Secondary battery and battery pack comprising same

Abstract

Disclosed are a secondary battery and a battery pack. A secondary battery includes: a case including an opening; the electrode assembly is arranged in the shell; an upper cover disposed in the opening; a lower cover facing the upper cover and connected to the electrode assembly; the exhaust plate is arranged between the upper cover and the lower cover and comprises a first exhaust surface and a second exhaust surface which are opposite to each other; a first notch concavely formed from the first exhaust surface toward the second exhaust surface; and a second notch concavely formed from the second exhaust surface toward the first exhaust surface.

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] Typically, due to the recent surge in 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. Therefore, research and development to improve the performance of lithium-ion rechargeable batteries is actively underway.

[0003] A lithium secondary battery is a battery that includes a positive electrode, a negative electrode, and an electrolyte. The positive and negative electrodes contain active materials capable of inserting and deintercalating lithium ions, and the lithium secondary battery generates energy through oxidation / reduction reactions when lithium ions are inserted / deintercalated at the positive and negative electrodes.

[0004] The above information, disclosed in the art that forms the background of this disclosure, is provided to improve the understanding of the background of this disclosure and may therefore include information that does not constitute related art. Summary of the Invention

[0005] According to an embodiment of the present disclosure, a secondary battery and battery pack are provided that can reduce the deformation of the exhaust plate when the internal pressure of the housing increases.

[0006] The above and other aspects and features of this disclosure will be described in the following description of some embodiments of this disclosure, or will become apparent from the following description of some embodiments 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 disposed in the housing; a top cover disposed in the opening; a bottom cover facing the top cover and connected to the electrode assembly; an exhaust plate disposed between the top cover and the bottom cover, and including a first exhaust surface and a second exhaust surface opposite to each other; a first recess formed recessed from the first exhaust surface toward the second exhaust surface; and a second recess formed recessed from the second exhaust surface toward the first exhaust surface.

[0008] The first exhaust surface may face the upper cover, and the second exhaust surface may face the lower cover.

[0009] The first notch and the second notch can face each other.

[0010] The second notch may be forged.

[0011] The width of at least a portion of the second notch may be greater than the width of the first notch.

[0012] The depth of the second notch can be greater than the depth of the first notch.

[0013] The width of the first notch can decrease toward the second exhaust surface.

[0014] The cross-sectional shape of the first notch can be trapezoidal.

[0015] The cross-sectional shape of the first notch can be triangular.

[0016] The width of the second notch can decrease toward the first exhaust surface.

[0017] The cross-sectional shape of the second notch can be trapezoidal.

[0018] The cross-sectional shape of the second notch can be triangular.

[0019] The exhaust plate may further include a bridging portion between the first recess and the second recess.

[0020] The thickness of the bridging portion can be greater than or equal to 0.04 mm and less than or equal to 0.1 mm.

[0021] The secondary battery may further include an extended notch that is connected to the second notch and recessed from the end portion of the second notch facing the first notch toward the first exhaust surface.

[0022] The width of the extended notch can be smaller than the width of the second notch.

[0023] The secondary battery may further include a third recess formed recessed from the first exhaust surface toward the second exhaust surface and spaced apart from the first recess.

[0024] The first notch and the second notch may face each other, and the third notch and the second notch may be misaligned.

[0025] The depth of the third notch can be greater than the depth of the first notch.

[0026] According to one or more embodiments of the present disclosure, a battery pack includes: a housing; and a plurality of secondary batteries housed in the housing, wherein each of the plurality of secondary batteries includes: a casing including an opening; an electrode assembly in the casing; a top cover disposed in the opening; a bottom cover facing the top cover and connected to the electrode assembly; an exhaust plate between the top cover and the bottom cover, and including a first exhaust surface and a second exhaust surface opposite to each other; a first recess formed recessed from the first exhaust surface toward the second exhaust surface; and a second recess formed recessed from the second exhaust surface toward the first exhaust surface. Attached Figure Description

[0027] The accompanying drawings illustrate some embodiments of this disclosure and further describe aspects and features of this disclosure together with the detailed description thereof. However, this disclosure should not be construed as limited to the drawings.

[0028] Figure 1 This is a perspective view schematically illustrating the configuration of a secondary battery according to an embodiment of the present disclosure;

[0029] Figure 2 It is an illustrative example. Figure 1 A cross-sectional view of the configuration of the secondary battery;

[0030] Figure 3 This is a view that schematically illustrates the configuration of a cover assembly according to an embodiment of the present disclosure;

[0031] Figure 4 yes Figure 3 A magnified view of half of the cover component;

[0032] Figure 5 This is a view schematically illustrating the configuration of a first notch and a second notch according to an embodiment of the present disclosure;

[0033] Figure 6 This is a view schematically illustrating a modified operation of an exhaust plate according to an embodiment of the present disclosure;

[0034] Figure 7 This is a view schematically illustrating the configuration of a first notch and a second notch according to another embodiment of the present disclosure;

[0035] Figure 8 This is a view schematically illustrating the configuration of a first notch and a second notch according to another embodiment of the present disclosure;

[0036] Figure 9 This is a view schematically illustrating the configuration of a first notch and a second notch according to another embodiment of the present disclosure;

[0037] Figure 10This is a view schematically illustrating the configuration of an extended notch according to another embodiment of the present disclosure;

[0038] Figure 11 This is a view schematically illustrating the configuration of a secondary battery according to another embodiment of the present disclosure;

[0039] Figure 12 This is a view schematically illustrating the configuration of a third notch according to an embodiment of the present disclosure; and

[0040] Figure 13 This is a perspective view schematically illustrating the configuration of a battery pack according to an embodiment of the present disclosure. Detailed Implementation

[0041] In this document, some embodiments of the present disclosure will be described in further 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 consistent with the technical spirit of the present disclosure, based on the inventor's ability to be his / her own lexicographer to appropriately define the terms.

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

[0043] It should be understood that when a component or layer is described as being "on," "connected to," or "attached to" another component or layer, it can be directly on, connected to, or attached to the other component or layer, or one or more intermediate components or layers may be present. When a component or layer is described as being "directly" on, directly connected to, or directly attached to another component or layer, no intermediate components or layers are present. For example, when a first component is described as being "attached" or "connected" to a second component, the first component can be directly attached to or connected to the second component, or the first component can be indirectly attached to or connected to the second component via one or more intermediate components.

[0044] In the accompanying drawings, the dimensions of individual elements, layers, etc., may be enlarged for clarity of illustration. The same reference numerals indicate the same or similar elements. As used herein, the term "and / or" includes any and all combinations of one or more associated listed items. 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 before / after the list of elements, rather than modifying individual elements in the 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 of A, B, and C," or "at least one selected from A, B, and C" are used to specify a list of elements A, B, and C, the phrase may refer to any and all suitable combinations or subsets of A, B, and C, 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,” “about,” and similar terms are used as approximations rather than terms of degree and are intended to take into account the inherent variations in measurements or calculations that would be apparent to a person 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 portions, these elements, components, regions, layers, and / or portions are not limited by these terms. These terms are used to distinguish one element, component, region, layer, or portion from another element, component, region, layer, or portion. Therefore, without departing from the teachings of the exemplary embodiments, the first element, component, region, layer, or portion discussed below may be referred to as the second element, component, region, layer, or portion.

