Secondary battery and battery pack comprising same

Abstract

Disclosed are a secondary battery and a battery pack including the same. The secondary battery includes: a case including an opening; an electrode assembly accommodated in the case; an electrode tab connected to the electrode assembly; a cover plate closing the opening; a terminal coupled to the cap plate; and a current collecting member including a plate portion coupled to the electrode tab such that a current flows between the plate portion and the electrode tab, a terminal coupling portion protruding from the plate portion to be coupled to the terminal such that the current flows between the terminal coupling portion and the terminal, and a thermal capacity increasing portion protruding from the plate portion to be coupled to the terminal. The heat capacity increasing portion protrudes from the plate portion and does not contact the cap plate and the terminal.

Description

Technical Field

[0001] An aspect of the embodiments of this disclosure relates to a secondary battery and a battery pack including the secondary battery. Background Technology

[0002] Generally speaking, with the recent rapid proliferation of battery-powered electronic devices such as mobile phones, laptops, and electric vehicles, the demand for rechargeable batteries with high energy density and high capacity has increased rapidly. Accordingly, research and development to improve the performance of lithium-ion rechargeable batteries are actively underway.

[0003] A lithium secondary battery is a battery that includes a positive electrode and a negative electrode containing active materials capable of intercalating and deintercalating lithium ions, as well as an electrolyte, and generates electrical energy through oxidation and reduction reactions during the intercalation / deintercalation of lithium ions at the positive and negative electrodes.

[0004] The information disclosed in this background section is provided to enhance the understanding of the background technology of this disclosure, and therefore may contain information that does not constitute related technology. Summary of the Invention

[0005] According to an embodiment of the present disclosure, a secondary battery and a battery pack including the secondary battery are provided, wherein the heat generation of the current collector connecting the electrode terminals and the current collector is reduced.

[0006] However, the technical aspects and objectives to be achieved by this disclosure are not limited to those described above, and those skilled in the art will clearly understand other aspects and objectives not described above through the following description of this disclosure.

[0007] According to one or more embodiments of the present disclosure, a secondary battery includes: a housing including an opening; an electrode assembly housed within the housing; electrode tabs connected to the electrode assembly; a cover plate closing the opening; terminals connected to the cover plate; and a current collector including a plate portion, a terminal connection portion, and a heat capacity enhancement portion, the plate portion being connected to the electrode tabs such that current flows between the plate portion and the electrode tabs, the terminal connection portion protruding from the plate portion to connect to a terminal such that current flows between the terminal connection portion and the terminal, and the heat capacity enhancement portion protruding from the plate portion and not contacting the cover plate and the terminal.

[0008] The plate portion may include: a first plate portion that overlaps with the terminal; and a second plate portion that extends from the first plate portion in a stepped shape and is connected to the electrode tab, wherein the terminal connection portion may include a first contact protrusion protruding from the first plate portion to connect to the terminal.

[0009] The terminal may include a thick portion and a thin portion that is thinner than the thick portion, and the thin portion may be soldered to the first contact protrusion.

[0010] The terminal connection portion may further include a second contact protrusion that protrudes from the first plate portion and avoids the first contact protrusion to connect to the terminal.

[0011] The terminal may include a raised through-hole, a second contact protrusion end portion is inserted into the raised through-hole, and the inserted end portion of the second contact protrusion into the raised through-hole may be soldered to the inner surface of the raised through-hole.

[0012] The second contact protrusion may include multiple second contact protrusions, and the multiple second contact protrusions may be symmetrically positioned around the first contact protrusion.

[0013] The second contact protrusion may include a plurality of second contact protrusions, and the plurality of second contact protrusions may be located at opposite end portions of the plate portion in the width direction.

[0014] The heat capacity increase section may include a first non-contact protrusion that protrudes from the second plate portion toward the cover plate.

[0015] The second plate portion can be welded to the electrode terminal piece. The second plate portion can include a welding portion on the portion welded to the electrode terminal piece, and the first non-contact protrusion can protrude from the second plate portion and avoid the welding portion.

[0016] The first non-contact protrusion can be set to be offset to one side in the width direction of the second plate portion.

[0017] The first non-contact protrusion can extend parallel to the longitudinal direction of the second plate portion.

[0018] The first non-contact protrusion may include a plurality of first non-contact protrusions, and the plurality of first non-contact protrusions may be arranged along the longitudinal direction of the second plate portion.

[0019] The first non-contact protrusion may include multiple first non-contact protrusions, and the multiple first non-contact protrusions may be symmetrically positioned around the first contact protrusion.

[0020] The heat capacity increase portion may further include a second non-contact protrusion that protrudes from the first plate portion toward the terminal and avoids the first contact protrusion.

[0021] The second non-contact protrusion can extend parallel to the longitudinal direction of the plate portion.

[0022] The second non-contact protrusion may include a plurality of second non-contact protrusions, and the plurality of second non-contact protrusions may be arranged along the longitudinal direction of the plate portion.

[0023] The second non-contact protrusion may include multiple second non-contact protrusions, and the multiple second non-contact protrusions may be symmetrically positioned around the first contact protrusion.

[0024] The secondary battery may further include: an insulator, located in the housing between the cover and the electrode assembly, and including an insulating material.

[0025] The insulator may include: a base portion between the cover plate and the heat capacity increase portion; and an insulating reinforcement layer stacked on the base portion.

[0026] According to one or more embodiments of the present disclosure, a battery pack includes: a housing; and a plurality of secondary batteries, wherein each of the plurality of secondary batteries includes: a housing including an opening; an electrode assembly received within the housing; electrode tabs connected to the electrode assembly; a cover plate closing the opening; terminals connected to the cover plate; and a current collector including a plate portion, a terminal connection portion, and a heat capacity enhancement portion, the plate portion being connected to the electrode tabs such that current flows between the plate portion and the electrode tabs, the terminal connection portion protruding from the plate portion to be connected to a terminal such that current flows between the terminal connection portion and the terminal, and the heat capacity enhancement portion protruding from the plate portion and not contacting the cover plate and the terminals. Attached Figure Description

[0027] The above and other aspects, objects, features, and advantages of this disclosure will become more apparent to those skilled in the art from the more detailed description of some embodiments thereof with reference to the accompanying drawings, in which:

[0028] Figure 1 This is a perspective view illustrating a secondary battery according to an embodiment of the present invention.

[0029] Figure 2 It is a diagram. Figure 1 An exploded perspective view of a secondary battery;

[0030] Figure 3 It is a diagram. Figure 2 A schematic diagram of the structure of the electrode assembly and electrode terminals;

[0031] Figure 4 It is along Figure 1 A cross-sectional view of line S1-S1;

[0032] Figure 5 The illustration, according to an embodiment, can provide... Figure 1 A perspective view of the current collector in a secondary battery;

[0033] Figure 6 It is a diagram. Figure 5 Plan view of the flow collection component;

[0034] Figure 7 The illustration, according to another embodiment, can provide... Figure 1 A perspective view of the current collector in a secondary battery;

[0035] Figure 8 It is a diagram. Figure 7 Plan view of the flow collection component;

[0036] Figure 9 The illustration, according to another embodiment, can provide... Figure 1 A perspective view of the current collector and terminals in a secondary battery;

[0037] Figure 10 It is a diagram. Figure 9 Plan view of the current collector and terminals;

[0038] Figure 11 The illustration, according to another embodiment, can provide... Figure 1 A perspective view of the current collector and terminals in a secondary battery;

[0039] Figure 12 It is a diagram. Figure 11 A plan view of the current collector and terminals; and

[0040] Figure 13 This is a schematic perspective view illustrating the structure of a battery pack according to an embodiment of the present invention. Detailed Implementation

[0041] In this document, some embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. The terms or words used in this specification and claims should not be construed as limited to their ordinary or dictionary meanings, and should be interpreted as having meanings and concepts consistent with the technical spirit of the present disclosure, based on the principle that the inventor is capable of being their own lexicographer to appropriately define the concepts of the terms.

[0042] The embodiments described in this specification and the configurations shown in the accompanying drawings are provided as some exemplary embodiments of this disclosure and do not necessarily represent all technical ideas, aspects, and features of this disclosure. Accordingly, it should be understood that various equivalents and modifications that can replace or modify the embodiments described herein may exist at the time of filing this application.

[0043] It should be understood that when an element or layer is referred to as being "on," "connected to," or "linked to" another element or layer, it may be directly on, directly connected to, or linked to the other element or layer, or one or more intermediary elements or layers may be present. When an element or layer is referred to as being "directly on," "directly connected to," or "directly linked to" another element or layer, no intermediary element or layer is present. For example, when a first element is described as being "linked" or "connected to" a second element, the first element may be directly linked to or connected to the second element, or the first element may be indirectly linked to or connected to the second element via one or more intermediary elements.

[0044] In the figures, the dimensions of various elements, layers, etc., may be exaggerated for clarity. The same reference numerals denote the same or similar elements. As used herein, the term “and / or” includes any and all combinations of one or more of the items listed. Furthermore, the use of “may” in describing embodiments of this disclosure refers to “one or more embodiments of this disclosure.” Expressions such as “at least one of…” and “any one of…” modify the entire list of elements when following it, and not individual elements within that list. When phrases such as “at least one of A, B, and C,” “at least one of A, B, or C,” “at least one selected from the group consisting of A, B, and C,” or “at least one selected from A, B, and C” are used to refer to a list of elements A, B, and C, the phrase may refer to any one of A, B, and C and all suitable combinations or subsets of them, such as A, B, C, A and B, A and C, B and C, or A and B and C. As used herein, the term “use” may be considered synonymous with the term “utilize.” As used herein, the terms “substantially,” “approximately,” and similar terms are used as approximate terms rather than as terms of degree, and are intended to describe the inherent variation of a measured or calculated value that would be recognized by one of ordinary skill in the art.

