Composite substrate for rechargeable lithium battery and rechargeable lithium battery including same

Abstract

A composite substrate and a rechargeable lithium battery are disclosed. The composite substrate includes a support layer, a first metal layer on a top surface of the support layer, a second metal layer on a bottom surface of the support layer, and at least one tab embedded between the support layer and at least one of the first metal layer and the second metal layer. The tab includes an embedded portion and an exposed portion.

Description

[0001] This application claims priority to Korean Patent Application No. 10-2024-0061936, filed on May 10, 2024, with the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference. Technical Field

[0002] Examples of this disclosure relate to composite substrates for rechargeable lithium batteries and rechargeable lithium batteries including the composite substrates. Background Technology

[0003] With the increasing use of battery-powered electronic devices, such as mobile phones, laptops, and electric vehicles, there is a demand for rechargeable batteries with high energy density and high capacity.

[0004] A rechargeable lithium battery typically includes a positive electrode, a negative electrode, and an electrolyte. The positive and negative electrodes contain active materials capable of inserting and deintercalating lithium ions, and the battery generates electrical energy through redox reactions during lithium ion insertion and deintercalation. Summary of the Invention

[0005] Example embodiments of this disclosure include composite substrates having desired or improved adhesion and contact resistance with the tabs.

[0006] Example embodiments of this disclosure include a rechargeable lithium battery incorporating the composite substrate.

[0007] According to an example embodiment of this disclosure, a composite substrate for a rechargeable lithium battery may include a support layer, a first metal layer on a top surface of the support layer, a second metal layer on a bottom surface of the support layer, and at least one terminal piece embedded between the support layer and at least one of the first and second metal layers. The terminal piece may include an embedded portion and an exposed portion.

[0008] According to an example embodiment of this disclosure, a composite substrate for a rechargeable lithium battery may include a support layer, a first functional layer on a top surface of the support layer, a first metal layer on a top surface of the first functional layer, a second functional layer on a bottom surface of the support layer, a second metal layer on a bottom surface of the second functional layer, and at least one terminal piece embedded between the support layer and at least one of the first and second functional layers. The terminal piece may include an embedded portion and an exposed portion.

[0009] According to an example embodiment of this disclosure, a rechargeable lithium battery may include: a composite substrate including a support layer and a metal layer on the support layer; a battery cell on the metal layer; and at least one terminal piece between the metal layer and the support layer. Attached Figure Description

[0010] Figure 1 A simplified conceptual diagram illustrating a rechargeable lithium battery according to an example embodiment of the present disclosure is shown.

[0011] Figures 2 to 5 A simplified diagram illustrating a rechargeable lithium battery according to an example embodiment of the present disclosure is shown.

[0012] Figure 6 A cross-sectional view is shown illustrating a rechargeable lithium battery according to an example embodiment of the present disclosure.

[0013] Figure 7 A plan view illustrating a composite substrate according to an example embodiment of the present disclosure is shown.

[0014] Figure 8A It shows along Figure 7 A sectional view taken by line A-A'.

[0015] Figure 8B It shows along Figure 7 A sectional view taken by line A-A'.

[0016] Figure 9 A plan view illustrating a composite substrate according to an example embodiment of the present disclosure is shown.

[0017] Figure 10 A plan view illustrating a composite substrate according to an example embodiment of the present disclosure is shown.

[0018] Figure 11 A plan view illustrating a composite substrate according to an example embodiment of the present disclosure is shown.

[0019] Figure 12 The diagram shows the embedded part. Figure 11 A plan view of the first terminal piece in the composite substrate.

[0020] Figure 13 A plan view illustrating a composite substrate according to an example embodiment of the present disclosure is shown.

[0021] Figure 14 The diagram shows the embedded part. Figure 13 A plan view of the first terminal piece in the composite substrate.

[0022] Figure 15 A cross-sectional view is shown illustrating a rechargeable lithium battery according to an example embodiment of the present disclosure.

[0023] Figure 16 It shows Figure 15 Enlarged view of the composite substrate. Detailed Implementation

[0024] To fully understand the structure and effects of this disclosure, some exemplary embodiments of the disclosure will be described with reference to the accompanying drawings. However, it should be noted that this disclosure is not limited to the following exemplary embodiments, but can be implemented in various forms. Rather, the exemplary embodiments are provided merely to disclose this disclosure and to give those skilled in the art a full understanding of its scope.

[0025] In this specification, it will be understood that when an element is referred to as being on another element, the element may be directly on said other element, or an intervening element may be present between them. In the accompanying drawings, the thickness of some components is exaggerated for the purpose of effectively explaining the technical content. Throughout the specification, the same reference numerals refer to the same elements.