[0046] For ease of description, this document uses spatial relative terms such as “below,” “under,” “down,” “above,” and “up” to describe the relationship between one element or feature and another element or feature as shown in the figures. It should be understood that spatial relative terms are intended to encompass different orientations of the device in use or operation, in addition to the orientation depicted in the figures. For example, if the device in the figures is flipped, an element described as “below” or “under” other elements or features can be oriented as “above” or “upon” other elements or features. Thus, the term “below” can encompass both above and below orientations. The device can be positioned in other ways (e.g., rotated 90 degrees or in other orientations), and the spatial relative descriptors 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 is intended to include the plural form as well, unless the context expressly indicates otherwise. It should be further understood that the terms “comprising” and / or “including” as used in this specification 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 ranges disclosed and / or enumerated herein are intended to include all subranges with the same numerical precision contained within the enumerated ranges. For example, the range “1.0 to 10.0” is intended to include all subranges between (and including) the enumerated minimum value of 1.0 and the enumerated maximum value of 10.0, i.e., a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0, such as 2.4 to 7.6. Any maximum numerical limit enumerated herein is intended to include all lower numerical limits contained therein, and any minimum numerical limit enumerated in this specification is intended to include all higher numerical limits contained therein. Therefore, the applicant reserves the right to amend this specification, including the claims, to expressly enumerate any subranges contained within the scope expressly enumerated herein.

[0049] Referring to two compared elements, features, etc., as “identical” may mean that they are identical or substantially identical. Therefore, the phrase “identical” or “substantially identical” can include cases with deviations considered low in the art, such as less than 5%. Furthermore, when a parameter is said to be consistent in a given region, this may mean that it is consistent in terms of average value.

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

[0051] When any element is described as being arranged (or positioned or placed) "above (or below)" or "on top (or under)" a component, this may mean that the element is positioned to contact the upper (or lower) surface of the component, and may also mean that another component may be located between the component and any arbitrary element arranged (or positioned or placed) on (or under) 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 intermediate components may exist between them, through which the component may be "connected," "linked," or "attached" to the other component. 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 intermediate parts may exist between them, such that the part and the other part are indirectly electrically connected to each other.

[0053] Throughout this specification, unless otherwise stated, when “A and / or B” is stated, it means A, B, or A and B. In other words, “and / or” includes any or all combinations of the listed items. Unless otherwise indicated, when “C to D” is stated, it means C or more and D or fewer.

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

[0055] The terminology used herein is intended to describe embodiments of this disclosure and is not intended to be limiting.

[0056] Figure 1 This is a perspective view schematically illustrating the configuration of a secondary battery according to an embodiment of the present disclosure; and Figure 2 It is an illustrative example. Figure 1 A cross-sectional view of the configuration of the secondary battery.

[0057] refer to Figure 1 and Figure 2 According to one embodiment, the secondary battery 2 may include a housing 100, an electrode assembly 200, a cover assembly 300, a first recess 400, and a second recess 500.

[0058] In this document, the secondary battery 2 will be described as an example of a cylindrical battery as a lithium-ion secondary battery. However, this disclosure is not limited thereto, and the secondary battery 2 may be, for example, a lithium polymer battery or a prismatic battery.

[0059] The housing 100 can generally form the exterior of the secondary battery 2. In one embodiment, the housing 100 can be provided as conductive. For example, the housing 100 can comprise at least one material selected from steel, stainless steel, aluminum, and aluminum alloys. Thus, the housing 100 can protect the electrode assembly 200 from external impacts and perform a heat dissipation function to dissipate the heat generated during the charging and discharging operations of the electrode assembly 200 to the outside.

[0060] According to one embodiment, the housing 100 may include a sidewall portion 110 having a cylindrical shape. The central axis C of the housing 100 may be the central axis of the sidewall portion 110 of the housing 100, which will be described below. In one embodiment, two or opposite end portions of the sidewall portion 110 perpendicular to the central axis C of the housing 100 may be formed as open.

[0061] The housing 100 may further include a bottom portion 120 that closes the lower end portion of the sidewall portion 110. According to one embodiment, the bottom portion 120 may be formed in a generally circular plate shape and may be positioned facing the lower end portion of the sidewall portion 110. The bottom portion 120 may be disposed perpendicular to the central axis C of the housing 100. The circumference of the bottom portion 120 may be joined to the lower end portion of the sidewall portion 110. In one embodiment, the bottom portion 120 may be integrally formed with the sidewall portion 110 by a drawing process or the like, or it may be manufactured separately from the sidewall portion 110 and then joined to the sidewall portion 110 by welding or the like.

[0062] The housing 100 may also include an opening 130 that opens the upper portion of the sidewall portion 110. The opening 130 may provide a path through which the electrode assembly 200, described below, is inserted into the housing 100 in the upper region of the housing 100, and provide space for mounting the cover assembly 300, described below. According to one embodiment, the opening 130 may be an empty space surrounded by the upper region of the sidewall portion 110 located on the opposite side of the bottom portion 120.

[0063] According to one embodiment, the housing 100 may also include a rolled edge portion 140.

[0064] The rolled edge portion 140 may protrude into the housing 100. The rolled edge portion 140 may limit the insertion of the cover assembly 300, which is described below, into the housing 100 beyond a certain or predetermined distance, and may prevent or substantially prevent the electrode assembly 200 from separating from the housing 100.

[0065] According to one embodiment, a rolled edge portion 140 may be provided at the upper end of the sidewall portion 110. The central portion of the rolled edge portion 140 may be recessed toward the central axis C of the housing 100. In one embodiment, the rolled edge portion 140 may be integrally formed with the sidewall portion 110, or it may be manufactured separately from the sidewall portion 110 and then attached to the sidewall portion 110.

[0066] In this document, an example of a secondary battery 2 including a rolled edge portion 140 according to one embodiment will be described, but the present disclosure is not limited thereto, and the secondary battery 2 may be configured with the rolled edge portion 40 omitted.

[0067] Electrolytes can be filled into the housing 100. Electrolytes can be injected into the housing 100 through the opening 130.

[0068] The electrode assembly 200 can be a unit structure that performs charging and discharging operations in the secondary battery 2. 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.

[0069] The electrode assembly 200 can be disposed in the housing 100. The electrode assembly 200 can be inserted into the housing 100 through the opening 130 of the housing 100.

[0070] In one embodiment, the electrode assembly 200 may have a cylindrical shape with a winding hole formed in its central portion. In another embodiment, the electrode assembly 200 may be wound clockwise or counterclockwise around the winding hole while the first electrode 210, diaphragm 230, and second electrode 220 are stacked. Therefore, the electrode assembly 200 may have a generally core-shaped design. The central axis of the winding hole may be coaxial with the central axis C of the housing 100. In addition to a circular shape, the cross-sectional shape of the electrode assembly 200 may be designed to have any of a variety of shapes, such as an elliptical shape, a polygonal shape, etc.

[0071] The first electrode 210, the diaphragm 230, and the second electrode 220 can be arranged in concentric circles from the winding hole along the radial direction of the electrode assembly 200. The two or opposite end portions of each of the first electrode 210, the second electrode 220, and the diaphragm 230, parallel to the central axis C of the housing 100, can be configured to face the bottom portion 120 and the opening 130 of the housing 100, respectively.

[0072] The first electrode 210 can be used as the positive electrode of the electrode assembly 200. The first electrode 210 can be formed in the form of a foil containing a metallic material including aluminum or an aluminum alloy. The type, size, shape, etc. of the first electrode 210 are not particularly limited, as long as it is conductive and does not cause chemical changes in the secondary battery 2.

