Secondary battery and method of manufacturing secondary battery

Abstract

A secondary battery and a method of manufacturing the secondary battery are disclosed. The secondary battery includes: an electrode assembly including electrode terminals; a housing housing the electrode assembly therein; a connecting member electrically connected to the electrode terminals; side terminals electrically connected to the connecting member; a cover plate coupled to an opening in the housing, with the side terminals passing through the cover plate; a first insulator insulating the cover plate from the connecting member; and a first joint joining the first insulator and the cover plate. According to the invention, integrating the insulator for insulating the cover plate and the electrode assembly by thermal fusion eliminates unnecessary processes, thereby simplifying the assembly process and improving insulation reliability.

Description

Technical Field

[0001] Embodiments of this disclosure relate to a secondary battery and a method of manufacturing a 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 inserting and deintercalating lithium ions) and an electrolyte. The lithium secondary battery generates electrical energy through oxidation and reduction reactions when lithium ions are inserted into or deintercalated from the positive and negative electrodes.

[0004] The information disclosed above in the art that forms the background of this disclosure is provided to enhance 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 invention, a secondary battery and a method of manufacturing the secondary battery are provided, which can simplify the assembly process and improve insulation reliability by using thermal fusion to integrate insulators for insulating the cover plate and electrode assembly to eliminate unnecessary processes.

[0006] The above and other aspects and features of this disclosure will be described in, or will be 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: an electrode assembly including electrode terminals; a housing housing the electrode assembly therein; a connecting member electrically connected to the electrode terminals; a side terminal electrically connected to the connecting member; a cover plate coupled to an opening in the housing, with the side terminal passing through the cover plate; a first insulator insulating the cover plate from the connecting member; and a first coupling portion coupling the first insulator and the cover plate.

[0008] The first joint may include: a first groove in the cover plate; and a first protrusion on the first insulator to be inserted into the first groove and melted to fill the first groove.

[0009] The first groove may have a shape that widens in the insertion direction of the first protrusion, and the first protrusion may be longer than the depth of the first groove before melting.

[0010] The volume of the first protrusion may be less than or equal to the internal volume of the first groove.

[0011] The inlet width of the first groove can be smaller than the inner width of the first groove.

[0012] A receiving groove may be formed around the first protrusion, the receiving groove accommodating the molten first protrusion when it melts.

[0013] The first groove may include a protrusion inserted into the receiving groove.

[0014] The inlet width of the first groove can be smaller than the inner width of the first groove.

[0015] The side terminal may include: a boss terminal disposed on the connecting member and passing through the cover plate; and an external terminal disposed outside the cover plate and welded to the boss terminal, and a second insulator between the side terminal and the cover plate.

[0016] The second insulator can be joined by a second joint, and the second joint may include: a second groove formed in each of the outer terminal and the cover plate, facing each other; and a second protrusion formed on the second insulator to insert into the second groove and melt to fill the second groove.

[0017] The boss terminal and the external terminal may include corresponding tapered portions.

[0018] According to one or more embodiments of the present disclosure, a method of manufacturing a secondary battery includes: forming a first groove in a cover plate; bonding a first insulator to the cover plate; and combining the cover plate with side terminals.

[0019] The process of forming the first groove in the cover plate may include: forming a linear groove in the lower surface of the cover plate; and forming the inlet width of the linear groove to be narrower than the inner width of the linear groove by circumferential machining of the outside of the linear groove.

[0020] In the process of attaching the first insulator to the cover plate, a first protrusion of the first insulator can be inserted into the first groove, and the first protrusion can be melted to fill the first groove with the melted first protrusion, the melted first protrusion then hardening.

[0021] The volume of the first protrusion may be less than or equal to the internal volume of the first groove.

[0022] A receiving groove may be formed around the first protrusion, the receiving groove accommodating the molten first protrusion when it melts.

[0023] In the process of incorporating the first insulator into the cover plate, the first protrusion can be melted and thermally fused by a heating rod arranged on the cover plate.

[0024] In the process of incorporating the first insulator into the cover plate, the first protrusion can be melted and thermally fused by ultrasonic welding applied to the first insulator.

[0025] In the process of incorporating the first insulator into the cover plate, the first insulator may be transparent, and the first protrusion is melted and thermally fused by laser welding applied to the first insulator.

[0026] The side terminal may include: a boss terminal on the connecting member and passing through the cover plate; and an external terminal located outside the cover plate and coupled to the boss terminal, and the coupling of the cover plate and the side terminal may include: forming a second groove in the cover plate and the external terminal; inserting a second protrusion of a second insulator into the second groove and melting the second protrusion such that the melted second protrusion fills the second groove; and welding the boss terminal and the external terminal. 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 being limited to the drawings:

[0028] Figure 1 This is a perspective view schematically illustrating the configuration of a battery pack according to one or more embodiments of the present invention;

[0029] Figure 2 This is a perspective view schematically illustrating the configuration of a secondary battery according to an embodiment of the present invention;

[0030] Figure 3 It is an illustrative example. Figure 2 An exploded perspective view of the secondary battery configuration;

[0031] Figure 4 It is along Figure 2 A cross-sectional view taken from line IV-IV;

[0032] Figure 5 This is a view that schematically illustrates the configuration of an electrode assembly according to an embodiment of the present invention;

[0033] Figure 6 This is a cross-sectional view illustrating the configuration of the main parts of a secondary battery according to an embodiment of the present invention;

[0034] Figure 7This is a schematic view illustrating the formation of the first groove of the cover plate according to an embodiment of the present invention;

[0035] Figure 8 These are views illustrating various shapes of the first recess of a secondary battery according to an embodiment of the present invention;

[0036] Figure 9 This is a schematic view illustrating the connection of the first joint of the secondary battery according to an embodiment of the present invention;

[0037] Figure 10 This is a view illustrating the thermal fusion of the first joint of a secondary battery according to an embodiment of the present invention via a heating rod;

[0038] Figure 11 This is a view illustrating the thermal fusion of the first joint of a secondary battery according to an embodiment of the present invention via ultrasonic welding;

[0039] Figure 12 This is a view illustrating the thermal fusion of the first joint of a secondary battery according to an embodiment of the present invention via laser welding;

[0040] Figure 13 This is a cross-sectional view illustrating the thermally fused state of the first junction of a secondary battery according to an embodiment of the present invention;

[0041] Figure 14 This is a photograph of the first groove of the cover plate according to an embodiment of the present invention;

[0042] Figure 15 This is a perspective view schematically illustrating a first protrusion of a secondary battery according to another embodiment of the present invention;

[0043] Figure 16 It is an illustrative example. Figure 15 A view of the first joint of the secondary battery;

[0044] Figure 17 This is a cross-sectional view schematically illustrating a modified example of the first protrusion according to an embodiment of the present invention;

[0045] Figure 18 This is a cross-sectional view illustrating the thermally fused state of the first junction of a secondary battery according to an embodiment of the present invention;

[0046] Figure 19 This is a schematic cross-sectional view illustrating the first junction of a secondary battery according to another embodiment of the present invention;

[0047] Figure 20 It is an illustrative example. Figure 19 A view showing the formation of the first groove in the secondary battery;

[0048] Figure 21 This is a schematic view illustrating the connection of the first joint of the secondary battery according to an embodiment of the present invention;

[0049] Figure 22 This is a cross-sectional view illustrating the thermally fused state of the first junction of a secondary battery according to an embodiment of the present invention; and

[0050] Figure 23 This is a flowchart illustrating, schematically, a method for manufacturing a secondary battery according to one or more embodiments of the present invention. Detailed Implementation

[0051] 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 common or dictionary meanings, but 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 his / her own lexicographer to appropriately define the concepts of the terms.

