Battery pack

Abstract

The present invention provides a battery pack including tabs for connecting two or more battery cells. The present invention provides a battery pack including tabs made of two or more materials. [Solution] The present disclosure relates to a battery pack, and the technical problem to be solved is to provide a battery pack that includes a highly reliable weldable tab to a battery cell. To this end, the present disclosure provides a battery pack that includes a plurality of battery cells, including a first battery cell and a second battery cell; and tabs for electrically connecting the plurality of battery cells, wherein the tabs include a first joint made of a first material, which is joined to the first battery cell, and a second joint made of a second material, which is joined to the second battery cell.

Description

[Technical Field]

[0001] Reference to related applications This application is based on the priority claim of Korean Patent Application No. 10-2024-0134113, filed with the Korean Intellectual Property Office on 2 October 2024, and incorporates its full disclosure by reference herein.

[0002] Technical field This disclosure relates to a battery pack. [Background technology]

[0003] Generally, with the rapid proliferation of battery-powered electronic devices such as mobile phones, laptops, and electric vehicles, the demand for high-energy-density, high-capacity battery cells has been rapidly increasing. This has led to active research and development efforts to improve the performance of lithium battery cells.

[0004] A lithium battery cell is a battery that includes a positive electrode and a negative electrode containing an active material that allows for the insertion and deintercalation of lithium ions, and an electrolyte. It generates electrical energy through oxidation and reduction reactions that occur when lithium ions are inserted into and deintercalated from the positive and negative electrodes.

[0005] The aforementioned information disclosed in the technology underlying such inventions is merely for the purpose of improving understanding of the background of the present invention, and therefore may include information that does not constitute prior art. [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] The present invention aims to provide a battery pack that includes tabs for connecting two or more battery cells.

[0007] For example, an object of the present invention is to provide a battery pack including a tab containing two or more materials.

[0008] However, the technical problems to be solved by the present invention are not limited to the problems described above, and other problems not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

Means for Solving the Problems

[0009] The battery pack according to the present invention for solving technical problems includes a first battery cell; and a plurality of battery cells including a second battery cell; and a tab for electrically connecting the plurality of battery cells; the tab is joined to the first battery cell and includes a first joint portion containing a first material; and is joined to the second battery cell and includes a second joint portion containing a second material.

Effects of the Invention

[0010] According to the present invention, it is possible to provide a battery pack including a tab with improved welding reliability.

[0011] According to the present invention, it is possible to provide a battery pack including a tab with high price competitiveness.

[0012] However, the effects obtainable through the present invention are not limited to the effects described above, and other technical effects not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

Brief Description of the Drawings

[0013] The drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further understand the technical idea of the present invention together with the detailed description of the invention to be described later. Therefore, the present invention should not be construed as being limited only to the matters described in such drawings. [Figure 1] FIG. 1 is a perspective view schematically showing the configuration of a battery pack according to an embodiment of the present invention. [Figure 2] Figure 2 is a schematic perspective view showing a battery cell according to one embodiment of the present invention. [Figure 3] Figure 3 is a schematic cross-sectional view showing the configuration of a battery cell according to one embodiment of the present invention. [Figure 4] Figure 4 is a schematic diagram showing the configuration of a battery pack including a tab according to one embodiment of the present invention. [Figure 5] Figure 5 is a schematic top view showing the configuration of a battery cell according to one embodiment of the present invention. [Figure 6] Figure 6 is a schematic side view showing the configuration of a battery pack including a tab according to one embodiment of the present invention. [Figure 7] Figure 7 is a schematic perspective view showing the top of a tab according to one embodiment of the present invention. [Figure 8] Figure 8 is a schematic perspective view showing the bottom of a tab according to one embodiment of the present invention. [Figure 9] Figure 9 is a schematic perspective view showing the top of a tab according to one embodiment of the present invention. [Figure 10] Figure 10 is a schematic perspective view showing the top of a tab according to one embodiment of the present invention. [Modes for carrying out the invention]

[0014] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Prior to this, terms and words used in this specification and in the claims should not be interpreted in a manner limited to their ordinary or dictionary meanings, but rather should be interpreted in a manner consistent with the technical idea of ​​the present invention, based on the principle that inventors may appropriately define the concepts of terms in order to best describe their invention. Accordingly, it should be understood that the embodiments described herein and the configurations shown in the drawings represent only some of the most preferred embodiments of the present invention and do not represent the entire technical idea of ​​the present invention, and that there may be various equivalents and modifications that can substitute for them at the time of filing. Furthermore, as used herein, “comprise, include” and / or “comprising, including” specify the presence of the shapes, figures, stages, actions, members, elements and / or groups thereof mentioned, and do not exclude the presence or addition of one or more other shapes, figures, actions, members, elements and / or groups thereof.

[0015] Furthermore, to aid in understanding the invention, the accompanying drawings are not shown to actual scale, and the dimensions of some components may be exaggerated. Also, the same component may be assigned the same reference numeral in different embodiments.

[0016] The statement that two comparison objects are "identical" means that they are "substantially identical." Therefore, substantial identity may include deviations that are considered low in this industry, for example, deviations of 5% or less. Furthermore, the uniformity of a parameter within a given domain may mean uniformity from an average perspective.

[0017] While terms like "first," "second," etc., are used to describe various components, these components are, of course, not limited by these terms. These terms are used solely to distinguish one component from another, and unless otherwise stated, the first component may be the second component.

[0018] Throughout the specification, unless otherwise stated, each component may be singular or plural.

[0019] The placement of any component "above (or below)" or "above (or below)" a component can mean not only that any component is placed in contact with the top (or bottom) surface of the component, but also that other components may be interposed between the component and any component placed on (or below) it.

[0020] Furthermore, when any component is described as being "on," "connected to," or "coupled to" another component, it should be understood that the components may be directly connected to or linked to each other, but may also be "interposed" between each component, or each component may be "connected," "coupled," or "linked" through other components. Also, when any part is said to be electrically coupled to another part, this includes not only cases where they are directly connected, but also cases where they are connected with another element in between.

