Secondary battery, battery module, and method for manufacturing secondary battery

Abstract

A secondary battery, a battery module, and / or a method for manufacturing a secondary battery are disclosed. The secondary battery includes a case accommodating an electrode assembly and a terminal coupled to the case, and the terminal includes a softening region.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2024-0124171, filed on September 11, 2024, with the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] The embodiments of this disclosure relate to secondary batteries, battery modules, and / or methods for manufacturing secondary batteries. Background Technology

[0004] Generally speaking, with the rapid supply of battery-powered electronic devices (such as mobile phones, laptops, electric vehicles, etc.), the demand for rechargeable batteries with high energy density and high capacity is increasing rapidly. Correspondingly, research and development to improve the performance of lithium rechargeable batteries are actively underway.

[0005] 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, as well as an electrolyte, and generates electrical energy due to oxidation and reduction reactions when lithium ions are inserted into or deintercalated from the positive and negative electrodes.

[0006] The information disclosed in the background section of this disclosure is provided to improve the understanding of the background of this disclosure, and accordingly, the information disclosed in the background section of this disclosure may include information that does not constitute relevant information. Summary of the Invention

[0007] According to one aspect of the present invention, a secondary battery, a battery module, and / or a method for manufacturing a secondary battery are provided, wherein at least a portion of the terminals are softened. According to another aspect of the present invention, a secondary battery, a battery module, and / or a method for manufacturing a secondary battery are provided, exhibiting improved weldability to connecting members.

[0008] According to another aspect of the embodiments of the present invention, a secondary battery, a battery module, and / or a method for manufacturing a secondary battery are provided, wherein a pattern is formed on at least a portion of a terminal.

[0009] According to another aspect of the embodiments of the present invention, a secondary battery, a battery module, and / or a method for manufacturing a secondary battery are provided, wherein at least a portion of the terminals have roughness.

[0010] However, the aspects of this disclosure and the technical problems to be solved by this disclosure are not limited to the foregoing aspects and problems, and those skilled in the art will clearly understand from the following description of the invention disclosed herein other aspects and problems not mentioned.

[0011] According to one or more embodiments of the present invention, a secondary battery includes a housing housing an electrode assembly and terminals coupled to the housing, wherein the terminals include a softened region.

[0012] According to one or more embodiments of the present invention, a battery module includes a plurality of secondary batteries, a housing containing the plurality of secondary batteries, and a connecting member. Each of the plurality of secondary batteries includes an electrode assembly, a housing containing the electrode assembly, and a terminal connected to the housing and including a softening region. The connecting member is engaged with the softening region and connected to two or more of the plurality of secondary batteries.

[0013] According to one or more embodiments of the present invention, a method for manufacturing a secondary battery includes forming a softening region. Attached Figure Description

[0014] The following figures, included together with this specification, illustrate some embodiments of the invention and are provided together with the following detailed description of the invention to further understand the technical concept of the invention; however, the invention is not to be construed as limited to the subject matter described in these figures, wherein:

[0015] Figure 1 A diagram illustrating the configuration of a battery module according to an embodiment of the present disclosure;

[0016] Figure 2 For illustrative purposes Figure 1 A plan view of the battery module configuration;

[0017] Figure 3 A diagram illustrating the configuration of a secondary battery according to an embodiment of the present invention;

[0018] Figure 4 For illustrative purposes Figure 3 A cross-sectional view of the configuration of the secondary battery;

[0019] Figure 5 The cross-sectional view of the terminal is shown to illustrate its purpose.

[0020] Figures 6A to 6C A top view illustrating a terminal according to an embodiment of the present invention;

[0021] Figure 7 This is a top view of a terminal according to an embodiment of the present invention;

[0022] Figure 8 A view illustrating an example of a pattern according to an embodiment of the present invention;

[0023] Figure 9 A diagram illustrating the hardness difference between terminals including and excluding softened regions according to an embodiment of the present invention; and

[0024] Figure 10 This is a diagram used to describe the weld strength based on the hardness difference. Detailed Implementation

[0025] 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 limited to having a general or dictionary meaning, but should be interpreted as having meanings and concepts consistent with the technical concept of the present disclosure, based on the inventor's ability to appropriately define the concepts of the terms to best describe the principles of his / her invention as his / her own lexicographer. Accordingly, the embodiments disclosed in this specification and the configurations shown in the drawings are merely some exemplary embodiments of the present disclosure and do not necessarily represent the full technical spirit of the present disclosure. It should be understood that various equivalents and modifications may be made to replace these exemplary embodiments at the time of filing this application.

[0026] Furthermore, when used in this specification, "comprise" or "include" and / or "comprising" or "including" indicates the presence of the mentioned shape, quantity, step, operation, component, element and / or group thereof, and does not exclude the presence or addition of one or more other shapes, quantities, steps, operations, components, elements and / or groups thereof.

[0027] Furthermore, to aid in understanding this disclosure, the accompanying drawings may not be drawn to actual scale, and the dimensions (e.g., thickness) of some components may be enlarged. Additionally, the same reference numerals may be given to the same components in different embodiments.

[0028] The description of two objects being compared as "identical" means that the two objects are identical or substantially identical. Accordingly, "identical" or "substantially identical" may include deviations that are considered low in the art (e.g., deviations within 5%). Furthermore, the uniformity of parameters in a particular region may mean uniformity from an average perspective.

[0029] Although terms such as "first" and "second" can be used to describe various components, these components are not limited by these terms. These terms are used to distinguish one component from another, and unless otherwise stated, a first component may be a second component.

[0030] Throughout this instruction manual, unless otherwise stated, each component may be singular or plural.

[0031] The phrase "any component is placed on the 'upper (or lower)' of a component or on the 'above (or below)' of a component" can mean not only that any component is positioned in contact with the upper (or lower) surface of the component, but also that another component can be inserted between the component and any component positioned on (or below) the component.

[0032] Furthermore, when it is disclosed that a particular component is “on” another component, “connected to” or “linked to” another component, it should be understood that these components may be directly connected or linked to each other, or that another component may be “inserted” between these components, or that these components may be “connected,” “linked,” or “linked” through another component.

[0033] As used in this specification, the term "and / or" includes any one and all combinations of the associated listed items. Furthermore, when describing embodiments of this disclosure, the use of "may" refers to "one or more embodiments of this disclosure." The term "one or more" before / after a list of elements modifies the entire list of elements and does not modify any individual element in the list.

