collector. The positive electrode active material layer includes a positive electrode active material and may also include a binder and / or a conductive material.

[0053] The positive electrode active material may be contained in an amount of 90 wt % to 99.5 wt % based on 100 wt % of the positive electrode active material layer, and each of the binder and the conductive material may be contained in an amount of 0.5 wt % to 5 wt % based on 100 wt % of the positive electrode active material layer.

[0054] The first tab 1211 is electrically connected to a first current collector plate 131 and a rivet terminal 140 , which will be described below, to serve as a current flow path between the first electrode plate 121 and the rivet terminal 140 .

[0055] In one or more embodiments, the second electrode plate 122 may be provided by applying a second active material 1223 such as graphite or carbon to a second current collector 1222 formed of a metal foil such as copper or nickel, and may include a second tab 1221 extending and protruding in an upward direction of the second current collector 1222 (e.g., an area where the second active material 1223 is not coated). The extended and protruding second tab 1221 may be referred to as a second uncoated tab or a second substrate tab, and the second tab 1221 may be aligned at the same or similar position to form a plurality of tabs by a winding process, a substrate stamping process, or a substrate slotting process of the electrode assembly 120. In one or more embodiments, the second tab 1221 may include a lead tab that is separately provided and welded to the second current collector 1222. The second tab 1221 is electrically connected to the second current collector plate 132 to serve as a current flow path between the second electrode plate 122 and the housing 110.

[0056] In one or more embodiments, the second active material includes a material capable of reversibly intercalating / deintercalating lithium ions, lithium metal, an alloy of lithium metal, a material capable of doping and dedoping lithium, or a transition metal oxide.

[0057] Materials capable of reversibly inserting / extracting lithium ions may include, for example, crystalline carbon, amorphous carbon, or a combination thereof. Examples of crystalline carbon may be graphite such as natural graphite or artificial graphite, and examples of amorphous carbon may include soft carbon or hard carbon, mesophase pitch carbide, calcined coke, etc.

[0058] Si-based negative electrode active materials or Sn-based negative electrode active materials can be used as materials capable of doping and de-doping lithium. Si-based negative electrode active materials may include silicon, silicon-carbon composites, SiO x (0 < x < 2), Si-based alloys, or a combination thereof.

[0059] The silicon-carbon composite may be a composite of silicon and amorphous carbon. According to one or more embodiments, the silicon-carbon composite may be in the form of silicon particles and amorphous carbon coated on the surface of the silicon particles.

[0060] The silicon-carbon composite may also include crystalline carbon. For example, the silicon-carbon composite may include a core containing crystalline carbon and silicon particles and an amorphous carbon coating on the surface of the core.

[0061] The negative electrode for a lithium secondary battery may include a current collector (e.g., a second current collector) and a negative electrode active material layer (e.g., a second active material layer) formed on the current collector. The negative electrode active material layer includes a negative electrode active material and may also include a binder and / or a conductive material.

[0062] In one or more embodiments, the negative electrode active material layer may include 90 wt% to 99 wt% of the negative electrode active material, 0.5 wt% to 5 wt% of the binder, and 0 wt% to 5 wt% of the conductive material. A non-aqueous binder, an aqueous binder, a dry binder, or a combination thereof may be used as the binder. When an aqueous binder is used as the negative electrode binder, a cellulose-based compound capable of imparting viscosity may also be included.

[0063] The separator 123 may be disposed (located) between the first electrode plate 121 and the second electrode plate 122 to prevent a short circuit between the first electrode plate 121 and the second electrode plate 122 and to allow lithium ions to move therebetween. In one or more embodiments, the separator 123 is formed to be slightly wider than the width of each of the first electrode plate 121 and the second electrode plate 122, such that the separator 123 may protrude further upward, downward, leftward, and rightward than each of the first electrode plate 121 and the second electrode plate 122. Accordingly, the separator 123 may prevent the first electrode plate 121 and the second electrode plate 122 from directly contacting the housing 110 in the upward and downward directions and / or the leftward and rightward directions of the electrode assembly 120. In one or more embodiments, the separator 123 may protrude and extend a predetermined length in the upward and downward directions of the electrode assembly 120 where the first tab 1211 and the second tab 1221 do not exist.