[0026] Unless otherwise specified in this specification, singular expressions may include plural expressions. Additionally, unless otherwise specified, the phrase "A or B" may mean "A but not B," "B but not A," and "A and B." The terms "comprising / including" and / or variations thereof as used in this specification do not exclude the presence or addition of one or more other components.

[0027] As used herein, the term "combination thereof" may refer to mixtures, stacks, complexes, copolymers, alloys, blends, or reaction products.

[0028] Unless otherwise defined in this specification, particle size may refer to the average particle size. Additionally, particle size refers to the average particle size (D) when the cumulative volume in the particle size distribution is approximately 50% by volume. 50 Average particle size (D) 50 The particle size distribution (D) can be measured using methods well known to those skilled in the art, such as by a particle size analyzer, transmission electron microscopy (TEM) images, or scanning electron microscopy (SEM) images. Alternatively, a dynamic light scattering measurement device can be used to perform data analysis, counting the number of particles in each particle size range, from which the average particle size (D) can be calculated. 50 The difference is that the average particle size (D) can be measured using laser scattering. 50 In the laser scattering method, target particles are distributed in a dispensing solvent and introduced into a laser scattering particle measuring device (e.g., the commercially available MT3000 from Microtrac). They are then irradiated with 28 kHz ultrasound at a power of 60 W. The average particle size (D) is then calculated in the measuring device using a 50% standard of particle size distribution. 50 ).

[0029] When the terms “approximately” or “substantially” are used in conjunction with numerical values ​​in this specification, it means that the relevant numerical value is included within a tolerance of ±10% around the stated value. When a range is specified, the range includes all values ​​within that range, such as increments of 0.1%.

[0030] Figure 1 A simplified conceptual diagram illustrating a rechargeable lithium battery according to an example embodiment of the present disclosure is shown. (Refer to...) Figure 1 A rechargeable lithium battery may include a positive electrode 10, a negative electrode 20, a separator 30, and an electrolyte ELL.

[0031] The positive electrode 10 and the negative electrode 20 can be separated from each other by a diaphragm 30. The diaphragm 30 can be disposed between the positive electrode 10 and the negative electrode 20. The positive electrode 10, the negative electrode 20 and the diaphragm 30 can be in contact with the electrolyte ELL. The positive electrode 10, the negative electrode 20 and the diaphragm 30 can be immersed in the electrolyte ELL.

[0032] The electrolyte ELL can be or includes a medium through which lithium ions are transferred between the positive electrode 10 and the negative electrode 20. In the electrolyte ELL, lithium ions can move toward one of the positive electrode 10 and the negative electrode 20 through the membrane 30.

[0033] Positive electrode 10 The positive electrode 10 for a rechargeable lithium battery may include a current collector COL1 and a positive electrode active material layer AML1 formed on the current collector COL1. The positive electrode active material layer AML1 may include a positive electrode active material and further include a binder and / or a conductive material.

[0034] For example, the positive electrode 10 may further include additives capable of constituting a sacrificial positive electrode.

[0035] The amount of positive electrode active material relative to 100 wt% of the positive electrode active material layer AML1 can be from about 90 wt% to about 99.5 wt%. The amounts of binder and conductive material relative to 100 wt% of the positive electrode active material layer AML1 can each be from about 0.5 wt% to about 5 wt%.

[0036] The binder can improve the adhesion between the positive electrode active material particles and also improve the adhesion between the positive electrode active material and the current collector COL1. The binder may include, for example, at least one of 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 or nylon, but this disclosure is not limited thereto.

[0037] A conductive material can provide conductivity to the electrodes without causing chemical changes in the battery. Any suitable conductive material can constitute a conductive material for a battery. For example, a conductive material may include: at least one carbon-based material, such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, carbon nanofiber, and carbon nanotube; metal powders or metal fibers including one or more of copper, nickel, aluminum, and silver; conductive polymers, such as polyphenylene derivatives; or mixtures thereof.

[0038] Aluminum (Al) can form current collector COL1, but this disclosure is not limited thereto.

[0039] Positive electrode active material The positive electrode active material in the positive electrode active material layer AML1 may include compounds that can reversibly insert and extract lithium (e.g., lithiation intercalation compounds). For example, the positive electrode active material may include at least one of a composite oxide comprising lithium and one or more metals such as cobalt, manganese, nickel, and combinations thereof.

[0040] The composite oxide may include lithium transition metal composite oxides, such as lithium nickel oxides, lithium cobalt oxides, lithium manganese oxides, lithium iron phosphate compounds, cobalt-free lithium nickel manganese oxides, or combinations thereof, at least one of these.