[0073] The first electrode 210 can be electrically connected to the cover assembly 300, which will be described below. In one embodiment, the first electrode 210 serves as the positive electrode of the electrode assembly 200, and the cover assembly 300 can serve as the positive electrode terminal of the secondary battery 2. For example, the first electrode 210 can be electrically connected to the cover assembly 300 via the first electrode connector E1.

[0074] The first electrode tab E1 according to an embodiment may include a conductive metal material such as copper, copper alloy, nickel, or nickel alloy. The first electrode tab E1 may be disposed on the upper side of the electrode assembly 200, and two or opposite end portions of the first electrode tab E1 may be respectively connected to the first electrode 210 and the cover assembly 300. The end portion of the first electrode tab E1 may be directly connected to the first electrode 210, or may be indirectly connected to the first electrode 210 through a separate current collector plate (not shown) connected to the first electrode 210.

[0075] The first active material layer may be coated on at least a part of the first electrode 210. The first active material layer may be coated on two or opposite surfaces of the first electrode 210, or may be coated on only one surface of the first electrode 210.

[0076] In one embodiment, the first electrode 210 serves as a positive electrode, and the first active material layer may include a positive electrode active material.

[0077] The positive electrode active material may be a compound capable of reversibly intercalating and deintercalating lithium (lithiated intercalation compound). In one embodiment, a composite oxide of lithium and one or more types of metals selected from cobalt, manganese, nickel, iron, and combinations thereof may be used.

[0078] For example, the positive electrode active material may include at least one of lithium iron phosphate (LiFePO4, LFP), lithium manganese iron phosphate (LiMnFePO4, LMFP), and lithium nickel cobalt manganese oxide (LiNixCoyMnzO2, NCM). Here, 0 < x < 1, 0 < y < 1, 0 < z < 1, and x + y + z = 1 may be satisfied. The positive electrode active material may include only one of lithium iron phosphate (LiFePO4, LFP), lithium manganese iron phosphate (LiMnFePO4, LMFP), and lithium nickel cobalt manganese (LiNixCoyMnzO2, NCM), or may also include two or all of lithium iron phosphate (LiFePO4, LFP), lithium manganese iron phosphate (LiMnFePO4, LMFP), and lithium nickel cobalt manganese (LiNixCoyMnzO2, NCM).

[0079] The first active material layer may further include a positive electrode conductive material.

[0080] The positive electrode conductive material imparts conductivity to the first active material layer, and any suitable material that does not cause a chemical change and is conductive may be used. Examples of the positive electrode conductive material may include: carbon-based materials such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, carbon nanofiber, carbon nanotube, etc.; metal-based materials in the form of metal powders or metal fibers containing copper, nickel, aluminum, silver, etc.; conductive polymers such as polyphenyl derivatives; or mixtures thereof.

[0081] The first active material layer may also include a positive electrode binder.

[0082] The positive electrode binder ensures that the particles constituting the positive electrode active material adhere well to each other and also ensures that the positive electrode active material adheres well to the first electrode 210.

[0083] Examples of positive electrode binders may include non-aqueous binders, aqueous binders, dry binders, or combinations thereof.

[0084] Non-aqueous adhesives may include polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene-propylene copolymer, polystyrene, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamide-imide, polyimide, or combinations thereof.

[0085] Waterborne adhesives can be selected from 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.

[0086] If an aqueous binder is used as the positive electrode binder, it may further include a cellulose-based compound capable of imparting viscosity. As a cellulose-based compound, one or more types selected from carboxymethyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, and their alkali metal salts may be used in combination. In one embodiment, Na, K, or Li may be used as the alkali metal.

[0087] Dry adhesives are fibrous polymeric materials and can be, for example, polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polyethylene oxide, or combinations thereof.

[0088] The second electrode 220 can be used as the negative electrode of the electrode assembly 200. The second electrode 220 can be formed in the shape of a foil having a metallic material including copper, copper alloy, nickel, or nickel alloy. The second electrode 220 can be configured to be spaced apart from the first electrode 210 by a gap (e.g., a certain gap) and face the first electrode 210.

[0089] The second electrode 220 can be electrically connected to the housing 100. For example, the second electrode 220 can be electrically connected to the housing 100 via a second electrode connector E2. In one embodiment, the second electrode 220 serves as the negative electrode of the electrode assembly 200, and the housing 100 can serve as the negative electrode terminal of the secondary battery 2. According to one embodiment, the second electrode connector E2 can include a conductive metal material such as copper, a copper alloy, nickel, or a nickel alloy. The second electrode connector E2 can be disposed on the lower side of the electrode assembly 200, and two or opposite end portions of the second electrode connector E2 can be respectively connected to the second electrode 220 and the bottom portion 120 of the housing 100. The end portions of the second electrode connector E2 can be directly connected to the second electrode 220, or indirectly connected to the second electrode 220 via a separate current collector (not shown) connected to the second electrode 220.

[0090] The type, size, and shape of the second electrode 220 are not particularly limited, as long as it is conductive and does not cause chemical changes in the secondary battery 2.

[0091] The second active material layer may be applied to at least a portion of the second electrode 220. The second active material layer may be applied to two or opposite surfaces of the second electrode 220, or it may be applied to only one surface of the second electrode 220.

[0092] 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.

[0093] The negative electrode active material may include materials capable of reversibly inserting and de-intercalating lithium ions, lithium metal, lithium and metal alloys, materials capable of doping and de-doping lithium, or transition metal oxides.

[0094] Materials capable of reversibly inserting and deintercalating lithium ions can include carbon-based negative electrode active materials, such as crystalline carbon, amorphous crystalline carbon, or combinations thereof. Examples of crystalline carbon can be graphite, such as amorphous, plate-like, sheet-like, spherical, or fibrous natural or artificial graphite, and examples of amorphous carbon can be soft or hard carbon, mesophase pitch carbides, calcined coke, etc.

[0095] Alloys of lithium and metals selected from 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.

[0096] Si-based or Sn-based negative electrode active materials can be used as materials capable of doping and dedoping lithium. Si-based negative electrode active materials can be silicon, silicon-carbon composites, or SiO₂. x(x is 1 or 2), Si-Q alloy (Q is selected from 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 combinations thereof. Sn-type negative electrode active materials can be Sn, SnO. x (x is 1 or 2, for example SnO2), Sn alloys or combinations thereof.

[0097] Silicon-carbon composites can be composites of silicon and amorphous carbon. Silicon-carbon composites can be in the form of silicon particles whose surfaces are coated with amorphous carbon. For example, a silicon-carbon composite can include secondary particles (cores) in which primary silicon particles are aggregated, and an amorphous carbon coating (shell) on the surface of the secondary particles. The amorphous carbon can be located between the primary silicon particles; therefore, for example, the primary silicon particles can be coated with amorphous carbon. The secondary particles can be dispersed in an amorphous carbon matrix.

[0098] Silicon-carbon composites may also include crystalline carbon. For example, a silicon-carbon composite may include a core comprising crystalline carbon and silicon particles, and an amorphous carbon coating on the surface of the core.

[0099] Si-based or Sn-based negative electrode active materials can be used in combination with carbon-based negative electrode active materials.

[0100] The second active material layer may also include a negative electrode conductive material and a negative electrode binder.

[0101] The negative electrode conductive material imparts conductivity to the second active material layer, and any suitable material that does not cause chemical change and is conductive can be used. Examples of negative electrode conductive materials may include: carbon-based materials, such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fibers, carbon nanofibers, carbon nanotubes, etc.; metallic materials in the form of metal powders or metal fibers containing copper, nickel, aluminum, silver, etc.; conductive polymers such as polyphenyl derivatives; or mixtures thereof.