[0064] In one or more embodiments, the electrode assembly 120 may be hollow in a substantially central region, and the hollow central region may be referred to as a core 124. The core 124 may be used as a path through which the pressure is discharged when the internal pressure of the secondary battery is greater than a reference pressure. In one or more embodiments, the internal pressure may be applied to the termination plate 113 through the core 124, and the exhaust recess 1134 of the termination plate 113 may be broken so that the internal pressure may be reduced.

[0065] In one or more embodiments, the electrode assembly 120 may be housed in the housing 110 together with the electrolyte. The electrolyte solution may include an organic solvent such as ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC) and / or dimethyl carbonate (DMC), and a lithium salt such as LiPF6 and LiBF4. In one or more embodiments, the electrolyte may be in a liquid phase, a solid phase, or a gel phase.

[0066] The current collector plate assembly 130 may include a first current collector plate 131 and a second current collector plate 132. The current collector plate assembly 130 may further include an insulating plate 133.

[0067] The first current collector plate 131 may electrically connect the first electrode plate 121 of the electrode assembly 120 with the riveted terminal 140. The first current collector plate 131 may include or be referred to as a current collector, a conductor, or a conductive lead. The first current collector plate 131 may be made of aluminum or an aluminum alloy. The first current collector plate 131 may be manufactured by punching a metal plate using a die and a punch, or by casting a molten metal. In one or more embodiments, the first current collector plate 131 may include a first current collector plate first connection region 1311, a first current collector plate connection region 1312 (e.g., a step), and a first current collector plate second connection region 1313. The first current collector plate first connection region 1311 may be electrically connected to the plurality of first tabs 1211 described above by a method such as laser welding. The first current collector plate connection region 1312 may be bent from the first current collector plate first connection region 1311 and extend in an upward direction. The first current collector plate second connection region 1313 may be bent and extended from the first current collector plate connection region 1312 to be electrically connected to the riveted terminal 140 by a method such as laser welding. In this manner, the first current collector plate 131 may serve as a current flow path between the electrode assembly 120 and the rivet terminal 140 .

[0068] The second current collector plate 132 may electrically connect the second electrode plate 122 of the electrode assembly 120 and the housing 110 (e.g., the riveted plate 111). The second current collector plate 132 may include or be referred to as a current collector, a conductor, or a conductive lead. The second current collector plate 132 may be made of copper, a copper alloy, nickel, or a nickel alloy. The second current collector plate 132 may be manufactured by punching a metal plate using a mold and a punch or by casting a molten metal. In one or more embodiments, the second current collector plate 132 may include a second current collector plate first connection region 1321, a second current collector plate connection region 1322 (e.g., a step), and a second current collector plate second connection region 1323. The second current collector plate first connection region 1321 may be electrically connected to the above-mentioned plurality of second tabs 1221 by a method such as laser welding. The second current collector plate connection region 1322 may be bent from the second current collector plate first connection region 1321 and extend in an upward direction. The second collector plate second connection region 1323 may be bent and extended from the second collector plate connection region 1322 to be electrically connected to the case 110 (eg, the riveted plate 111) by a method such as laser welding. In this manner, the second collector plate 132 may serve as a current flow path between the electrode assembly 120 and the case 110.

[0069] The insulating plate 133 may be placed (located) between the first collector plate 131 and the second collector plate 132. In one or more embodiments, the insulating plate 133 may be located on substantially the same horizontal plane as the first collector plate 131 and the second collector plate 132 or at least a portion thereof. In one or more embodiments, a partial region (portion) of the insulating plate 133 may be placed (located) between the second collector plate second connection region 1323 and the electrode assembly 120. The insulating plate 133 may include or be referred to as an insulator, an insulating block, or an insulating spacer. In one or more embodiments, the insulating plate 133 may be made of polypropylene, polyethylene, ethylene propylene diene monomer rubber (EPDM), or nylon that does not react with the electrolyte. In one or more embodiments, the first collector plate 131, the second collector plate 132, and the insulating plate 133 may be manufactured by a double injection method.