[0041] For example, the positive electrode active material may include a compound represented by one of the following chemical formulas: Li a A 1- b X b O 2-c D c (Where, 0.90≤a≤1.8, 0≤b≤0.5, and 0≤c≤0.05); Li a Mn 2-b X b O 4-c D c (Where, 0.90≤a≤1.8, 0≤b≤0.5, and 0≤c≤0.05); Lia Ni 1-b-c Co b X c O 2-α D α (Where, 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, and 0<α<2); Li a Ni 1-b-c Mn b X c O 2-α D α (Where, 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, and 0<α<2); Li a Ni b Co c L 1 d G e O2 (where 0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, and 0≤e≤0.1); Li a NiG b O2 (where 0.90 ≤ a ≤ 1.8 and 0.001 ≤ b ≤ 0.1); Li a CoG b O2 (where 0.90 ≤ a ≤ 1.8 and 0.001 ≤ b ≤ 0.1); Li a Mn 1-b G b O2 (where 0.90 ≤ a ≤ 1.8 and 0.001 ≤ b ≤ 0.1); Li a Mn2G b O4 (where 0.90 ≤ a ≤ 1.8 and 0.001 ≤ b ≤ 0.1); Li a Mn 1-g G g PO4 (where 0.90 ≤ a ≤ 1.8 and 0 ≤ g ≤ 0.5); Li (3-f) Fe2(PO4)3 (where 0≤f≤2); Li a FePO4 (where 0.90≤a≤1.8).

[0042] In the above chemical formula, A is or includes Ni, Co, Mn or a combination thereof; X is or includes Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, rare earth elements or a combination thereof; D is or includes O, F, S, P or a combination thereof; G is or includes Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V or a combination thereof; L 1 It may include or include Mn, Al or combinations thereof.

[0043] For example, the positive electrode active material can be or includes a high-nickel positive electrode active material, wherein the nickel content of the high-nickel positive electrode active material is equal to or greater than about 80 mol%, equal to or greater than about 85 mol%, equal to or greater than about 90 mol%, equal to or greater than about 91 mol%, or equal to or greater than about 94 mol% and equal to or less than about 99 mol%, relative to 100 mol% of the metals other than lithium in the lithium transition metal complex oxide. High-nickel positive electrode active materials can achieve high capacity and therefore can be used in high-capacity and high-density rechargeable lithium batteries.

[0044] negative electrode 20 The negative electrode 20 for a rechargeable lithium battery may include a current collector COL2 and a negative electrode active material layer AML2 positioned on the current collector COL2. The negative electrode active material layer AML2 may include a negative electrode active material and may also include a binder and / or a conductive material.

[0045] For example, the negative electrode active material layer AML2 may include about 90 wt% to about 99 wt% of negative electrode active material, about 0.5 wt% to about 5 wt% of binder, and about 0 wt% to about 5 wt% of conductive material.

[0046] The binder can improve the adhesion between the negative electrode active material particles and also improve the adhesion between the negative electrode active material and the current collector COL2. The binder may include at least a non-aqueous binder, an aqueous binder, a dry binder, or a combination thereof.

[0047] Non-aqueous adhesives may include at least one of polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene-propylene copolymer, polystyrene, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamide-imide, polyimide, or combinations thereof.

[0048] Waterborne adhesives may include at least one of the following: 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, or combinations thereof.

[0049] When an aqueous binder constitutes a negative electrode binder, it may further include a cellulose compound capable of providing viscosity. The cellulose compound may include one or more of carboxymethyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, and their alkali metal salts. The alkali metal may include at least one of Na, K, or Li.

[0050] The dry binder may include a fibrillatable polymer material, for example, at least one of polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidene fluoride - hexafluoropropylene copolymer, polyethylene oxide, or a combination thereof.

[0051] The conductive material can provide conductivity to the electrode, and any suitable conductive material that does not cause chemical changes in the battery can constitute the conductive material for constructing the battery. For example, the conductive material may include: carbonaceous materials, such as at least one of natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, carbon nanofiber, and carbon nanotube; metal powders or metal fibers including one or more of copper, nickel, aluminum, and silver; conductive polymers, such as polyphenylene derivatives; or a mixture thereof.

[0052] The current collector COL2 may include at least one of copper foil, nickel foil, stainless - steel foil, titanium foil, nickel foam, copper foam, a polymer substrate coated with a conductive metal, or a combination thereof.

[0053] Negative electrode active material The negative electrode active material in the negative electrode active material layer AML2 may include at least one of a material that can reversibly intercalate and deintercalate lithium ions, lithium metal, a lithium metal alloy, a material that can be doped and undoped with lithium, or a transition metal oxide.

[0054] The material that can reversibly intercalate and deintercalate lithium ions may include carbonaceous negative electrode active materials, for example, at least one of crystalline carbon, amorphous carbon, or a combination thereof. For example, crystalline carbon may include graphite, such as at least one of unshaped, flaky, lamellar, spherical, or fibrous natural graphite or artificial graphite, and amorphous carbon may include at least one of soft carbon, hard carbon, mesophase pitch carbon, or calcined coke.