[0052] 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 may exist to replace or modify the embodiments described herein at the time of filing this application.

[0053] 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 can 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 can be directly linked to or connected to the second element, or the first element can be indirectly linked to or connected to the second element via one or more intermediary elements.

[0054] In the figures, the dimensions of various elements, layers, etc., may be exaggerated 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 of the associated listed items. Furthermore, in describing embodiments of this disclosure, the use of “may” 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, not 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 indicate 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 approximate terms rather than as terms of degree, and are intended to take into account the inherent variations in measured or calculated values ​​that would be recognized by one of ordinary skill in the art.

[0055] 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.

[0056] For ease of description, spatial relative terms such as “below,” “under,” “down,” “above,” and “above” are 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 cover different orientations of the device in use or operation other than 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 “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.

[0057] 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 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.

[0058] 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., 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 described herein is intended to include all lower numerical limits contained therein, and any minimum numerical limit described herein 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.

[0059] 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 in terms of average value.

[0060] Throughout this specification, unless otherwise stated, each element may be singular or plural.

[0061] 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.

[0062] Furthermore, it should be understood that when an element is referred to as "connected," "linked," or "attached" to another element, these elements may be directly "connected," "linked," or "attached" to each other, or one or more intermediary elements may exist between them, through which the element may be "connected," "linked," or "attached" to the other element. Additionally, when a component is referred to as "electrically connected" to another component, the component may be directly electrically connected to the other component, or one or more intermediary elements may exist between them, allowing the component to be indirectly electrically connected to the other component.

[0063] 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 of the listed items. Unless otherwise stated, the phrase "C to D" means C and below D.

[0064] The terminology used in this specification is for describing embodiments of this disclosure and is not intended to limit this disclosure.

[0065] Figure 1 This is a perspective view schematically illustrating the configuration of a battery pack according to an embodiment of the present invention.

[0066] refer to Figure 1 According to an embodiment of the present invention, the battery pack 1 may include a casing 10 and a secondary battery 2 (see Figure 2 ).

[0067] The housing 10 can roughly form the appearance of the battery pack and provide space to accommodate the secondary battery 2.

[0068] According to an embodiment, the housing 10 may include a housing body 11 and a cover 12.

[0069] The outer casing 11 can have a box shape, with an empty interior and open sides. However, the cross-sectional shape of the outer casing 11 is not limited to... Figure 1 The rectangular shape shown is an example, but it can have any shape of various shapes, such as polygons, circles, ellipses or other shapes.

[0070] The cover 12 can be attached to the housing body 11 and can close the interior space of the housing body 11. In one example, the cover 12 can be formed with a generally plate shape and can be set as an open side facing 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, mating, etc.

[0071] The secondary battery 2 can be used as a unit structure for storing and supplying power in the battery pack 1.

[0072] The secondary battery 2 can be disposed within the housing 10. Multiple secondary batteries 2 can be provided. The multiple secondary batteries 2 can be disposed in the longitudinal direction of the housing 10 (based on...). Figure 1 (in the +X axis direction) and width direction (based on) Figure 1 At least one of the +Y axis directions is arranged in two or more rows. Figure 1 For example, multiple secondary batteries 2 are arranged in twelve rows along the longitudinal direction of the housing 10, but the arrangement of the multiple secondary batteries 2 is not limited to this and can have any of various forms. The multiple secondary batteries 2 can be arranged parallel to each other. The number of secondary batteries 2 can be designed in any of various ways depending on the size, shape, etc. of the housing 10.

[0073] Multiple secondary batteries 2 can be electrically connected to each other. As an example, adjacent secondary batteries 2 can be connected in series or in parallel via busbars. The busbars can be formed of conductive materials such as copper, aluminum, nickel, etc. The specific shape of the busbars can be any of various shapes capable of electrically connecting adjacent secondary batteries 2.

[0074] Figure 2 This is a perspective view schematically illustrating the configuration of a secondary battery according to an embodiment of the present invention; Figure 3 It is an illustrative example. Figure 2 An exploded perspective view of the secondary battery configuration; Figure 4 It is along Figure 2 A cross-sectional view taken from line IV-IV; and Figure 5 This is a view that schematically illustrates the configuration of an electrode assembly according to an embodiment of the present invention.

[0075] The first direction described below can refer to... Figure 2 and Figure 3 The -X axis direction, the second direction can refer to the direction based on Figure 2 and 3 The +Y axis direction, and the third direction can be pointed to based on Figure 2 and Figure 3 The -Z axis direction.

[0076] In this document, an example of a prismatic lithium-ion secondary battery 2 will be described. However, this disclosure is not limited thereto, and, for example, the secondary battery may be a lithium polymer battery or a cylindrical battery.

[0077] refer to Figures 2 to 5 According to the embodiment, the secondary battery 2 may include an electrode assembly 200, a housing 100, a connecting member 300, a side terminal 400, a cover plate 450, and a first insulator 500.

[0078] The electrode assembly 200 may include an electrode plate and electrode terminals. The electrode plate may include a positive electrode plate 210 and a negative electrode plate 220, and the electrode terminals may include a positive electrode terminal 240 and a negative electrode terminal 250.

[0079] The positive electrode plate 210 can be used as the positive electrode of the electrode assembly 200.

[0080] The positive electrode plate 210 according to the embodiment may have the shape of a foil comprising a metallic material such as aluminum or an aluminum alloy. Two surfaces or opposite surfaces of the positive electrode plate 210 may be arranged perpendicular to the first direction. The type, size, shape, etc., of the positive electrode plate 210 are not particularly limited, as long as it is conductive and does not cause chemical changes in the secondary battery 2. The cross-sectional shape of the positive electrode plate 210 may have, in addition to... Figure 5 Any shape other than the rectangular shape illustrated.

[0081] Multiple positive electrode plates 210 can be provided. The multiple positive electrode plates 210 can be arranged in a first direction between the front surface portion 112 and the rear surface portion 113 of the housing 100. The number of positive electrode plates 210 can vary depending on the charging capacity of the secondary battery 2, etc.