[0045] It should be understood that although the terms “first,” “second,” “third,” etc., may be used herein to describe various elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms are used to distinguish one element, component, region, layer, or segment from another element, component, region, layer, or segment. Therefore, without departing from the teachings of the exemplary embodiments, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment.

[0046] For ease of description, spatial relative terms such as “below,” “under,” “down,” “above,” and “above” may be used herein to describe the relationship between one element or feature and another element or feature as shown in the figure. It should be understood that spatial relative terms are intended to encompass different orientations of the device in use or operation besides the orientation depicted in the figure. For example, if the device in the figure is flipped, an element described as “below” or “under” other elements or features would then be oriented as “above” or “above” other elements or features. Therefore, the term “below” can encompass both above and below orientations. The device may be oriented in other ways (e.g., rotated 90 degrees or in other orientations), and the spatial relative descriptive terms used herein should be interpreted accordingly.

[0047] The terminology used herein is for the purpose of describing embodiments of this disclosure and is not intended to limit this disclosure. As used herein, the singular form “a” is intended to include the plural form as well, unless the context clearly indicates otherwise. It should be further understood that, when used in this specification, the terms “comprising” and / or “including” specify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0048] Furthermore, any numerical range disclosed and / or described herein is intended to include all subranges with the same numerical precision contained within the described range. For example, the range “1.0 to 10.0” is intended to include all subranges between (and including) the described minimum value of 1.0 and the described maximum value of 10.0, i.e., having a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0, such as, for example, 2.4 to 7.6. Any maximum numerical limit described herein is intended to include all lower numerical limits contained therein, and any minimum numerical limit described in this specification is intended to include all higher numerical limits contained therein. Accordingly, the applicant reserves the right to amend this specification (including the claims) to explicitly describe any subranges contained within the scope explicitly described herein.

[0049] Referring to two compared elements, features, etc., as “identical” can mean that they are identical or substantially identical. Therefore, the phrase “identical” or “substantially identical” can include cases with a deviation considered low in the art (e.g., 5% or less). Additionally, when a parameter is said to be consistent in a given region, it can mean that it is consistent with respect to the average value.

[0050] Throughout this specification, unless otherwise stated, each element may be singular or plural.

[0051] When any element is referred to as being arranged (or located or positioned) "above (or below)" or "on (or below)" a component, it may mean that the element is placed in contact with the upper (or lower) surface of the component, and may also mean that another component may be located between the component and any element arranged (or located or positioned) on (or below) the component.

[0052] Furthermore, it should be understood that when a component is referred to as "connected," "linked," or "attached" to another component, these components may be directly "connected," "linked," or "attached" to each other, or one or more intermediary components may exist between them, allowing the component to be "connected," "linked," or "attached" to the other component via one or more intermediary components. Additionally, when a part is referred to as "electrically connected" to another part, the part may be directly electrically connected to the other part, or one or more intermediary components may exist between them, allowing the part and the other part to be indirectly electrically connected to each other.

[0053] Throughout this specification, unless otherwise stated, the phrase "A and / or B" means A, B, or A and B. That is, "and / or" includes any one or all combinations of the listed items. Unless otherwise stated, the phrase "C to D" means C and above, and D and below.

[0054] The terminology used in this specification is for describing embodiments of this disclosure and is not intended to limit this disclosure.

[0055] Figure 1 This is a perspective view illustrating a secondary battery according to an embodiment of the present invention; and Figure 2 It is a diagram. Figure 1 An exploded perspective view of a secondary battery. Figure 3 It is a diagram. Figure 2 A schematic diagram of the structure of the electrode assembly and electrode terminals; and Figure 4 It is along Figure 1 A cross-sectional view of line S1-S1. Figure 5 The illustration, according to an embodiment, can provide... Figure 1 A perspective view of the current collector in a secondary battery; and Figure 6 It is a diagram. Figure 5 Plan view of the flow collection component. Figure 7 The illustration, according to an embodiment, can provide... Figure 1 A perspective view of the current collector in a secondary battery; and Figure 8 It is a diagram. Figure 7 Plan view of the flow collection component. Figure 9 The illustration, according to an embodiment, can provide... Figure 1 A perspective view of the current collector and terminals in a secondary battery; and Figure 10 It is a diagram. Figure 9 Plan view of the current collector and terminals. Figure 11 The illustration, according to an embodiment, can provide... Figure 1 A perspective view of the current collector and terminals in a secondary battery; and Figure 12 It is a diagram. Figure 11 Plan view of the current collector and terminals.

[0056] In this document, prismatic lithium-ion secondary batteries will be described as examples of secondary batteries. However, the invention is not limited thereto; for example, the secondary battery may be a lithium polymer battery or a cylindrical battery.

[0057] refer to Figures 1 to 6 According to an embodiment of the present disclosure, a secondary battery 100 includes a housing 101, an electrode assembly 200, electrode terminals 301 and 302, a cover plate 501, terminals 530 and 540, and a current collector 400A.

[0058] The housing 101 can form the overall appearance of the secondary battery 100 and accommodate the electrode assembly 200. The housing 101 may include a bottom portion (not shown), a front portion 120, a rear portion 130, and a pair of side portions 140.

[0059] based on Figure 1 The bottom portion can form the lower exterior of the housing 101. According to an embodiment, the bottom portion can have a rectangular plate shape. The front portion 120, the rear portion 130, and a pair of side portions 140 can form the circumferential exterior of the housing 101.

[0060] based on Figure 1 Each of the front portion 120, rear portion 130, and a pair of side portions 140 according to the embodiment may have a plate shape extending upward from the edge of the bottom portion. The front portion 120, rear portion 130, and pair of side portions 140 may be arranged to surround a space on the bottom portion. In one embodiment, the front portion 120, rear portion 130, and pair of side portions 140 may form a rectangular cross-sectional shape.

[0061] In one embodiment, the front portion 120 and the rear portion 130 may be arranged parallel to each other. In one embodiment, the area of ​​the front portion 120 may be the same as the area of ​​the rear portion 130. A pair of side portions 140 may be arranged parallel to each other. The areas of the pair of side portions 140 may be the same. The area of ​​each of the pair of side portions 140 may be smaller than the area of ​​each of the front portion 120 and the rear portion 130.

[0062] The housing 101 includes an opening 160. According to an embodiment, the opening 160 may be a space surrounded by the upper portion of the front portion 120, the upper portion of the rear portion 130, and the upper portions of a pair of side portions 140. The opening 160 may connect the internal space and the external space of the housing 101. Accordingly, the housing 101 according to an embodiment may have a cuboid shape with an open upper side.

[0063] In this document, the width direction of the secondary battery can be a direction intersecting the front portion 120 and the rear portion 130, and can be referred to as the first direction. The direction intersecting the pair of side portions 140 can be referred to as the second direction. The direction perpendicular to the first and second directions and intersecting the bottom portion and the cover plate 501 of the secondary battery can be referred to as the third direction. Figure 1 , Figure 2 and Figure 4 In this diagram, the X-axis can be parallel to the first direction, the Y-axis can be parallel to the second direction, and the Z-axis can be parallel to the third direction.

[0064] The electrode assembly 200 can be used as a unit structure for performing charging and discharging operations in the secondary battery 100. The electrode assembly 200 can be housed in the housing 101. The electrode assembly 200 may include a first electrode 210, a second electrode 220, and a separator 230 disposed between the first electrode 210 and the second electrode 220. The first electrode 210, separator 230, and second electrode 220 may be provided as a plurality of first electrodes 210, a plurality of separators 230, and a plurality of second electrodes 220.

[0065] In this document, an example of an electrode assembly 200 in a stacked configuration will be described, wherein a plurality of first electrodes 210, a plurality of diaphragms 230, and a plurality of second electrodes 220 are sequentially stacked in a second direction. However, the electrode assembly 200 is not limited to this configuration and may be configured such that the first electrodes 210, diaphragms 230, and second electrodes 220 are wound around a winding axis in a clockwise or counterclockwise direction while being stacked.

[0066] The first electrode 210 can be used as either the positive electrode or the negative electrode of the electrode assembly 200. In this document, an example of the first electrode 210 being the positive electrode of the electrode assembly 200 will be described. However, the first electrode 210 is not limited to this and can also be used as the negative electrode of the electrode assembly 200.

[0067] The first electrode 210 according to the embodiment can be formed in the shape of a foil comprising a metallic material such as aluminum or an aluminum alloy. The type, size, and shape of the first electrode 210 are not specifically limited, as long as the first electrode 210 does not cause a chemical change in the secondary battery and is conductive. Except... Figure 3 In addition to the rectangular shape shown in the figure, the cross-sectional shape of the first electrode 210 can be designed to have any of a variety of shapes.