[0102] The negative electrode binder ensures that the particles constituting the negative electrode active material adhere well to each other, and also ensures that the negative electrode active material adheres well to the second electrode 220.

[0103] Examples of negative electrode adhesives may include non-aqueous adhesives, aqueous adhesives, dry adhesives, or combinations thereof.

[0104] Non-aqueous adhesives may include polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene-propylene copolymer, polystyrene, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamide-imide, polyimide, or combinations thereof.

[0105] Waterborne adhesives can be selected from 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.

[0106] If an aqueous binder is used as the negative electrode binder, it may also include a cellulose compound capable of imparting viscosity. The cellulose compound may be used in combination with one or more types of carboxymethyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, and their alkali metal salts. In one embodiment, Na, K, or Li may be used as the alkali metal.

[0107] Dry adhesives are fibrous polymeric materials and can be, for example, polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polyethylene oxide, or combinations thereof.

[0108] A diaphragm 230 may be disposed between the first electrode 210 and the second electrode 220. The diaphragm 230 can prevent or substantially prevent short circuits between the first electrode 210 and the second electrode 220, while allowing lithium ions to move between the first electrode 210 and the second electrode 220.

[0109] As the separator 230, a multilayer membrane of polyethylene, polypropylene, polyvinylidene fluoride or two or more layers thereof can be used, and a mixed multilayer membrane such as a polyethylene / polypropylene double-layer separator, a polyethylene / polypropylene / polyethylene triple-layer separator or a polypropylene / polypropylene / polypropylene triple-layer separator can be used.

[0110] The diaphragm 230 may include a porous substrate and a coating comprising an organic material, an inorganic material, or a combination thereof on one or two or opposite surfaces of the porous substrate.

[0111] The porous substrate can be a polymer film or a copolymer or mixture of two or more of the following polymers selected from polyolefins (such as polyethylene and polypropylene), polyesters (such as polyethylene terephthalate and polybutylene terephthalate), polyacetal, polyamide, polyimide, polycarbonate, polyetheretherketone, polyaryletherketone, polyetherimide, polyamideimide, polybenzimidazole, polyethersulfone, polyphenylene ether, cyclic olefin copolymers, polyphenylene sulfide, polyethylene naphthalate, glass fiber, and polytetrafluoroethylene (e.g., Teflon).

[0112] Organic materials may include polymers such as polyvinylidene fluoride or (meth)acrylic acid polymers.

[0113] In one embodiment, the inorganic material may include, but is not limited to, inorganic particles selected from Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, SrTiO3, BaTiO3, Mg(OH)2, boehmite, and combinations thereof.

[0114] Organic and inorganic materials can exist as a mixture in a coating, or as a coating containing organic materials and a coating containing inorganic materials stacked together.

[0115] The first insulating plate 201 and the second insulating plate 202 can be respectively disposed on both sides or opposite sides of the electrode assembly 200. The first insulating plate 201 and the second insulating plate 202 can include insulating materials such as rubber, polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), etc.

[0116] According to one embodiment, the first insulating plate 201 can be formed to have a generally circular plate shape. The first insulating plate 201 can be disposed between the upper surface of the electrode assembly 200 and the cover assembly 300. Therefore, the first insulating plate 201 can prevent the upper surface of the electrode assembly 200 from directly contacting the cover assembly 300, and insulate the electrode assembly 200 and the cover assembly 300 from each other. A through hole (not shown) through which the first electrode contact E1 can pass can be formed in the first insulating plate 201.

[0117] According to one embodiment, the second insulating plate 202 can be formed to have a generally circular plate shape. The second insulating plate 202 can be disposed between the lower surface of the electrode assembly 200 and the bottom portion 120 of the housing 100. Therefore, the second insulating plate 202 can prevent direct contact between the lower surface of the electrode assembly 200 and the bottom portion 120 of the housing 100, and insulate the electrode assembly 200 and the bottom portion 120 of the housing 100 from each other. A through-hole (not shown) through which the second electrode contact E2 can pass can be formed in the second insulating plate 202.

[0118] The cover assembly 300 can be attached to the housing 100 and can be configured to face the electrode assembly 200. The cover assembly 300 can seal the housing 100. For example, the cover assembly 300 can be disposed in the upper portion of the sidewall portion 110, i.e., in the opening 130. The cover assembly 300 can be configured to face the electrode assembly 200 along a direction parallel to the central axis C of the housing 100.

[0119] The cover assembly 300 can be electrically connected to the first electrode 210 via the first electrode terminal E1. In one embodiment, the first electrode 210 serves as the positive electrode of the electrode assembly 200, and the cover assembly 300 can serve as the positive electrode terminal of the secondary battery.

[0120] Figure 3 This is a view schematically illustrating the configuration of a cover assembly according to an embodiment of the present disclosure; and Figure 4 yes Figure 3 A magnified view of half of the cover component.

[0121] refer to Figures 1 to 4 According to one embodiment, the cover assembly 300 may include an upper cover 310, a lower cover 320, an exhaust plate 330, and an extension portion 340.

[0122] The upper cover 310 may form the upper exterior of the cover assembly 300. The upper cover 310 may be electrically connected to the first electrode 210 via the lower cover 320 and the vent plate 330, which will be described below. In one embodiment, the central axis of the upper cover 310 may be coaxially positioned with the central axis C of the housing 100. The central portion of the upper cover 310 may protrude outward from the housing 100. The upper cover 310 may comprise a conductive material such as nickel, aluminum, copper, etc.

[0123] According to one embodiment, the top cover 310 may include a small diameter portion 311, a large diameter portion 312, and a bridging portion 313.

[0124] In one embodiment, the small-diameter portion 311 and the large-diameter portion 312 may be circular plates with different diameters. The diameter of the small-diameter portion 311 may be smaller than the diameter of the large-diameter portion 312. In one embodiment, the central axes of the small-diameter portion 311 and the large-diameter portion 312 may be coaxial with the central axis C of the housing 100. The small-diameter portion 311 and the large-diameter portion 312 may be positioned facing each other along a first direction. The small-diameter portion 311 may be disposed above the large-diameter portion 312. The small-diameter portion 311 may protrude outward from the housing 100. The large-diameter portion 312 may have an annular shape with a hollow center.

[0125] A bridging portion 313 may be disposed between a small-diameter portion 311 and a large-diameter portion 312. Two or opposite end portions of the bridging portion 313 may be connected to the outer peripheral surface of the small-diameter portion 311 and the outer peripheral surface of the large-diameter portion 312, respectively. In one embodiment, the bridging portion 313 may have a curved surface shape extending from the small-diameter portion 311 to the large-diameter portion 312.

[0126] A cover hole 314 for discharging gases or the like generated in the housing 100 to the outside of the housing 100 can be formed in the cover 310. According to one embodiment, the cover hole 314 may have a hole shape that passes through the bridging portion 313 of the cover 310. A plurality of cover holes 314 may be provided. The plurality of cover holes 314 may be arranged at intervals (e.g., a certain interval) along the circumference of the central portion of the cover 310.

[0127] The lower cover 320 can be configured to face the upper cover 310 and can be electrically connected to the electrode assembly 200.

[0128] According to one embodiment, the lower cover 320 can be formed into a generally circular plate shape. The lower cover 320 can be disposed within the housing 100. The lower cover 320 can be disposed below the upper cover 310. That is, the lower cover 320 can be disposed between the upper cover 310 and the electrode assembly 200. In one embodiment, the central axis of the lower cover 320 can be coaxially arranged with the central axis C of the housing 100. The upper surface of the lower cover 320 can be configured to be spaced apart from the lower surface of the upper cover 310.