[0082] The positive electrode plate 210 may include a first active material layer 211 and a first uncoated portion 212.

[0083] The first active material layer 211 may be provided in the form of being applied to at least a portion of the positive electrode plate 210. The first active material layer 211 may be applied to both surfaces or opposite surfaces of the positive electrode plate 210, or it may be applied to only one surface of the positive electrode plate 210.

[0084] In one embodiment, the positive electrode plate 210 serves as the positive electrode, and the first active material layer 211 may include the positive electrode active material.

[0085] The positive electrode active material can be a compound capable of reversibly inserting and deintercalating lithium (lithiation intercalation compound). In one embodiment, one or more composite oxides of lithium with metals selected from cobalt, manganese, nickel, and combinations thereof can be used.

[0086] In one example, the positive electrode active material may include lithium iron phosphate oxide (LiFePO4, LFP), lithium manganese iron phosphate oxide (LiMnFePO4, LMFP), and lithium nickel cobalt manganese oxide (LiNi). x Co y Mn zat least one of O2, NCM). Here, 0 < x < 1, 0 < y < 1, 0 < z < 1, and x + y + z = 1 can be satisfied. The positive electrode active material can include 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 only one of O2, NCM), and can include 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 any two or all of O2, NCM).

[0087] The first active material layer 211 may further include a positive electrode conductive material.

[0088] The positive electrode conductive material imparts conductivity to the first active material layer 211, and any suitable material that does not cause chemical changes and is conductive can be used. Examples of the positive electrode conductive material can include: 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.

[0089] The first active material layer 211 may further include a positive electrode binder.

[0090] The positive electrode binder can attach the particles constituting the positive electrode active material to each other well and also attach the positive electrode active material to the positive electrode plate 210 well.

[0091] [[ID=​​​​​Waterborne adhesives can be selected from styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, (meth)acrylonitrile-butadiene rubber, (meth)acrylic rubber, butyl rubber, fluoroelastomers, 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.

[0094] If an aqueous binder is used as the positive electrode binder, it can further contain a cellulose compound to impart viscosity. The cellulose compound can be used by mixing one or more of carboxymethyl cellulose, hydroxypropyl methylcellulose, methylcellulose, and their alkali metal salts. In one embodiment, Na, K, or Li can be used as the alkali metal.

[0095] Dry adhesives can be fibrous polymeric materials, such as polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polyethylene oxide, or combinations thereof.

[0096] The positive electrode plate 210 may include a first uncoated portion 212 to which the first active material layer 211 is not coated. According to an embodiment, the first uncoated portion 212 may be located at an end region of the positive electrode plate 210 facing the opening 118 of the housing 100. However, the form of the first uncoated portion 212 is not limited thereto, and in one embodiment, the first uncoated portion 212 may be formed over the entire edge region of the positive electrode plate 210.

[0097] The negative electrode plate 220 can be used as the negative electrode of the electrode assembly 200.

[0098] The negative electrode plate 220 according to the embodiment may have the shape of a foil comprising a metallic material such as copper, copper alloy, nickel, or nickel alloy. The two surfaces or opposite surfaces of the negative electrode plate 220 may be arranged perpendicular to the first direction. The type, size, shape, etc., of the negative electrode plate 220 are not particularly limited, as long as the negative electrode plate 220 is conductive and does not cause chemical changes in the secondary battery. The cross-sectional shape of the negative electrode plate 220 may have, in addition to... Figure 5 Any shape other than the rectangle shape shown.

[0099] Multiple negative electrode plates 220 may be provided. The multiple negative electrode plates 220 may be arranged in a first direction between the front surface portion 112 and the rear surface portion 113 of the housing 100. Multiple positive electrode plates 210 and negative electrode plates 220 may be alternately arranged in the first direction. The positive electrode plates 210 and negative electrode plates 220 may be spaced apart from each other by a distance (e.g., a predetermined distance) in the first direction.

[0100] The negative electrode plate 220 and the positive electrode plate 210 may be arranged to face each other in a first direction.

[0101] The negative electrode plate 220 may include a second active material layer 221 and a second uncoated portion 222.

[0102] The second active material layer 221 may be provided in a form coated on at least a part of the negative electrode plate 220. The second active material layer 221 may be coated on two surfaces or opposite surfaces of the negative electrode plate 220, or may be coated on only one surface of the negative electrode plate 220.

[0103] In one embodiment, the negative electrode plate 220 serves as a negative electrode, and the second active material layer 221 may include a negative electrode active material.

[0104] The negative electrode active material may include a material capable of reversibly inserting / extracting lithium ions, lithium metal, an alloy of lithium and a metal, a material capable of doping and dedoping lithium, or a transition metal oxide.

[0105] The material capable of reversibly inserting / extracting lithium ions may be a carbon-based negative electrode active material, such as crystalline carbon, amorphous carbon, or a combination thereof. Examples of crystalline carbon may include graphite, such as natural graphite or artificial graphite in amorphous, plate-like, flaky, spherical, or fibrous forms, and examples of amorphous carbon may include soft carbon or hard carbon, mesophase pitch carbide, calcined coke, etc.

[0106] In one embodiment, as an alloy of lithium and a metal, an alloy of lithium and a metal selected from Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Ra, Ge, Al, and Sn may be used.

[0107] As a material capable of doping and dedoping lithium, a Si-based negative electrode active material or a Sn-based negative electrode active material may be used. The Si-based negative electrode active material may include silicon, a silicon-carbon composite, SiO x (0 < x ≤ 2), a Si-Q alloy (where 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 a combination thereof. The Sn-based negative electrode active material may include Sn, SnO2, a Sn-based alloy, or a combination thereof.

[0108] Silicon-carbon composites can be composites of silicon and amorphous carbon. According to one embodiment, the silicon-carbon composite can be in the form of silicon particles with amorphous carbon coated on their surface. For example, the 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 also be located between the primary silicon particles; for example, the primary silicon particles can be coated with amorphous carbon. The secondary particles can be dispersed in an amorphous carbon matrix.

[0109] The silicon-carbon composite may further include crystalline carbon. For example, the silicon-carbon composite may include a core comprising crystalline carbon and silicon particles, and an amorphous carbon coating on the surface of the core.

[0110] Si-based or Sn-based negative electrode active materials can be used in combination with carbon-based negative electrode active materials.

[0111] The second active material layer 221 may further include a negative electrode conductive material and a negative electrode binder.

[0112] The negative electrode conductive material imparts conductivity to the second active material layer 221, 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, and carbon nanotubes; 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.

[0113] The negative electrode binder can effectively attach the particles constituting the negative electrode active material to each other, and also effectively attach the negative electrode active material to the positive electrode plate 220.