[0021] As used herein, the terms "and / or" include any and all combinations of one or more of the related listed items. Furthermore, when describing embodiments of the Disclosure, the use of "may also" refers to "one or more embodiments of the Disclosure." Expressions such as "at least one" and "one or more" preceding a list of elements modify the entire list of elements, not individual elements of the list.

[0022] Throughout the specification, "A and / or B" means A, B, or A and B unless otherwise specified, and "C to D" means C or greater and D or less unless otherwise specified.

[0023] When syntax 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 A, B, and C", or "at least one selected from A, B, and C" is used to specify a list of elements A, B, and C, the syntax can refer to any suitable combination.

[0024] The term “use” may be considered synonymous with the term “utilize.” As used herein, “substantially,” “about,” and similar terms are used as approximations, not terms of degree, to account for the inherent variability of measured or calculated values ​​as perceived by a person of general skill in the art.

[0025] In this specification, terms such as first, second, third, etc., may be used to describe various elements, components, regions, layers, and / or sections, but these elements, components, regions, layers, and / or sections should not be limited by these terms. The terms are used to distinguish one element, component, region, drawing layer, or section from other elements, components, regions, drawing layers, or sections. Accordingly, the first elements, components, regions, layers, or sections discussed below may be named second elements, components, regions, layers, or sections without departing from the teaching of the exemplary embodiments.

[0026] As shown in the drawings, spatial relative terms such as “beneath,” “below,” “lower,” “above,” and “upper” may be used herein for ease of explanation to describe the relationship between one element or feature and another. Spatially relative positions are understood to encompass different orientations of the device in use or operation, in addition to the orientation depicted in the figure. For example, if the device in the drawing is inverted, an element described as “beneath” or “below” another element will be understood as “above” or “upper” a different element. Thus, the term “beneath” can encompass both upward and downward directions. The terms used herein are for the purpose of describing embodiments of the disclosure and are not intended to limit the disclosure.

[0027] Figure 1 is a schematic perspective view showing the configuration of a battery pack according to one embodiment of the present invention.

[0028] A battery pack 1000 according to one embodiment of the present invention may include a housing 1100 and a battery cell 100.

[0029] The housing 1100 forms the general appearance of the battery pack and can provide a space in which the battery cells 100 can be housed.

[0030] The housing 1100 may include a housing body 1110 and a cover 1120.

[0031] The housing body 1110 may be formed to have the shape of a box with an open interior and one side open. The cross-sectional shape of the housing body 1110 is not limited to the rectangle shown in Figure 1, but can be redesigned to various shapes such as polygons, circles, or ellipses.

[0032] The cover 1120 can be coupled to the housing body 1110 and close off the internal space of the housing body 1110. For example, the cover 1120 may be formed to have a substantially plate shape and positioned to face the open side of the housing body 1110. The cover 1120 may be fixed to the housing body 1110 by various types of coupling methods such as bolting, welding, or fitting.

[0033] The battery cell 100 can function as a unit structure that stores and supplies power to the battery pack.

[0034] Multiple battery cells 100 may be provided. Multiple battery cells 100 may be arranged inside the housing 1100 in various patterns such as a grid or a zigzag configuration. Multiple battery cells 100 may be arranged side by side. The number of battery cells 100 can be varied depending on the size, shape, etc. of the housing 1100. The detailed configuration of the battery cells will be described later.

[0035] The following describes a battery cell 100 according to one embodiment of the present invention.

[0036] Figure 2 is a schematic perspective view showing a battery cell according to one embodiment of the present invention.

[0037] Figure 3 is a schematic cross-sectional view showing the configuration of a battery cell according to one embodiment of the present invention.

[0038] In Figures 2 and 3, 100 represents a battery cell according to one embodiment of the present invention.

[0039] Referring to Figures 2 and 3, the battery cell 100 according to this embodiment (including, for example, the battery cell 100 described with reference to Figure 1) includes an electrode assembly 10 and a case 20 that houses the electrode assembly 10. The battery cell 100 further includes a rivet 30 that is inserted into a hole 20h formed on one side of the case 20 and electrically connected to the electrode assembly 10, and a cap plate 60 that covers an opening formed on the other side of the case 20. However, the components of the battery cell 100 are not limited to the components shown in Figures 2 and 3, and the battery cell 100 may include only some of the components shown in Figures 2 and 3, and / or further include other components in addition to those shown in Figures 2 and 3.

[0040] In the following explanation, we will use the example that battery cell 100 is a cylindrical battery as a lithium-ion battery cell. However, the present invention is not limited to this, and the battery cell may be a lithium polymer battery or a prismatic battery.

[0041] The electrode assembly 10 can function as a unit structure that performs power charging and discharging operations in the battery cell 100.

[0042] The electrode assembly 10 includes a first electrode and a second electrode. The first electrode is either a positive or negative electrode. The second electrode is either a negative or positive electrode and has a different polarity from the first electrode.

[0043] Furthermore, the electrode assembly 10 may further include a separation membrane between the first electrode and the second electrode. The electrode assembly 10 can prevent the first electrode and the second electrode from coming into contact with each other and prevent a short circuit from occurring between the first electrode and the second electrode. Thus, the electrode assembly 10 may be formed by laminating the first electrode, the second electrode, and the separation membrane provided between the first electrode and the second electrode.

[0044] At this time, when the electrode assembly 10 forms a cylindrical shape, the laminated structure including the first electrode, the second electrode, and the separation membrane can be wound to form a jelly-roll body. For example, the electrode assembly 10 can have a form wound clockwise or counterclockwise along the winding axis. The cross-sectional shape of the electrode assembly 10 can be designed and changed into various shapes such as an elliptical shape or a polygonal shape in addition to a circular shape. Here, the winding axis can mean a straight line passing through the central portion of the electrode assembly 10.

[0045] A detailed description of each component of the electrode assembly 10 is as follows.

[0046] positive electrode active material As the positive electrode active material, a compound (lithiated intercalation compound) capable of reversible intercalation and deintercalation of lithium can be used. Specifically, one or more of composite oxides of metals selected from cobalt, manganese, nickel, and combinations thereof and lithium can be used.

[0047] The composite oxide may be a lithium transition metal composite oxide. Specific examples include lithium nickel-based oxides, lithium cobalt-based oxides, lithium manganese-based oxides, lithium iron phosphate-based compounds, cobalt-free nickel-manganese-based oxides, or combinations thereof.