[0070] The riveted terminal 140 may pass through and be coupled to the housing 110. In one or more embodiments, the riveted terminal 140 may pass through and be coupled to a terminal hole 1111 provided in the riveted plate 111. In one or more embodiments, an insulating gasket 1431 may be placed (located) between the riveted terminal 140 and the terminal hole 1111. In one or more embodiments, the riveted terminal 140 may include a relatively wide head 141 and a relatively narrow body 142 extending from the head 141 in a downward direction to pass through the terminal hole 1111. In one or more embodiments, the riveted terminal 140 may also include a recess 1411 extending from the head 141 toward the body 142 to a predetermined depth. The thickness of the body 142 of the riveted terminal 140 is reduced by the recess 1411, which increases the energy transfer from the laser beam used during manufacturing to the first collector plate 131 (e.g., the first collector plate second connection region 1313), thereby allowing the riveted terminal 140 and the first collector plate 131 to be laser welded to each other. In one or more embodiments, the upper insulator 1432 may be placed (located) between the head 141 and the riveted plate 111. In one or more embodiments, the lower insulator 1433 may be placed (located) at the periphery of the body portion 142 passing through the riveted plate 111. In one or more embodiments, the lower insulator 1433 may be placed (located) between the collector plate assembly 130 and the riveted plate 111. In one or more embodiments, the recess 1411 may present a specific surface with a substantially flat member (e.g., metal) after the welding process. In one or more embodiments, after the welding process, the metal member may be bonded to the recess 1411 or close the upper end of the recess 1411.

[0071] The insulating member 150 may surround (or substantially surround) the periphery of each of the electrode assembly 120 and the collector plate assembly 130. In one or more embodiments, the insulating member 150 may be in contact with the periphery of each of the electrode assembly 120 and the collector plate assembly 130. The insulating member 150 may surround (or substantially surround) the periphery of each of the first collector plate 131 and the second collector plate 132. In one or more embodiments, the insulating member 150 may be in contact with the periphery of each of the first collector plate 131 and the second collector plate 132. The insulating member 150 may include or be referred to as an insulating ring, an insulating tape, an insulating film, or an insulator. In one or more embodiments, the insulating member 150 may be substantially in the form of a circular ring. In one or more embodiments, the insulating member 150 may surround (or substantially surround) the upper periphery of the electrode assembly 120 (or surround or substantially surround the portion of the electrode assembly 120 close to the upper periphery). In one or more embodiments, the insulating member 150 may be in contact with the upper periphery of the electrode assembly 120 (or contact with the portion of the electrode assembly 120 close to the upper periphery). In one or more embodiments, a partial area (portion) of the insulating member 150 surrounds the outer periphery (outer arc) of the first current collector plate first connection area 1311, so that the outer periphery of the first current collector plate first connection area 1311 does not contact the side wall 112 of the case 110. In one or more embodiments, a partial area (portion) of the insulating member 150 supports the second current collector plate second connection area 1323 from below, so that the second current collector plate second connection area 1323 is in close contact with the riveted plate 111 during the laser welding process. As described above, a partial area (portion) of the insulating plate 133 is placed (located) between the second current collector plate second connection area 1323 and the electrode assembly 120, so that the second current collector plate second connection area 1323 is in close contact with the riveted plate 111. In one or more embodiments, the insulating member 150 may be made of polypropylene, polyethylene, EPDM, or nylon that does not react with the electrolyte.

[0072] In this way, the present disclosure can provide a secondary battery 100 having low resistance and a short current path by arranging the first tab 1211 (e.g., a positive electrode tab) and the second tab 1221 (e.g., a negative electrode tab) of the electrode assembly 120 in the same direction (e.g., in an upward direction) so as to be electrically connected to the first terminal (e.g., a rivet terminal 140) and the second terminal (e.g., the case 110), respectively. In addition, the present disclosure can provide a secondary battery 100 that allows a relatively large electrode assembly to be accommodated inside the case 110 by having a first collector plate 131 (e.g., a positive electrode collector plate) and a second collector plate 132 (e.g., a negative electrode collector plate) that are three-dimensionally combined and arranged in the same area to occupy a small volume in the internal space of the case 110.

[0073] Figure 2A and Figure 2B 1 and 2 are respectively a plan view and a perspective view showing an electrode assembly 120 of a secondary battery 100 according to one or more embodiments of the present disclosure. Figure 2A and Figure 2B As shown in , the electrode assembly 120 according to one or more embodiments of the present disclosure may include a plurality of first tabs 1211 and a plurality of second tabs 1221 protruding and extending in an upward direction. In one or more embodiments, the plurality of first tabs 1211 and the plurality of second tabs 1221 may be symmetrical to each other around a core 124 (e.g., an empty space) located at the center or central portion of the electrode assembly 120.