[0114] Examples of negative electrode adhesives may include non-aqueous adhesives, aqueous adhesives, dry adhesives, or combinations thereof.

[0115] Examples of 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.

[0116] Waterborne adhesives can be selected from styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, (meth)acrylonitrile-butadiene rubber, (meth)acrylic rubber, butyl rubber, fluoroelastomers, 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.

[0117] If an aqueous binder is used as the negative electrode binder, it can further contain a cellulose compound to impart viscosity. The cellulose compound can be used by mixing one or more of carboxymethyl cellulose, hydroxypropyl methylcellulose, methylcellulose, and their alkali metal salts. In one embodiment, Na, K, or Li can be used as the alkali metal.

[0118] Dry adhesives can be fibrous polymeric materials, such as polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polyethylene oxide, or combinations thereof.

[0119] The negative electrode plate 220 may include a second uncoated portion 222 to which the second active material layer 221 is not coated. According to an embodiment, the second uncoated portion 222 may be located at the other end region of the negative electrode plate 220, which faces another opening in the housing 100. However, the form of the second uncoated portion 222 is not limited thereto, and in one embodiment, the second uncoated portion 222 may be formed over the entire edge region of the negative electrode plate 220.

[0120] A diaphragm 230 may be disposed between the positive electrode plate 210 and the negative electrode plate 220. The diaphragm 230 can prevent or substantially prevent short circuits between the positive electrode plate 210 and the negative electrode plate 220, while allowing lithium ions to move between the positive electrode plate 210 and the negative electrode plate 220.

[0121] 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 positive electrode plate 210 and the negative electrode plate 220 from being directly exposed to the outside of the electrode assembly 200.

[0122] 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 two-layer separator, a polyethylene / polypropylene / polyethylene three-layer separator, a polypropylene / polyethylene / polypropylene three-layer separator, etc., can be used.

[0123] 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 both or opposite surfaces of the porous substrate.

[0124] The porous substrate can be a polymer film formed from any polymer selected from 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).

[0125] Organic materials may include polymers such as polyvinylidene fluoride or (meth)acrylic acid polymers.

[0126] Inorganic materials may include, but are 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.

[0127] Organic and inorganic materials can exist as a mixture in a single coating, or they can exist as a stack of coatings containing organic materials and coatings containing inorganic materials.

[0128] The positive electrode terminal 240 can be connected to the positive electrode plate 210. The positive electrode terminal 240 can provide an electrical connection between the positive electrode plate 210 and the connection member 300 described below.

[0129] Multiple positive electrode tabs 240 may be provided. Each positive electrode tab 240 may extend from a different positive electrode plate 210 in a second direction. Multiple positive electrode tabs 240 may be stacked in a first direction.

[0130] The positive electrode contact 240 can be bent in a first direction. That is, the end portion of the positive electrode contact 240 can have a bent shape in the first direction. Accordingly, the positive electrode contact 240 can increase the contact area with the sub-plate of the connecting member 300, which will be described below. The positive electrode contact 240 can be bent inside the housing 100 in a direction from the front surface portion 112 to the rear surface portion 113 and in a direction from the rear surface portion 113 to the front surface portion 112.

[0131] When the positive electrode tab 240 is bent in the first direction, the sum of the thicknesses of the plurality of positive electrode tabs 24 stacked in the first direction may be greater than the thickness of the electrode assembly 200 in the first direction. In one embodiment, among the plurality of positive electrode tabs 240 stacked in the first direction, the ends of some positive electrode tabs positioned relatively close to the rear surface portion 113 may protrude from the electrode assembly 200 toward the rear surface portion 113.

[0132] The negative electrode terminal 250 can be connected to the negative electrode plate 220. The negative electrode terminal 250 can provide an electrical connection between the negative electrode plate 220 and the connection member 300 described below.

[0133] Multiple negative electrode tabs 250 may be provided. Each negative electrode tab 250 may extend from a different negative electrode plate 220 in a direction opposite to the second direction. Multiple negative electrode tabs 250 may be stacked in the first direction.

[0134] The negative electrode tab 250 can be bent in a direction opposite to the first direction. That is, the end portion of the negative electrode tab 250 can have a shape that is bent in a direction opposite to the first direction. Accordingly, the negative electrode tab 250 can increase the contact area with the sub-plate of the connecting member 300, which will be described below. The negative electrode tab 250 can be bent inside the housing 100 in a direction from the rear surface portion 113 toward the front surface portion 112 and in a direction from the front surface portion 112 toward the rear surface portion 113.

[0135] When the negative electrode tab 250 is bent in a direction opposite to the first direction, the sum of the thicknesses of the plurality of negative electrode tabs 150 stacked in the first direction can be greater than the thickness of the electrode assembly 200 in the first direction. In one embodiment, among the plurality of negative electrode tabs 250 stacked in the first direction, the ends of some negative electrode tabs 250 positioned relatively close to the front surface portion 112 can protrude from the electrode assembly 200 toward the front surface portion 112.

[0136] The housing 100 according to an embodiment may include a bottom portion 111, a front surface portion 112, a rear surface portion 113, a top portion 117, and an opening 118. That is, in one embodiment, the housing 100 has a cuboid shape and may be formed as a hollow structure with openings 118 on both sides or opposite sides.

[0137] The top portion 117 may form the appearance of the upper side of the housing 100. According to an embodiment, the top portion 117 may have a rectangular plate shape. The top portion 117 may be positioned to face the bottom portion 111 in a third direction. The top portion 117 may be spaced apart from the bottom portion 111 by a distance (e.g., a predetermined distance) in a direction opposite to the third direction.

[0138] The electrode terminals of the electrode assembly 200 can be oriented toward each opening 118.

[0139] The housing 100 according to the embodiment may further include an exhaust port 120 and an exhaust element 130.

[0140] According to the embodiment, the vent 120 may have the shape of a hole that vertically passes through the top portion 117 in a third-order direction. In the event of thermal runaway of the secondary battery due to overcurrent or the like, the vent 120 can provide a path for flames, gases, smoke, etc., formed in the housing 100 to be discharged to the outside of the housing 100. The cross-sectional shape of the vent 120 may be any of various shapes, such as elliptical, circular, polygonal, etc.

[0141] The vent 130 can be installed in the vent 120 and opens and closes in response to changes in the internal pressure of the housing 100. That is, during normal operation of the secondary battery, the vent 130 can prevent or substantially prevent leakage of electrolytes or other substances from the housing 100 by closing the vent 120, or prevent or substantially prevent the entry of moisture, foreign matter, etc., into the housing 100. In the event of thermal runaway of the secondary battery, the vent 130 can release flames, gases, smoke, etc., formed within the housing 100 to the outside of the housing 100 by opening the vent 120.

[0142] According to the embodiment, the exhaust member 130 can be formed to have a generally plate shape. The exhaust member 130 can be fixed to the top portion 117 of the housing 100 by any of various types of connection methods such as welding, bolting, mating, etc.