[0034] Throughout this instruction manual, unless otherwise stated, “A and / or B” means A, B, or A and B, and unless otherwise indicated, “C to D” means greater than or equal to C and less than or equal to D.

[0035] When phrases such as “at least one of A, B and C”, “at least one of the groups selected from A, B and C”, or “at least one of A, B and C” are used to refer to a list of elements A, B and C, these phrases may refer to any one and all appropriate combinations.

[0036] The term “use” may be considered synonymous with the term “utilize”. As used in this specification, the terms “substantially,” “about,” and other similar terms are used as approximations rather than terms of degree, and are intended to take into account the inherent variation in measurements or calculations that would be recognized by those skilled in the art.

[0037] Although the terms “first,” “second,” “third,” etc., may be used in this specification to describe various elements, components, areas, layers, and / or portions, these elements, components, areas, layers, and / or portions are not limited by these terms. These terms are used to distinguish one element, component, area, layer, or portion from another element, component, area, layer, or portion. Accordingly, without departing from the teachings of this disclosure, the first element, component, area, layer, or portion described below may refer to the second element, component, area, layer, or portion.

[0038] Spatially related terms, such as “below,” “under,” “down,” “above,” and “above,” are used to describe the relationship between one element or feature shown in the accompanying drawings and another element or feature. These spatially related terms are provided to interpret this disclosure according to various states of manufacture or use and are not intended to limit the disclosure. For example, if the elements or features in the drawings are reversed, elements described as “below” or “under” become “above” or “above.” Accordingly, “below” is a concept that encompasses both “above” and “below.”

[0039] The terminology used in this specification is intended to describe embodiments of this disclosure and is not intended to limit this disclosure.

[0040] Figure 1 A diagram illustrating the configuration of a battery module according to an embodiment of the present disclosure.

[0041] Figure 2 For illustrative purposes Figure 1 A plan view of the battery module configuration.

[0042] refer to Figure 1 and Figure 2 A battery module 1000 according to one or more embodiments may include a housing 1100, a secondary battery 100, and a busbar 1200.

[0043] The housing 1100 can form the overall exterior of the battery module 1000 and provide space therein for accommodating the secondary battery 100.

[0044] According to the embodiments, the housing 1100 may include a housing body 1110 and a cover 1120.

[0045] The outer casing 1110 may have the shape of a box with an empty interior and an open side. However, the cross-sectional shape of the outer casing 1110 is not limited to... Figure 1 The quadrilateral shape shown in the figure can be any of various shapes (such as polygonal shapes, circular shapes, elliptical shapes, etc.).

[0046] The cover 1120 can be attached to the housing body 1110 and enclose the internal space of the housing body 1110. For example, the cover 1120 can be formed with a general plate shape and can be configured as an open side facing the housing body 1110. The cover 1120 can be fixed to the housing body 1110 by any of a variety of connection methods (such as bolting, welding, assembly, etc.).

[0047] The secondary battery 100 can be used as a unit structure in the battery module 1000 for storing and supplying power.

[0048] Multiple secondary batteries 100 can be provided. Within the housing 1100, the multiple secondary batteries 100 can be configured to form any of various patterns (such as grid shapes, zigzag shapes, etc.). The multiple secondary batteries 100 can be arranged parallel to each other. Depending on the size, shape, etc., of the housing 1100, many secondary batteries 100 can be designed in various ways. The configuration of the secondary batteries 100 will be described below.

[0049] Busbar 1200 allows multiple secondary batteries 100 to be electrically connected to each other. Multiple secondary batteries 100 can be connected in series and / or parallel via busbar 1200. For example, in housing 1100, busbar 1200 can connect secondary batteries 100 arranged in the same row in parallel, and can connect secondary batteries 100 arranged in two adjacent rows in series. Busbar 1200 can be formed of an electrically conductive material (such as copper, aluminum, nickel, etc.).

[0050] refer to Figure 2 According to the embodiments, the bus bar 1200 may include a main bus bar 1210, a first branch bus bar 1220, and a second branch bus bar 1230.

[0051] The main busbar 1210 can be disposed between adjacent rows of secondary batteries 100. Multiple main busbars 1210 can be provided. The main busbars 1210 can extend in a straight line between rows of secondary batteries 100, or, in some embodiments, can be regularly curved into a zigzag shape. Multiple main busbars 1210 can each be disposed between different adjacent rows of secondary batteries 100. Multiple main busbars 1210 can be electrically connected to each other.

[0052] In one embodiment, the first branch busbar 1220 may extend from the main busbar 1210 toward a rivet or terminal of the secondary battery 100, as described below. The first branch busbar 1220 may be mechanically and electrically connected to the rivet by means of laser welding, ultrasonic welding, or the like.

[0053] The second branch busbar 1230 may extend from the main busbar 1210 toward the housing of the secondary battery 100 described below. The second branch busbar 1230 may be mechanically and electrically connected to the housing by means of laser welding, ultrasonic welding, etc.

[0054] In this document, a secondary battery 100 according to an embodiment of the present invention will be described.

[0055] Figure 3 A diagram illustrating the configuration of a secondary battery according to an embodiment of the present invention.

[0056] Figure 4 For illustrative purposes Figure 3 A cross-sectional view of the configuration of the secondary battery.

[0057] exist Figure 3 and Figure 4 In the figures, reference numeral 100 indicates a secondary battery according to an embodiment of the present invention.

[0058] refer to Figure 3 and Figure 4 The secondary battery 100 according to the embodiment (including, for example) Figure 1 and Figure 2 The secondary battery 100 shown includes an electrode assembly 10 and a housing 20 housing the electrode assembly 10. The secondary battery 100 further includes terminals 30 and a cover plate 60. The terminals 30 are inserted into holes 20h formed in one side of the housing 20 and are electrically connected to the electrode assembly 10. The cover plate 60 covers an opening formed in the other side of the housing 20. However, the components of the secondary battery 100 are not limited to... Figure 1 The components shown in the diagram, and the secondary battery 100 may only include Figure 3 and Figure 4 Some of the components shown, and / or may further include, in addition to Figure 3 and Figure 4 Other components besides those shown in the diagram.