[0048] As an example, a compound represented by any one 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-cCo 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 c L 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);Li a FePO4 (0.90 ≤ a ≤ 1.8).

[0049] 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; L1 is Mn, Al or a combination thereof.

[0050] As an example, the positive electrode active material may be a high-nickel positive electrode active material in which the nickel content relative to 100 mol% of the metal excluding lithium is 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 in a lithium transition metal composite oxide. High-nickel positive electrode active materials can achieve high capacity and can be applied to high-capacity, high-density lithium batteries.

[0051] positive electrode The positive electrode for battery cell 100 may include a current collector and a positive electrode active material layer formed on the current collector. The positive electrode active material layer includes a positive electrode active material and may further include a binder and / or conductive material.

[0052] For example, the positive electrode may further contain additives that can act as a sacrificial positive electrode.

[0053] The content of the positive electrode active material is 90% to 99.5% by weight relative to 100% by weight of the positive electrode active material layer, and the content of the binder and conductive material may be 0.5% to 5% by weight, respectively, relative to 100% by weight of the positive electrode active material layer.

[0054] The binder plays a role in ensuring good adhesion between positive electrode active material particles and good adhesion of the positive electrode active material to the current collector. Typical examples of binders include, but are not limited to, polyvinyl alcohol, carboxymethylcellulose, hydroxypropylcellulose, diacetylcellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, polymers containing ethylene oxide, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, (meth)acrylate styrene-butadiene rubber, epoxy resin, (meth)acrylic resin, polyester resin, nylon, etc.

[0055] Conductive materials are used to impart conductivity to electrodes, and any electronically conductive material that does not cause chemical changes can be used in the battery that is constructed from them. Examples of conductive materials include carbon-based substances such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjenblack, carbon fibers, carbon nanofibers, and carbon nanotubes; metallic substances containing copper, nickel, aluminum, silver, etc., in the form of metal powders or metal fibers; conductive polymers such as polyphenylene derivatives; or mixtures thereof.

[0056] Al can be used as the current collector, but it is not limited to this.

[0057] negative electrode active material The negative electrode active material includes a substance capable of reversibly intercalating / deintercalating lithium ions, lithium metal, an alloy of lithium metal, a substance that can be doped and dedoped with lithium, or a transition metal oxide.

[0058] Materials capable of reversibly intercalating / deintercalating lithium ions may include carbon-based negative electrode active materials, such as crystalline carbon, amorphous carbon, or combinations thereof. Examples of crystalline carbon include graphite such as amorphous, plate-like, flake-like, spherical, or fibrous natural or artificial graphite, while examples of amorphous carbon include soft carbon or hard carbon, mesophase pitch carbide, and calcined coke.

[0059] As lithium metal alloys, alloys of lithium with metals selected from Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Ra, Ge, Al, and Sn can be used.

[0060] As a substance that can be doped and undoped with lithium, a Si-based negative electrode active material or a Sn-based negative electrode active material can be used. The Si-based negative electrode active material can be silicon, a silicon-carbon composite, SiO x (0 < x < 2), a Si-Q alloy (Q is selected from alkali metals, alkaline earth metals, group 13 elements, group 14 elements (excluding Si), group 15 elements, group 16 elements, transition metals, rare earth elements, and combinations thereof), or a combination thereof. The Sn-based negative electrode active material can be Sn, SnO2, a Sn-based alloy, or a combination thereof.

[0061] The silicon-carbon composite can be a composite of silicon and amorphous carbon. According to one embodiment, the silicon-carbon composite can be in a form in which amorphous carbon is coated on the surface of silicon particles. For example, it may include secondary particles (cores) formed by granulating primary silicon particles and an amorphous carbon coating layer (shell) located on the surface of the secondary particles. Amorphous carbon may also be located between the primary silicon particles. For example, the primary silicon particles may be coated with amorphous carbon. The secondary particles may be dispersed and present in an amorphous carbon matrix.

[0062] The silicon-carbon composite can further contain crystalline carbon. For example, the silicon-carbon composite may include a core containing crystalline carbon and silicon particles and an amorphous carbon coating layer located on the surface of the core.

[0063] The Si-based negative electrode active material or the Sn-based negative electrode active material can be used by mixing with a carbon-based negative electrode active material.

[0064] negative electrode The negative electrode for the battery cell 100 includes a current collector and a negative electrode active material layer located on the current collector. The negative electrode active material layer contains a negative electrode active material and may further contain a binder and / or a conductive material.

[0065] For example, the negative electrode active material layer may contain 90% to 99% by weight of the negative electrode active material, 0.5% to 5% by weight of the binder, and 0% to 5% by weight of the conductive material.

[0066] The binder plays a role in ensuring good adhesion between the negative electrode active material particles and good adhesion between the negative electrode active material and the current collector. Non-aqueous binders, aqueous binders, dry binders, or combinations thereof can be used as binders.

[0067] Examples of non-aqueous binders include polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene propylene copolymer, polystyrene, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamide-imide, polyimide, or combinations thereof.

[0068] The aqueous binder can be selected from styrene-butadiene rubber, (meth)acrylate styrene-butadiene rubber, (meth)acrylonitrile-butadiene rubber, (meth)acrylic rubber, butyl rubber, fluororubber, polyethylene oxide, polyvinylpyrrolidone, polyepichlorohydrin, 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.

[0069] When using an aqueous binder as the negative electrode binder, it may further contain a cellulosic compound that can impart viscosity. This cellulosic compound can be a mixture of one or more carboxymethylcellulose, hydroxypropylmethylcellulose, methylcellulose, or alkali metal salts thereof. As the alkali metal, Na, K, or Li can be used.

[0070] The dry binder may be a polymer material that can be fiberized, such as polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polyethylene oxide, or a combination thereof.

[0071] Conductive materials are used to impart conductivity to electrodes, and any electronically conductive material that does not cause chemical changes can be used in the battery that is constructed from them. Specific examples include carbon-based materials such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjenblack, carbon fibers, carbon nanofibers, and carbon nanotubes; metallic materials containing copper, nickel, aluminum, silver, etc., in the form of metal powders or metal fibers; conductive polymers such as polyphenylene derivatives; or mixtures thereof.