[0143] Figure 6 This is a cross-sectional view illustrating the configuration of the main parts of a secondary battery according to an embodiment of the present invention; Figure 7 This is a view schematically illustrating the formation of the first groove in the cover plate according to an embodiment of the present invention; Figure 8 These are views illustrating various shapes of the first recess of a secondary battery according to embodiments of the present invention; and Figure 9 This is a schematic view illustrating the connection of the first joint of the secondary battery according to an embodiment of the present invention.

[0144] refer to Figures 6 to 9 According to the embodiment, the connecting member 300 may include a sub-plate that contacts and is connected to the electrode terminals of the electrode assembly 200, and a current collector 320 that is welded to the sub-plate on one side and welded to the side terminal 400 on the other side.

[0145] In one embodiment, a pair of connecting members 300 may be provided. The connecting members 300 are configured to contact and connect to the electrode terminals, and may be provided on both sides of the housing 100 or opposite to each other and connected to the positive electrode terminal 240 and the negative electrode terminal 250, respectively.

[0146] The subplate may form the appearance of one side of the connecting member 300 and may be connected to the electrode terminals. The subplate may include a center plate 312 and side plates 314 extending from the center plate 312 on both sides or opposite sides.

[0147] In one embodiment, the center plate 312 may form the central appearance of the sub-plate and may fully support the side plates 314 on both sides or opposite sides. The center plate 312 may be formed to have a generally flat plate shape. In one embodiment, the side plates 314 and the electrode tabs may be joined together by laser welding or ultrasonic welding. Accordingly, welding lines connecting to the electrode tabs may be formed on the side plates 314, and these welding lines may simultaneously (e.g., concurrently) secure multiple stacked electrode tabs to the side plates 314.

[0148] The current collector 320 according to the embodiment can be formed of a material capable of conducting electric current (such as aluminum, copper, or nickel). The current collector 320 can be disposed between the electrode assembly 200 and the cover plate 450 so as to face each other.

[0149] One side of the current collector 320 can be connected to a sub-plate. For example, the current collector 320 can be connected to the upper portion of the center plate 312. The current collector 320 can be connected by any of a variety of connection methods such as welding and bolting.

[0150] According to an embodiment, the side terminal 400 can be electrically connected to the connecting member 300. In one embodiment, the side terminal 400 may include a boss terminal 410 formed on the connecting member 300 to pass through the cover plate 450 and an external terminal 420 located outside the cover plate 450 and soldered to the boss terminal 410.

[0151] In one embodiment, a pair of side terminals 400 may be provided. The side terminals 400 are coupled to the connecting member 300 and may be provided on both sides or opposite sides of the housing 100 to be electrically connected to the positive electrode terminal 240 and the negative electrode terminal 250 respectively via the connecting member 300.

[0152] The boss terminal 410 may be integrally formed with the current collector 320 and protrude from the center portion of the current collector 320. The boss terminal 410 may be connected to an external terminal 420 disposed on the outside of the cover plate 450. For example, the boss terminal 410 may pass through the cover plate 450 and contact the lower end portion of the external terminal 420. The upper surface of the boss terminal 410 may be connected to the lower end portion of the external terminal 420 by any of a variety of connection methods such as welding, bolting, etc.

[0153] Corresponding tapered portions 430 are formed in the boss terminal 410 and the external terminal 420, and the contact surface can be widened due to the tapered portions 430, thereby improving the reliability of the electrical connection.

[0154] According to an embodiment, the cover plate 450 can seal the opening 118. In one embodiment, the cover plate 450 may include a pair of cover plates 450 to seal two openings 118 or opposite openings 118 of the housing 100.

[0155] According to an embodiment, the cover plate 450 may have a flat plate shape. The cover plate 450 may be disposed in an opening 118 of the housing 100. The cover plate 450 may be configured to face the electrode terminals of the electrode assembly 200. In one embodiment, the edge region of the cover plate 450 may be connected to the end portions of each of the bottom portion 111, the front surface portion 112, the rear surface portion 113, and the top portion 117 by any of a variety of connection methods such as welding, bolting, mating, etc.

[0156] According to an embodiment, the first insulator 500 can insulate the cover plate 450 from the connecting member 300. The first insulator 500 may have a generally flat plate shape.

[0157] In one embodiment, the first insulator 500 may be formed of an insulating material such as polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), rubber, etc.

[0158] The first insulator 500 and the cover plate 450 may be joined by a first joint 600. For example, the first joint 600 may include a first groove 610 formed in the cover plate 450 and a first protrusion 620 formed on the first insulator 500 to be inserted into the first groove 610 and melted to fill the first groove 610.

[0159] The first groove 610 may be formed in a shape that widens in the insertion direction of the first protrusion 620, and the first protrusion 620 may be formed to be longer than the depth of the first groove 610.

[0160] More specifically, a first groove 610 may be formed in the lower surface of the cover plate 450, and a first protrusion 620 may be formed in the upper surface of the first insulator 500.

[0161] refer to Figure 7 The formation of the first groove 610 is described. As illustrated, the entrance width D2 of the first groove 610 can be formed to be smaller than the inner width D1 of the first groove 610 by performing a secondary ring machining on the outside of the linear groove after the initial linear groove machining.

[0162] In one embodiment, the depth t of the linear groove is no greater than 50% of the thickness T of the cover plate.

[0163] The locking portion can be formed on the inlet side of the first groove 610 by secondary ring machining. Since the locking portion protrudes towards the center from the inner surface of the first groove 610, the inner surface can be formed as an inclined surface, thus allowing the first groove 610 to be formed into a shape that gradually widens towards the top. This provides resistance to forces in the separation direction of the first protrusion 620, thereby improving the bonding force.

[0164] The volume of the first protrusion 620 may be less than or equal to the internal volume of the first groove 610. This can prevent or substantially prevent the molten first protrusion 620 (e.g., molten resin) from flowing out of the first groove 610 when the first protrusion 620 melts, thereby preventing or substantially preventing the cover plate 450 and the first insulator 500 from separating.

[0165] Figure 8 This is a view illustrating various shapes of the first recess of a secondary battery according to an embodiment of the present invention.

[0166] refer to Figure 8 The first groove 610 can be formed in any shape of various shapes. That is, the first groove 610 can be formed in any shape of various shapes such as circular, slotted, or rectangular with rounded corners.

[0167] Although not illustrated, the first groove 610 can be formed in any shape other than those described above, such as a square, a star, etc.

[0168] Figure 9 This is a schematic view illustrating the connection of the first joint of the secondary battery according to an embodiment of the present invention.

[0169] refer to Figure 9 According to the present invention, the first protrusion 620 and the first groove 610 can be joined by thermal fusion. With the first protrusion 620 inserted into the first groove 610, the first protrusion 620 can be filled by being squeezed and melted, and then hardened and joined.