[0129] In one embodiment, the area of ​​the lower cover 320 may be smaller than the cross-sectional area of ​​the electrode assembly 200 perpendicular to the central axis C of the housing 100. However, the area of ​​the lower cover 320 is not limited to this, and may be the same as or larger than the cross-sectional area of ​​the electrode assembly 200.

[0130] The lower cover 320 may include a conductive material, such as nickel, aluminum, or copper. The lower cover 320 may be electrically connected to the electrode assembly 200.

[0131] For example, the end portion of the first electrode terminal block E1 extending from the first electrode 210 can be connected to the lower surface of the lower cover 320 by any of the various types of connection methods such as welding.

[0132] The lower cover 320 can be electrically connected to the upper cover 310 via the exhaust plate 330 described below.

[0133] A lower cover hole 321, which passes vertically through the lower cover 320, can be formed in the lower cover 320. The lower cover hole 321 provides a path for, for example, gas generated in the housing 100 in the event of an overcurrent to flow through the lower cover 320. Multiple lower cover holes 321 can be provided. The multiple lower cover holes 321 can be arranged circumferentially around the central axis of the lower cover 320.

[0134] An vent plate 330 may be disposed between the upper cover 310 and the lower cover 320. The vent plate 330 provides a conductive path for current between the upper cover 310 and the lower cover 320 during normal operation of the secondary battery 2. The vent plate 330 may comprise a conductive material such as nickel, aluminum, or copper.

[0135] If an overcurrent occurs, the exhaust plate 330 may deform due to the pressure of the gas generated in the housing 100 and block the electrical connection between the upper cover 310 and the lower cover 320. If the internal pressure of the housing 100 rises above a certain amplitude (e.g., a set amplitude), the exhaust plate 330 may rupture and open a gas discharge path between the upper cover hole 314 and the lower cover hole 321.

[0136] According to one embodiment, the exhaust plate 330 can be formed to have a generally circular plate shape.

[0137] The exhaust plate 330 may include a first exhaust surface 330a and a second exhaust surface 330b that are opposite to each other.

[0138] According to one embodiment, the first exhaust surface 330a and the second exhaust surface 330b can be two or opposite surfaces of the exhaust plate 330 that are perpendicular to the central axis C of the housing 100. The first exhaust surface 330a can be configured to face the upper cover 310, and the second exhaust surface 330b can be configured to face the lower cover 320.

[0139] The exhaust plate 330 may include a contact portion 331.

[0140] According to one embodiment, the contact portion 331 can protrude from the exhaust plate 330 to the lower cover 320 and can contact the lower cover 320. The contact portion 331 can electrically connect the exhaust plate 330 and the lower cover 320. Therefore, the current generated from the first electrode 210 can be transmitted to the upper cover 310 sequentially through the first electrode terminal E1, the lower cover 320, the exhaust plate 330 and the extension portion 340.

[0141] The contact portion 331 may be formed in the central portion of the exhaust plate 330. In one embodiment, the central axis of the contact portion 331 may be coaxial with the central axis C of the housing 100.

[0142] If the exhaust plate 330 deforms due to increased internal pressure in the housing 100, the contact portion 331 can be separated from the lower cover 320. Therefore, if an overcurrent occurs, the electrical connection between the lower cover 320 and the exhaust plate 330 can be broken.

[0143] In one embodiment, a cover insulator 301 may be disposed between the exhaust plate 330 and the lower cover 320. The cover insulator 301 can prevent or substantially prevent the remaining area of ​​the exhaust plate 330, except for the contact portion 331, from directly contacting the lower cover 320. Therefore, the cover insulator 301 allows the exhaust plate 330 and the lower cover 320 to be electrically connected only through the contact portion 331, which will be described below.

[0144] In one embodiment, the cover insulator 301 according to one embodiment can be formed to have a hollow annular shape. In one embodiment, the central axis of the cover insulator 301 can be coaxially positioned with the central axis C of the housing 100 and the central axis of the vent plate 330. The upper surface of the cover insulator 301 can contact the lower surface of the vent plate 330, and the lower surface of the cover insulator 301 can contact the upper surface of the lower cover 320. The cover insulator 301 can be formed of an insulating material such as polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), etc.

[0145] The extension portion 340 can extend from the exhaust plate 330 and can be connected to the top cover 310. The extension portion 340 can support the top cover 310 relative to the exhaust plate 330 and provide an electrical connection between the top cover 310 and the exhaust plate 330. In one embodiment, the extension portion 340 can be formed of the same material as the exhaust plate 330. In one embodiment, the extension portion 340 can be integrally formed with the exhaust plate 330, or it can be coupled to the exhaust plate 330 after being manufactured separately from the exhaust plate 330.

[0146] The extension portion 340 according to this embodiment may include a support portion 341 and a hinge portion 342.

[0147] The support portion 341 may form the exterior of one side of the extension portion 340 and may be connected to the top cover 310.

[0148] According to one embodiment, the support portion 341 can be configured to surround the end portion of the upper cover 310, and in one embodiment, surround the edge region of the large-diameter portion 312. For example, the support portion 341 can have a generally U-shaped cross-sectional shape. The end portion of the support portion 341 can contact the upper surface of the large-diameter portion 312, and the other end portion of the support portion 341 can be bent downwards and can contact the lower surface of the large-diameter portion 312. The support portion 341 can be attached to the upper cover 310 by any of various types of joining methods such as laser welding, ultrasonic welding, resistance welding, etc.

[0149] The support portion 341 can be configured to face the rolled edge portion 140 along a first direction. For example, the support portion 341 can be located on the upper side of the rolled edge portion 140. Therefore, when assembling the secondary battery 2, the rolled edge portion 140 can limit the cover assembly 300 from being inserted into the housing 100 by a certain distance (e.g., a set distance).

[0150] The hinge portion 342 can form the exterior of the other side of the extension portion 340 and can be disposed between the support portion 341 and the exhaust plate 330. The hinge portion 342 can connect the support portion 341 and the exhaust plate 330 to each other, and causes the exhaust plate 330 to deform if the internal pressure of the housing 100 increases.

[0151] According to one embodiment, the hinge portion 342 may have a generally annular shape and may be disposed between the support portion 341 and the exhaust plate 330. The inner peripheral surface of the hinge portion 342 may be connected to the exhaust plate 330, and the outer peripheral surface of the hinge portion 342 may be connected to the other end portion of the support portion 341. In one embodiment, the hinge portion 342 may extend downward from the outer peripheral surface to the inner peripheral surface in a stepped manner. For example, the central portion of the hinge portion 342 may have a cross-section bent into an L-shape.

[0152] If an overcurrent occurs, the exhaust plate 330 can deform based on the hinge portion 342. For example, if the internal pressure of the housing 100 increases due to the overcurrent, the gas flowing through the lower cover hole 321 presses upward against the exhaust plate 330, and the exhaust plate 330 can deform in a way that the central portion bulges upward due to the change in the bending angle of the hinge portion 342.

[0153] According to one embodiment, the housing 100 may further include a press-fit portion 150 that fixes the position of the cover assembly 300 and prevents or substantially prevents the cover assembly 300 from separating from the housing 100.

[0154] According to one embodiment, the crimping portion 150 can extend from the upper end portion of the rolled edge portion 140. The end portion of the crimping portion 150 can be bent toward the central axis C of the housing 100. The inner surface of the crimping portion 150 can be configured to surround the outer peripheral surface of the support portion 341.