[0059] In this document, an example in which the secondary battery 100 is a cylindrical lithium-ion secondary battery will be described. However, the invention is not limited thereto, and the secondary battery 100 may be, for example, a lithium polymer battery, and may be, for example, a prismatic battery.

[0060] The electrode assembly 10 can be used as a unit structure for charging and discharging electrical energy in the secondary battery 100.

[0061] The electrode assembly 10 includes a first electrode and a second electrode. The first electrode is either a positive electrode or a negative electrode. The second electrode is either a positive electrode or a negative electrode and has a different polarity from the first electrode.

[0062] Additionally, the electrode assembly 10 may further include a diaphragm between the first electrode and the second electrode. The diaphragm prevents or substantially prevents the first electrode and the second electrode from contacting each other, and prevents or substantially prevents a short circuit between the first electrode and the second electrode. Accordingly, the electrode assembly 10 may be formed by stacking the first electrode, the second electrode, and providing the diaphragm between the first electrode and the second electrode.

[0063] In an embodiment, the electrode assembly 10 may be formed into a cylindrical shape, and the stacked structure including a first electrode, a second electrode, and a diaphragm may be wound to form an electrode core. For example, the electrode assembly 10 may have a shape that is wound clockwise or counterclockwise around a winding axis. In addition to a circular shape, the cross-sectional shape of the electrode assembly 10 may be any of various shapes (such as an elliptical shape, a polygonal shape, etc.). Here, the winding axis may refer to a straight line passing through the central portion of the electrode assembly 10 (e.g., the winding core).

[0064] Further detailed descriptions of the components of electrode assembly 10 are as follows.

[0065] Positive electrode active material

[0066] As the positive electrode active material, compounds capable of reversibly inserting and deintercalating lithium (lithiation-intercalated compounds) can be used. In embodiments, one or more composite oxides of lithium and metals selected from cobalt, manganese, nickel, and combinations thereof can be used.

[0067] The composite oxide may be a lithium transition metal composite oxide, and examples may include lithium nickel oxides, lithium cobalt oxides, lithium manganese oxides, lithium iron phosphate compounds, cobalt-free nickel manganese oxides, or combinations thereof.

[0068] As an example, a compound represented by any of the following chemical formulas can be used: Li a A 1-b X b O 2-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); Li a Mn 2-b X b O 4-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); Li a Ni 1-b-c Co b X c O 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0≤α≤2); Li a Ni 1-b- c Mn b X c O 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0≤α≤2); Li a Ni b Co cL 1 d G e O2 (0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, 0≤e≤0.1); Li a NiG b O2(0.90≤a≤1.8, 0.001≤b≤0.1); Li a CoG b O2(0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn 1-b G b O2(0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn2G b O4(0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn 1-g G g PO4(0.90≤a≤1.8, 0≤g≤0.5); Li (3-f) Fe2(PO4)3 (0≤f≤2); and Li a FePO4 (0.90≤a≤1.8).

[0069] In the above chemical formula, A is Ni, Co, Mn, or a combination thereof; X is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, rare earth elements, or a combination thereof; D is O, F, S, P, or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; and L 1 It is Mn, Al, or a combination thereof.

[0070] As an example, the positive electrode active material can be a high-nickel positive electrode active material, based on 100 mol% of metals other than lithium in a lithium transition metal complex oxide (high-nickel positive electrode active material), wherein the high-nickel positive electrode active material has a nickel content of 80 mol% or more, 85 mol% or more, 90 mol% or more, 91 mol% or more, or 94 mol% or more and 99 mol% or less. High-nickel positive electrode active materials can achieve high capacity and are therefore applicable to high-capacity, high-energy-density lithium batteries.

[0071] positive electrode

[0072] The positive electrode for the secondary battery 100 may include a positive electrode current collector and a positive electrode active material layer formed on the positive electrode current collector. The positive electrode active material layer may include a positive electrode active material and may further include a binder and / or a conductive material.

[0073] As an example, the positive electrode may further contain components that can be used as a sacrificial positive electrode.

[0074] In an embodiment, based on a 100wt% positive electrode active material layer, the content of the positive electrode active material can be in the range of 90wt% to 99wt%, and based on a 100wt% positive electrode active material layer, the content of the binder and the conductive material can each be in the range of 0.5wt% to 5wt%.

[0075] The binder enables the positive electrode active material particles to adhere well to each other, and also enables the positive electrode active material to adhere well to the positive electrode current collector. Representative examples of binders may include, but are not limited to, polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene oxide-containing polymers, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, epoxy resin, (meth)acrylate resin, polyester resin, nylon, etc.

[0076] Conductive materials can impart conductivity to electrodes, and in the configured battery, any suitable conductive material that does not cause chemical changes can be used. Examples of 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 polyphenylene derivatives; or mixtures thereof.

[0077] In this embodiment, the Al foil can be used as a positive electrode current collector, but the embodiment is not limited to this.

[0078] Negative electrode active material

[0079] The negative electrode active material may include materials capable of reversibly inserting and de-intercalating lithium ions, lithium metal, lithium-metal alloys, materials capable of doping and de-doping lithium, or transition metal oxides.

[0080] Materials capable of reversibly inserting and deintercalating lithium ions may include carbon-based negative electrode active materials, such as crystalline carbon, amorphous carbon, or combinations thereof. Examples of crystalline carbon may include graphite (such as amorphous, tabular, flake, spherical, or fibrous natural or artificial graphite), and examples of amorphous carbon may include soft carbon, hard carbon, mesophase pitch carbides, calcined coke, etc.

[0081] In embodiments, an alloy of lithium with a metal 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 an alloy of lithium and a metal.

[0082] Si-based negative electrode active materials and / or Sn-based negative electrode active materials can be used as materials capable of doping and de-doping lithium. The Si-based negative electrode active materials can include silicon, silicon-carbon composites, SiO x (0 < x ≤ 2, for example, SiO2), Si-Q alloys (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. The Sn-based negative electrode active materials can be Sn, SnO k (0 < k ≤ 2, for example, SnO2), Sn-based alloys, or combinations thereof.

[0083] The silicon-carbon composite can be a composite of silicon and amorphous carbon. According to an embodiment, the silicon-carbon composite can be in the form of silicon particles surface-coated with amorphous carbon. For example, the silicon-carbon composite can include secondary particles (cores) in which silicon primary particles are aggregated and an amorphous carbon coating (shells) located on the surfaces of the secondary particles. The amorphous carbon can be located between the silicon primary particles, and for example, the silicon primary particles can be coated with amorphous carbon. The secondary particles can be dispersed in an amorphous carbon matrix.