[0170] This thermal fusion can be achieved in a variety of ways.

[0171] Figure 10 This is a view illustrating the thermal fusion of the first joint of a secondary battery according to an embodiment of the present invention via a heating rod; Figure 11 This is a view illustrating the thermal fusion of the first joint of a secondary battery according to an embodiment of the present invention via ultrasonic welding; and Figure 12 This is a view illustrating the thermal fusion of the first joint of a secondary battery according to an embodiment of the present invention via laser welding.

[0172] refer to Figure 10The first protrusion 620 and the first groove 610 can be thermally fused together by a heating rod HR. More specifically, when the heating rod HR is placed on the cover plate 450 made of aluminum, and the first protrusion 620 is inserted into the first groove 610 and the first insulator 500 is pressed toward the cover plate 450, the first protrusion 620 melts, and the molten first protrusion 620 (e.g., molten resin) fills the first groove 610 and hardens, so that the cover plate 450 and the first insulator 500 can be joined.

[0173] refer to Figure 11 The first protrusion 620 and the first groove 610 can be thermally fused together by ultrasonic welding. Ultrasonic welding is a non-contact welding technique that uses high-frequency vibrations to join two materials. This method can quickly and efficiently join thermoplastic and metal parts. That is, a cover plate 450 made of aluminum and a first insulator 500 made of plastic can be joined.

[0174] More specifically, while the first protrusion 620 is inserted, a support plate is supported on the side of the cover plate 450, and an ultrasonic generator UG is provided on the side of the first insulator 500 to generate a high-frequency electrical signal, which causes high-frequency friction on the mating surface between the first protrusion 620 and the first groove 610, causing the first protrusion 620 to melt, and the melted first protrusion 620 (e.g., molten resin) fills the first groove 610 and hardens, thereby joining the cover plate 450 and the first insulator 500.

[0175] refer to Figure 12 The first protrusion 620 and the first groove 610 can be thermally fused together by laser welding. For laser welding, the first insulator 500 is made of a transparent material.

[0176] More specifically, when the first protrusion 620 is inserted into the first groove 610, the support plate is supported on the side of the cover plate 450, the laser oscillator LO is provided on the side of the first insulator 500, and by irradiating a strong laser beam, a high-temperature heat source is formed at the mating surface between the first protrusion 620 and the first groove 610, causing the first protrusion 620 to melt, and the melted first protrusion 620 (e.g., molten resin) fills the first groove 610 and hardens, thereby joining the cover plate 450 and the first insulator 500.

[0177] Figure 13 This is a cross-sectional view illustrating the thermally fused state of the first junction of a secondary battery according to an embodiment of the present invention; and Figure 14 This is a photograph of the first groove of the cover plate according to an embodiment of the present invention.

[0178] refer to Figure 13 and Figure 14The first protrusion 620 can be melted and filled into the first groove 610 by a thermal fusion process, and after a period of time, the cover plate 450 and the first insulator 500 can be hardened and integrated into a single component. At this time, the groove formed by the secondary ring processing is also filled by the melted first protrusion 620 (e.g., melted resin), thereby improving the bonding strength.

[0179] The second insulator 700 can be provided between the side terminal 400 and the cover plate 450. The second insulator 700 can be joined by the second joint 800.

[0180] refer to Figure 6 According to this embodiment, the second insulator 700 can be formed of an insulating material such as polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), rubber, etc. Furthermore, the shape of the second insulator 700 can be formed as a shape surrounding the circumferential surface of the boss terminal 410, between the outer terminal 420 and the cover plate 450, and surrounding a portion of the outer surface of the outer terminal 420.

[0181] In one embodiment, the second coupling portion 800 may include a second groove 810 formed in each of the outer terminal 420 and the cover plate 450 facing each other, and a second protrusion 820 formed on the second insulator 700 to be inserted into the second groove 810 and melted to fill the second groove 810.

[0182] In one embodiment, the thermal fusion bonding between the second protrusion 820 and the second groove 810 is the same as the thermal fusion bonding of the first joint 600 described above.

[0183] In this document, a secondary battery 2 according to another embodiment of the present disclosure will be described.

[0184] The secondary battery 2 according to this embodiment can be configured to differ from the secondary battery 2 according to the previous embodiment of this disclosure only in the configuration of the first joint 600.

[0185] Accordingly, in the description of the secondary battery 2 according to this embodiment, only the configuration of the first joint 600, which is different from that of the secondary battery 2 according to the previous embodiment of this disclosure, will be described.

[0186] For the remaining configurations of the secondary battery 2 according to this embodiment, the description of the secondary battery 2 according to the previous embodiment of the present invention can be applied as is.

[0187] Figure 15 This is a perspective view schematically illustrating a first protrusion of a secondary battery according to another embodiment of the present invention; Figure 16 It is an illustrative example. Figure 15 A view of the first joint of the secondary battery; Figure 17This is a cross-sectional view schematically illustrating a modified example of the first protrusion according to an embodiment of the present invention; and Figure 18 This is a cross-sectional view illustrating the thermally fused state of the first junction of a secondary battery according to an embodiment of the present invention.

[0188] refer to Figures 15 to 18 According to this embodiment, the first joint 600 may include a first groove 610 formed in the cover plate 450 and a first protrusion 620 formed on the first insulator 500 to be inserted into the first groove 610 and melted to fill the first groove 610.

[0189] The first groove 610 may be formed in a shape that widens in the insertion direction of the first protrusion 620, and the first protrusion 620 may be formed to be longer than the depth of the first groove 610.

[0190] More specifically, a first groove 610 may be formed in the lower surface of the cover plate 450, and a first protrusion 620 may be formed in the upper surface of the first insulator 500.

[0191] When the first groove 610 is formed, the inlet width D2 of the first groove 610 (see...) Figure 7 The inner width D1, which is smaller than the first groove 610, can be formed by performing a secondary ring machining on the outside of the linear groove after the initial linear groove machining (see...). Figure 7 ).

[0192] In one embodiment, the depth t of the linear groove (see...) Figure 7 The thickness of the cover plate is not greater than T (see [reference]). Figure 7 50% of ).

[0193] The locking portion can be formed on the inlet side of the first groove 610 by secondary ring machining. Since the locking portion protrudes towards the center from the inner surface of the first groove 610, the inner surface can be formed as an inclined surface, thus allowing the first groove 610 to be formed into a shape that gradually widens towards the top. This provides resistance to forces in the separation direction of the first protrusion 620, thereby improving the bonding force.

[0194] In one embodiment, the volume of the first protrusion 620 may be less than or equal to the internal volume of the first groove 610. This prevents or substantially prevents the molten first protrusion 620 (e.g., molten resin) from flowing out of the first groove 610 when the first protrusion 620 melts, thereby preventing or substantially preventing the cover plate 450 and the first insulator 500 from detaching.