[0072] As the negative electrode current collector, copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, polymer substrates coated with conductive metal, and combinations thereof can be selected.

[0073] separation membrane Depending on the type of battery cell, a separation membrane may be present between the positive and negative electrodes. Such separation membranes can be made of polyethylene, polypropylene, polyvinylidene fluoride, or multilayer membranes of two or more layers thereof. Mixed multilayer membranes such as polyethylene / polypropylene two-layer separation membranes, polyethylene / polypropylene / polyethylene three-layer separation membranes, and polypropylene / polyethylene / polypropylene three-layer separation membranes can also be used.

[0074] The separation membrane may include a porous substrate and a coating layer containing organic, inorganic, or a combination thereof located on one or both sides of the porous substrate.

[0075] The porous substrate may be a polymer film formed from one polymer selected from polyethylene, polyolefins such as polypropylene, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyacetal, polyamide, polyimide, polycarbonate, polyetherketone, polyaryletherketone, polyetherimide, polyamideimide, polybenzimidazole, polyethersulfone, polyphenylene oxide, cyclic olefin copolymer, polyphenylene sulfide, polyethylene naphthalate, glass fiber, Teflon, and polytetrafluoroethylene, or from copolymers or mixtures of two or more of these polymers.

[0076] The organic material may include polyvinylidene fluoride polymers or (meth)acrylic polymers.

[0077] The 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.

[0078] Organic and inorganic materials may exist mixed in a single coating layer, or in a form in which a coating layer containing organic materials and a coating layer containing inorganic materials are stacked.

[0079] Case 20 houses such an electrode assembly 10. Case 20 seals the housed electrode assembly 10 together with the electrolyte.

[0080] electrolyte The electrolyte for battery cell 100 contains a non-aqueous organic solvent and a lithium salt.

[0081] Non-aqueous organic solvents act as a medium through which ions involved in the electrochemical reactions of batteries can move.

[0082] Non-aqueous organic solvents may be carbonate-based, ester-based, ether-based, ketone-based, or alcohol-based solvents, aprotic solvents, or combinations thereof.

[0083] Examples of carbonate-based solvents that can be used include 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), and butylene carbonate (BC).

[0084] Suitable ester solvents include methyl acetate, ethyl acetate, n-propyl acetate, dimethyl acetate, methyl propionate, ethyl propionate, decanolide, mevalonolactone, valerolactone, and caprolactone.

[0085] As ether-based solvents, dibutyl ether, tetraglyme, diglyme, dimethoxyethane, 2-methyltetrahydrofuran, 2,5-dimethyltetrahydrofuran, tetrahydrofuran, etc. can be used. As ketone-based solvents, cyclohexanone, etc. can be used. As alcohol-based solvents, ethyl alcohol, isopropyl alcohol, etc. can be used, and as aprotic solvents, nitriles such as R-CN (where R is a linear, branched, or cyclic hydrocarbon group having 2 to 20 carbon atoms, and may include a double bond, aromatic ring, or ether group); amides such as dimethylformamide; dioxolanes such as 1,3-dioxolane and 1,4-dioxolane; sulfolanes, etc. can be used.

[0086] Non-aqueous organic solvents can be used alone or in combination of two or more.

[0087] Furthermore, when using carbonate-based solvents, cyclic carbonates and linear carbonates can be mixed and used together, and the cyclic carbonates and linear carbonates may be mixed in a volume ratio of 1:1 to 1:9.

[0088] Lithium salts are substances that dissolve in organic solvents and act as a source of lithium ions in batteries, enabling the basic operation of lithium batteries and facilitating the movement of lithium ions between the positive and negative electrodes. Typical examples of lithium salts include 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 F2 x+1 SO2)(C y F 2y+1 SO2) (where x and y are integers from 1 to 20), may contain one or more selected from lithium trifluoromethanesulfonate, lithium tetrafluoroethanesulfonate, lithium difluorobis(oxalate)phosphate (LiDFOB), and lithium bis(oxalate)porate (LiBOB).

[0089] As described above, the case 20 is sealed after housing the electrode assembly 10 and the electrolyte. For example, the case 20 can be sealed with a cap plate 60.

[0090] Specifically, the case 20 forms the general appearance of the battery cell 100. The case 20 includes a top surface that forms the top of a cylindrical shape, and side surfaces that are connected to the outer circumferential surface of the top surface, extend vertically from the top surface, and form the sides.

[0091] The case 20 may have a hole 20h formed on its upper surface. The hole 20h is formed to penetrate the upper surface of the case 20. The hole 20h may be located in the center of the upper surface of the case 20. The hole 20h may be formed, for example, on the upper side of the winding core portion of the electrode assembly 10. The shape of the hole 20h can correspond to the shape of the rivet 30. For example, if the cross-section of the rivet 30 is circular, the cross-section of the hole 20h may be formed to be circular. In this case, the diameter of the cross-section of the hole 20h is larger than the diameter of the cross-section of the rivet 30.

[0092] In this case, the case 20 may have an open bottom section. The case 20 can be sealed inside by sealing the opening with the cap plate 60. This prevents the electrolyte from leaking out of the case 20 and protects the electrode assembly 10.

[0093] Case 20 can be manufactured from, for example, steel, stainless steel, aluminum, aluminum alloy, a combination thereof, or equivalents thereof.

[0094] The cap plate 60 covers the opening of the case 20 and seals the case 20.

[0095] In this case, the battery cell 100 may further include a gasket 80 to ensure further sealing of the case 20. The gasket 80 may be formed, for example, in a ring shape. The gasket 80 may be positioned between the cap plate 60 and the inner surface of the case 20, while surrounding the outer surface of the cap plate 60. Through this, the gasket 80 can prevent the electrolyte inside the battery cell 100 from leaking out or causing safety problems.