[0084] The silicon-carbon composite can further include crystalline carbon. For example, the silicon-carbon composite can include a core containing crystalline carbon and silicon particles and an amorphous carbon coating located on the surface of the core.

[0085] The Si-based negative electrode active materials and / or the Sn-based negative electrode active materials can be used in combination with carbon-based negative electrode active materials.

[0086] Negative electrode

[0087] The negative electrode for the secondary battery 100 can include a negative electrode current collector and a negative electrode active material layer located on the negative electrode current collector. The negative electrode active material layer can include negative electrode active materials and can further include a binder and / or a conductive material.

[0088] In an embodiment, for example, based on 100 wt% of the negative electrode active material layer, the negative electrode active material layer can include 90 wt% to 99.5 wt% of negative electrode active materials, 0.5 wt% to 5 wt% of a binder, and 0 wt% to 5 wt% of a conductive material.

[0089] The binder can enable good attachment of the negative electrode active material particles and also enable good attachment of the negative electrode active materials to the negative electrode current collector. A non-aqueous binder, an aqueous binder, a dry binder, or a combination thereof can be used as the binder.

[0090] 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.

[0091] The waterborne adhesive 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.

[0092] If the aqueous binder is used as a binder in the negative electrode active material layer, it may further contain a cellulose compound to impart viscosity. This cellulose compound can be used by mixing one or more of carboxymethyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, and their alkali metal salts. In embodiments, Na, K, or Li may be used as the alkali metal.

[0093] The dry binder is a polymeric material capable of being fibrous, and may be, for example, polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polyethylene oxide, or a combination thereof.

[0094] Conductive materials can impart conductivity to electrodes, and in the configured battery, any suitable conductive material that does not cause chemical changes can be used. Specific examples 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 polyphenylene derivatives; or mixtures thereof.

[0095] As the negative electrode current collector, one selected from copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, polymer substrate coated with conductive metal, and combinations thereof can be used.

[0096] diaphragm

[0097] Depending on the type of secondary battery 100, a separator may be present between the positive and negative electrodes. As a separator, a polyethylene separator, a polypropylene separator, a polyvinylidene fluoride separator, or a multilayer membrane of two or more layers thereof (such as a polyethylene / polypropylene double-layer separator, a polyethylene / polypropylene / polypropylene triple-layer separator, or a polypropylene / polypropylene / polypropylene triple-layer separator) may be used.

[0098] The diaphragm may include a porous substrate and a coating located on one or both sides (e.g., two opposite sides) of the porous substrate, the coating containing organic materials, inorganic materials, or a combination thereof.

[0099] The porous substrate may be a polymer film formed from polymers selected from the following polymers or copolymers or mixtures thereof: 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).

[0100] In embodiments, the organic material may include polyvinylidene fluoride polymers or (meth)acrylic acid polymers.

[0101] 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.

[0102] Organic and inorganic materials can exist as a mixture in a coating, or as a stack of coatings containing organic materials and coatings containing inorganic materials.

[0103] The housing 20 houses the electrode assembly 10. The housing 20 seals the housed electrode assembly 10 together with the electrolyte.

[0104] electrolyte

[0105] The electrolyte used in the secondary battery 100 may include non-aqueous organic solvents and lithium salts.

[0106] Non-aqueous organic solvents can be used as a medium through which ions participating in the electrochemical reactions of the battery can move.

[0107] Non-aqueous organic solvents may include carbonate solvents, ester solvents, ether solvents, ketone solvents, alcohol solvents, aprotic solvents, or combinations thereof.

[0108] Carbonate solvents may include any one of dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC), methyl ethyl carbonate (MEC), ethylene carbonate (EC), propylene carbonate (PC), butyl carbonate (BC), etc.

[0109] Ester solvents may include any one of methyl acetate, ethyl acetate, n-propyl acetate, dimethyl acetate, methyl propionate, ethyl propionate, decanoic acid lactone, mevalonate lactone, caprolactone, etc.

[0110] Ether solvents may include any one of dibutyl ether, tetraethylene glycol dimethyl ether, diethylene glycol dimethyl ether, ethylene glycol dimethyl ether, 2-methyltetrahydrofuran, 2,5-dimethyltetrahydrofuran, tetrahydrofuran, etc. In embodiments, ketone solvents may include cyclohexanone, etc. Ethanol, isopropanol, etc. may be used as alcohol solvents, and nitrile solvents (such as R-CN (R is a straight-chain hydrocarbon group, branched hydrocarbon group, or cyclic hydrocarbon group having 2 to 20 carbon atoms, and may include double bonds, aromatic rings, or ether groups)), amides (such as dimethylformamide), dioxolane (such as 1,3-dioxolane or 1,4-dioxolane), sulfolane, etc., may be used as aprotic solvents.

[0111] Non-aqueous organic solvents can be used alone or in combination of two or more.

[0112] In the embodiments, if a carbonate solvent is used, cyclic carbonates and chain carbonates can be mixed and used, and cyclic carbonates and chain carbonates can be mixed in a volume ratio of 1:1 to 1:9.

[0113] Lithium salts are substances dissolved in non-aqueous organic solvents and act as a source of lithium ions in batteries, ensuring the basic operation of lithium batteries and facilitating the movement of lithium ions between the positive and negative electrodes. Representative examples of lithium salts include those selected from LiPF6, LiBF4, LiSbF6, LiAsF6, LiClO4, LiAlO2, LiAlCl4, LiPO2F2, LiCl, LiI, LiN(SO3C2F5)2, Li(FSO2)2N (lithium bis(fluorosulfonyl)imide (LiFSI)), LiC4F9SO3, and LiN(C x F 2x+1 SO2)(C y F 2y+1 SO2 (where x and y are integers from 1 to 20), lithium trifluoromethanesulfonate, lithium tetrafluoroethanesulfonate, lithium difluorobis(oxalate)phosphate (LiDFBOP), and lithium bis(oxalate)borate (LiBOB) are one or more of these.

[0114] As described above, the housing 20 is sealed after receiving the electrode assembly 10 and the electrolyte. For example, the housing 20 can be sealed by a cover plate 60.