[0068] The first electrode 210 can be provided as a plurality of first electrodes 210. The plurality of first electrodes 210 can be disposed in a first direction between the front portion 120 and the rear portion 130 of the housing 101. For example, the design of the number of first electrodes 210 can be varied depending on the charging capacity of the secondary battery.

[0069] The first active material layer can be coated on at least a part of the first electrode 210. In one embodiment, the first active material layer can be coated on both surfaces or opposite surfaces of the first electrode 210. In another embodiment, the first active material layer can be coated only on one surface of the first electrode 210.

[0070] In one embodiment, the first electrode 210 serves as a positive electrode, and the first active material layer can include a positive electrode active material.

[0071] The positive electrode active material can be a compound capable of reversibly intercalating and deintercalating lithium (lithiated intercalation compound). In one embodiment, one or more composite oxides of metals selected from the group consisting of cobalt, manganese, nickel, iron, and combinations thereof and lithium can be used as the positive electrode active material.

[0072] For example, the positive electrode active material can include at least one of lithium iron phosphate oxide (LiFePO4, LFP), lithium manganese iron phosphate oxide (LiMnFePO4, LMFP), and lithium nickel cobalt manganese oxide (LiNi x Co y Mn z O2, NCM). Here, 0 < x < 1, 0 < y < 1, 0 < z < 1, and x + y + z = 1. In one embodiment, the positive electrode active material can include only one of lithium iron phosphate oxide (LiFePO4, LFP), lithium manganese iron phosphate oxide (LiMnFePO4, LMFP), and lithium nickel cobalt manganese oxide (LiNi x Co y Mn z O2, NCM), or can include two or all of lithium iron phosphate oxide (LiFePO4, LFP), lithium manganese iron phosphate oxide (LiMnFePO4, LMFP), and lithium nickel cobalt manganese oxide (LiNi x Co y Mn z O2, NCM).

[0073] The first active material layer can further include a positive electrode conductive material.

[0074] The positive electrode conductive material imparts conductivity to the positive electrode active material layer, and any suitable material that does not cause chemical changes and is conductive can be used as the positive electrode conductive material. Examples of the positive electrode conductive material can be carbon-based materials (such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, carbon nanofiber, and carbon nanotube), metal-based materials in the form of metal powders or metal fibers containing copper, nickel, aluminum, silver, etc., conductive polymers (such as polyphenylene derivatives), or mixtures thereof.

[0075] The first active material layer may further include a positive electrode binder.

[0076] The positive electrode binder effectively attaches the particles constituting the positive electrode active material to each other and effectively attaches the positive electrode active material to the first electrode 210. Examples of positive electrode binders include non-aqueous binders, aqueous binders, dry binders, or combinations thereof.

[0077] Non-aqueous adhesives may be polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene-propylene copolymer, polystyrene, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamide-imide, polyimide, or combinations thereof.

[0078] Waterborne adhesives may be selected from the group consisting of styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, (meth)acrylonitrile-butadiene rubber, (meth)acrylic rubber, butyl rubber, fluororubber, polyethylene oxide, polyvinylpyrrolidone, polyepoxychloropropane, polyphosphazene, poly(meth)acrylonitrile, ethylene propylene diene copolymer, polyvinylpyridine, chlorosulfonated polyethylene, latex, polyester resin, (meth)acrylic resin, phenolic resin, epoxy resin, polyvinyl alcohol, and combinations thereof.

[0079] If an aqueous binder is used as the positive electrode binder, the first active material layer may further comprise a cellulose compound that imparts viscosity. One or more of carboxymethyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, and their alkali metal salts may be mixed and used as the cellulose compound. Sodium, potassium, or lithium may be used as the alkali metal.

[0080] Dry adhesives are fibrous polymer materials and can be, for example, polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polyethylene oxide, or combinations thereof.

[0081] Although not illustrated in the accompanying drawings, the first electrode 210 may include a first uncoated portion to which the first active material layer is not applied. The first uncoated portion may be located in the upper region of the first electrode 210 facing the opening 160 within the housing 101. However, the first uncoated portion is not limited thereto, and in one embodiment, it may be formed over the entire edge region of the first electrode 210.

[0082] The second electrode 220 can be used as the other one of the positive and negative electrodes of the electrode assembly 200. In this document, an example of the second electrode 220 being the negative electrode of the electrode assembly 200 will be described. However, the second electrode 220 is not limited to this and can also be used as the positive electrode of the electrode assembly 200.

[0083] The second electrode 220 can be provided as a plurality of second electrodes 220. The plurality of second electrodes 220 can be disposed in a first direction between the front portion 120 and the rear portion 130 of the housing 101. The first electrode 210 and the second electrode 220 can be disposed alternately in the first direction. The second electrode 220 can be spaced apart from the first electrode 210 by a distance (e.g., a predetermined distance) in the first direction.

[0084] The second electrode 220 according to the embodiment can be formed in the shape of a foil comprising a metallic material such as copper, a copper alloy, nickel, or a nickel alloy. The type, size, and shape of the second electrode 220 are not specifically limited, as long as the second electrode 220 does not cause a chemical change in the secondary battery and is conductive. Except... Figure 3 In addition to the rectangular shape shown in the figure, the cross-sectional shape of the second electrode 220 can be designed to have any of a variety of shapes.

[0085] The second active material layer may be applied to at least a portion of the second electrode 220. In one embodiment, the second active material layer may be applied to both surfaces or opposite surfaces of the second electrode 220. In another embodiment, the second active material layer may be applied to only one surface of the second electrode 220.

[0086] In one embodiment, the second electrode 220 is used as a negative electrode, and the second active material layer may include a negative electrode active material.

[0087] The negative electrode active material may include materials in which lithium ions can be reversibly inserted and / or from which lithium ions can be reversibly inserted and extracted, lithium metal, lithium metal alloys, materials that can be doped in lithium and can be dedoped from lithium, or transition metal oxides.

[0088] Materials in which lithium ions can be reversibly inserted and / or extracted can include carbon-based negative electrode active materials, such as crystalline carbon, amorphous carbon, or combinations thereof. Examples of crystalline carbon can be graphite, such as natural or artificial graphite in amorphous, tabular, flake, spherical, or fibrous form, and examples of amorphous carbon can be soft or hard carbon, mesophase pitch carbides, calcined coke, etc.

[0089] Lithium, as well as alloys of metals selected from the group consisting of Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Ra, Ge, Al, and Sn, can be used as lithium metal alloys.

[0090] Si-based or Sn-based negative electrode active materials can be used as materials that can be doped into lithium and dedoped from lithium. Si-based negative electrode active materials can be silicon, silicon-carbon composites, or SiO₂. x(0 < x ≤ 2), Si-Q alloy (Q is selected from the group consisting of alkali metals, alkaline earth metals, Group 13 elements, Group 14 elements (excluding Si), Group 15 elements, Group 16 elements, transition metals, rare earth elements, and combinations thereof) or a combination thereof. The Sn-based negative electrode active material can be Sn, SnO2, a Sn-based alloy, or a combination thereof.

[0091] The silicon-carbon composite can be a composite of silicon and amorphous carbon. According to one embodiment, the silicon-carbon composite can have a form including silicon particles coated with amorphous carbon on the surface. For example, the silicon-carbon composite can include secondary particles (cores) in which silicon primary particles are aggregated and an amorphous carbon coating (shell) on the surface of the secondary particles. Amorphous carbon can also be located between the silicon primary particles, such that, for example, the silicon primary particles can be coated with amorphous carbon. The secondary particles can be dispersed and present in an amorphous carbon matrix.

[0092] The silicon-carbon composite can further include crystalline carbon. For example, the silicon-carbon composite can include a core containing crystalline carbon and silicon particles and an amorphous carbon coating on the surface of the core.

[0093] The Si-based negative electrode active material or the Sn-based negative electrode active material can be used in combination with a carbon-based negative electrode active material.

[0094] In one embodiment, the second active material layer can further include a negative electrode conductive material and a negative electrode binder.

[0095] The negative electrode conductive material imparts conductivity to the second active material layer, and any suitable material that does not cause a chemical change and is conductive can be used as the negative electrode conductive material. Examples of the negative electrode conductive material can be carbon-based materials (such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, carbon nanofiber, and carbon nanotube), metal-based materials in the form of metal powders or metal fibers containing copper, nickel, aluminum, silver, etc., conductive polymers (such as polyphenylene derivatives), or mixtures thereof.

[0096] The negative electrode binder attaches the particles constituting the negative electrode active material to each other well and attaches the negative electrode active material to the second electrode 220 well.

[0097] Examples of the negative electrode binder can be a non-aqueous binder, an aqueous binder, a dry binder, or a combination thereof.

[0098] The non-aqueous binder can include polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene propylene copolymer, polystyrene, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamideimide, polyimide, or a combination thereof.

[0099] Waterborne adhesives may be selected from the group consisting of styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, (meth)acrylonitrile-butadiene rubber, (meth)acrylic rubber, butyl rubber, fluororubber, polyethylene oxide, polyvinylpyrrolidone, polyepoxychloropropane, polyphosphazene, poly(meth)acrylonitrile, ethylene propylene diene copolymer, polyvinylpyridine, chlorosulfonated polyethylene, latex, polyester resin, (meth)acrylic resin, phenolic resin, epoxy resin, polyvinyl alcohol, and combinations thereof.