[0096] In this case, the case 20 may have a beading portion 21 to fix the position of the cap plate 60 relative to the opening of the case 20. For example, the beading portion 21 is formed on the underside of the case 20. The beading portion 21 is formed by recessing the case 20 from the outside inward. The beading portion 21 prevents the cap plate 60 from entering the case 20 further through the opening of the case 20 via such recess. In this case, the case 20 may further have a crimping portion 22 to fix the position of the cap plate 60 relative to the opening of the case 20. The crimping portion 22 may be formed by rounding the end of the opening of the case 20 toward the inside of the case 20. For example, the crimping portion 22 may be formed by bending toward the case 20 after the cap plate 60 has been placed in the opening of the case 20. Through this, the cap plate 60 can cover the opening of the case 20.

[0097] In this case, the cap plate 60 can also function as a vent. For example, the cap plate 60 may include a groove 61. The groove 61 may break if the pressure inside the case 20 becomes high or the temperature rises. If the groove 61 breaks, gas generated from inside the case 20 can be released to the outside.

[0098] The case 20 is electrically connected to the electrode assembly 10 housed inside the case 20. For example, the case 20 is electrically connected to the second electrode. The second electrode may be, for example, the negative electrode.

[0099] The battery cell 100 may further include a second current collector plate 70 located at the bottom of the electrode assembly 10 to electrically connect the case 20 to the second electrode. For example, the second current collector plate 70 may be located between the bottom of the electrode assembly 10 and the top of the cap plate 60.

[0100] In this case, the second current collector plate 70 and the cap plate 60 may be insulated from each other by a gasket 80. The second current collector plate 70 is, for example, a negative electrode current collector plate. The second current collector plate 70 collects current by being connected to the second electrode. For example, the second current collector plate 70 is connected to the tab of the second electrode. The second current collector plate 70 is also connected to the case 20. Through this, the case 20 is electrically connected to the second electrode and can have the same polarity as the second electrode. That is, for example, the case 20 can have the polarity of the negative electrode.

[0101] The rivet 30 is inserted into a hole 20h formed on the upper surface of the case 20. The rivet 30 is inserted into the hole 20h and electrically connected to the electrode assembly 10 housed inside the case 20. For example, the rivet 30 is electrically connected to the first electrode. The first electrode may be, for example, the positive electrode.

[0102] The battery cell 100 may further include a first current collector plate 40 located on top of the electrode assembly 10 to electrically connect the rivet 30 to 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 to collect current. For example, the first current collector plate 40 is connected to the tab of the first electrode. The first current collector plate 40 is also connected to the rivet 30. Through this, the rivet 30 is electrically connected to the first electrode and can have the same polarity as the first electrode. That is, for example, the rivet 30 can have positive electrode polarity.

[0103] In this case, the rivet 30 may contain a conductive material in order to be electrically connected to the first electrode. For example, the rivet 30 may contain a metal. For example, the rivet 30 may contain aluminum (Al).

[0104] The battery cell 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 the first current collector plate 40 and the case 20 from being electrically connected.

[0105] Through this configuration, the battery cell 100 according to one embodiment of the present invention can provide a battery with improved capacity by eliminating the upper beading portion. Furthermore, the battery cell 100 can solve the safety or financial problems that may arise if the battery cell 100 explodes upwards by positioning the cap plate 60 at the bottom.

[0106] Figure 4 is a schematic diagram showing the configuration of a battery pack including a tab according to one embodiment of the present invention.

[0107] A battery pack 1000 according to one embodiment of the present invention includes a plurality of battery cells 100, including a first battery cell 100a and a second battery cell 100b, and a tab 200 that electrically connects the plurality of battery cells 100, the tab 200 including a first joint 210 that is joined to the first battery cell 100a and a second joint 220 that is joined to the second battery cell 100b.

[0108] As explained with reference to Figure 1, the battery pack 1000 includes a plurality of battery cells 100. As explained with reference to Figures 2 and 3, the battery cells 100 may include, for example, cylindrical batteries.

[0109] The multiple battery cells 100 include, for example, a first battery cell 100a and a second battery cell 100b. However, this is merely an example, and the multiple battery cells 100 included in the battery pack 1000 may be three or more.

[0110] The first battery cell 100a and the second battery cell 100b may be formed to the same specifications. Furthermore, the first battery cell 100a and the second battery cell 100b may be arranged adjacent to each other. In this case, a portion of the side surface of the first battery cell 100a and a portion of the side surface of the second battery cell 100b may face each other.

[0111] The first battery cell 100a and the second battery cell 100b may be electrically connected by a tab 200.

[0112] The tab 200 electrically connects at least two of the multiple battery cells 100. Although not shown in the figures, the tab 200 can be mounted on, for example, a protection circuit module to electrically connect the battery cells 100. In this case, the protection circuit module may include a printed circuit board (not shown) and one or more tabs 200 mounted on the printed circuit board.

[0113] For example, tab 200 electrically connects the first battery cell 100a and the second battery cell 100b. Figure 4 shows an example where tab 200 connects a pair of battery cells 100 containing two battery cells 100a and 100b, but tab 200 can also electrically connect multiple pairs of battery cells 100.

[0114] For example, the tab 200 includes a first connection 210 connected to the first battery cell 100a and a second connection 220 connected to the second battery cell 100b.

[0115] The first junction 210 is electrically connected to the first electrode of the first battery cell 100a. The second junction 220 is electrically connected to the second electrode of the second battery cell 100b. The second electrode of the second battery cell 100b may have a different polarity from the first electrode of the first battery cell 100a. For example, if the first electrode of the first battery cell 100a is positive, then the second electrode of the second battery cell 100b is negative. Or, for example, if the first electrode of the first battery cell 100a is negative, then the second electrode of the second battery cell 100b is positive.

[0116] Thus, the battery pack 1000 according to one embodiment of the present invention electrically connects a plurality of battery cells 100 included in the battery pack 1000 via tabs 200.

[0117] In this case, if the bonding force between the tab 200 and the battery cell 100 is insufficient, the electrical connection between the tab 200 and the battery cell 100 may weaken. In this case, the battery pack 1000 may not receive sufficient electrical energy from the battery cell 100, or it may cause safety problems during the charging and discharging process. Therefore, the tab 200 needs to be firmly fixed to each of two or more battery cells 100.

[0118] The following describes in detail a method that can improve the reliability of the connection between tab 200 and battery cell 100.

[0119] Figure 5 is a schematic top view showing the configuration of a battery cell according to one embodiment of the present invention.