[0055] The lithium metal alloy may include an alloy of lithium and at least one metal such as Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Ra, Ge, Al, and Sn.

[0056] The material that can be doped and undoped with lithium may include Si - based negative electrode active materials or Sn - based negative electrode active materials. The Si - based negative electrode active materials may include silicon, silicon - carbon composites, SiO x (where 0 < x < 2), Si - Q alloys (where Q is an alkali metal, an alkaline earth metal, a Group 13 element, a Group 14 element (except Si), a Group 15 element, a Group 16 element, a transition metal, a rare earth element, or a combination thereof), or at least one of a combination thereof. The Sn - based negative electrode active materials may include at least one of Sn, SnO2, Sn - based alloys, or a combination thereof.

[0057] Silicon-carbon composites can be or include composites of silicon and amorphous carbon. According to example embodiments, the silicon-carbon composite can have a structure in which amorphous carbon is coated on the surface of silicon particles. For example, the silicon-carbon composite can include secondary particles (cores) in which primary silicon particles are assembled and an amorphous carbon coating (shell) located on the surface of the secondary particles. Amorphous carbon can also be located between the primary silicon particles; for example, the primary silicon particles can be coated with amorphous carbon. The secondary particles can be dispersed in an amorphous carbon matrix.

[0058] Silicon-carbon composites may also include crystalline carbon. For example, a silicon-carbon composite may include a core comprising crystalline carbon and silicon particles, and may also include an amorphous carbon coating positioned on the surface of the core.

[0059] Si-based or Sn-based negative electrode active materials can be used in combination with carbon-based negative electrode active materials.

[0060] Diaphragm 30 Depending on the type of rechargeable lithium battery, the separator 30 may be present between the positive electrode 10 and the negative electrode 20. The separator 30 may include one or more of polyethylene, polypropylene, and polyvinylidene fluoride, and may have multiple layers of them, such as polyethylene / polypropylene bilayer separators, polyethylene / polypropylene / polypropylene trilayer separators, and polypropylene / polypropylene / polypropylene trilayer separators.

[0061] The diaphragm 30 may include a porous substrate and a coating positioned on one or two opposite surfaces of the porous substrate, the coating comprising at least an organic material, an inorganic material, or a combination thereof.

[0062] The porous substrate may be or include a polymer layer comprising a polyolefin (such as at least one of polyethylene and polypropylene), a polyester (such as polyethylene terephthalate and polybutylene terephthalate), a polyacetal, a polyamide, a polyimide, a polycarbonate, a polyetherketone, a polyaryletherketone, a polyetherimide, a polyamideimide, a polybenzimidazole, a polyethersulfone, a polyphenylene ether, a cyclic olefin copolymer, a polyphenylene sulfide, a polyethylene naphthalate, a glass fiber, a Teflon and a polytetrafluoroethylene, or a copolymer or mixture of two or more of the materials mentioned above.

[0063] Organic materials may include polyvinylidene fluoride copolymers or (meth)acrylic acid copolymers.

[0064] Inorganic materials may include inorganic particles of at least one of Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, SrTiO3, BaTiO3, Mg(OH)2, boehmite, or combinations thereof, but this disclosure is not limited thereto.

[0065] Organic and inorganic materials can be mixed in a coating or exist as a stack of coatings containing organic materials and coatings containing inorganic materials.

[0066] Electrolyte ELL Electrolytes (ELLs) used in rechargeable lithium batteries may include at least a non-aqueous organic solvent and a lithium salt.

[0067] Non-aqueous organic solvents can serve as media for transporting ions that participate in the electrochemical reactions of a battery.

[0068] Non-aqueous organic solvents may include at least one of carbonate solvents, ester solvents, ether solvents, ketone solvents, alcohol solvents, aprotic solvents, or combinations thereof.

[0069] Carbonate solvents may include at least 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), or butyl carbonate (BC).

[0070] Ester solvents may include at least one of methyl acetate, ethyl acetate, n-propyl acetate, dimethyl acetate, methyl propionate, ethyl propionate, decanoic acid lactone, mevalonate lactone, valproic acid lactone, or caprolactone.

[0071] Ether solvents may include at least one of dibutyl ether, tetraethylene glycol dimethyl ether, diethylene glycol dimethyl ether, dimethoxyethane, 2-methyltetrahydrofuran, 2,5-dimethyltetrahydrofuran, or tetrahydrofuran. Ketone solvents may include cyclohexanone. Alcohol solvents may include ethanol or isopropanol. Aprotic solvents may include: nitriles, such as R-CN (wherein R is a hydrocarbon group having a C2 to C20 straight-chain, branched, or cyclic structure, and may include double bonds, aromatic rings, or ether groups); amides, such as dimethylformamide; dioxolane, such as 1,3-dioxolane or 1,4-dioxolane; or sulfolane.