[0074] In one or more embodiments, the plurality of first tabs 1211 may have a planar circular sector shape or a planar sector shape having a center C, an outer arc 1211a, and an inner arc 1211b. The length of the outer arc 1211a may be greater than the length of the inner arc 1211b. In one or more embodiments, the inner angle of the plurality of first tabs 1211 may be less than about 180°, for example, may be in the range of about 10° to about 180°, about 40° to about 160°, or about 80° to about 120°. When the inner angle of the plurality of first tabs 1211 is greater than about 180°, the first tab 1211 may contact the second tab 1221, and when the inner angle of the plurality of first tabs 1211 is less than about 10°, the contact area or welding area with the first current collector plate 131 may be relatively small (e.g., insufficiently small). In one or more embodiments, the plurality of first tabs 1211 may have an approximately rectangular planar shape. In one or more embodiments, the plurality of first tabs 1211 may have a rectangular plan shape having a center C, an outer arc 1211 a , and an inner arc 1211 b .

[0075] In one or more embodiments, the plurality of second tabs 1221 may be disposed at a position spaced apart from the plurality of first tabs 1211, and may have a planar circular sector shape or a planar sector shape having a center C, an outer arc 1221a, and an inner arc 1221b. The length of the outer arc 1221a may be greater than the length of the inner arc 1221b. In one or more embodiments, the inner angle of the plurality of second tabs 1221 may be less than about 180°, for example, may be in the range of about 10° to about 180°, about 40° to about 160°, or about 80° to about 120°. When the inner angle of the plurality of second tabs 1221 is greater than about 180°, the second tabs 1221 may contact the first tabs 1211, and when the inner angle of the plurality of second tabs 1221 is less than about 10°, the contact area or welding area with the second current collector plate 132 may be relatively small (e.g., insufficiently small). In one or more embodiments, the plurality of second tabs 1221 may have an approximately rectangular planar shape. In one or more embodiments, the plurality of second tabs 1221 may have a rectangular plan shape having a center C, an outer arc 1221 a , and an inner arc 1221 b .

[0076] In one or more embodiments, a portion of the diaphragm 123 may protrude and extend into an area where the plurality of first tabs 1211 and the plurality of second tabs 1221 do not protrude and extend. In one or more embodiments, the upper sides of the plurality of first tabs 1211, the upper sides of the plurality of second tabs 1221, and the upper side of the diaphragm 123 may be substantially coplanar with each other.

[0077] FIG. 3A to FIG. 3D 1 is a plan view showing a non-folded state of an electrode assembly 120 of a secondary battery according to one or more embodiments of the present disclosure. FIG. 3A to FIG. 3D In each of the first electrode plate 121 and the second electrode plate 122 , the left end is a winding start end (a portion where winding starts), and the right end is a winding end end (a portion where winding ends). For convenience of description, the separator is not shown.

[0078] In one or more embodiments, Figure 3A As shown in , the first and second tabs 1211 and 1221 may be formed by a substrate punching method. The width of each of the first and second tabs 1211 and 1221 may gradually increase from a winding start end toward a winding end end.

[0079] In one or more embodiments, Figure 3B As shown in , the first terminal tab 1211 and the second terminal tab 1221 may be grooved after punching the substrate. The width of each of the first terminal tab 1211 and the second terminal tab 1221 may gradually increase from the winding start end toward the winding end end.

[0080] In one or more embodiments, Figure 3C As shown in , the first terminal tab 1211 and the second terminal tab 1221 may be separately provided (formed) and respectively connected to the first electrode plate 121 and the second electrode plate 122. In one or more embodiments, each of the first active material 1213 and the second active material 1223 may be provided by a pattern coating method, and the first active material 1213 and the second active material 1223 may not be provided in the area (e.g., the area corresponding to the entire vertical length) to which the first terminal tab 1211 and the second terminal tab 1221 are attached.

[0081] In the first active material 1213 and the second active material 1223, as Figure 3D As shown in , the first terminal tab 1211 and the second terminal tab 1221 may be separately provided (formed) and respectively connected to the first electrode plate 121 and the second electrode plate 122. In one or more embodiments, each of the first active material 1213 and the second active material 1223 may be provided (formed) by a pattern coating method, and the first active material 1213 and the second active material 1223 may not be provided in the area to which the first terminal tab 1211 and the second terminal tab 1221 are attached (e.g., an area corresponding to a portion of the entire vertical length).