[0155] The gasket G may be disposed between the crimped portion 150 and the cover assembly 300. The gasket G may electrically insulate the housing 100 and the cover assembly 300 from each other and prevent or substantially prevent the introduction or discharge of moisture or electrolyte between the housing 100 and the cover assembly 300.

[0156] According to one embodiment, the gasket G may comprise an insulating material such as rubber, polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), etc. The gasket G may be formed to have a generally annular shape. In one embodiment, the gasket G may have a generally U-shaped cross-section. The outer surface of the gasket G may be in close contact with the inner surfaces of the crimped portion 150 and the rolled edge portion 140. The inner surface of the gasket G may surround (e.g., encircle) the outer surface of the support portion 341 and may be in close contact with the outer surface of the support portion 341.

[0157] The first notch 400 can be formed recessedly from the first exhaust surface 330a.

[0158] Figure 5 This is a view schematically illustrating the configuration of a first notch and a second notch according to an embodiment of the present disclosure; and Figure 6 This is a view schematically illustrating a modified operation of an exhaust plate according to an embodiment of the present disclosure.

[0159] According to one embodiment, the first notch 400 may have a groove shape formed recessed from the first exhaust surface 330a toward the second exhaust surface 330b. In one embodiment, the first notch 400 may be formed into an annular shape along an arc centered on the central axis C of the housing 100.

[0160] The width of the first notch 400 may decrease toward the second exhaust surface 330b. For example, the cross-sectional shape of the first notch 400 may be trapezoidal, with the width of the end portion facing the second exhaust surface 330b being narrower than the width of the end portion passing through the first exhaust surface 330a.

[0161] The second notch 500 can be formed recessedly from the second exhaust surface 330b.

[0162] According to one embodiment, the second recess 500 may have a groove shape formed recessed from the second exhaust surface 330b toward the first exhaust surface 330a. In one embodiment, the second recess 500 may be formed into an annular shape along an arc centered on the central axis C of the housing 100.

[0163] The width of the second notch 500 may decrease toward the first exhaust surface 330a. For example, the cross-sectional shape of the second notch 500 may be trapezoidal, with the width of the end portion facing the first exhaust surface 330a being narrower than the width of the end portion passing through the second exhaust surface 330b.

[0164] The second recess 500 can be configured to face the first recess 400. For example, the center line of the first recess 400 and the center line of the second recess 500, which are parallel to the central axis C of the housing 100, can be aligned on the same straight line.

[0165] A bridging portion 332 may be formed between the first recess 400 and the second recess 500. According to one embodiment, the bridging portion 332 may be a portion of the entire exhaust plate 330 disposed between the first recess 400 and the second recess 500. The thickness H3 of the bridging portion 332 may be formed to be thinner than the depth H1 of the first recess 400 and the depth H2 of the second recess 500 relative to the thickness of the exhaust plate 330. Therefore, if the internal pressure of the housing 100 increases, the bridging portion 332 may preferentially deform and rupture, potentially causing current blocking and exhaust operations of the exhaust plate 330.

[0166] According to one embodiment, the secondary battery 2 can relatively reduce the depth H1 of the first notch 400 while maintaining the thickness H3 of the bridging portion 332 the same as that of the first notch 400 and the second notch 500, which are positioned facing each other, with the bridging portion 332 located between the first notch 400 and the second notch 500. Therefore, compared to the case where the first notch 400 is formed only in the exhaust plate 330, under the same load conditions, the deformation angle of the bridging portion 332 can be relatively reduced, and cracking or fatigue failure in the bridging portion 332 can be prevented or substantially prevented before the internal pressure of the housing 100 reaches the burst pressure.

[0167] According to one embodiment, the thickness H3 of the bridging portion 332 can be greater than or equal to 0.04 mm and less than or equal to 0.1 mm.

[0168] If the thickness H3 of the bridging portion 332 is less than 0.04 mm, the rupture pressure of the bridging portion 332 may be excessively reduced, and the exhaust operation of the exhaust plate 330 may be unnecessarily performed due to small pressure changes in the housing 100.

[0169] If the thickness H3 of the bridging portion 332 is greater than 0.1 mm, the rupture pressure of the bridging portion 332 may increase excessively, and the exhaust operation of the exhaust plate 330 may not be performed smoothly.

[0170] In one embodiment, the depth H2 of the second notch 500 can be greater than the depth H1 of the first notch 400. For example, the depth H1 of the first notch 400 can be 0.1 mm, and the depth H2 of the second notch 500 can be 0.1 mm to 0.16 mm.

[0171] The width of at least a portion of the second notch 500 may be greater than the width of the first notch 400.

[0172] In one embodiment, the entire width of the second notch 500 may be greater than the width of the first notch 400. That is, the minimum width of the second notch 500 may be greater than the maximum width W1 of the first notch 400. Here, the minimum width of the second notch 500 may refer to the width of the end portion of the second notch 500 that is configured to face the first exhaust surface 330a, and the maximum width W2 of the second notch 500 may refer to the width of the other end portion of the second notch 500 that is located in the same plane as the second exhaust surface 330b. Similarly, the minimum width of the first notch 400 may refer to the width of the end portion of the first notch 400 that is configured to face the second exhaust surface 330b, and the maximum width W1 of the first notch 400 may refer to the width of the other end portion of the first notch 400 that is located in the same plane as the first exhaust surface 330a. However, this disclosure is not limited thereto, and the maximum width W1 of the first notch 400 may have a value between the minimum width and the maximum width W2 of the second notch 500.

[0173] In one embodiment, the second notch 500 can be formed by forging. That is, the second notch 500 can be formed recessed inward from the second vent surface 330b by using an extrusion device to press the second vent surface 330b facing the first notch 400. Therefore, the bridging portion 332 can have a relatively high density compared to the same thickness, thus reducing the amount of deformation of the housing 100 due to internal pressure.

[0174] In this document, an experimental example of a secondary battery according to an embodiment of the present disclosure will be described.

[0175] Comparative Example 1

[0176] First, an exhaust plate 330 is manufactured in which a first recess 400 is formed in a first exhaust surface 330a and a second recess 500 is not formed in a second exhaust surface 330b.

[0177] In Comparative Example 1, the bridging portion 332 refers to the portion of the exhaust plate 330 disposed between the second exhaust surface 330b and the end portion of the first recess 400. In Comparative Example 1, the depth H1 of the first recess 400 is formed to be 0.23 mm, and the thickness H3 of the bridging portion 332 is formed to be 0.07 mm.

[0178] Example A

[0179] An exhaust plate 330 is manufactured in which a first recess 400 is formed in a first exhaust surface 330a and a second recess 500 is formed in a second exhaust surface 330b.

[0180] In Example A, the depth H1 of the first notch 400 is formed to be 0.1 mm, the depth H2 of the second notch 500 is formed to be 0.12 mm, and the thickness H3 of the bridging portion 332 is formed to be 0.08 mm.

[0181] Example B

[0182] In Example B, an exhaust plate 330 is manufactured in which the depth H2 of the second notch 500 is 0.14 mm and the thickness H3 of the bridging portion 332 is 0.06 mm.

[0183] Example C

[0184] In Example C, an exhaust plate 330 is manufactured in which the depth H2 of the second notch 500 is 0.16 mm and the thickness H3 of the bridging portion 332 is 0.04 mm.

[0185] Experimental Example

[0186] For Comparative Examples 1, A, B, and C above, a pressure of 10 kgf / cm² is repeatedly applied to the second exhaust surface 330b of the exhaust plate 330. 2 The pressure applied, and whether cracks appear in the bridging part 332, are measured as shown in Table 1 below. The number of pressure applications is set to 2400.