[0115] The housing 20 forms the overall exterior of the secondary battery 100. In one embodiment, the housing 20 includes an upper surface and a side surface, the upper surface forming a cylindrical upper portion, and the side surface connecting to the outer surface of the upper surface and extending vertically from the upper surface to form a side portion.

[0116] The housing 20 may have a hole 20h formed in its upper surface. The hole 20h is formed by passing through the upper surface of the housing 20. The hole 20h may be located at the center of the upper surface of the housing 20. The hole 20h may be formed at a location, for example, perpendicular to the winding core of the electrode assembly 10 and parallel to a plane (e.g., ground) parallel to the upper surface of the housing 20. The shape of the hole 20h may correspond to the shape of the terminal 30. For example, if the cross-section of the terminal 30 is circular, the cross-section of the hole 20h may be formed in a circular shape. In this case, the diameter of the cross-section of the hole 20h is larger than the diameter of the cross-section of the terminal 30.

[0117] The housing 20 may have an open cylindrical lower portion. The housing 20 may have an interior that is sealed by a cover plate 60 sealing the opening. Accordingly, the housing 20 may prevent or substantially prevent electrolyte leakage to the outside and protect the electrode assembly 10.

[0118] The housing 20 may be made of, for example, steel, stainless steel, aluminum, aluminum alloy, a combination thereof, or equivalent materials.

[0119] The cover plate 60 seals the housing 20 while covering the opening in the housing 20.

[0120] In one embodiment, the secondary battery 100 may further include a gasket 80 to further ensure a sealed housing 20. The gasket 80 is formed, for example, in a ring shape. The gasket 80 may surround the outer surface of the cover plate 60 while being located between the inner surface of the cover plate 60 and the housing 20. Accordingly, the gasket 80 may prevent or substantially prevent electrolyte leakage from the inside of the secondary battery 100 to the outside or cause safety issues.

[0121] In one embodiment, a pressing portion 21 may be formed in the housing 20 to fix the position of the cover plate 60 relative to the opening of the housing 20. For example, the pressing portion 21 is formed on the lower side of the housing 20. The pressing portion 21 is formed by recessing the housing 20 inward. Due to the recess, the pressing portion 21 prevents or substantially prevents the cover plate 60 from further entering the housing 20 from the opening of the housing 20. In another embodiment, a crimping portion 22 may be further formed in the housing 20 to fix the position of the cover plate 60 relative to the opening of the housing 20. The crimping portion 22 may be formed by curling the end of the opening of the housing 20 toward the inside of the housing 20. For example, the crimping portion 22 may be formed by bending the end of the opening of the housing 20 toward the inside of the housing 20 after the cover plate 60 is provided in the opening of the housing 20. Accordingly, the cover plate 60 may cover the opening of the housing 20.

[0122] In one embodiment, the cover plate 60 may simultaneously (e.g., synchronously) serve as an exhaust port. In another embodiment, for example, the cover plate 60 may include a groove 61. If the pressure or temperature inside the housing 20 increases, the groove 61 may rupture. The groove 61 may rupture to release gas generated inside the housing 20 to the outside.

[0123] In one embodiment, the housing 20 is electrically connected to the electrode assembly 10 housed within the housing 20. In another embodiment, for example, the housing 20 is electrically connected to a second electrode. The second electrode may be, for example, a negative electrode.

[0124] The secondary battery 100 may further include a second current collector 70 located below the electrode assembly 10 to electrically connect the housing 20 and the second electrode. For example, the second current collector 70 may be located between the bottom of the electrode assembly 10 and the top of the cover plate 60. In this case, the second current collector 70 and the cover plate 60 may be insulated from each other by a gasket 80. In an embodiment, the second current collector 70 is, for example, a negative electrode current collector. The second current collector 70 is connected to the second electrode. For example, the second current collector 70 is connected to a terminal block of the second electrode. In an embodiment, the second current collector 70 is coupled to the housing 20. Accordingly, the housing 20 may be electrically connected to the second electrode and have the same polarity as the second electrode. That is, for example, the housing 20 may have a negative polarity.

[0125] Terminal 30 is inserted into a hole 20h formed in the upper surface of housing 20. Terminal 30 is inserted into hole 20h and electrically connected to electrode assembly 10 housed in housing 20. For example, terminal 30 is electrically connected to a first electrode. The first electrode may be, for example, a positive electrode.

[0126] The secondary battery 100 may further include a first current collector plate 40 located on top of the electrode assembly 10 to electrically connect the terminal 30 and the first electrode. The first current collector plate 40 is, for example, a positive electrode current collector plate. The first current collector plate 40 is connected to the first electrode. For example, the first current collector plate 40 is connected to a terminal piece of the first electrode. Additionally, the first current collector plate 40 is connected to the terminal 30. Accordingly, the terminal 30 may be electrically connected to the first electrode and have the same polarity as the first electrode. That is, for example, the terminal 30 may have a positive polarity.

[0127] In this case, terminal 30 may include a conductive material for electrical connection with the first electrode. In some embodiments, terminal 30 may include, for example, a metal. In some embodiments, terminal 30 may include, for example, aluminum (Al).

[0128] In one embodiment, the secondary battery 100 may further include an insulating layer 90. The insulating layer 90 may be provided on the first current collector plate 40. The insulating layer 90 prevents or substantially prevents electrical connection between the first current collector plate 40 and the housing 20.

[0129] With this configuration, the secondary battery 100 according to an embodiment of the present invention can provide a battery with improved capacity by removing the pressing edge portion 21 from its upper part. Additionally, the secondary battery 100 can avoid safety or cost issues that might arise if the secondary battery 100 explodes upwards by placing the cover plate 60 at its lower part.

[0130] Figure 5 A cross-sectional view of the terminal is shown for illustrative purposes.

[0131] exist Figures 1-4 The present invention describes a secondary battery 100 and a battery module 1000 including the secondary battery 100 according to an embodiment of the present invention. As described above, the battery module 1000 includes a plurality of secondary batteries 100.