[0195] Additionally, a receiving groove 630 for accommodating the molten first protrusion 620 (e.g., molten resin) when the first protrusion 620 melts can be formed around the first protrusion 620.

[0196] The receiving groove 630 can prevent the molten first protrusion 620 from overflowing from the space of the first groove 610 when the first protrusion 620 melts, so as to prevent or substantially prevent the cover plate 450 and the first insulator 500 from detaching.

[0197] In one embodiment, reference Figure 17 Multiple first protrusions 620 can be formed to be inserted into the first groove 610 and melted. Because multiple first protrusions 620 are formed, melting can be performed quickly and process time can be reduced.

[0198] In this document, a secondary battery 2 according to another embodiment of the present invention will be described.

[0199] According to this embodiment, the secondary battery 2 can be configured such that it is connected to the first joint 600. Figure 2 The secondary battery 2 is different.

[0200] Accordingly, in the description of the secondary battery 2 according to this embodiment, only those related to... Figure 2 Detailed configuration of the different first joints 600 of the secondary battery 2.

[0201] The remaining configurations of the secondary battery 2 according to this embodiment can be applied as is. Figure 2 Description of secondary battery 2.

[0202] Figure 19 This is a schematic cross-sectional view illustrating the first junction of a secondary battery according to another embodiment of the present invention; Figure 20 It is an illustrative example. Figure 19 A view showing the formation of the first groove in the secondary battery; Figure 21 It is an illustrative example. Figure 19 A view of the engagement of the first joint of the secondary battery; and Figure 22 This is an example Figure 19 A cross-sectional view of the thermally fused first junction of the secondary battery.

[0203] refer to Figures 19 to 22 According to this embodiment, the first joint 600 may include a first groove 610 formed in the cover plate 450 and a first protrusion 620 formed on the first insulator 500 to be inserted into the first groove 610 and melted to fill the first groove 610.

[0204] The first groove 610 may be formed in a shape that widens in the insertion direction of the first protrusion 620, and the first protrusion 620 may be formed to be longer than the depth of the first groove 610.

[0205] More specifically, a first groove 610 may be formed in the lower surface of the cover plate 450, and a first protrusion 620 may be formed in the upper surface of the first insulator 500.

[0206] A receiving groove 630 for receiving the molten first protrusion 620 (e.g., molten resin) when the first protrusion 620 melts can be formed around the first protrusion 620.

[0207] The receiving groove 630 can prevent or substantially prevent the molten first protrusion 620 from overflowing from the space of the first groove 610 when the first protrusion 620 melts, so as to prevent or substantially prevent the cover plate 450 and the first insulator 500 from detaching.

[0208] Additionally, the first groove 610 may include a protrusion 640 inserted into the receiving groove 630.

[0209] When forming the first groove 610, the inlet width D2 of the first groove 610 (see...) Figure 7 The inner width D1, which is smaller than the first groove 610, can be formed by performing a secondary ring machining on the outside of the linear groove after the initial linear groove machining (see...). Figure 7 ).

[0210] The initial linear groove machining can form a linear groove on the inner side of the protrusion 640, and the secondary ring machining can be performed on the outer side of the protrusion 640, so that a locking portion including the protrusion 640 can be formed on the entrance side of the first groove 610. Since the locking portion including the protrusion 640 protrudes towards the center from the inner surface of the first groove 610, the inner surface can form an inclined surface, so the first groove 610 can be formed into a shape that gradually widens towards the top.

[0211] This can provide resistance to the force in the separation direction of the first protrusion 620, thereby improving the bonding force.

[0212] In one embodiment, the depth t of the linear groove (see...) Figure 7 ) not greater than 450 T of the cover plate (see Figure 7 50% of ).

[0213] The volume of the first protrusion 620 can be less than or equal to the internal volume of the first groove 610. This can prevent or substantially prevent the molten first protrusion 620 (e.g., molten resin) from flowing out of the first groove 610 when the first protrusion 620 melts, thereby preventing or substantially preventing the cover plate 450 and the first insulator 500 from detaching. Furthermore, the receiving groove 630 can prevent or substantially prevent the molten first protrusion 620 (e.g., molten resin) from flowing out of the first groove 610, and the protrusion 640 received in the receiving groove 630 can improve the bonding strength.

[0214] In addition, the linear groove processing can be guided by the protrusion 640, and as the depth of the first groove 610 increases, the resistance to the force in the separation direction increases, thereby improving the bonding force.

[0215] This document describes methods for manufacturing secondary batteries according to various embodiments of the present invention.

[0216] Figure 23 This is a flowchart illustrating, schematically, a method for manufacturing a secondary battery according to various embodiments of the present invention.

[0217] refer to Figures 1 to 23 The method for manufacturing a secondary battery according to this embodiment may include a first groove forming operation S100, a first bonding operation S200, and a second bonding operation S300.

[0218] First, a first protrusion 620 is integrally formed on the first insulator 500 to protrude from the first insulator 500 so as to be inserted into the first groove 610.

[0219] The first groove forming operation S100 for forming the first groove 610 in the cover plate 450 may include a primary linear groove processing operation S110 for forming a linear groove in the lower surface of the cover plate 450 and a secondary ring processing operation S120 for forming a narrow inlet width of the linear groove by ring processing on the outer side of the linear groove (i.e., forming the inlet width of the linear groove to be narrower than the inner width of the linear groove).

[0220] In other words, the linear groove can be formed in the lower surface of the cover plate 450 made of aluminum by extrusion, and the locking portion can be formed on the inlet side of the linear groove by ring machining to surround the linear groove on the outside, thereby forming the first groove 610. The inlet width of the first groove 610 can be formed to be smaller than the inner width. Here, the term "ring machining" refers to the secondary machining step in which the linear groove / first groove (in the circumferential direction) is circumferentially surrounded to form the locking portion at the inlet side of the linear groove / first groove.

[0221] Subsequently, a first bonding operation S200 is performed. The first bonding operation S200 is used to bond the first insulator 500 to the cover plate 450, and by inserting the first protrusion 620 of the first insulator 500 into the first groove 610, melting the first protrusion 620, and filling and hardening the molten first protrusion 620 (e.g., molten resin) into the first groove 610, the first insulator 500 can be integrated into the cover plate 450 as a single component.

[0222] In one embodiment, the melting of the first protrusion 620 can be achieved by means such as Figure 10 The heating rod HR shown in the example is melted, and then... Figure 11 The ultrasonic generator UG shown in the example is used for melting or by means of, for example Figure 12 The laser oscillator LO illustrated in the example is melted to achieve this.

[0223] The first protrusion 620 and the first groove 610 can be thermally fused together by melting the first protrusion 620.