[0082] FIG. 4A to FIG. 4C sectional view, plan view, and perspective view respectively illustrate a current collector plate assembly 130 and an insulating member 150 of a secondary battery 100 according to one or more embodiments of the present disclosure. Figure 4D 1 is a perspective view showing a state in which a current collector plate assembly 130 and an insulating member 150 are coupled to an electrode assembly 120 according to one or more embodiments of the present disclosure. FIG. 4A to FIG. 4D As shown in , the collector plate assembly 130 may include a first collector plate 131, a second collector plate 132, and an (optional) insulating plate 133, and the insulating member 150 may be in contact with both the electrode assembly 120 and the collector plate assembly 130. In one or more embodiments, the insulating member 150 may surround at least a portion of the electrode assembly 120 and at least a portion of the collector plate assembly 130.

[0083] The first current collector plate 131 may include a first current collector plate first connection region 1311, a first current collector plate connection region 1312 (e.g., a step) extending upward from the first current collector plate first connection region 1311, and a first current collector plate second connection region 1313 extending from the first current collector plate connection region 1312. In one or more embodiments, the first current collector plate first connection region 1311 may have a planar circular sector shape or a planar sector shape having a center C, an outer arc 1311a, and an inner arc 1311b. The length of the outer arc 1311a may be greater than the length of the inner arc 1311b. In one or more embodiments, the first current collector plate second connection region 1313 may have a disc shape having a center. In one or more embodiments, in the first current collector plate first connection region 1311, a plurality of welding lines WL may be arranged in a straight line shape (e.g., radial welding lines WL), and the first tab 1211 and the first current collector plate first connection region 1311 may be electrically connected to each other through the welding lines WL. In one or more embodiments, the first terminal tab 1211 may be pressed or bent in an inward or outward direction and welded to the first current collector plate first connection region 1311. In one or more embodiments, in the first current collector plate second connection region 1313, a plurality of welding lines WL may be arranged in a ring shape (e.g., a ring-shaped welding line WL), and the rivet terminal 140 and the first current collector plate second connection region 1313 may be electrically connected to each other through the welding line WL. In one or more embodiments, the planar shape of the first current collector plate first connection region 1311 may be the same or similar to the planar shape of the first terminal tab 1211. In one or more embodiments, the first current collector plate first connection region 1311 may have a shape overlapping the first terminal tab 1211.

[0084] The second current collector plate 132 may include a second current collector plate first connection region 1321, a second current collector plate connection region 1322 (e.g., a step) extending upward from the second current collector plate first connection region 1321, and a second current collector plate second connection region 1323 extending from the second current collector plate connection region 1322. In one or more embodiments, the second current collector plate first connection region 1321 may have a planar circular sector shape or a planar sector shape having a center C, an outer arc 1321a, and an inner arc 1321b. In the first current collector plate connection region 1312, the second current collector plate first connection region 1321 may be symmetrical with the first current collector plate first connection region 1311 with respect to the core 124 of the electrode assembly 120 or with respect to the first current collector plate second connection region 1313. In one or more embodiments, the second current collector plate second connection region 1323 may have a semi-annular (semi-circular) ring plate shape having a center. In one or more embodiments, the center C of the second current collector plate second connection region 1323 may coincide with the center C of the core 124 of the electrode assembly 120 or the first current collector plate second connection region 1313 .

[0085] In one or more embodiments, in the second collector plate first connection region 1321, a plurality of welding lines WL may be arranged in a straight line shape (e.g., radial welding lines WL), and the second tab 1221 and the second collector plate first connection region 1321 may be electrically connected to each other through the welding lines WL. In one or more embodiments, the second tab 1221 may be pressed or bent in an inward or outward direction and welded to the second collector plate first connection region 1321. In one or more embodiments, in the second collector plate second connection region 1323, a plurality of welding lines WL may be arranged in a dotted line shape, and a portion of the housing 110 (e.g., the rivet plate 111) and the second collector plate second connection region 1323 may be electrically connected to each other through the welding lines WL. In one or more embodiments, the planar shape of the second collector plate first connection region 1321 may be the same or similar to the planar shape of the second tab 1221. In one or more embodiments, the second collector plate first connection region 1321 may have a shape overlapping the second tab 1221.