[0132] Multiple secondary batteries 100 are connected to a connecting member for electrical connection to each other and / or to an external location. The connecting member may include components that engage with the secondary battery 100 for electrical connection to the secondary battery 100. The connecting member may include, for example, a busbar 1200 and / or a terminal block (not shown). In this document, a case in which the connecting member includes a busbar 1200 is described as an example. For example, if the secondary battery 100 includes a cover assembly (not shown), the secondary battery 100 can be connected to the busbar 1200 via the cover assembly. For example, if the secondary battery 100 includes a terminal 30 (see... Figure 3 and Figure 4 Then, the secondary battery 100 can be connected to the busbar 1200 via terminal 30 (see...). Figure 3 and Figure 4 ).

[0133] As the demand for secondary batteries 100 increases, the demand for high-capacity and safe battery modules 1000 also increases.

[0134] To increase the capacity of the battery module 1000, the battery module 1000 includes a larger number of secondary batteries 100 and / or the secondary batteries 100 have increased capacity. Furthermore, as the size of the secondary batteries 100 increases, higher capacity can be achieved.

[0135] In addition, to improve the safety of the battery module 1000, it is desirable for the secondary battery 100 to receive electricity stably and be subjected to less external impact.

[0136] One or more embodiments of the present invention provide a safe and high-capacity secondary battery 100 and / or battery module 1000. For example, a battery module 1000 according to one or more embodiments of the present invention includes a plurality of secondary batteries 100. In an embodiment, the battery module 1000 may include a plurality of secondary batteries 100 having increased dimensions. In this case, to improve the safety of the battery module 1000, a method is provided in which the secondary batteries 100 can be stably connected to the inner and outer sides of the battery module 1000. For example, the battery module 1000 provides a method in which the plurality of secondary batteries 100 can be connected to a busbar 1200 with high strength. This method will be described in further detail below.

[0137] exist Figure 5 In section 200, terminals (such as those according to embodiments of the present invention) are explained. Figure 3 and Figure 4 Terminal 30).

[0138] like Figure 5 As shown, terminal 200 includes a metal layer 210 and a plating layer 220 formed on the metal layer 210.

[0139] Figures 1-5 The present invention describes a structure in which the secondary battery 100 is connected to the busbar 1200 via terminal 200 (or terminal 30), but the secondary battery 100 according to one or more embodiments of the present disclosure is not limited thereto. The secondary battery 100 may be connected to the busbar 1200 and / or connecting tabs via a cover assembly and / or cover plate 60. In this case, the description of terminal 200 according to embodiments of the present disclosure may be applied to the cover assembly and / or cover plate 60 in the same or similar manner.

[0140] The metal layer 210 performs the basic function of the terminal 200. For example, the metal layer 210 is electrically connected to the electrode assembly 10. The metal layer 210 serves as a channel through which current can move from the outside toward the electrode assembly 10 or from the electrode assembly 10 toward the outside.

[0141] Accordingly, the metal layer 210 includes an electrically conductive material. For example, the metal layer 210 may include metals such as aluminum (Al), copper (Cu), and nickel (Ni).

[0142] The plating 220 is formed by depositing a coating onto the surface of the metal layer 210. The plating 220 protects the metal layer 210. Additionally, the plating 220 may contribute to the physical properties of the metal layer 210. For example, the plating 220 may prevent or substantially prevent oxidation of the metal layer 210 and / or improve the strength of the metal layer 210. The plating 220 may include, for example, a metal (such as nickel (Ni)).

[0143] In one embodiment, coating 220 may be formed to have a thickness greater than or equal to the intended thickness of coating 220 (i.e., mass diffusion occurs, such that coating 220 includes an additional coating). In another embodiment, coating 220 may additionally form an oxide film upon contact with air. In yet another embodiment, coating 220 may have a contaminant film deposited on both the inner and outer sides of coating 220 upon contact with the outside.

[0144] The plating 220, including additional coatings, oxide films, contaminant films, etc., can adversely affect the formation of the weld portion between the terminal 200 and the busbar 1200. For example, if quality diffusion occurs in the plating 220, or if an oxide film and / or contaminant film is formed on the inside or outside of the plating 220, the weld strength between the terminal 200 and the busbar 1200 can be reduced. In this case, a short circuit may occur in the secondary battery 100 and / or the battery module 1000 including the secondary battery 100, or the capacity of the secondary battery 100 and / or the battery module 1000 including the secondary battery 100 may be reduced.

[0145] Therefore, a secondary battery 100 according to one or more embodiments of the present invention includes a housing 20 housing an electrode assembly 10 and terminals 200 coupled to the housing 20. In this case, the terminals 200 may include a softened area.

[0146] In this case, the softened zone refers to a region with low hardness (surface hardness).

[0147] For example, a softened region refers to a region with a lower hardness than a non-softened region. Accordingly, a softened region according to an embodiment of the present disclosure may be considered to be included when the hardness of a portion of the terminal 200 is different from that of another portion.

[0148] In an embodiment, a softened region refers to a region having a hardness less than or equal to a specific (e.g., predetermined) hardness. In an embodiment, for example, the specific (e.g., predetermined) hardness is 500 HV or less. For example, if terminal 200 includes a region with a specific (e.g., predetermined) hardness of 500 HV or less in a portion of its area, then terminal 200 is considered to include a softened region.

[0149] In one embodiment, a softening zone may be formed on the entire outer surface of the terminal 200. In this case, the softening zone may be formed on the upper surface of the terminal 200. For example, the softening zone may be formed in the area where the terminal 200 is intended to be connected to the busbar 1200.

[0150] In this case, a softening zone may be formed on the plating layer 220. The softening zone may be formed on the plating layer 220 to improve the quality of the terminal 200.

[0151] In an embodiment, the softened area can be formed, for example, by surface treatment of the terminal 200 (e.g., plating 220). In this case, the surface treatment may include at least one of, for example, laser treatment, polishing, and / or etching. Laser treatment is a process in which the softened area is formed on the surface of the terminal 200 by irradiating the terminal 200 with a laser. Polishing is a process in which the softened area is formed on the surface of the terminal 200 by applying physical force to the terminal 200. Etching is a process in which the softened area is formed on the surface of the terminal 200 by applying a chemical treatment to the terminal 200.

[0152] Thus, the secondary battery 100 according to the embodiments of the present disclosure can illustrate a method for improving the connection strength (e.g., welding strength) between the secondary battery 100 and the busbar 1200 by means of a terminal 200 including a softening zone.

[0153] Figures 6A to 6C A top view illustrating a terminal according to an embodiment of the present invention.