[0224] In one embodiment, the volume of the first protrusion 620 may be less than or equal to the internal volume of the first groove 610. This can prevent, or substantially prevent, the molten first protrusion 620 (e.g., molten resin) from overflowing to the outside of the first groove 610 when the first protrusion 620 is melted in the first bonding operation S200 described below.

[0225] At the same time, such as Figures 15 to 18 As shown, a receiving groove 630 may be formed around the first protrusion 620. When the first protrusion 620 melts, the receiving groove 630 can prevent or substantially prevent the molten first protrusion 620 from overflowing from the space of the first recess 610. Accordingly, the cover plate 450 and the first insulator 500 can be tightly joined together to prevent or substantially prevent detachment, etc.

[0226] Subsequently, a second joining operation S300 is performed. The second joining operation S300 is used to join the cover plate 450 and the side terminal 400, and may include a second groove forming operation S310, a melting operation S320, and a terminal forming operation S330.

[0227] In this case, by combining the cover plate 450 and the side terminal 400, the side terminal 400 may include a boss terminal 410 formed on the connecting member 300 to pass through the cover plate 450 and an external terminal 420 located outside the cover plate 450 and coupled to the boss terminal 410.

[0228] In the second groove forming operation S310, when the second groove 810 is formed in each of the cover plate 450 and the external terminal 420, the second groove 810 is formed by pressing in the upper surface of the cover plate 450 and the lower surface of the external terminal 420.

[0229] In addition, during the melting operation S320, the second protrusion 820 formed on the second insulator 700 is inserted into the second groove 810 formed in the cover plate 450 and the external terminal 420, and the second protrusion 820 is melted to fill the second groove 810, thereby integrating the external terminal 420 and the cover plate 450 into a single component through the second insulator 700.

[0230] Subsequently, terminal forming operation S330 is used to integrate the boss terminal 410 and the external terminal 420 by welding, and to join the tapered portion 430 corresponding to the upper portion of the boss terminal 410 and the interior of the external terminal 420 by welding to form the side terminal 400.

[0231] Accordingly, the first insulator 500, the second insulator 700, and the side terminal 400 can be integrated into a single component in the cover plate 450. The cover plate 450, integrated into a single component as described above, can be attached to the housing 100.

[0232] According to one or more embodiments of the present invention, integrating the insulators used to insulate the cover plate and electrode assembly by thermal fusion can eliminate unnecessary processes, thereby simplifying the assembly process and improving insulation reliability.

[0233] According to one or more embodiments of the present invention, conventional insulation and cover plates are integrated by thermal fusion rather than insert injection, thereby reducing manufacturing costs.

[0234] According to one or more embodiments of the present invention, by forming a narrow inlet width, the shape of the groove in which the protrusion of the insulator melts and fills has resistance to forces in the separation direction, which can improve the bonding force to reduce product defects and improve product reliability.

[0235] 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 from the above description of this disclosure other aspects and technical effects not mentioned.

[0236] While this disclosure has been described with reference to some exemplary 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.

Claims

1. A secondary battery, comprising: Electrode assembly, including electrode terminals; A housing that accommodates the electrode assembly; The connecting component is electrically connected to the electrode terminals; The side terminal is electrically connected to the connecting member; A cover plate is attached to an opening in the housing, and the side terminals pass through the cover plate; A first insulator insulates the cover plate from the connecting member; as well as The first joint connects the first insulator and the cover plate.

2. The secondary battery according to claim 1, wherein the first coupling portion comprises: A first groove is located in the cover plate; as well as A first protrusion, on the first insulator, is inserted into the first groove and melts to fill the first groove.

3. The secondary battery according to claim 2, wherein the first groove has a shape that widens in the insertion direction of the first protrusion, and The first protrusion is longer than the depth of the first groove before melting.

4. The secondary battery according to claim 3, wherein the volume of the first protrusion is less than or equal to the internal volume of the first groove.

5. The secondary battery according to claim 3, wherein the inlet width of the first groove is smaller than the inner width of the first groove.

6. The secondary battery according to claim 2, wherein a receiving groove is formed around the first protrusion, the receiving groove receiving the molten first protrusion when the first protrusion melts.

7. The secondary battery according to claim 6, wherein the first groove includes a protrusion inserted into the receiving groove.

8. The secondary battery according to claim 7, wherein the inlet width of the first groove is smaller than the inner width of the first groove.

9. The secondary battery according to any one of claims 1 to 8, wherein the side terminal comprises: A boss terminal is disposed on the connecting member and passes through the cover plate; as well as External terminals are located on the outside of the cover plate and are welded to the boss terminals. The second insulator is between the side terminal and the cover plate.

10. The secondary battery according to claim 9, wherein the second insulator is joined by a second joint, and The second joint includes: A second groove is present in each of the outer terminals and the cover plate, facing each other. as well as A second protrusion is formed on the second insulator to insert into the second groove and melt to fill the second groove.

11. The secondary battery according to claim 9, wherein the boss terminal and the external terminal include corresponding tapered portions.

12. A method for manufacturing a secondary battery, the method comprising: A first groove is formed in the cover plate; The first insulator is attached to the cover plate; as well as Combine the cover plate and the side terminals.

13. The method of claim 12, wherein forming the first groove comprises: A linear groove is formed in the lower surface of the cover plate; as well as The inlet width of the linear groove is made narrower than the inner width of the linear groove by machining the outer ring of the linear groove.

14. The method according to claim 12, wherein, In the process of attaching the first insulator to the cover plate, a first protrusion of the first insulator is inserted into the first groove, and the first protrusion is melted to fill the first groove with the melted first protrusion, the melted first protrusion then hardening.

15. The method of claim 14, wherein the volume of the first protrusion is less than or equal to the internal volume of the first groove.

16. The method of claim 14, wherein a receiving groove is formed around the first protrusion, the receiving groove receiving the molten first protrusion when the first protrusion melts.

17. The method of claim 14, wherein, In the process of incorporating the first insulator into the cover plate, the first protrusion is melted and thermally fused by a heating rod arranged on the cover plate.

18. The method according to claim 14, wherein, In the process of incorporating the first insulator into the cover plate, the first protrusion is melted and thermally fused by ultrasonic welding applied to the first insulator.

19. The method of claim 14, wherein, In the process of incorporating the first insulator into the cover plate, the first insulator is transparent, and the first protrusion is melted and thermally fused by laser welding applied to the first insulator.

20. The method according to any one of claims 14 to 19, wherein the side terminal comprises: A boss terminal is located on the connecting member and passes through the cover plate; as well as External terminals, located on the outside of the cover plate and coupled to the boss terminals, and The process of combining the cover plate and the side terminal includes: A second groove is formed in the cover plate and the external terminal; The second protrusion of the second insulator is inserted into the second groove, and the second protrusion is melted so that the melted second protrusion fills the second groove; and Weld the boss terminal and the external terminal.

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