[0120] Figure 6 is a schematic side view showing the configuration of a battery pack including a tab according to one embodiment of the present invention.

[0121] The battery cell 100 includes an electrode assembly 10 containing a first electrode and a second electrode; a rivet 30 connected to the first electrode; and a case 20 housing the electrode assembly 10 and connected to the second electrode, the rivet 30 being fitted into a hole 20h on one side of the case 20.

[0122] As shown in Figure 5, the battery cell 100 includes a rivet 30 electrically connected to the first electrode and a case 20 electrically connected to the second electrode.

[0123] As mentioned above, the rivet 30 is connected to the first electrode. The case 20 is connected to the second electrode. In other words, the case 20 and the rivet 30 have opposite polarities. In this case, if the case 20 and the rivet 30 come into contact, a short circuit may occur between the case 20 and the rivet 30.

[0124] To prevent such problems, the battery cell 100 may further include an insulator 50 that insulates the space between the case 20 and the rivet 30.

[0125] The insulator 50 is located on the underside of the terminal plate 35. The insulator 50 is also located on the upper side of the case 20. The insulator 50 contains insulating material. The insulator 50 is located between the case 20 and the rivet 30, and can insulate the space between the case 20 and the rivet 30. This prevents a short circuit from occurring between the case 20 and the rivet 30.

[0126] For example, the first battery cell 100a includes a rivet 30a electrically connected to a first electrode and a case 20a electrically connected to a second electrode. The first battery cell 100a may further include an insulator 50a that insulates the space between the case 20a and the rivet 30a.

[0127] For example, the second battery cell 100b includes a rivet 30b electrically connected to the first electrode and a case 20b electrically connected to the second electrode. The second battery cell 100b may further include an insulator 50b that insulates the space between the case 20b and the rivet 30b.

[0128] Tab 200 electrically connects multiple battery cells 100.

[0129] To this end, the tab 200 includes a first joint 210 that is joined to the first battery cell 100a and contains the first material, and a second joint 220 that is joined to the second battery cell 100b and contains the second material.

[0130] The first joint 210 is joined to the rivet 30a of the first battery cell 100a. For example, the lower part of the first joint 210 is joined to the upper surface of the first battery cell 100a. For example, the first joint 210 may be joined to the rivet 30a of the first battery cell 100a by welding.

[0131] In this case, the first joint 210 may include the first material in order to improve the welding reliability with the rivet 30a of the first battery cell 100a.

[0132] The first material includes a material that is readily electrically connected to the first electrode of the first battery cell 100a. For example, the first material includes a conductive material. The conductive material includes, for example, a metal.

[0133] Furthermore, the first material includes a material that is easily welded to the rivet 30a of the first battery cell 100a. For example, the first joint 210 may include the same material as the rivet 30a of the first battery cell 100a. For example, if the rivet 30a of the first battery cell 100a includes aluminum (Al), the first joint 210 may also include aluminum (Al). Alternatively, for example, the first joint 210 may include a material that is not identical to the material included in the rivet 30a of the first battery cell 100a, but is easily welded to the material included in the rivet 30a of the first battery cell 100a. For example, if the rivet 30a of the first battery cell 100a includes aluminum (Al), the first joint 210 may include nickel (Ni), copper (Cu), tungsten (W), silver (Ag), gold (Au), or an alloy containing at least one of these.

[0134] Thus, the first material included in the first joint 210 can be determined by the material included in the rivet 30a of the first battery cell 100a.

[0135] The second joint 220 is joined to the case 20b of the second battery cell 100b. For example, the second joint 220 is joined to the top surface of the case of the second battery cell 100b. For example, the second joint 220 may be joined to the case of the second battery cell 100b by welding.

[0136] In this case, the second joint 220 may include a second material to improve the welding reliability with the case 20b of the second battery cell 100b.

[0137] The second material includes a material that is readily electrically connected to the second electrode of the second battery cell 100b. For example, the second material includes a conductive material. The conductive material includes, for example, a metal.

[0138] Furthermore, the second material includes a material that is easily welded to the case 20b of the second battery cell 100b. For example, the second joint 220 may include the same material as the case 20b of the second battery cell 100b. For example, if the case 20b of the second battery cell 100b includes iron (Fe), stainless steel, etc., the second joint 220 may include iron (Fe), stainless steel, etc. Alternatively, for example, the second joint 220 may include a material that is not identical to the material contained in the case 20b of the second battery cell 100b, but has excellent weld reliability after welding to the case 20b of the second battery cell 100b. For example, if the case 20b of the second battery cell 100b includes iron, SUS, etc., the second joint 220 may include copper (Cu), nickel (Ni), tungsten (W), silver (Ag), gold (Au), titanium (Ti), or an alloy containing at least one of these.

[0139] Thus, the second material included in the second joint 220 can be determined by the material included in the case 20b of the second battery cell 100b.

[0140] In this case, the first material and the second material may be different. In this way, the tab 200 can be configured such that the first joint 210 and the second joint 220 each contain different materials, thereby improving the weld strength of the objects to which the first joint 210 and the second joint 220 are joined. It goes without saying that if the materials included in the objects to which the first joint 210 and the second joint 220 are joined are the same, then the first material and the second material are identical. Furthermore, for example, the second joint 220 may be formed from an alloy of the first material and the second material. For example, the second joint 220 may be formed in a clad form of the first material and the second material.

[0141] As a result, the first joint 210 and the second joint 220 may each be formed from separate structures. The tab 200 may also include a connecting portion 230 that connects the first joint 210 and the second joint 220. For example, the connecting portion 230 may be formed by joining one side of the first joint 210 and one side of the second joint 220.

[0142] Thus, the tab 200 according to one embodiment of the present invention can improve the welding reliability with a plurality of battery cells 100 via joints 210 and 220, each containing different materials.

[0143] Figure 7 is a schematic perspective view showing the top of a tab according to one embodiment of the present invention.

[0144] Figure 8 is a schematic perspective view showing the bottom of a tab according to one embodiment of the present invention.

[0145] As explained with reference to Figures 5 and 6, the tab 200 may include a first joint 210; a second joint 220; and a connecting portion 230 that connects the first joint 210 and the second joint 220.