[0154] exist Figures 6A to 6C An example of a softening zone formed on terminal 200 will be described below.

[0155] The softening area according to embodiments of the present invention includes, for example, a pattern. The pattern may be formed, for example, by engraving, embossing, and / or combinations thereof. The pattern may be formed in, for example, straight lines, spiral shapes, dot shapes, circles, polygons, and / or combinations thereof. However, the pattern according to embodiments of this disclosure is not limited to the reference pattern. Figures 6A to 6C The content described, and the pattern may include any shape that can be formed on the terminal 200 by engraving, embossing and / or a combination thereof.

[0156] Figure 6A An example is shown in which the pattern is formed with straight lines, such as in linear pattern 201a. In the implementation, as... Figure 6A As shown, the linear pattern 201a can be formed as multiple straight lines spaced equally apart. In an embodiment, the width of the straight lines and the spacing between the straight lines can be set differently depending on the size of the terminal 200. However, compared with... Figure 6A Unlike other linear patterns, linear pattern 201a can be formed as multiple straight lines of the same width that are not equally spaced. In one embodiment, linear pattern 201a can be formed as multiple straight lines of different widths that are equally spaced. In another embodiment, linear pattern 201a can be formed as multiple straight lines of different widths that are not equally spaced.

[0157] Figure 6BAn example is shown in which the pattern is formed in a spiral shape, such as in spiral pattern 201b. Spiral pattern 201b can be formed, for example, in a spiral shape spiraling outward from the center of terminal 200. In one embodiment, spiral pattern 201b can be formed with a uniform width from the center outwards. In another embodiment, spiral pattern 201b can be formed with a width that gradually increases from the center outwards. In yet another embodiment, spiral pattern 201b can be formed with a width that gradually decreases from the center outwards. In yet another embodiment, spiral pattern 201b can be formed with a width that repeatedly increases or decreases from the center outwards.

[0158] Figure 6C An example is shown in which the pattern is formed in an elliptical shape, such as in elliptical pattern 201c. Circular pattern 201c may include, for example, multiple elliptical shapes.

[0159] In one embodiment, multiple circular shapes may be formed to have the same size. In another embodiment, such as... Figure 6C As shown, multiple circular shapes can be arranged adjacent to each other in a simple cube (SC) structure. In the implementation, with Figure 6C Unlike in the previous method, multiple circular shapes can be arranged adjacent to each other in a face-centered cubic (FCC) structure. In the implementation, with Figure 6C Unlike in the past, multiple circular shapes can be arranged adjacent to each other in a body-centered cube (BCC) structure.

[0160] In one embodiment, the multiple circular shapes may have different sizes. In another embodiment, the multiple circular shapes may contain each other to form a shape resembling a ◎. In yet another embodiment, the multiple circular shapes may be arranged to touch or be spaced apart from each other without containing each other.

[0161] The softened region according to an embodiment of the invention can be formed, for example, by laser processing.

[0162] In one embodiment, the laser processing involves, for example, irradiating the terminal 200 with a laser having a frequency in the range of 10 kHz to 1000 kHz to form a softened region. In another embodiment, the laser processing involves irradiating the terminal 200 with a laser at a speed in the range of, for example, 10 mm / s to 10,000 mm / s to form a softened region. If the laser deviates from this frequency range and / or irradiation speed, the solderability of the softened region may be deteriorated. Therefore, in this embodiment, the laser is irradiated with a frequency in the range of, for example, 10 kHz to 1000 kHz and / or at a speed in the range of 10 mm / s to 10,000 mm / s. As a result, the softened region can be formed with a hardness of, for example, 500 HV or less.

[0163] Figure 7This is a top view of a terminal according to an embodiment of the present invention.

[0164] Figure 7 The terminal 200 before the softening zone is formed (before processing) and the terminal 200 after the softening zone is formed (after processing) are shown.

[0165] from Figure 7 The terminals 200 before and after the formation of the softened zone are visible. The terminals 200 after the formation of the softened zone may have roughness on the surface.

[0166] For example, the softened area may include a pattern of multiple straight lines with roughness (e.g., Figure 6A The linear pattern 201a described in [the document](link to document 201a) is used. For example, the softening region may include a spiral pattern with roughness (e.g., [the pattern described in document 201a](link to document 201a)). Figure 6B (as described in the spiral pattern 201b). However, examples of softened areas are not limited to this, and softened areas may include any of various types of patterns and / or have roughness formed on the terminal 200.

[0167] In this case, a softened region can be formed while having roughness on the surface of the terminal 200. In one embodiment, the roughness (Ra) can be, for example, 0.01 μm to 2.50 μm. In another embodiment, the roughness (Ra) can be, for example, 0.01 μm to 2.00 μm. In another embodiment, the roughness (Ra) can be, for example, 0.01 μm to 1.90 μm. In another embodiment, the roughness (Ra) can be, for example, 0.01 μm to 1.80 μm. In another embodiment, the roughness (Ra) can be, for example, 0.01 μm to 1.70 μm. In another embodiment, the roughness (Ra) can be, for example, 0.01 μm to 1.60 μm. In another embodiment, the roughness (Ra) can be, for example, 0.01 μm to 1.50 μm. In another embodiment, the roughness (Ra) can be, for example, 0.01 μm to 1.30 μm. In another embodiment, the roughness (Ra) can be, for example, 0.01 μm to 1.00 μm.

[0168] If the roughness (Ra) is less than 0.01 μm, there may be almost no softening effect because no etching effect occurs. If the roughness (Ra) exceeds 2.50 μm, irregular oxidation may subsequently occur on the surface, which adversely affects the surface characteristics. Therefore, in the embodiments, the softened area is formed with a roughness (Ra) of 0.01 μm or greater and 2.50 μm or less.

[0169] The softened area can be formed, for example, by polishing. The polishing process includes any of a variety of processes that can, for example, grind the surface of the terminal 200 by applying a physical force to the surface of the terminal 200. The polishing process may include, for example, grinding the upper surface of the terminal 200 with sandpaper to form the softened area.

[0170] With this configuration, the secondary battery 100 according to one or more embodiments of the present invention can be exemplified as a method for improving weldability with the busbar 1200.

[0171] Figure 8 A view illustrating an example of a pattern according to an embodiment of the present invention.