[0187] Table 1

[0188] H1(mm) H2 (mm) H3 (mm) Are there any cracks? Comparative Example 1 0.23 0 0.07 O Example A 0.1 0.12 0.08 X Example B 0.1 0.14 0.06 X Example C 0.1 0.16 0.04 X

[0189] As the results of the experiment, it can be seen that cracks appeared in the bridging portion 332 in Comparative Example 1, but no cracks appeared in the bridging portion 332 in Example A. Furthermore, it can be seen that no cracks appeared in the bridging portion 332 in Examples B and C, where the thickness of the bridging portion 332 is less than that of Comparative Example 1. Therefore, it can be seen that when the second notch 500 is formed in the second exhaust surface 330b, the deformation of the bridging portion 332 is reduced, thus preventing cracks from appearing in the bridging portion 332.

[0190] In this document, a secondary battery 2 according to another embodiment of the present disclosure will be described.

[0191] According to one embodiment, the secondary battery 2 can be configured differently from the secondary battery 2 of the previously described embodiment according to this disclosure in terms of the configuration of the first notch 400.

[0192] Therefore, in the description of the secondary battery 2 according to this embodiment, a detailed configuration of the first notch 400, which is different from that of the secondary battery 2 according to the previously described embodiment of this disclosure, will be described.

[0193] For the remaining configurations of the secondary battery 2 according to this embodiment, the description of the secondary battery 2 according to the previously described embodiments of this disclosure can be applied as is.

[0194] Figure 7 This is a view schematically illustrating the configuration of a first notch and a second notch according to an embodiment of the present disclosure.

[0195] refer to Figure 7 According to one embodiment, the cross-section of the first notch 400 can be formed to have a triangular shape, wherein the width of the end portion facing the second exhaust surface 330b converges to a point.

[0196] Therefore, the secondary battery 2 according to this embodiment can cause stress concentration at the end portion of the first notch 400, so that if the internal pressure of the housing 100 rises above the pressure of the exhaust plate 330 for exhaust operation, the bridging portion 332 can break more quickly.

[0197] In this document, a secondary battery 2 according to another embodiment of the present disclosure will be described.

[0198] According to this embodiment, the secondary battery 2 can be configured in relation to the configuration of the second notch 500 as described in this embodiment. Figure 1 The secondary battery 2 in the embodiment is different.

[0199] Therefore, in the description of the secondary battery 2 according to this embodiment, the description will be consistent with that according to Figure 1 The detailed configuration of the second notch 500 of the secondary battery 2 in the embodiment.

[0200] For the remaining configurations of the secondary battery 2 according to this embodiment, the same principle can be applied. Figure 1 Description of the secondary battery 2 in the embodiment.

[0201] Figure 8 This is a view schematically illustrating the configuration of a first notch and a second notch according to another embodiment of the present disclosure.

[0202] refer to Figure 8 According to this embodiment, the cross-section of the second notch 500 can be formed to have a triangular shape, wherein the width of the end portion facing the first exhaust surface 330a converges to a point.

[0203] Therefore, according to this embodiment, the secondary battery 2 can cause stress concentration at the end portion of the second notch 500, so that if the internal pressure of the housing 100 rises above the pressure of the exhaust plate 330 for exhaust operation, the bridging portion 332 can break more quickly.

[0204] In this document, a secondary battery 2 according to another embodiment of the present disclosure will be described.

[0205] According to this embodiment, the secondary battery 2 can be configured in a manner similar to that of the first notch 400 and the second notch 500 in detail. Figure 1 The secondary battery 2 in the embodiment is different.

[0206] Therefore, in the description of the secondary battery 2 according to this embodiment, the description will be consistent with that according to Figure 1 The detailed configuration of the different first notch 400 and second notch 500 of the secondary battery 2 in the embodiment.

[0207] For the remaining configurations of the secondary battery 2 according to this embodiment, the same principle can be applied. Figure 1 Description of the secondary battery 2 in the embodiment.

[0208] Figure 9 This is a view schematically illustrating the configuration of a first notch and a second notch according to another embodiment of the present disclosure.

[0209] refer to Figure 9 According to this embodiment, the cross-section of the first notch 400 can be formed to have a triangular shape, wherein the width of the end portion facing the second exhaust surface 330b is concentrated at a point, and the cross-section of the second notch 500 according to this embodiment can be formed to have a triangular shape, wherein the width of the end portion facing the first exhaust surface 330a is concentrated at a point.

[0210] Therefore, the secondary battery 2 according to this embodiment can cause stress concentration at the end portions of the first notch 400 and the second notch 500, so that if the internal pressure of the housing 100 rises above the pressure at which the exhaust plate 330 is vented, the bridging portion 332 can break more quickly.

[0211] In this document, a secondary battery 2 according to another embodiment of the present disclosure will be described.

[0212] The secondary battery 2 according to this embodiment may further include an extended notch 501.

[0213] According to this embodiment, the secondary battery 2 can be configured to further include an extended notch 501 and be connected to the... Figure 1 The secondary battery 2 in the embodiment is different.

[0214] Therefore, in the description of the secondary battery 2 according to this embodiment, the description will be based on... Figure 1 The extended notch 501 is not described in the secondary battery 2 of the embodiment.

[0215] For the remaining configurations of the secondary battery 2 according to this embodiment, the same principle can be applied. Figure 1Description of the secondary battery 2 in the embodiment.

[0216] Figure 10 This is a view schematically illustrating the configuration of an extended notch according to another embodiment of the present disclosure.

[0217] refer to Figure 10 The extended notch 501 can be connected to the second notch 500.

[0218] According to this embodiment, the extended recess 501 may have a groove shape formed recessed from the end portion of the second recess 500 facing the first recess 400 toward the first exhaust surface 330a. In one embodiment, the extended recess 501 may be formed into an annular shape along an arc centered on the central axis C of the housing 100.

[0219] The extension notch 501 can be configured to face the first notch 400. For example, the center line of the extension notch 501, which is parallel to the central axis C of the housing 100, and the center line of the first notch 400 can be aligned on the same straight line. In one embodiment, the bridging portion 332 can be a portion of the vent plate 330 located between the extension notch 501 and the first notch 400. Therefore, if the internal pressure of the housing 100 increases, the secondary battery 2 according to this embodiment can further reduce the deformation of the bridging portion 332 by further reducing the depth of the first notch 400.

[0220] The width of the extended notch 501 may decrease toward the first exhaust surface 330a. For example, the cross-sectional shape of the extended notch 501 may be trapezoidal, wherein the width of the end portion facing the first exhaust surface 330a is narrower than the width of the end portion connected to the second notch 500.

[0221] The width of at least a portion of the extended notch 501 may be greater than the width of the first notch 400.

[0222] In one embodiment, the entire width of the extended notch 501 may be greater than the width of the first notch 400. That is, the minimum width of the extended notch 501 may be greater than the maximum width W1 of the first notch 400. Here, the minimum width of the extended notch 501 may refer to the width of the end portion of the extended notch 501 that is configured to face the first exhaust surface 330a, and the maximum width W3 of the extended notch 501 may refer to the width of the extended notch 501 located at the other end portion connected to the second notch 500. However, this disclosure is not limited thereto, and the maximum width W1 of the first notch 400 may have a value between the minimum width and the maximum width W3 of the extended notch 501.

[0223] In this document, a secondary battery 2 according to another embodiment of the present disclosure will be described.