[0086] In one or more embodiments, the first collector plate first connection region 1311 and the second collector plate first connection region 1321 may be located on the same or similar plane (e.g., coplanar or substantially coplanar), and the first collector plate second connection region 1313 may be located closer to the electrode assembly 120 than the second collector plate second connection region 1323 (e.g., the second collector plate second connection region 1323 may be higher than the first collector plate second connection region 1313). Therefore, the collector plate assembly 130 is provided with a compact thickness and thus occupies a relatively small volume inside the secondary battery 100. Therefore, a relatively large electrode assembly 120 may be provided inside the secondary battery 100.

[0087] As described above, the insulating plate 133 may be disposed (located) between the first collector plate 131 and the second collector plate 132. In one or more embodiments, a partial region (portion) of the insulating plate 133 may also be disposed (located) between the second collector plate second connection region 1323 and the electrode assembly 120. In one or more embodiments, the insulating plate 133 may have a planar circular sector shape or a planar sector shape having a center C, an outer arc 133a, and an inner arc 133b. As described above, the first collector plate 131, the second collector plate 132, and the insulating plate 133 may be manufactured by a double injection method so that an integrated collector plate assembly 130 may be formed.

[0088] Figure 5 is a schematic diagram showing a laser welding method in a method of manufacturing a secondary battery 100 according to one or more embodiments of the present disclosure. Figure 5 As shown in , a laser beam is applied to the concave portion 1411 of the rivet terminal 140 so that the body portion 142 of the rivet terminal 140 can be electrically connected to the second connection region 1313 of the first current collector plate. Figure 5 As shown in , a laser beam is applied along the outer circumference of the case 110 (eg, the rivet plate 111 ) so that the rivet plate 111 may be electrically connected to the second connection region 1323 of the second current collector plate.

[0089] In this manner, a first current path is provided through the riveted terminal 140 (ie, the first terminal), the first current collector plate 131, and the first electrode plate 121, and a second current path is provided through the case 110 or the riveted plate 111 (ie, the second terminal), the second current collector plate 132, and the second electrode plate 122. Therefore, the internal resistance of the secondary battery 100 can be reduced by providing a relatively short first current path and a relatively short second current path.

[0090] Figure 6 2 is a cross-sectional view showing a secondary battery 200 according to one or more embodiments of the present disclosure. In addition to further providing a conductive ring plate 210, Figure 6The secondary battery 200 shown in FIG. Figure 1A and Figure 1B The secondary battery 100 shown in FIG. Figure 6 As shown in , the conductive ring plate 210 can be mechanically / electrically attached to a partial area (portion) of the housing 110 as the periphery of the riveted terminal 140 (for example, on the riveted plate 111). In one or more embodiments, the conductive ring plate 210 can be welded to the riveted plate 111 by a laser beam. The conductive ring plate 210 can be provided with a material similar to or the same as the material of the riveted plate 111. In one or more embodiments, the upper surface of the conductive ring plate 210 can form a plane similar to or the same as the upper surface of the riveted terminal 140 (for example, the upper surface of the conductive ring plate 210 can be coplanar or substantially coplanar with the upper surface of the riveted terminal 140). Therefore, the busbars (not shown) connected to the riveted terminal 140 and the conductive ring plate 210 can have the same height or substantially the same height. In one or more embodiments, the upper surface of the conductive ring plate 210 can be lower than the upper surface of the riveted terminal 140. Therefore, the busbars (not shown) connected to the riveted terminal 140 and the conductive ring plate 210 can have different heights.

[0091] In this manner, the present disclosure may provide a secondary battery 200 having a flat surface between a first terminal (eg, a riveted terminal 140 ) and a second terminal (eg, the case 110 ) by disposing a conductive ring plate 210 on the second terminal (eg, the riveted plate 111 of the case 110 ).