[0100] If an aqueous binder is used as the negative electrode binder, the first active material layer may further comprise a cellulose compound providing adhesion. One or more of carboxymethyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, and their alkali metal salts may be mixed and used as the cellulose compound. In one embodiment, sodium, potassium, or lithium may be used as the alkali metal.

[0101] Dry adhesives are polymeric materials that can be fibrous and can be, for example, polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polyethylene oxide, or combinations thereof.

[0102] The second electrode 220 may include a second uncoated portion where the second active material layer is not applied. According to an embodiment, the second uncoated portion may be located in the upper region of the second electrode 220 facing the opening 160 within the housing 101. However, the second uncoated portion is not limited thereto, and in one embodiment, it may be formed over the entire edge region of the second electrode 220.

[0103] A diaphragm 230 may be disposed between the first electrode 210 and the second electrode 220. The diaphragm 230 may allow lithium ions to move between the first electrode 210 and the second electrode 220 and prevent or substantially prevent short circuits between the first electrode 210 and the second electrode 220.

[0104] In one embodiment, the diaphragm 230 may be configured to completely cover the surface area of ​​the electrode assembly 200. Accordingly, the diaphragm 230 may prevent or substantially prevent the first electrode 210 and the second electrode 220 from being directly exposed to the outside of the electrode assembly 200.

[0105] In one embodiment, a multilayer membrane having two or more layers of polyethylene, polypropylene, polyvinylidene fluoride, or the like can be used as membrane 230, and a mixed multilayer membrane such as a two-layer membrane having polyethylene / polypropylene, a three-layer membrane having polyethylene / polypropylene / polyethylene, or a three-layer membrane having polypropylene / polyethylene / polypropylene can be used as membrane 230.

[0106] The diaphragm 230 may include a porous substrate and a coating on one or both or opposite surfaces of the porous substrate, comprising an organic material, an inorganic material, or a combination thereof.

[0107] The porous substrate may be a polymer selected from the group consisting of polyolefins (such as polyethylene and polypropylene), polyesters (such as polyethylene terephthalate and polybutylene terephthalate), polyacetal, polyamide, polyimide, polycarbonate, polyetherketone, polyaryletherketone, polyetherimide, polyamideimide, polybenzimidazole, polyethersulfone, polyphenylene ether, cyclic olefin copolymers, polyphenylene sulfide, polyethylene naphthalate, glass fiber and polytetrafluoroethylene (e.g., Teflon), or a polymer film formed from copolymers or mixtures of two or more of these.

[0108] Organic materials may include polymers such as polyvinylidene fluoride or (meth)acrylic acid polymers.

[0109] Inorganic materials may include, but are not limited to, inorganic particles selected from the group consisting of Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, SrTiO3, BaTiO3, Mg(OH)2, boehmite and combinations thereof.

[0110] Organic and inorganic materials can exist as a mixture in a coating, or as a stack of coatings including organic materials and coatings including inorganic materials.

[0111] Electrode terminals 301 and 302 are connected to electrode assembly 200. First electrode terminal 301 may be connected to first electrode 210 and may protrude outward from electrode assembly 200. In one embodiment, first electrode 210 is a positive electrode, and first electrode terminal 301 may be used as a positive electrode terminal of secondary battery 100. However, first electrode terminal 301 is not limited thereto; if first electrode 210 is a negative electrode, first electrode terminal 301 may be used as a negative electrode terminal of secondary battery 100.

[0112] According to an embodiment, the first electrode tab 301 may extend from the electrode assembly 200 in a third direction. That is, the first electrode tab 301 may extend toward the opening 160 of the housing 101. According to an embodiment, the first electrode tab 301 may include a first internal electrode tab 310 and a first external electrode tab 320.

[0113] The first internal electrode connector 310 may be spaced apart from the first external electrode connector 320 in the second direction. As an example, the first external electrode connector 320 and the first internal electrode connector 310 may be arranged sequentially in the second direction. That is, the first external electrode connector 320 may be positioned at a distance (e.g., a predetermined distance) from the first internal electrode connector 310 in the second direction. The first external electrode connector 320 may be positioned relatively closer to the side portion 140 of the first terminal 530 than the first internal electrode connector 310.

[0114] According to an embodiment, the first internal electrode terminal block 310 may be an assembly of a plurality of first internal terminal blocks 311 formed by slotting the first uncoated portions of a plurality of first electrodes 210. The first external electrode terminal block 320 may be an assembly of a plurality of first external terminal blocks 321 formed by slotting the first uncoated portions of a plurality of first electrodes 210.

[0115] The secondary battery 100 according to an embodiment may further include a second electrode terminal 302. The second electrode terminal 302 may be connected to the second electrode 220 and extend outwardly from the electrode assembly 200. In one embodiment, the second electrode 220 is a negative electrode, and the second electrode terminal 302 may serve as a negative electrode terminal of the secondary battery 100. However, the second electrode terminal 302 is not limited thereto; if the second electrode 220 is a positive electrode, the second electrode terminal 302 may serve as a positive electrode terminal of the secondary battery 100.

[0116] According to the embodiment, the second electrode tab 302 can extend from the electrode assembly 200 in a third direction. That is, the second electrode tab 302 can extend toward the opening 160 of the housing 101.

[0117] The first electrode connector 301 may be disposed separately from the second electrode connector 302 in the second direction. As an example, the second electrode connector 302 may be disposed at a position that is spaced apart from the first electrode connector 301 by a distance (e.g., a predetermined distance) in the second direction.

[0118] The second electrode connector 302 according to the embodiment may include a second internal electrode connector 330 and a second external electrode connector 340.

[0119] The second internal electrode connector 330 may be spaced apart from the second external electrode connector 340 in the second direction. That is, the second external electrode connector 340 may be disposed at a position spaced apart from the second internal electrode connector 330 by a distance (e.g., a predetermined distance) in the second direction. The second external electrode connector 340 may be disposed relatively closer to the side portion 140 of the second terminal 540 than the second internal electrode connector 330.

[0120] The second internal electrode terminal block 330 according to the embodiment may be an assembly of a plurality of second internal terminal blocks 331 formed by slotting the second uncoated portions of a plurality of second electrodes 220. The second external electrode terminal block 340 may be an assembly of a plurality of second external terminal blocks 341 formed by slotting the second uncoated portions of a plurality of second electrodes 220.

[0121] The cover 501 closes the opening 160 of the housing 101. Terminals 530 and 540 are connected to the cover 501. In one embodiment, the secondary battery 100 further includes a pair of gaskets 550 and 560, and the cover 501, terminals 530 and 540, and gaskets 550 and 560 constitute a cover assembly 500.

[0122] The cover assembly 500 can be attached to the housing 101 and can seal the housing 101. The cover assembly 500 can be configured to face the electrode assembly 200 from the third-side upward.

[0123] The cover plate 501 may be formed as a generally flat rectangular plate. The cover plate 501 may be positioned at a distance (e.g., a predetermined distance) from the electrode assembly 200 in a third-order direction. The cover plate 501 may be positioned parallel to the bottom portion of the housing 101. The cover plate 501 may be connected to the housing 101 by any of a variety of connection methods such as welding, bolting, and mating.

[0124] A pair of terminals 530 and 540 are connected to a cover plate 501. The pair of terminals 530 and 540 may include a first terminal 530 and a second terminal 540. The first terminal 530 and the second terminal 540 may be connected to two ends or opposite ends of the cover plate 501 in its longitudinal direction, spaced apart from each other.

[0125] The first terminal 530 can protrude outward from the cover plate 501. The first terminal 530 can be electrically connected to the first electrode 210. Since the first electrode 210 according to the embodiment is used as a positive electrode, the first terminal 530 can be illustrated as the positive electrode terminal of the secondary battery 100.

[0126] The second terminal 540 can protrude outward from the cover plate 501. The second terminal 540 can be electrically connected to the second electrode 220. Since the second electrode 220 according to the embodiment is used as a negative electrode, the second terminal 540 can be illustrated as the negative electrode terminal of the secondary battery 100.

[0127] The upper ends of a pair of terminals 530 and 540 may protrude upward from the cover plate 501. Although the figures illustrate an example of a rectangular cross-sectional shape for each of the terminals 530 and 540, the cross-sectional shape of each of the terminals 530 and 540 is not limited to this, and the cross-sectional shape can be varied to any of a variety of shapes such as circular, elliptical, and polygonal. The terminals 530 and 540 may be formed of a conductive material such as aluminum, nickel, or copper.

[0128] The first terminal 530 may include a thick portion 531 and a thin portion 533 having a thickness less than that of the thick portion 531 in a third direction. The thin portion 533 may be formed in the central portion of the first terminal 530. Figure 4 As shown, the thin portion 533 can be aligned with and welded to the first contact protrusion 411 of the current collector 400A.

[0129] Like the first terminal 530, the second terminal 540 may also include a thick portion and a thin portion having a thickness smaller than that of the thick portion in a third direction. Like the first terminal 530, the thin portion of the second terminal 540 may be aligned with and connected to the first contact protrusion 411 of the current collector 400A.

[0130] The through hole through which the first contact protrusion 411 passes can be formed in the cover plate 501, so that the first contact protrusion 411 passes through the cover plate 501 and is welded to the thin portion 533.

[0131] A pair of gaskets 550 and 560 can electrically insulate the cover 501 from a pair of terminals 530 and 540 and prevent or substantially prevent moisture or foreign matter from being introduced between the cover 501 and the pair of terminals 530 and 540.