[0172] A pattern according to an embodiment of the present invention can be formed by at least partially overlapping an initial pattern. The pattern formed by at least partially overlapping the initial pattern has, for example, an overlap rate of 0% or greater and 99% or less. The initial pattern can be... Figures 6A to 6C and Figure 7 The linear pattern 201a, spiral pattern 201b, circular pattern 201c, or a portion thereof, are shown, but this disclosure is not limited thereto. The overlap ratio refers to the ratio of the area of ​​the overlapping portion of two overlapping initial patterns to the area of ​​one initial pattern.

[0173] Figure 8 An image showing the upper surface of terminal 200 and schematic diagrams of the upper surface in which the initial patterns overlap each other by 0%, 25%, 50%, 75%, and 99%. Therefore, patterns can be formed by completely or partially overlapping the initial patterns.

[0174] In this way, by overlapping initial patterns to form a pattern, the amount of etching can be controlled by controlling the heat applied to the surface. In addition, the surface roughness can be controlled by the pattern formed by overlapping initial patterns.

[0175] exist Figures 6A to 6C The example described includes a softened area with a pattern. Figure 7 The example described is a softened region with roughness. Figure 8 The example described is an example of a pattern formed by at least partially overlapping an initial pattern. However, examples of softened regions are not limited to this.

[0176] Although not shown, the softened area may include both a pattern and a roughness. For example, the softened area may be formed with a spiral engraving pattern, and the surface roughness (Ra) may be formed to be 0.01 μm to 1.50 μm.

[0177] Additionally, although not shown, the softened area may simultaneously (e.g., synchronously) include a pattern and a roughness formed by overlapping all or part of the initial pattern. In an embodiment, for example, the softened area may be formed by overlapping 50% to create a triangular engraved pattern, and the surface roughness Ra may be formed to be 0.01 μm to 1.50 μm.

[0178] Figure 9A diagram illustrating the hardness difference between terminals including a softened region and terminals not including a softened region according to an embodiment of the present invention.

[0179] Figure 10 A graph illustrating the weld strength based on hardness differences.

[0180] exist Figure 9 In this context, "after processing" refers to the terminal 200 including the softened area according to an embodiment of the present invention. Figure 9 In this context, "before processing" refers to conventional terminals excluding the softened area.

[0181] like Figure 9 As shown, the terminal 200 including the softened region according to an embodiment of the present invention is formed to have a lower hardness than a conventional terminal without the softened region.

[0182] at the same time, Figure 10 Experimental data describing the weld strength based on the hardness of the softened zone included in terminal 200 are shown. Figure 10 The diagram shows: "Before plating", terminal 200 before plating 220 is formed; SPL 1, SPL 2 and SPL 3, terminals 200 including softened regions with hardness of 110HV to 500HV; SPL 4 and SPL 5, terminals 200 with hardness of 500HV to 600HV; and SPL 6 and SPL 7, terminals 200 with hardness of 600HV or greater.

[0183] Before plating, the terminal 200 does not exhibit problems such as weld dispersion or reduced weld strength. However, in the case of the terminal 200 before plating, the plating layer 220 is not formed, resulting in a reduction in the physical properties of the terminal 200. In SPL 1 to SPL 3, problems such as weld dispersion or reduced weld strength do not exist. In SPL 4 and SPL 5, weld dispersion occurs. In SPL 6 and SPL 7, weld strength decreases.

[0184] Thus, the terminal 200 according to an embodiment of the present invention includes a softened region having a hardness within an appropriate range (e.g., 500 HV or less, or e.g., 110 HV or greater and 500 HV or less), thereby providing a method for improving the welding strength with the busbar 1200.

[0185] According to one or more embodiments of the present invention, a secondary battery with improved weldability, a battery module including the secondary battery, and / or a method for manufacturing a secondary battery are provided.

[0186] For example, a secondary battery according to one or more embodiments of the present invention may have improved solderability between the terminals and the connecting pieces.

[0187] According to one or more embodiments of the present invention, a secondary battery with improved processing capability, a battery module including the secondary battery, and / or a method for manufacturing a secondary battery are provided.

[0188] However, the aspects and technical 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 description of the invention other aspects and technical effects not mentioned.

[0189] Although this disclosure has been described with reference to some embodiments shown in the accompanying drawings, these embodiments are merely examples and those skilled in the art will understand that various modifications and equivalents are possible.

[0190] Accordingly, the scope of the present disclosure should be defined by the claims.

Claims

1. A secondary battery, comprising: Housing that houses the electrode assembly; and Terminals are connected to the housing. The terminal includes a softened area.

2. The secondary battery according to claim 1, wherein the softened region has a hardness of 500 HV or less.

3. The secondary battery according to claim 1, wherein the terminal comprises a metal layer and a plating layer on the metal layer, and The softened area is formed in the coating.

4. The secondary battery according to claim 1, wherein the softening region is formed by surface treatment, and The surface treatment includes at least one of laser treatment, polishing treatment and etching treatment.

5. The secondary battery according to claim 1, wherein the softening region comprises a pattern formed by engraving.

6. The secondary battery according to claim 5, wherein the pattern includes at least one of straight lines, spiral shapes, dot shapes, circles, and polygons.

7. The secondary battery of claim 5, wherein the pattern is formed by at least partially overlapping an initial pattern.

8. The secondary battery of claim 7, wherein the pattern formed by at least partially overlapping the initial pattern has an overlap rate of 0% or greater and 99% or less.

9. The secondary battery according to claim 1, wherein the softened region is formed having a roughness Ra of 0.01 μm to 1.50 μm.

10. A battery module, comprising: A plurality of secondary batteries, each according to any one of claims 1 to 9; The outer casing houses the plurality of secondary batteries; as well as A connecting member is engaged with the softened area and electrically connected to at least some of the plurality of secondary batteries.

11. A method for manufacturing a secondary battery according to any one of claims 1 to 9, the method comprising forming the softened region in the terminal.

12. The method of claim 11, wherein when the softened region is formed by laser processing, the laser processing comprises forming the softened region by irradiating a laser having a frequency in the range of 10 kHz to 1000 kHz.

13. The method of claim 11, wherein when the softened region is formed by laser processing, the laser processing comprises forming the softened region by irradiating the region with a laser at a speed in the range of 10 mm / s to 10,000 mm / s.

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