[0092] Figure 7 1 is a cross-sectional view showing a secondary battery 300 according to one or more embodiments of the present disclosure. In addition to the termination plate 313 being coupled to the side wall 112 of the housing 110 by the provided curling portion 1121 and the crimping portion 1122, Figure 7 The secondary battery 300 shown in FIG. Figure 1A and Figure 1B The secondary battery 100 shown in FIG. Figure 7As shown in , the inwardly concave crimping portion 1121 and the inwardly bent crimping portion 1122 may be (optionally) provided at the lower end of the side wall 112 of the housing 110. In one or more embodiments, the terminating plate 313 may be coupled between the crimping portion 1121 and the crimping portion 1122. In one or more embodiments, the insulating gasket 114 may be located between the crimping portion 1121 and the crimping portion 1122, so that the terminating plate 313 may be coupled while the insulating gasket 114 is placed (located) between the crimping portion 1121 and the crimping portion 1122. In one or more embodiments, instead of providing the crimping portion 1121 and the crimping portion 1122, the terminating plate 313 may be directly welded to the side wall 112, or the terminating plate 113 may be coupled to the side wall 112 by a crimping method or a seaming method.

[0093] In one or more embodiments, the termination plate 313 may include a vent recess 3134 in its upper surface so that the termination plate 313 is relatively thin at the vent recess 3134. In one or more embodiments, the termination plate 313 may include a peripheral region 3131 fitted between the curling portion 1121 and the crimping portion 1122, an inner region 3132 connected to the peripheral region 3131 and lower than the peripheral region 3131, and a central region 3133 connected to the inner region 3132 and higher than the inner region 3132. The vent recess 3134 may be provided in the inner region 3132. In one or more embodiments, the central region 3133 may be closer to the electrode assembly 120 than the peripheral region 3131 and the inner region 3132. The vent recess 3134 may include or be referred to as a safety vent.

[0094] In one or more embodiments, the termination plate 313 may further include an injection hole 3135 and a plug 3136 in the injection hole 3135. The injection hole 3135 may be provided in the termination plate 313 (e.g., the central region 3133), and the injection hole 3135 may be closed by the plug 3136. Therefore, the electrolyte may be injected through the injection hole 3135, and the injection hole 3135 may be closed by the plug 3136, thereby preventing leakage of the electrolyte. In one or more embodiments, such an injection hole and a plug may be provided in the riveted plate 111, which may be applicable to all of the above-mentioned embodiments.

[0095] Figure 8 1 is a cross-sectional view showing a secondary battery 400 according to one or more embodiments of the present disclosure. In addition to the termination plate 313 being welded and fixed to the side wall 112 of the housing 110, Figure 8 The secondary battery 400 shown in FIG. Figure 7 The secondary battery 300 shown in FIG. Figure 8As shown in , the termination plate 313 can be fixed to the side wall 112 of the shell 110 by laser welding. In one or more embodiments, after the termination plate 313 is bonded to the side wall 112 of the shell 110, a laser beam can be irradiated to the position where the periphery of the termination plate 313 contacts the side wall 112. Therefore, the periphery of the termination plate 313 and a partial area of ​​the side wall 112 melt and cool, so that the termination plate 313 can be bonded to the side wall 112 of the shell 110. As described above, according to the present disclosure, by providing a secondary battery 400 without curling, the space occupied by the curling portion and the crimping portion can be eliminated. Therefore, the present disclosure can provide a relatively high-capacity secondary battery 400 by allowing a relatively large electrode assembly 120 to be accommodated in the shell 110.

[0096] The present disclosure may provide a secondary battery having low resistance and a short current path by arranging a first tab (e.g., a positive electrode tab) and a second tab (e.g., a negative electrode tab) of an electrode assembly in the same direction so as to be electrically connected to a first terminal (e.g., a riveted terminal) and a second terminal (e.g., a case), respectively.

[0097] The present disclosure can provide a secondary battery that allows a relatively large electrode assembly to be accommodated inside a case by having a first current collector plate (e.g., a positive electrode current collector plate) and a second current collector plate (e.g., a negative electrode current collector plate) that are three-dimensionally combined and arranged in the same area to occupy a small volume in the internal space of the case.

[0098] The present disclosure may provide a secondary battery having a flat surface between a first terminal (eg, a riveted terminal) and a second terminal (eg, a housing) by providing a conductive ring plate on the second terminal.

[0099] The above description is only an embodiment for realizing the secondary battery according to the present disclosure, and the present disclosure is not limited to the above embodiment. As claimed in the appended claims, the technical spirit of the present disclosure includes the scope that various changes can be made by those skilled in the art without departing from the concept of the present disclosure.