[0132] Each of the pair of gaskets 550 and 560 may include an insulating material. For example, each of the pair of gaskets 550 and 560 may be formed of an insulating material such as polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), or rubber. The pair of gaskets 550 and 560 may be fixed between the cover plate 501 and the pair of terminals 530 and 540 by press fitting, injection molding, bonding, etc.

[0133] The cover assembly 500 according to the embodiment may further include an exhaust port 505 and a single exhaust element 520.

[0134] The vent 505 can be formed as a hole extending through the cover 501 in a third-order upward direction. The vent 505 provides a channel through which flames, gases, smoke, etc., generated in the housing 101 can be discharged to the outside of the housing 101 should thermal runaway occur in the secondary battery 100 due to overcurrent or the like. The vent 505 can be located between the first terminal 530 and the second terminal 540. The cross-sectional shape of the vent 505 can be designed to be any of various shapes, such as elliptical, circular, and polygonal.

[0135] The individual vent 520 can be installed in the vent 505 and can be opened or closed in response to changes in the internal pressure of the housing 101. That is, when the secondary battery 100 is operating normally, the individual vent 520 can prevent electrolytes and other substances from being discharged from the housing 101 to the outside of the housing 101 by closing the vent 505, or prevent moisture, foreign matter, etc., from being introduced into the housing 101. If thermal runaway occurs in the secondary battery 100, the individual vent 520 can open the vent 505 to allow flames, gases, smoke, etc., generated in the housing 101 to be discharged to the outside of the housing 101.

[0136] In one embodiment, the individual vent member 520 may be formed in the shape of a plate. The individual vent member 520 may be fixed to the cover plate 501 by any of a variety of connection methods such as welding, bolting, and mating. The individual vent member 520 may be disposed in the vent hole 505 or above or below the cover plate 501 so as to face the vent hole 505 in a third-party upward direction.

[0137] In one embodiment, the thickness of the individual vent 520 in the third direction may be less than the thickness of the cover plate 501. Accordingly, the individual vent 520 may easily break or rupture when the internal pressure of the housing 101 increases. In one embodiment, the individual vent 520 may include a notch formed recessed inward from the individual vent 520 so that it ruptures first if the internal pressure of the housing 101 increases.

[0138] The cover assembly 500 may further include an electrolyte injection hole 508 and a sealing plug 525. The electrolyte injection hole 508 is formed to pass through the cover plate 501, and the sealing plug 525 closes the electrolyte injection hole 508, allowing the sealing plug 525 to open the electrolyte injection hole 508. The electrolyte injection hole 508 may be separately disposed from the vent hole 505 in the longitudinal direction of the cover plate 501. The electrolyte injection hole 508 may be located between the first terminal 530 and the second terminal 540.

[0139] The cover assembly 500 according to an embodiment may further include an insulator 570.

[0140] An insulator 570 may be located between the cover plate 501 and the electrode assembly 200. The insulator 570 insulates the cover plate 501 from the electrode assembly 200 by preventing or substantially preventing direct contact between them. The insulator 570 may also fix the position of the electrode assembly 200 within the housing 101. If the cover plate 501 deforms inward toward the housing 101 due to external impacts, the insulator 570 may prevent or substantially prevent damage to the electrode assembly 200.

[0141] The insulator 570 can be configured to face the electrode assembly 200 in the housing 101 in a third-party orientation. That is, the electrode assembly 200, the insulator 570, and the cover plate 501 can be arranged sequentially in the third-party orientation.

[0142] Insulator 570 may include insulating material. For example, insulator 570 may be formed of insulating material such as PE, PP, PET or rubber.

[0143] The insulator 570 may include a body 571 and an insulating reinforcement layer 580. The body 571 may include a base portion 572 extending in a second direction to overlap with the cover plate 501 in a third direction, a skirt portion 577 bent from the outer corner of the base portion 572 to project toward the electrode assembly 200, and a spacer portion 573 projecting from the base portion 572 to contact the cover plate 501 and separate the base portion 572 from the cover plate 501. In one embodiment, the body 571 may be integrally formed by a method such as injection molding.

[0144] An insulating reinforcement layer 580 is stacked on the base portion 572. In one embodiment, for example, an adhesive tape or adhesive can be used to attach a film comprising insulating material to the base portion 572 to form the insulating reinforcement layer 580. In another embodiment, a coating agent comprising insulating material can be applied to the base portion 572 and cured to form the insulating reinforcement layer 580. Even if the current collector 400A collides with the insulator 570 due to an external impact applied to the secondary battery 100, the insulator 570 will not be damaged due to the insulating reinforcement layer 580. Accordingly, short circuits between the current collector 400A and the cover plate 501, as well as fire accidents caused by short circuits, can be prevented or substantially prevented.

[0145] Current collectors 400A are provided as a pair to be matched one-to-one with a pair of terminals 530 and 540. Each current collector 400A may include a plate portion 401, a terminal connection portion, and a heat capacity increase portion. The plate portion 401 is connected to each of the electrode tabs 301 and 302, allowing current to flow between them. The current collector 400A corresponding to the first terminal 530 may be connected to the first electrode tab 301, and the current collector 400A corresponding to the second terminal 540 may be connected to the second electrode tab 302. The current collectors 400A connected to the first terminal 530 and the first electrode tab 301 will be described in more detail here.

[0146] The plate portion 401 includes a first plate portion 403 positioned to overlap with the first terminal 530 in a third direction, and a second plate portion 405 extending from the first plate portion 403 in a stepped shape and connected to the first electrode tab 301. The second plate portions 405 may be provided as a pair. The pair of second plate portions 405 may be disposed one on each side or opposite sides of the first plate portion 403, with the first plate portion 403 situated between the pair of second plate portions 405. The plate portion 401 may extend in a second direction.

[0147] A terminal connection portion protrudes from the plate portion 401 to connect to the first terminal 530, allowing current to flow between them. The terminal connection portion may include a first contact protrusion 411 protruding from the first plate portion 403 to connect to the first terminal 530. The first contact protrusion 411 may extend upward in a third direction. In one embodiment, the cross-sectional shape of the first contact protrusion 411 may be circular. As described above, the thin portion 533 of the first terminal 530 may be welded to the first contact protrusion 411.

[0148] The heat capacity increase portion protrudes from the plate portion 401 and does not contact the cover plate 501 and the first terminal 530. The heat capacity increase portion may include a first non-contact protrusion 421 protruding from the second plate portion 405 toward the cover plate 501. For example, the first non-contact protrusion 421 may be provided as a pair of first non-contact protrusions 421 disposed one-to-one on a pair of second plate portions 405.

[0149] The second plate portion 405 can be soldered to the first electrode tab 301. For example, the first internal electrode tab 310 belonging to the first electrode tab 301 can be soldered to the second plate portion 405 closer to the vent 505 in a pair of second plate portions 405, and the first external electrode tab 320 can be soldered to the other second plate portion 405.

[0150] The second plate portion 405 may include weld portions 407 formed at each welded portion in the electrode tabs 310 and 320. The weld portions 407 may be formed to extend in a straight line in a first direction and to be spaced apart from each other in a second direction.

[0151] The first non-contact protrusion 421 may protrude from the second plate portion 405 and avoid the weld portion 407. The first non-contact protrusion 421 may be configured to be offset to one side in the width direction of the second plate portion 405. For example, based on Figure 6 The weld portion 407 formed by welding to the first internal electrode terminal piece 310 is positioned biased in the negative (-) direction of the X-axis, and the weld portion 407 formed by welding to the first external electrode terminal piece 320 is positioned biased in the positive (+) direction of the X-axis.

[0152] Accordingly, a first non-contact protrusion 421 protruding from the second plate portion 405 closer to the exhaust port 505 of a pair of second plate portions 405 can be positioned biased in the positive (+) direction of the X-axis, and a first non-contact protrusion 421 protruding from the other second plate portion 405 can be positioned biased in the negative (-) direction of the X-axis.

[0153] The first non-contact protrusion 421 can extend parallel to the longitudinal direction of the second plate portion 405. Figure 5 and Figure 6 In the embodiment illustrated in the figure, the longitudinal direction of the plate portion 401 and the longitudinal direction of the second plate portion 405 may be parallel to the second direction, and the width direction of the plate portion 401 and the width direction of the second plate portion 405 may be parallel to the first direction.

[0154] The first non-contact protrusion 421 can be provided as a total of a pair of first non-contact protrusions 421 disposed one-to-one on a pair of second plate portions 405. In one embodiment, the pair of first non-contact protrusions 421 can be symmetrically positioned around the first contact protrusion 411.

[0155] The heat capacity increase portion may further include a second non-contact protrusion 425, which protrudes from the first plate portion 403 toward the terminal 530 and avoids the first contact protrusion 411. The second non-contact protrusion 425 may extend parallel to the longitudinal direction of the plate portion 401.

[0156] The second non-contact protrusion 425 can be provided as a plurality of second non-contact protrusions 425. For example, the second non-contact protrusions 425 can be provided as a pair of second non-contact protrusions 425. In one embodiment, the plurality of second non-contact protrusions 425 can be symmetrically positioned around the first contact protrusion 411.