[0072] Non-aqueous organic solvents can be used alone or in combination of two or more.

[0073] In addition, when using carbonate solvents, cyclic carbonates and chain carbonates can be mixed and used, and cyclic carbonates and chain carbonates can be mixed in a volume ratio of about 1:1 to about 1:9.

[0074] Lithium salts can be or include materials dissolved in non-aqueous organic solvents to form a supply source of lithium ions in the battery, enabling the rechargeable lithium battery to operate substantially and facilitating the movement of lithium ions between the positive and negative electrodes. Lithium salts can include, for example, LiPF6, LiBF4, LiSbF6, LiAsF6, LiClO4, LiAlO2, LiAlCl4, LiPO2F2, LiCl, LiI, LiN(SO3C2F5)2, Li(FSO2)2N (lithium bis(fluorosulfonyl)imide, LiFSI), LiC4F9SO3, LiN(C F 2x+1 SO2)(C y F 2y+2 At least one of the following: (SO2) (where x and y are integers between 1 and 20), lithium trifluoromethane sulfonate, lithium tetrafluoroethane sulfonate, lithium difluorobis(oxalate)phosphate (LiDFBOP), and lithium bis(oxalate)borate (LiBOB).

[0075] Rechargeable lithium batteries Based on their shape, rechargeable lithium batteries can be classified as cylindrical, prismatic, pouch-shaped, and coin-shaped. Figures 2 to 5 A simplified diagram illustrating a rechargeable lithium battery according to an example embodiment is shown. Figure 2 A cylindrical battery is shown. Figure 3 A prismatic battery is shown. Figure 4 and Figure 5 A pouch-type battery is shown. (See reference) Figures 2 to 5 The rechargeable lithium battery 100 may include an electrode assembly 40 with a separator 30 disposed between a positive electrode 10 and a negative electrode 20, and may also include a housing 50 for accommodating the electrode assembly 40. The positive electrode 10, the negative electrode 20, and the separator 30 may be immersed in an electrolyte (not shown). Figure 2 As shown, the rechargeable lithium battery 100 may include a sealing member 60 of the sealed housing 50. Additionally, as... Figure 3 As shown, the rechargeable lithium battery 100 may include a positive electrode lead connector 11, a positive electrode terminal 12, a negative electrode lead connector 21, and a negative electrode terminal 22. Figure 4 and Figure 5 As shown, the rechargeable lithium battery 100 may include Figure 5 The electrode connector 70 shown, or Figure 4 The positive electrode terminal 71 and negative electrode terminal 72 shown are provided, and the electrode terminals 70, 71, and 72 constitute an electrical path for inducing the current generated in the electrode assembly 40 to the outside.

[0076] In the following example embodiments, references to the above will be omitted. Figures 1 to 5The technical features of the rechargeable lithium batteries discussed are described in detail, and their differences will be discussed in detail.

[0077] Figure 6 A cross-sectional view of a rechargeable lithium battery according to an embodiment of the present disclosure is shown. Figure 6 The diagram illustrates a composite substrate CPS, a first battery cell CEL1 on one surface of the composite substrate CPS, and a second battery cell CEL2 on the other surface of the composite substrate CPS. A single dual-cell configuration can be achieved by... Figure 6 It consists of the first battery cell CEL1, the second battery cell CEL2, and the composite substrate CPS. Figure 6 The first battery cell CEL1, the second battery cell CEL2, and the composite substrate CPS can constitute the above reference. Figures 2 to 5 Electrode assembly 40 is discussed.

[0078] Each or one of the first battery cell CEL1 and the second battery cell CEL2 may include a first active material layer ACT1, a separator 30, a second active material layer ACT2, and a metal substrate MES. The first active material layer ACT1 may be disposed on a composite substrate CPS. The second active material layer ACT2 may be spaced apart from the first active material layer ACT1 by the separator 30. The metal substrate MES may be disposed on the second active material layer ACT2.

[0079] The first active substance layer ACT1 can be referenced above. Figure 1 The discussion focuses on one of the positive electrode active material layer AML1 and the negative electrode active material layer AML2. The second active material layer ACT2 can be as described above. Figure 1 The other of the positive electrode active material layer AML1 and the negative electrode active material layer AML2 discussed. In the exemplary embodiments of this disclosure, the first active material layer ACT1 may be or include the positive electrode active material layer AML1, and the second active material layer ACT2 may be or include the negative electrode active material layer AML2. The metal substrate MES may be or include the above-mentioned... Figure 1 The current collectors to be discussed are COL1 or COL2.