Claims

1. A secondary battery, comprising: a housing having a cylindrical shape; an electrode assembly accommodated in the housing and comprising a plurality of first terminal tabs protruding in a first direction and a plurality of second terminal tabs protruding in the first direction; a first current collector plate received in the housing and connected to the plurality of first terminal tabs; a second current collector plate configured to connect the plurality of second terminal tabs to the housing; a riveted terminal connected to the first current collector plate and passing through the housing; as well as An insulating member contacts an outer circumference of each of the electrode assembly, the first current collector plate, and the second current collector plate.

2. The secondary battery according to claim 1, wherein Each of the plurality of first tabs has a planar circular sector shape or a rectangular planar shape having a center, an outer arc, and an inner arc.

3. The secondary battery according to claim 2, wherein: An inner angle of each of the plurality of first terminal tabs is less than 180°.

4. The secondary battery according to claim 1, wherein The plurality of second terminal tabs are spaced apart from and face the plurality of first terminal tabs, and wherein each of the plurality of second terminal tabs has a planar circular sector shape or a rectangular planar shape having a center, an outer arc, and an inner arc.

5. The secondary battery according to claim 4, wherein An inner angle of each of the plurality of second terminal tabs is less than 180°.

6. The secondary battery according to claim 1, wherein The first current collector plate comprises: a first connection region of the first current collector plate connected to the plurality of first terminal tabs; a first collector plate connection region extending from the first collector plate first connection region along the first direction; and The first collector plate second connection region extends from the first collector plate connection region and is configured to be connected to the rivet terminal.

7. The secondary battery according to claim 6, wherein The first connection region of the first current collector plate has a planar circular sector shape having a center, an outer arc and an inner arc, and The second connection region of the first current collector plate has a disk shape having a center.

8. The secondary battery according to claim 1, wherein The second current collector plate comprises: a first connection region of the second current collector plate connected to the plurality of second terminal tabs; a second current collector plate connection region extending from the second current collector plate first connection region along the first direction; and A second collector plate second connection region extends from the second collector plate connection region and is configured to be connected to the case.

9. The secondary battery according to claim 8, wherein The first connection region of the second current collector plate has a planar circular sector shape having a center, an outer arc and an inner arc, and The second connection region of the second current collector plate has a semicircular ring plate shape with a center.

10. The secondary battery according to claim 9, wherein Portions of the insulating member support the second connection region of the second current collector plate.

11. The secondary battery according to claim 1, further comprising one or more insulating plates between the first current collector plate and the second current collector plate, in, The one or more insulating plates have a planar circular sector shape having a center, an outer arc, and an inner arc. 12 . The secondary battery according to claim 1 , further comprising a conductive ring plate attached to a portion of the case extending around a periphery of the riveted terminal.

13. The secondary battery according to claim 1, wherein The first current collector plate includes: a first current collector plate first connection region connected to the plurality of first terminal tabs; a first current collector plate connection region extending from the first current collector plate first connection region along the first direction; and a first current collector plate second connection region extending from the first current collector plate connection region and configured to be connected to the riveted terminal, and The second collector plate includes: a second collector plate first connection region connected to the plurality of second terminal tabs; a second collector plate connection region extending from the second collector plate first connection region along the first direction; and a second collector plate second connection region extending from the second collector plate connection region and configured to be connected to the housing.

14. The secondary battery according to claim 13, wherein: The first connection region of the first current collector plate and the first connection region of the second current collector plate are located on the same plane, and The first current collector plate second connection region is positioned closer to the electrode assembly than the second current collector plate second connection region.

15. The secondary battery according to claim 1, wherein The housing includes a rivet plate combined with the rivet terminal, a side wall welded to the rivet plate and extending in a second direction opposite to the first direction, and a termination plate integrally extending from the side wall.

16. The secondary battery according to claim 15, wherein The termination plate includes a safety vent.

17. The secondary battery according to claim 1, wherein The housing includes a rivet plate combined with the rivet terminal, a side wall integrally extending from the rivet plate in a second direction opposite to the first direction, and a termination plate configured to close one end of the side wall.

18. The secondary battery according to claim 17, wherein The termination plate includes a safety vent.

19. The secondary battery according to claim 17, wherein The terminating plate is fixed to the side wall by a crimping portion and a crimping portion on the side wall.

20. The secondary battery according to claim 17, wherein The terminating plate is fixed to the side wall by welding.

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