[0157] Of the pair of current collectors 400A included in the secondary battery 100, one current collector 400A, which is connected to the first internal electrode terminal 310 and the first external electrode terminal 320 of the first electrode terminal 301, has already been described in more detail above. However, the other current collector 400A may be the same as the current collector 400A described above, except that it is connected to the second internal electrode terminal 330 and the second external electrode terminal 340 of the second electrode terminal 302, and its repeated description will be omitted.

[0158] Figure 5 and Figure 6 The current collector 400A shown in the figure includes a heat capacity increasing section, which increases the heat capacity and thus reduces the heat generation of the current collector 400A in the secondary battery 100. Accordingly, overheating and fire caused by overheating in the secondary battery 100 can be prevented or substantially prevented during charging or discharging of the secondary battery 100.

[0159] refer to Figures 1 to 4 , Figure 7 and Figure 8 The secondary battery 100 disclosed herein may include Figure 7 and Figure 8 The current collector shown in the diagram is 400B, not... Figure 2 and Figure 4 The current collector component shown in the diagram is 400A.

[0160] Current collectors 400B are provided as a pair, each corresponding to a pair of terminals 530 and 540. Each current collector 400B includes a plate portion 401, a terminal connection portion, and a heat capacity increase portion. The plate portion 401 is connected to each of the electrode tabs 301 and 302, allowing current to flow between them. The current collector 400B corresponding to the first terminal 530 can be connected to the first electrode tab 301, and the current collector 400B corresponding to the second terminal 540 can be connected to the second electrode tab 302. The current collectors 400B connected to the first terminal 530 and the first electrode tab 301 will be described in more detail here.

[0161] The plate portion 401 includes a first plate portion 403 positioned to overlap with the first terminal 530 in a third direction, and a second plate portion 405 extending from the first plate portion 403 in a stepped shape and connected to the first electrode tab 301. The second plate portions 405 may be provided as a pair. The pair of second plate portions 405 may be disposed one on each side or opposite sides of the first plate portion 403, with the first plate portion 403 situated between the pair of second plate portions 405. The plate portion 401 may extend in a second direction.

[0162] A terminal connection portion protrudes from the plate portion 401 to connect to the first terminal 530, allowing current to flow between them. The terminal connection portion may include a first contact protrusion 411 protruding from the first plate portion 403 to connect to the first terminal 530. The first contact protrusion 411 may extend upward in a third direction. In one embodiment, the cross-sectional shape of the first contact protrusion 411 may be circular. As described above, the thin portion 533 of the first terminal 530 may be welded to the first contact protrusion 411.

[0163] The heat capacity increase portion protrudes from the plate portion 401 and does not contact the cover plate 501 and the first terminal 530. The heat capacity increase portion may include a first non-contact protrusion 431 protruding from the second plate portion 405 toward the cover plate 501. For example, the first non-contact protrusion 431 may be provided as a plurality of first non-contact protrusions 431 disposed on the second plate portion 405.

[0164] The second plate portion 405 can be soldered to the first electrode terminal piece 301. For example, the first inner electrode terminal piece 310 of the first electrode terminal piece 301 can be soldered to the second plate portion 405 closer to the vent 505 in a pair of second plate portions 405, and the first outer electrode terminal piece 320 can be soldered to the other second plate portion 405.

[0165] The second plate portion 405 may include a welding portion 407 formed at the portions where it is welded to the electrode tabs 310 and 320. In one embodiment, the welding portions 407 may be formed to extend in a straight line in a first direction and to be spaced apart from each other in a second direction.

[0166] The first non-contact protrusion 431 may protrude from the second plate portion 405 and avoid the welding portion 407. The first non-contact protrusion 431 may be configured to be offset to one side in the width direction of the second plate portion 405. For example, based on Figure 8 The weld portion 407 formed by welding to the first internal electrode terminal piece 310 can be positioned biased in the negative (-) direction of the X-axis, and the weld portion 407 formed by welding to the first external electrode terminal piece 320 can be positioned biased in the positive (+) direction of the X-axis.

[0167] Accordingly, a first non-contact protrusion 431 protruding from the second plate portion 405 closer to the exhaust port 505 of a pair of second plate portions 405 can be positioned biased in the positive (+) direction of the X-axis, and a first non-contact protrusion 431 protruding from the other second plate portion 405 can be positioned biased in the negative (-) direction of the X-axis.

[0168] The first non-contact protrusion 431 may extend upward in a third direction. The cross-sectional shape of the first non-contact protrusion 431 may be, for example, circular. Figure 7 and Figure 8 In the embodiment illustrated in the figure, the longitudinal direction of the plate portion 401 and the longitudinal direction of the second plate portion 405 may be parallel to the second direction, and the width direction of the plate portion 401 and the width direction of the second plate portion 405 may be parallel to the first direction.

[0169] A plurality of first non-contact protrusions 431 located on the second plate portion 405 may be arranged along the longitudinal direction of the second plate portion 405. In one embodiment, the plurality of first non-contact protrusions 431 may be symmetrically positioned around a first contact protrusion 411.

[0170] The heat capacity increase portion may further include a second non-contact protrusion 435, which protrudes from the first plate portion 403 toward the terminal 530 and avoids or is spaced apart from the first contact protrusion 411. The second non-contact protrusion 435 may extend upward in a third direction. The cross-sectional shape of the second non-contact protrusion 435 may be, for example, circular.

[0171] The second non-contact protrusion 435 can be provided as a plurality of second non-contact protrusions 435. The plurality of second non-contact protrusions 435 can be arranged along the longitudinal direction of the plate portion 401. In one embodiment, the plurality of second non-contact protrusions 435 can be symmetrically positioned around the first contact protrusion 411.

[0172] Of the pair of current collectors 400B included in the secondary battery 100, the current collector 400B that is connected to the first internal electrode terminal 310 and the first external electrode terminal 320 of the first electrode terminal 301 has already been described above. In one embodiment, the other current collector 400B is identical to the aforementioned current collector 400B, except that another current collector 400B is connected to the second internal electrode terminal 330 and the second external electrode terminal 340 of the second electrode terminal 302, and its repeated description will be omitted.

[0173] Figure 7 and Figure 8 The current collector 400B shown in the figure includes a heat capacity increasing section, which increases the heat capacity and thus reduces the heat generation of the current collector 400B in the secondary battery 100. Accordingly, overheating and fire caused by overheating in the secondary battery 100 can be prevented or substantially prevented during charging or discharging of the secondary battery 100.

[0174] refer to Figures 1 to 4 , Figure 9 and Figure 10The secondary battery 100 disclosed herein may include Figure 9 and Figure 10 The current collector shown in the diagram is 400C, not... Figure 2 and Figure 4 The current collector component shown in the diagram is 400A.

[0175] A pair of current collectors 400C are provided to correspond one-to-one with a pair of terminals included in the secondary battery 100. Each current collector 400C includes a plate portion 401, a terminal connection portion, and a heat capacity increasing portion. The plate portion 401 is connected to each of the electrode tabs 301 and 302, allowing current to flow between them. The pair of terminals includes a first terminal 530A and a second terminal (not shown).

[0176] The current collector 400C corresponding to the first terminal 530A can be connected to the first electrode terminal 301, and the current collector 400C corresponding to the second terminal can be connected to the second electrode terminal 302. Here, the current collector 400C connected to the first terminal 530A and the first electrode terminal 301 will be described in more detail.

[0177] The plate portion 401 includes a first plate portion 403 positioned to overlap with the first terminal 530A in a third direction, and a second plate portion 405 extending from the first plate portion 403 in a stepped shape and connected to the first electrode tab 301. The second plate portions 405 may be provided as a pair. The pair of second plate portions 405 may be disposed one on each side or opposite sides of the first plate portion 403, with the first plate portion 403 situated between the pair of second plate portions 405. The plate portion 401 may extend in a second direction.

[0178] A terminal connection portion protrudes from the plate portion 401 to connect to the first terminal 530A, allowing current to flow between them. The terminal connection portion may include a first contact protrusion 411 protruding from the first plate portion 403 to connect to the first terminal 530A. The first contact protrusion 411 may extend upward in a third direction. In one embodiment, the cross-sectional shape of the first contact protrusion 411 may be circular. As described above, the thin portion 533 of the first terminal 530A may be welded to the first contact protrusion 411.

[0179] The terminal connection portion further includes a second contact protrusion 414 that protrudes from the first plate portion 403 and avoids the first contact protrusion 411 to connect to the first terminal 530A. The first terminal 530A may include a raised through-hole 535 into which the end portion of the second contact protrusion 414 is inserted. In one embodiment, the end portion of the second contact protrusion 414 inserted into the raised through-hole 535 is soldered to the inner surface of the raised through-hole 535, and the second contact protrusion 414 and the first terminal 530A can be connected to allow current to flow between them.

[0180] The second contact protrusion 414 may extend in the longitudinal direction of the plate portion 401. The planar shape of the second contact protrusion 414 may be, for example, a quadrilateral shape, which is elongated in the direction parallel to the longitudinal direction of the plate portion 401. The protruding through-hole 535 may be an elongated hole extending to a length corresponding to the cross-sectional shape of the second contact protrusion 414.

[0181] In one embodiment, the end portion of the second contact protrusion 414 in the positive (+) direction of the Z-axis can be fitted into the protrusion through hole 535 and fixed to the inner surface of the protrusion through hole 535 by welding.