[0080] A first metal contact MTA1 can be disposed on one end of the metal substrate MES of the first battery cell CEL1, and a second metal contact MTA2 can be disposed on one end of the metal substrate MES of the second battery cell CEL2. The first metal contact MTA1 can be configured to apply a voltage to the metal substrate MES of the first battery cell CEL1. The second metal contact MTA2 can be configured to apply a voltage to the metal substrate MES of the second battery cell CEL2.

[0081] The first metal connector MTA1 and the second metal connector MTA2 can form the above reference. Figures 2 to 5 One of the positive electrode terminal block and the negative electrode terminal block (or the positive electrode lead terminal block and the negative electrode lead terminal block) discussed.

[0082] The composite substrate CPS may include a support layer SPL, a first metal layer MEL1 disposed on the top surface of the support layer SPL, and a second metal layer MEL2 disposed on the bottom surface of the support layer SPL. The first metal layer MEL1 of the composite substrate CPS may be in contact with the first active material layer ACT1 of the first battery cell CEL1. The second metal layer MEL2 of the composite substrate CPS may be in contact with the first active material layer ACT1 of the second battery cell CEL2. Each or one of the first metal layer MEL1 and the second metal layer MEL2 of the composite substrate CPS may correspond to the above reference. Figure 1 One of the current collectors COL1 and COL2 is being discussed.

[0083] The support layer SPL may include a polymer film. For example, the support layer SPL may include at least one of polyethylene terephthalate (PET) film, polyimide (PI) film, polyethylene (PE) film, polypropylene (PP) film, polyvinylidene chloride (PVDC) film, polystyrene (PS) film, polyethylene naphthalate (PEN) film, polytetrafluoroethylene (PTFE) film, polycarbonate (PC) film, polyamide (PA) film, or multiple films including combinations thereof, and may have desired or improved mechanical strength.

[0084] Each of the first metal layer MEL1 and the second metal layer MEL2 may include at least one of aluminum, aluminum alloy, copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, iron, iron alloy, silver, and silver alloy.

[0085] In the exemplary embodiments of this disclosure, each or one of the first metal layer MEL1 and the second metal layer MEL2 may have a thickness of about 200 nm to about 5 μm. When the first metal layer MEL1 or the second metal layer MEL2 has an irregular thickness, its thickness is represented by the thickness of the thickest portion of the first metal layer MEL1 or the second metal layer MEL2.

[0086] The support layer SPL can have a thickness of approximately 3 μm to approximately 10 μm. The thickness of the support layer SPL can be greater than the thickness of each of the first metal layer MEL1 and the second metal layer MEL2.

[0087] The composite substrate CPS may include a first terminal block TAB1 embedded between the first metal layer MEL1 and the support layer SPL. The first terminal block TAB1 may be configured to apply a voltage to the first metal layer MEL1.

[0088] The composite substrate CPS may include a second terminal block TAB2 embedded between the second metal layer MEL2 and the support layer SPL. The second terminal block TAB2 may be configured to apply a voltage to the second metal layer MEL2.

[0089] Each or one of the first connector TAB1 and the second connector TAB2 can constitute the above reference. Figures 2 to 5 The other of the positive electrode terminal block and negative electrode terminal block (or positive electrode lead terminal block and negative electrode lead terminal block) discussed. For example, the first terminal block TAB1 and the second terminal block TAB2 can constitute the positive electrode terminal block.

[0090] In an exemplary embodiment of this disclosure, each or one of the first terminal piece TAB1 and the second terminal piece TAB2 may have a thickness of about 1 μm to about 5 μm, for example, about 2 μm to about 3 μm.

[0091] Figure 7 A plan view illustrating a semiconductor device according to some example embodiments of the present disclosure is shown. Figure 8A It shows along Figure 7 A sectional view taken by line A-A'. Figure 8B It shows along Figure 7 A sectional view taken by line A-A'.

[0092] Reference Figure 7 and Figure 8A Each or one of the first terminal block TAB1 and the second terminal block TAB2 may include an embedded portion EMP and an exposed portion EXP. Each or one of the first metal layer MEL1 and the second metal layer MEL2 may include a first region MER1 in which a corresponding one of the first terminal block TAB1 and the second terminal block TAB2 is embedded, and may also include a second region MER2 in addition to the first region MER1.

[0093] In the example embodiment, refer to Figure 8A Each or one of the first metal layer MEL1 and the second metal layer MEL2 may have an irregular thickness on the second region MER2 in the third direction D3.