[0146] The first joint 210 includes a rivet joint 211, which is a region that is joined to the upper surface of the rivet 30a of the first battery cell 100a.

[0147] The rivet joint 211 may be formed in a flat plate shape corresponding to the upper surface shape of the rivet 30a in order to be easily joined to the rivet 30a of the first battery cell 100a. Alternatively, the rivet joint 211 may be formed in a circular shape when viewed from above, corresponding to the upper surface shape of the rivet 30a. However, the shape of the rivet joint 211 is formed in correspondence with the rivet 30a of the first battery cell 100a and is not limited thereto. For example, if the upper surface of the rivet 30a of the first battery cell 100a is formed with irregularities, the rivet joint 211 may also have irregularities to correspond to this.

[0148] The rivet joint 211 may be formed to correspond to the area of ​​the upper surface of the rivet 30a in order to electrically connect with the rivet 30a of the first battery cell 100a while reducing resistance. For example, if the area of ​​the rivet joint 211 is less than 30% of the area of ​​the upper surface of the rivet 30a, the electrical connection between the first joint 210 and the rivet 30a may be weak, or the electrical resistance between the first joint 210 and the rivet 30a may be high. Also, for example, if the area of ​​the rivet joint 211 exceeds 120% of the area of ​​the upper surface of the rivet 30a, the first joint 210 may interfere with the electrical connection between other adjacent tabs (not shown) and other adjacent battery cells (not shown).

[0149] As a result, for example, when viewed from above, the area of ​​the rivet joint 211 may be formed at 30% to 120% of the area of ​​the upper surface of the rivet 30a. Alternatively, for example, the area of ​​the rivet joint 211 may be formed at 50% to 110% of the area of ​​the upper surface of the rivet 30a. Alternatively, for example, the area of ​​the rivet joint 211 may be formed at 80% to 100% of the area of ​​the upper surface of the rivet 30a.

[0150] The second joint portion 220 includes a case joint portion 221, which is a region that is joined to the case 20b of the second battery cell 100b.

[0151] The case joint 221 may be joined to the upper surface of the case 20b of the second battery cell 100b. The case joint 221 may be formed in a flat plate shape corresponding to the shape of the upper surface of the case 20b in order to be easily joined to the upper surface of the case 20b of the second battery cell 100b. Alternatively, the case joint 221 may be formed in a circular, semicircular, or chord shape, including an opening through which the rivet 30b passes, when viewed from above, corresponding to the shape of the upper surface of the case 20b. Figure 7 shows a semicircular case joint 221 including an opening through which the rivet 30b passes.

[0152] The case joint 221 may be formed to correspond to the area of ​​the top surface of case 20b in order to electrically connect the second battery cell 100b to case 20b while reducing resistance. For example, if the area of ​​the case joint 221 is less than 10% of the area of ​​the top surface of case 20b, the electrical connection between the second joint 220 and case 20b may be weak, or the electrical resistance between the second joint 220 and case 20b may be high. Also, for example, if the area of ​​the case joint 221 exceeds 100% of the area of ​​the top surface of case 20b, the second joint 220 may interfere with the electrical connection between other adjacent tabs (not shown) and other adjacent battery cells (not shown).

[0153] As a result, for example, when viewed from above, the area of ​​the case joint 221 may be formed to be 10% to 100% of the area of ​​the upper surface of the case 20b. Alternatively, for example, the area of ​​the case joint 221 may be formed to be 20% to 80% of the area of ​​the upper surface of the case 20b. Alternatively, for example, the area of ​​the case joint 221 may be formed to be 20% to 60% of the area of ​​the upper surface of the case 20b. Alternatively, for example, the area of ​​the case joint 221 may be formed to be 30% to 60% of the area of ​​the upper surface of the case 20b. Alternatively, for example, the area of ​​the case joint 221 may be formed to be 40% to 55% of the area of ​​the upper surface of the case 20b.

[0154] Alternatively, although not shown in the figures, the second joint 220 may be joined to the side surface of the second battery cell 100b. In this case, the second joint 220 may be fitted to the side surface of the case of the second battery cell 100b. In this case, the second joint 220 may include an insulating layer formed on at least a portion of the second joint 220, which contains an insulating material, in order to avoid contact with other adjacent battery cells (for example, including the first battery cell 100a).

[0155] The connecting portion 230 connects the first joint portion 210 and the second joint portion 220, which are formed from different structural materials.

[0156] For example, the first joint 210 includes a first extension 212 extending from the riveted joint 211. The first extension 212 extends, for example, from the riveted joint 211 toward the second joint 220.

[0157] For example, the second joint 220 includes a second extension 223 extending from the case joint 221. The second extension 223 extends, for example, from the case joint 221 toward the first joint 210.

[0158] As shown in Figures 7 and 8, the connecting portion 230 is formed by joining at least a part of the first extension 212 and at least a part of the second extension 223.

[0159] For example, the connecting portion 230 may be formed by positioning at least a portion of the first extension 212 overlapping at least a portion of the second extension 223, and welding the overlapping area. Alternatively, contrary to the illustrations in Figures 7 and 8, for example, the connecting portion 230 may be formed by positioning at least a portion of the second extension 223 overlapping at least a portion of the first extension 212, and welding the overlapping area. Alternatively, for example, the connecting portion 230 may be formed by the contact between one end of the first extension 212 and one end of the second extension 223, and welding the contact area.

[0160] For example, the connecting portion 230 may be formed by ultrasonic welding at least a portion of the first extension 212 and at least a portion of the second extension 223. Through this method, the connecting portion 230 can be formed in a short time while increasing manufacturing efficiency.

[0161] Alternatively, for example, the connecting portion 230 may be formed by laser welding at least a portion of the first extension 212 and at least a portion of the second extension 223. For example, the connecting portion 230 may be formed by pulsed laser welding, single-mode laser welding, multi-mode laser welding, or green laser welding. Through this, the connecting portion 230 can be easily welded together at least a portion of the first extension 212 and at least a portion of the second extension 223, which may be made of different materials, without the need for additional deformation or design constraints.