[0182] The second contact protrusion 414 can be provided as a plurality of second contact protrusions 414. For example, the second contact protrusion 414 can be provided as a pair of second contact protrusions 414. In one embodiment, the pair of second contact protrusions 414 can be symmetrically positioned around the first contact protrusion 411. The pair of second contact protrusions 414 can be located on two end portions or opposite end portions of the plate portion 401 in the width direction.

[0183] The heat capacity increase portion protrudes from the plate portion 401 and does not contact the cover plate 501 and the first terminal 530A. The heat capacity increase portion may include a first non-contact protrusion 421 protruding from the second plate portion 405 toward the cover plate 501. For example, the first non-contact protrusion 421 may be provided as a pair of first non-contact protrusions 421 disposed one-to-one on a pair of second plate portions 405.

[0184] The second plate portion 405 can be soldered to the first electrode terminal piece 301. For example, the first inner electrode terminal piece 310 of the first electrode terminal piece 301 can be soldered to the second plate portion 405 closer to the vent 505 in a pair of second plate portions 405, and the first outer electrode terminal piece 320 can be soldered to the other second plate portion 405.

[0185] The second plate portion 405 may include a welding portion 407 formed at the portions where it is welded to the electrode tabs 310 and 320. In one embodiment, the welding portions 407 may be formed to extend in a straight line in a first direction and to be spaced apart from each other in a second direction.

[0186] A first non-contact protrusion 421 may protrude from the second plate portion 405 and avoid the weld portion 407. The first non-contact protrusion 421 may be positioned offset to one side in the width direction of the second plate portion 405. For example, based on... Figure 10 The weld portion 407 formed by welding to the first internal electrode terminal piece 310 is positioned biased in the negative (-) direction of the X-axis, and the weld portion 407 formed by welding to the first external electrode terminal piece 320 is positioned biased in the positive (+) direction of the X-axis.

[0187] Accordingly, a first non-contact protrusion 421 protruding from the second plate portion 405 closer to the exhaust port 505 of a pair of second plate portions 405 can be positioned biased in the positive (+) direction of the X-axis, and a first non-contact protrusion 421 protruding from the other second plate portion 405 can be positioned biased in the negative (-) direction of the X-axis.

[0188] The first non-contact protrusion 421 can be provided as a total of a pair of first non-contact protrusions 421 disposed one-to-one on a pair of second plate portions 405. In one embodiment, the pair of first non-contact protrusions 421 can be symmetrically positioned around the first contact protrusion 411.

[0189] Of the pair of current collectors 400C included in the secondary battery 100, the first internal electrode terminal 310 and the first external electrode terminal 320 connected to the first terminal 530A and the first electrode terminal 301 have already been described above. In one embodiment, except that the remaining current collectors 400C are connected to the second terminal and the second internal electrode terminal 330 and the second external electrode terminal 340 of the second electrode terminal 302, the remaining current collectors 400C may be the same as the current collectors 400C described above, and their repeated description will be omitted.

[0190] Figure 9 and Figure 10 The current collector 400C shown in the figure includes a heat capacity increasing section, which increases the heat capacity, thereby reducing the heat generation of the current collector 400C in the secondary battery 100. Accordingly, overheating and fire caused by overheating in the secondary battery 100 can be prevented or substantially prevented during charging or discharging of the secondary battery 100.

[0191] Furthermore, in the current collector 400C, since the terminal connection portion includes a second contact protrusion 414, a larger current can easily flow between the first terminal 530A and the current collector 400C. Accordingly, the heat generation of the current collector 400C can be further reduced, and the secondary battery can be charged or discharged more quickly.

[0192] refer to Figures 1 to 4 , Figure 11 and Figure 12 The secondary battery 100 of the present invention may include Figure 11 and Figure 12 The current collector shown in the diagram is 400D, not... Figure 2 and Figure 4 The current collector component shown in the diagram is 400A.

[0193] A pair of current collectors 400D are provided to correspond one-to-one with a pair of terminals included in the secondary battery 100. Each current collector 400D includes a plate portion 401, a terminal connection portion, and a heat capacity increasing portion. The plate portion 401 is connected to each of the electrode tabs 301 and 302, allowing current to flow between them. The pair of terminals includes a first terminal 530B and a second terminal (not shown).

[0194] The current collector 400D corresponding to the first terminal 530B can be connected to the first electrode terminal 301, and the current collector 400D corresponding to the second terminal can be connected to the second electrode terminal 302. Here, the current collector 400D connected to the first terminal 530B and the first electrode terminal 301 will be described in more detail.

[0195] The plate portion 401 includes a first plate portion 403 positioned to overlap with the first terminal 530B in a third direction, and a second plate portion 405 extending from the first plate portion 403 in a stepped shape and connected to the first electrode tab 301. The second plate portions 405 may be provided as a pair. The pair of second plate portions 405 may be disposed one on each side or opposite sides of the first plate portion 403, with the first plate portion 403 situated between the pair of second plate portions 405. The plate portion 401 may extend in a second direction.

[0196] A terminal connection portion protrudes from the plate portion 401 to connect to the first terminal 530B, allowing current to flow between them. The terminal connection portion may include a first contact protrusion 411 protruding from the first plate portion 403 to connect to the first terminal 530B. The first contact protrusion 411 may extend upward in a third direction. In one embodiment, the cross-sectional shape of the first contact protrusion 411 may be circular. As described above, the thin portion 533 of the first terminal 530B may be welded to the first contact protrusion 411.

[0197] The terminal connection portion further includes a second contact protrusion 417 that protrudes from the first plate portion 403 and avoids the first contact protrusion 411 to connect to the first terminal 530B. The first terminal 530B may include a raised through-hole 537 into which the end portion of the second contact protrusion 417 is inserted. In one embodiment, the end portion of the second contact protrusion 417 inserted into the raised through-hole 537 is soldered to the inner surface of the raised through-hole 537, and the second contact protrusion 417 and the first terminal 530B can be connected to allow current to flow between them.

[0198] The second contact protrusion 417 may extend upward in a third direction to contact the first terminal 530B. The cross-sectional shape of the second contact protrusion 417 may be, for example, circular. The through-hole 537 may be a circular through-hole corresponding to the cross-sectional shape of the second contact protrusion 417.

[0199] The end portion of the second contact protrusion 417 in the positive (+) direction of the Z-axis can be fitted into the protrusion through hole 537 and fixed to the inner surface of the protrusion through hole 537 by welding.

[0200] The second contact protrusion 417 can be provided as a plurality of second contact protrusions 417 disposed apart from each other. In one embodiment, the plurality of second contact protrusions 417 can be symmetrically positioned around the first contact protrusion 411. In one embodiment, the same number of the plurality of second contact protrusions 417 can be arranged at two end portions or opposite end portions of the plate portion 401 in its width direction.

[0201] The heat capacity increase portion protrudes from the plate portion 401 and does not contact the cover plate 501 and the first terminal 530B. The heat capacity increase portion may include a first non-contact protrusion 431 protruding from the second plate portion 405 toward the cover plate 501. For example, the first non-contact protrusion 431 may be provided as a plurality of first non-contact protrusions 431 disposed on the second plate portion 405.

[0202] The second plate portion 405 can be soldered to the first electrode terminal piece 301. For example, the first inner electrode terminal piece 310 of the first electrode terminal piece 301 can be soldered to the second plate portion 405 closer to the vent 505 in a pair of second plate portions 405, and the first outer electrode terminal piece 320 can be soldered to the other second plate portion 405.

[0203] The second plate portion 405 may include a welding portion 407 formed at the portions where it is welded to the electrode tabs 310 and 320. In one embodiment, the welding portions 407 may be formed to extend in a straight line in a first direction and to be spaced apart from each other in a second direction.

[0204] The first non-contact protrusion 431 may protrude from the second plate portion 405 and avoid the weld portion 407. The first non-contact protrusion 431 may be positioned offset to one side in the width direction of the second plate portion 405. For example, based on Figure 12 The weld portion 407 formed by welding to the first internal electrode terminal piece 310 is positioned biased in the negative (-) direction of the X-axis, and the weld portion 407 formed by welding to the first external electrode terminal piece 320 is positioned biased in the positive (+) direction of the X-axis.

[0205] Accordingly, a first non-contact protrusion 431 protruding from the second plate portion 405 closer to the exhaust port 505 of a pair of second plate portions 405 can be positioned biased in the positive (+) direction of the X-axis, and a first non-contact protrusion 431 protruding from the other second plate portion 405 can be positioned biased in the negative (-) direction of the X-axis.

[0206] The first non-contact protrusion 431 may extend upward in a third direction. The cross-sectional shape of the first non-contact protrusion 431 may be, for example, circular. A plurality of first non-contact protrusions 431 located on the second plate portion 405 may be arranged along the longitudinal direction of the second plate portion 405. In one embodiment, a plurality of first non-contact protrusions 431 may be symmetrically positioned around the first contact protrusion 411.

[0207] Of the pair of current collectors 400D included in the secondary battery 100, the first internal electrode terminal 310 and the first external electrode terminal 320 connected to the first terminal 530B and the first electrode terminal 301 have already been described above. Except for another current collector 400D connected to the second terminal and the second internal electrode terminal 330 and the second external electrode terminal 340 of the second electrode terminal 302, the other current collector 400D may be identical to the aforementioned current collectors 400D, and its repeated description will be omitted.