[0094] For example, the first metal layer MEL1 may have a first thickness TK1 on the second region MER2 in the third direction D3, and a second thickness TK2 on the third direction D3 in the portion adjacent to the first connector TAB1. The first metal layer MEL1 may have a third thickness TK3 on the first region MER1 in the third direction D3. The first connector TAB1 may have a fourth thickness TK4 in the third direction D3. The second thickness TK2 may be greater than the first thickness TK1. The sum of the third thickness TK3 and the fourth thickness TK4 may be substantially the same as the second thickness TK2.

[0095] In the example embodiment, refer to Figure 8B Each or one of the first metal layer MEL1 and the second metal layer MEL2 may have a substantially constant thickness on the second region MER2 in the third direction D3.

[0096] For example, the first metal layer MEL1 may have a first thickness TK1 on the second region MER2 in the third direction D3. The first metal layer MEL1 may have a third thickness TK3 on the first region MER1 in the third direction D3. The first connector TAB1 may have a fourth thickness TK4 on the third direction D3. The sum of the third thickness TK3 and the fourth thickness TK4 may be substantially the same as the first thickness TK1. The first region MER1 may correspond to the embedded portion EMP of the first connector TAB1 and the second connector TAB2.

[0097] Each or one of the first terminal block TAB1 and the second terminal block TAB2 may have a length L in the first direction D1. In an example embodiment, each or one of the first terminal block TAB1 and the second terminal block TAB2 may have a length L of about 10 mm to 100 mm, or about 10 mm to about 50 mm, in the first direction D1. The length L of the first terminal block TAB1 and the second terminal block TAB2 may have substantially the same construction.

[0098] The embedded portion EMP may have a length Lx in the first direction D1. The exposed portion EXP may have a length Ly in the first direction D1. The ratio of length Lx to length Ly (Lx / Ly) may be in the range of about 0.1 to about 10. For example, the ratio (Lx / Ly) may be in the range of about 0.2 to about 8 or about 0.5 to about 2. When the ratio (Lx / Ly) is less than the above range, the embedded terminal block may have reduced holding force and may therefore separate. When the ratio (Lx / Ly) is greater than the above range, a reduction in processability may occur during the manufacture of the electrode plate.

[0099] Each or one of the first terminal block TAB1 and the second terminal block TAB2 may have a width W1 in the second direction D2. In an example embodiment, each or one of the first terminal block TAB1 and the second terminal block TAB2 may have a width W1 of about 5 mm to about 30 mm in the second direction D2.

[0100] In an exemplary embodiment of this disclosure, the width W1 may be greater than the length Ly. The ratio of width W1 to length Ly (W1 / Ly) may be equal to or greater than about 1. For example, the ratio (W1 / Ly) may be in the range of about 1 to about 10, about 1 to about 5, or about 1 to about 2. When the ratio (W1 / Ly) is less than about 1, the problem of increased resistance of the terminals may occur. Figure 9 A plan view illustrating a composite substrate according to an example embodiment of the present disclosure is shown.

[0101] Reference Figure 9 The composite substrate CPS may include two first terminals TAB1a and TAB1b embedded in the first region MER1 of the first metal layer MEL1 along the second direction D2.

[0102] In the example embodiment, the first terminals TAB1a and TAB1b can be embedded at a distance W2 spaced apart along the second direction D2. The distance W2 can be in the range of approximately 20 mm to approximately 50 mm. When the distance W2 is greater than the above range, current may concentrate, causing overheating or damage. When the distance W2 between the first terminals TAB1a and TAB1b is less than the above range, there may be a problem of reduced current transmission efficiency.

[0103] Although not shown, the composite substrate CPS may also include two second tabs TAB2 embedded along the second direction D2 in the first region MER1 of the second metal layer MEL2. The second tabs TAB2 may be embedded at the same interval as the interval W2 of the two first tabs TAB1a, TAB1b in the second direction D2.

[0104] The first connectors TAB1a and TAB1b, and the two second connectors TAB2, can each have the same characteristics as referenced. Figure 7 , Figure 8A and Figure 8B The first connector TAB1 and the second connector TAB2 discussed have the same or similar construction.

[0105] Although not shown, the composite substrate CPS may include three or more first terminals TAB1 embedded along the second direction D2. Additionally, the composite substrate CPS may also include three or more second terminals TAB2 embedded along the second direction D2. In an example embodiment, the composite substrate CPS may include four, five, six, or seven of each of the first terminals TAB1 and the second terminals TAB2.

[0106] Figure 10 A plan view illustrating a composite substrate according to an example embodiment of the present disclosure is shown.

[0107] Reference Figure 10 The composite substrate CPS may include a first terminal piece TAB1 embedded in a first region MER1 of the first metal layer MEL1.

[0108] The embedded portion EMP of the first connector TAB1 can extend in the second direction D2. The exposed portion EXP of the first connector TAB1 can extend in the second direction D2.