[0224] Figure 11 This is a view schematically illustrating the configuration of a secondary battery according to another embodiment of the present disclosure.

[0225] refer to Figure 11 The secondary battery 2 according to this embodiment may also include a third notch 600.

[0226] According to this embodiment, the secondary battery 2 can be configured to further include a third notch 600 and be connected with the... Figure 1 The secondary battery 2 in the embodiment is different.

[0227] Therefore, in the description of the secondary battery 2 according to this embodiment, the description will be based on... Figure 1 The third notch 600 is not described in the secondary battery 2 of the embodiment.

[0228] For the remaining configurations of the secondary battery 2 according to this embodiment, the same principle can be applied. Figure 1 Description of the secondary battery 2 in the embodiment.

[0229] Figure 12 This is a view that schematically illustrates the configuration of the third notch according to this embodiment of the present disclosure.

[0230] refer to Figure 11 and Figure 12 According to this embodiment, the third recess 600 may have a groove shape formed recessed from the first exhaust surface 330a toward the second exhaust surface 330b. In one embodiment, the third recess 600 may be formed into an annular shape along an arc centered on the central axis C of the housing 100.

[0231] The third recess 600 can be configured to be spaced apart from the first recess 400. For example, the third recess 600 and the first recess 400 can be spaced apart from each other in a radial direction centered on the central axis C of the housing 100.

[0232] In one embodiment, the distance from the central axis C of the housing 100 to the third recess 600 may be greater than the distance from the central axis C of the housing 100 to the first recess 400. That is, the first recess 400 and the third recess 600 may be sequentially arranged from the central axis C of the housing 100 along the radial direction of the exhaust plate 330.

[0233] In one embodiment, the third notch 600 and the second notch 500 can be configured to be misaligned. That is, the center lines of the third notch 600 and the second notch 500 can be located on different straight lines that are parallel to each other.

[0234] An outer bridging portion 303 may be formed between the third recess 600 and the second exhaust surface 330b. According to this embodiment, the outer bridging portion 303 may refer to the portion of the exhaust plate 330 facing the third recess 600 in the entire area of ​​the exhaust plate 330.

[0235] In one embodiment, the depth H4 of the third notch 600 may be greater than the depth H1 of the first notch 400. In another embodiment, the thickness H5 of the outer bridging portion 303 may be less than the thickness of the bridging portion 332. Therefore, if the internal pressure of the housing 100 increases, the third notch 600 may cause the outer bridging portion 303 to rupture before the bridging portion 332.

[0236] This article will describe a battery pack including a secondary battery 2.

[0237] Figure 13 This is a perspective view schematically illustrating the configuration of a battery pack according to an embodiment of the present disclosure.

[0238] refer to Figure 13 According to one embodiment, the battery pack may include a housing 1 and a secondary battery 2.

[0239] The outer casing 1 can generally form the exterior of the battery pack and provide space to accommodate the secondary battery 2.

[0240] According to one embodiment, the housing 1 may include a housing body 11 and a cover 12.

[0241] The outer shell body 11 can be formed into a box shape with an internal hollow interior and an open side. However, the cross-sectional shape of the outer shell body 11 is not limited to... Figure 13 The quadrilateral shape shown in the figure can be any shape of various shapes such as polygonal shape, circular shape, elliptical shape, etc.

[0242] The cover 12 can be attached to the housing body 11 and enclose the interior space of the housing body 11. For example, the cover 12 can be formed to have a generally plate shape and can be configured as an open side facing the housing body 11. The cover 12 can be secured to the housing body 11 by any of various types of connection methods such as bolting, welding, assembly, etc.

[0243] The secondary battery 2 can be disposed in the housing 1. The secondary battery 2 described below can be any of the secondary batteries 2 according to the above embodiments.

[0244] Multiple secondary batteries 2 can be provided. The multiple secondary batteries 2 can be configured in any pattern, such as a grid shape, a sawtooth shape, etc., formed within the housing 1. The multiple secondary batteries 2 can be arranged parallel to each other. The number of secondary batteries 2 can be designed in various ways according to the size, shape, etc., of the housing 1.

[0245] Multiple secondary batteries 2 can be electrically connected via a busbar (not shown). The multiple secondary batteries 2 can be connected in series or parallel via the busbar. For example, the busbar can connect secondary batteries 2 arranged in the same row in parallel, and connect secondary batteries 2 arranged in two adjacent rows in the housing 1 in series. The busbar can be formed of a conductive material such as copper, aluminum, or nickel.

[0246] According to embodiments of this disclosure, different notches are formed on two or opposite surfaces of the exhaust plate, and if the internal pressure of the housing increases, the deformation of the bridging portion can be relatively reduced, and cracks in the bridging portion can be prevented or substantially prevented from occurring due to repeated input of loads less than the breaking pressure of the bridging portion.

[0247] However, the aspects and effects that can be obtained through this disclosure are not limited to those described above, and those skilled in the art will clearly understand other technical aspects and effects not mentioned from the following description of this disclosure.

[0248] While this disclosure has been described with reference to some embodiments shown in the accompanying drawings, these embodiments are merely illustrative, and it should be understood that those skilled in the art can derive various modifications and equivalent other embodiments based on these embodiments.

[0249] Therefore, the scope of this disclosure should be defined by the claims.

Claims

1. A secondary battery, comprising: The casing, including the opening; Electrode assembly, disposed within the housing; The top cover is arranged in the opening; The lower cover faces the upper cover and is connected to the electrode assembly; An exhaust plate is disposed between the upper cover and the lower cover, and includes a first exhaust surface and a second exhaust surface that are opposite to each other; The first notch is formed recessedly from the first exhaust surface toward the second exhaust surface; as well as The second notch is formed recessed from the second exhaust surface toward the first exhaust surface.

2. The secondary battery according to claim 1, wherein... The first exhaust surface faces the upper cover, and The second exhaust surface faces the lower cover.

3. The secondary battery according to claim 1, wherein the first notch and the second notch face each other.

4. The secondary battery according to claim 3, wherein the second notch is forged.

5. The secondary battery according to claim 3, wherein at least a portion of the width of the second notch is greater than the width of the first notch.

6. The secondary battery according to claim 3, wherein the depth of the second notch is greater than the depth of the first notch.

7. The secondary battery according to claim 3, wherein the width of the first notch decreases toward the second exhaust surface.

8. The secondary battery according to claim 7, wherein the cross-sectional shape of the first notch is trapezoidal or triangular.

9. The secondary battery according to claim 3, wherein the width of the second notch decreases toward the first exhaust surface.

10. The secondary battery according to claim 9, wherein the cross-sectional shape of the second notch is trapezoidal or triangular.

11. The secondary battery according to claim 3, wherein the vent plate further includes a bridging portion between the first recess and the second recess.

12. The secondary battery according to claim 11, wherein the thickness of the bridging portion is greater than or equal to 0.04 mm and less than or equal to 0.1 mm.

13. The secondary battery of claim 1, further comprising an extended recess connected to the second recess and recessedly formed from the end portion of the second recess facing the first recess toward the first exhaust surface.

14. The secondary battery according to claim 13, wherein the width of the extended notch is smaller than the width of the second notch.

15. The secondary battery of claim 1, further comprising a third recess formed recessed from the first exhaust surface toward the second exhaust surface and spaced apart from the first recess.

16. The secondary battery according to claim 15, wherein The first notch and the second notch face each other, and The third notch and the second notch are not aligned with each other.

17. The secondary battery according to claim 17, wherein the depth of the third notch is greater than the depth of the first notch.

18. 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 17.

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