[0208] Figure 11 and Figure 12 The current collector 400D shown in the figure includes a heat capacity increasing section, which increases the heat capacity and thus reduces the heat generation of the current collector 400D in the secondary battery 100. Accordingly, overheating and fire caused by overheating in the secondary battery 100 can be prevented or substantially prevented during charging or discharging of the secondary battery 100.

[0209] Furthermore, in the current collector 400D, since the terminal connection portion includes a second contact protrusion 417, a larger current can easily flow between the first terminal 530B and the current collector 400D. Accordingly, the heat generation of the current collector 400C can be further reduced, and the secondary battery can be charged or discharged more quickly.

[0210] Figure 13 This is a schematic perspective view illustrating the structure of a battery pack according to an embodiment of the present invention. (Reference) Figure 1 and Figure 13 According to an embodiment of the present invention, the battery pack 1 may include a housing 10, a secondary battery 100, and a busbar 3.

[0211] The housing 10 can form the overall appearance of the battery pack 1 and provide space to accommodate the secondary battery 100.

[0212] The housing 10 according to an embodiment may include a housing body 11 and a cover 12. The housing body 11 may be formed as a hollow box shape with an open side. However, the cross-sectional shape of the housing body 11 is not limited to this. Figure 13 The quadrilateral shape shown in the figure, and the design of the outer shell body 11 can be changed to any of various shapes such as other polygonal shapes, circular shapes and elliptical shapes.

[0213] The cover 12 can be attached to the housing body 11 and can close the interior space of the housing body 11. As an example, the cover 12 can be formed in a generally plate shape to face the open side of the housing body 11. The cover 12 can be secured to the housing body 11 by any of a variety of connection methods such as bolting, welding, and mating.

[0214] The secondary battery 100 can be used as a unit structure in the battery pack 1 for storing and supplying power.

[0215] The secondary battery 100 can be provided as multiple secondary batteries 100. The multiple secondary batteries 100 can be arranged in the longitudinal direction of the housing 10 (based on...). Figure 13 (in the X-axis direction) and width direction (based on) Figure 13 It can be arranged in two or more rows in any direction (Y-axis direction). Although Figure 13 An example is shown where multiple secondary batteries 100 are arranged in six rows along the longitudinal direction of the housing 10; however, the arrangement of the multiple secondary batteries 100 is not limited to this, and its design can be varied. The multiple secondary batteries 100 can be arranged parallel to each other. The number of secondary batteries 100 can be varied depending on the size, shape, etc., of the housing 10.

[0216] In a pair of adjacent secondary batteries 100, the first terminal 530 of one secondary battery 100 and the second terminal 540 of the other secondary battery 100 can be arranged to face each other in the longitudinal direction of the housing 10. That is, in adjacent secondary batteries 100, the front portion 120 of one secondary battery 100 can be arranged to face the rear portion 130 of the other secondary battery 100.

[0217] Multiple secondary batteries 100 can be electrically connected via busbar 3.

[0218] According to the embodiment, the busbar 3 can be disposed between the cover 12 and the secondary battery 100. Multiple busbars 3 can be provided. Each busbar 3 can connect a pair of adjacent secondary batteries 100 in series or in parallel.

[0219] As an example, busbar 3 can be connected to the first terminal 530 of one of a pair of adjacent secondary batteries 100 (see...). Figure 1 ) and the second terminal 540 of the other one (see Figure 1 Accordingly, multiple secondary batteries 100 can be connected in series via busbar 3.

[0220] However, the connection form of the busbar 3 is not limited to this, and the two sides or opposite sides of the busbar 3 can be connected to the first terminal 530 of any one of a pair of adjacent secondary batteries 100 and the second terminal 540 of the other one, or connected to the second terminal 540 of any one of a pair of adjacent secondary batteries 100 and the second terminal 540 of the other one.

[0221] Busbar 3 can be made of conductive materials such as copper, aluminum, or nickel. However, the specific shape of busbar 3 is not limited to this. Figure 13 The shape shown in the diagram is such that its design can be modified in various ways to electrically connect adjacent secondary batteries 100.

[0222] Multiple busbars 3 can be supported by busbar brackets 20 within the housing 10.

[0223] According to an embodiment, the busbar support 20 can be formed in a flat plate shape. The busbar support 20 can be disposed between the cover 12 and the secondary battery 100. The busbar 3 can be fixed to the busbar support 20 by any of a variety of connection methods such as mating, bolting, and injection molding. In one embodiment, the busbar support 20 can be formed of an electrically insulating polymer composite material.

[0224] According to embodiments of the present invention, the thermal capacity of the current collector is increased to reduce the heat generation of the current collector in the secondary battery. Accordingly, overheating and fires caused by overheating in the secondary battery can be prevented or substantially prevented during charging or discharging of the secondary battery.

[0225] However, the aspects and features of the present invention are not limited to those described above, and those skilled in the art will clearly understand from the detailed description provided above that other aspects and features not mentioned are also present.

[0226] Although the invention has been described with reference to some embodiments and accompanying drawings illustrating aspects thereof, the invention is not limited thereto. Those skilled in the art to which this invention pertains will be able to make various modifications and variations within the spirit of the invention and the claims and their equivalents.

Claims

1. A secondary battery, comprising: The casing, including the opening; Electrode assembly, housed within the housing; Electrode terminals are connected to the electrode assembly; Cover plate, to close the opening; Terminals are connected to the cover plate; as well as A current collector includes a plate portion, a terminal connection portion, and a heat capacity increasing portion. The plate portion is connected to the electrode terminal piece, allowing current to flow between the plate portion and the electrode terminal piece. The terminal connection portion protrudes from the plate portion to connect to the terminal, allowing current to flow between the terminal connection portion and the terminal. The heat capacity increasing portion protrudes from the plate portion and does not contact the cover plate or the terminal.

2. The secondary battery according to claim 1, wherein the plate portion comprises: The first plate portion overlaps with the terminal; as well as The second plate extends from the first plate in a stepped shape and connects to the electrode terminals. The terminal connection portion includes a first contact protrusion that protrudes from the first plate portion to connect to the terminal.

3. The secondary battery according to claim 2, wherein... The terminal includes a thick portion and a thin portion that is thinner than the thick portion, and The thin portion is welded to the first contact protrusion.

4. The secondary battery according to claim 2, wherein the terminal connection portion further includes a second contact protrusion that protrudes from the first plate portion and avoids the first contact protrusion to connect to the terminal.

5. The secondary battery according to claim 4, wherein... The terminal includes a raised through-hole, and the end portion of the second contact protrusion is inserted into the raised through-hole. The end portion of the second contact protrusion that is inserted into the through hole of the protrusion is welded to the inner surface of the through hole of the protrusion.

6. The secondary battery according to claim 4, wherein The second contact protrusion includes a plurality of second contact protrusions, and The plurality of second contact protrusions are symmetrically positioned around the first contact protrusion.

7. The secondary battery according to claim 4, wherein... The second contact protrusion includes a plurality of second contact protrusions, and The plurality of second contact protrusions are located at opposite end portions of the plate portion in the width direction.

8. The secondary battery according to claim 2, wherein the heat capacity increasing portion includes a first non-contact protrusion protruding from the second plate portion toward the cover plate.

9. The secondary battery according to claim 8, wherein The second plate portion is welded to the electrode terminal piece; The second plate portion includes a welded portion on the portion welded to the electrode terminal piece; and The first non-contact protrusion protrudes from the second plate portion and avoids the welded portion.

10. The secondary battery of claim 9, wherein the first non-contact protrusion is positioned biased to one side in the width direction of the second plate portion.

11. The secondary battery of claim 8, wherein the first non-contact protrusion extends parallel to the longitudinal direction of the second plate portion.

12. The secondary battery according to claim 8, wherein The first non-contact protrusion includes a plurality of first non-contact protrusions, and The plurality of first non-contact protrusions are arranged along the longitudinal direction of the second plate portion.

13. The secondary battery according to claim 8, wherein The first non-contact protrusion includes a plurality of first non-contact protrusions, and The plurality of first non-contact protrusions are symmetrically positioned around the first contact protrusion.

14. The secondary battery of claim 8, wherein the heat capacity increasing portion further includes a second non-contact protrusion that protrudes from the first plate portion toward the terminal and avoids the first contact protrusion.

15. The secondary battery of claim 14, wherein the second non-contact protrusion extends parallel to the longitudinal direction of the plate portion.

16. The secondary battery according to claim 14, wherein The second non-contact protrusion includes a plurality of second non-contact protrusions, and The plurality of second non-contact protrusions are arranged along the longitudinal direction of the plate portion.

17. The secondary battery according to claim 14, wherein The second non-contact protrusion includes a plurality of second non-contact protrusions, and The plurality of second non-contact protrusions are symmetrically positioned around the first contact protrusion.

18. The secondary battery according to any one of claims 1 to 17, further comprising: An insulator is located within the housing between the cover plate and the electrode assembly, and includes insulating material.

19. The secondary battery according to claim 18, wherein the insulator comprises: The base portion is located between the cover plate and the heat capacity increasing portion; as well as An insulating reinforcement layer is stacked on the substrate portion.

20. A battery pack, comprising: shell; as well as Multiple secondary batteries are housed within the casing; Each of the plurality of secondary batteries is a secondary battery according to any one of claims 1 to 19.

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