[0162] In this case, as explained with reference to Figures 2 and 3, the rivet 30 is formed protruding from one side of the case 20. This allows the first joint 210 and the second joint 220 connecting the rivet 30 of an adjacent battery cell 100 to the case 20 to be formed at different heights. This allows the second joint 220 to have a case joint 221 that abuts the case 20 and a second extension 223 that abuts the first joint 210 to be formed at different heights. The second joint 220 may further include a stepped portion 222 connecting the case joint 221 and the second extension 223. The first joint 210 may also further include a stepped portion connecting the rivet joint 211 and the first extension 212.

[0163] As described above, the connecting portion 230 may be formed by welding. In this case, for example, the connecting portion 230 may be formed by welding beads. This allows the connecting portion 230 to be formed at a distance from the battery cell 100 so that the welding beads do not interfere with the battery cell 100. For example, the connecting portion 230 may be formed at a distance from the rivet 30b of the second battery cell 100b. Alternatively, the connecting portion 230 may be formed at a distance from the case 20b of the second battery cell 100b. Furthermore, the connecting portion 230 may be formed at a distance from the rivet 30a and / or case 20a of the first battery cell 100a.

[0164] The first joint 210 and the second joint 220 may be formed with different area ratios. For example, if the first material is less expensive than the second material, the first extension 212 may be formed wider than the second extension 223, and the first extension 212 may extend further toward the second extension 223. Alternatively, if the first material is more expensive than the second material, the second extension 223 may be formed wider than the first extension 212, and the second extension 223 may extend further toward the first extension 212.

[0165] For example, the first material may include aluminum, and the second material may include copper. Thus, for example, the first material may include a material of lower cost than the second material. In this case, as shown in Figures 7 and 8, the welded portion 230 may be formed closer to the case joint 221 relative to the rivet joint 211. In this case, the welded portion 230 may be formed at a distance from the case 20b and / or rivet 30b of the second battery cell 100b without contact.

[0166] Figure 9 is a schematic perspective view showing the top of a tab according to one embodiment of the present invention.

[0167] Figure 10 is a schematic perspective view showing the top of a tab according to one embodiment of the present invention.

[0168] As described with reference to Figures 4 to 8, the tab 200 may include a first joint 210; a second joint 220; and a connecting portion 230 that connects the first joint 210 and the second joint 220.

[0169] In this case, the first joint 210 includes the first material, and the second joint 220 includes the second material. As explained with reference to Figures 7 and 8, the area ratio between the first joint 210 and the second joint 220 can be determined based on the cost and / or physical properties of the first and / or second materials. For example, if the price of the first material is higher than that of the second material, the area of ​​the first joint 210 may be formed to be larger than that of the second joint 220.

[0170] Figures 9 to 10 illustrate other shapes of the first joint 210 and the second joint 220.

[0171] For example, the second material may contain a material of lower cost than the first material. Or, for example, the second material may have better electrical conductivity and / or better ability to reduce electrical resistance than the first material.

[0172] In this case, for example, as shown in Figure 9, the second joint 220 may be formed to be wider than the first joint 210. For example, the second joint 220 includes a case joint 221 and a second extension 224. In this case, the second extension 224 may be formed to extend further toward the first joint 210. This allows the weld 230 to be formed closer to the rivet joint 211 than to the case joint 221.

[0173] Alternatively, for example, the second and first materials may all include expensive materials. Alternatively, the volume of the tab 200 may need to be reduced by other components included in the battery pack 1000. Alternatively, a reduction in the weight of the battery pack 1000 may be required.

[0174] In this case, for example, as shown in Figure 10, the first joint 210 and / or the second joint 220 may be formed in a narrow area.

[0175] Thus, the tab 200 according to one embodiment of the present invention can improve welding reliability with the battery cell 100 via joints (e.g., 210, 220) containing dissimilar materials. Furthermore, the battery pack 1000 according to one embodiment of the present invention can increase safety and / or charge / discharge efficiency by electrically connecting at least two or more of the multiple battery cells 100 via such tabs 200.

[0176] The present invention has been described with reference to embodiments shown in the drawings, which are illustrative only, and any person with ordinary skill in the art will understand that various modifications and equivalent other embodiments are possible therefrom.

[0177] Therefore, the scope of technical protection of the present invention should be defined by the claims. [Explanation of Symbols]

[0178] 100 battery cells 200 tabs 210 1st joint 220 Second joint 230 Connection section 1000 Battery Pack

Claims

1. Multiple battery cells including a first battery cell; and a second battery cell; and Includes tabs for electrically connecting the plurality of battery cells; The aforementioned tab is A first joint portion bonded to the first battery cell and comprising the first material; and A battery pack comprising: a second joint portion bonded to the second battery cell and comprising a second material;

2. The battery pack according to claim 1, wherein the first material and the second material are different.

3. The aforementioned battery cell is Electrode assembly including a first electrode and a second electrode; A rivet connected to the first electrode; and A case for housing the electrode assembly and connecting to the second electrode; The battery pack according to claim 1, wherein the rivet is fitted into a hole on one side of the case.

4. The first joint includes a rivet joint that is joined to the rivet of the first battery cell; The battery pack according to claim 3, wherein the second joint portion includes a case joint portion that is joined to the case of the second battery cell.

5. The battery pack according to claim 4, wherein the first joint portion comprises the same material as the rivet of the first battery cell.

6. The battery pack according to claim 4, wherein the second joint portion comprises the same material as the case of the second battery cell.

7. The case of the second battery cell contains iron (Fe), The battery pack according to claim 4, wherein the second joint portion includes at least one of copper (Cu), nickel (Ni), tungsten (W), silver (Ag), gold (Au), titanium (Ti), and alloys thereof.

8. The first joint includes a first extension extending from the rivet joint; and the second joint includes a second extension extending from the case joint; The battery pack according to claim 4, wherein the tab includes a connecting portion to which at least a portion of the first extension and at least a portion of the second extension are joined and connected.

9. The battery pack according to claim 8, wherein the connecting portion is formed at a distance from the rivet of the second battery cell.

10. The battery pack according to claim 8, wherein the connecting portion is formed at a distance from the case of the second battery cell.

11. The battery pack according to claim 4, wherein the case joint is welded and joined to one side of the case of the second battery cell.

12. The battery pack according to claim 1, wherein the second joint is formed of an alloy of the first material and the second material.

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