[0109] The first connector TAB1 may have a width W1 in the second direction D2. The embedded portion EMP and the exposed portion EXP may have the same width W1.

[0110] The width W1 of the first terminal piece TAB1 in the second direction D2 can be substantially the same as the width W3 of the first metal layer MEL1 in the second direction D2. Optionally, the ratio of width W1 to width W3 (W1 / W3) can be in the range of about 0.8 to about 1.

[0111] Figure 11 A plan view illustrating a composite substrate according to an example embodiment of the present disclosure is shown. Figure 12 The diagram shows the embedded part. Figure 11 A plan view of the first terminal piece in the composite substrate.

[0112] Reference Figure 11 and Figure 12 The composite substrate CPS may include a first terminal piece TAB1 embedded in a first region MER1 of the first metal layer MEL1.

[0113] The first connector TAB1 may include an embedded portion EMP and an exposed portion EXP. The width W1a of the embedded portion EMP in the second direction D2 may be greater than the width W1b of the exposed portion EXP in the second direction D2. The embedded portion EMP may extend in the second direction D2. The exposed portion EXP may have a shape that protrudes from the embedded portion EMP in the first direction D1. In an example embodiment, the width W1b of the exposed portion EXP in the second direction D2 may be in the range of approximately 5 mm to approximately 30 mm.

[0114] Figure 13 A plan view illustrating a composite substrate according to an example embodiment of the present disclosure is shown. Figure 14 The diagram shows the embedded part. Figure 13 A plan view of the first terminal piece in the composite substrate.

[0115] Reference Figure 13 and Figure 14 The composite substrate CPS may include a first terminal piece TAB1 embedded in a first region MER1 of the first metal layer MEL1.

[0116] The first connector TAB1 may include an embedded portion EMP and an exposed portion EXP, and the exposed portion EXP may include a first exposed portion EXP1 and a second exposed portion EXP2.

[0117] The width W1a of the embedded portion EMP in the second direction D2 can be substantially the same as the width W3 of the first metal layer MEL1 in the second direction D2. In another example, the ratio of width W1a to width W3 can be in the range of about 0.8 to about 1.

[0118] The sum of the widths W1b of the first exposed portion EXP1 and the second exposed portion EXP2 in the second direction D2 can be less than the width W1a of the embedded portion EMP in the second direction D2.

[0119] In the example embodiment, the width W1b of each of the first exposed portion EXP1 and the second exposed portion EXP2 in the second direction D2 can be in the range of about 5 mm to about 30 mm.

[0120] In an example embodiment, the distance W2 between the first exposed portion EXP1 and the second exposed portion EXP2 in the second direction D2 can be in the range of about 20 mm to about 50 mm.

[0121] Figure 15 A cross-sectional view is shown illustrating a rechargeable lithium battery according to an example embodiment of the present disclosure. Figure 16 It shows Figure 15 An enlarged view of the composite substrate.

[0122] Figure 15 The diagram illustrates a composite substrate CPS, a first battery cell CEL1 on one surface of the composite substrate CPS, and a second battery cell CEL2 on the other surface of the composite substrate CPS. A single dual-cell configuration can be achieved by... Figure 15 It consists of the first battery cell CEL1, the second battery cell CEL2, and the composite substrate CPS. Figure 15 The first battery cell CEL1, the second battery cell CEL2, and the composite substrate CPS can constitute the above reference. Figures 2 to 5 Electrode assembly 40 is discussed.

[0123] Figure 15 The first battery cell CEL1 and the second battery cell CEL2 can have the same characteristics as the reference. Figure 6 The first battery cell CEL1 and the second battery cell CEL2 discussed have the same structure.

[0124] A first metal contact MTA1 can be disposed on one end of the metal substrate MES of the first battery cell CEL1, and a second metal contact MTA2 can be disposed on one end of the metal substrate MES of the second battery cell CEL2. The first metal contact MTA1 can be configured to apply a voltage to the metal substrate MES of the first battery cell CEL1. The second metal contact MTA2 can be configured to apply a voltage to the metal substrate MES of the second battery cell CEL2.

[0125] The first metal connector MTA1 and the second metal connector MTA2 can form the above reference. Figures 2 to 5 One of the positive electrode terminal block and the negative electrode terminal block (or the positive electrode lead terminal block and the negative electrode lead terminal block) discussed.

[0126] Reference Figure 15 and Figure 16 The composite substrate CPS may include a support layer SPL, a first functional layer FCL1 disposed on the top surface of the support layer SPL, a first metal layer MEL1 disposed on the top surface of the first functional layer FCL1, a second functional layer FCL2 disposed on the bottom surface of the support layer SPL, and a second metal layer MEL2 disposed on the bottom surface of the second functional layer FCL2.

[0127] Figure 16 The support layer SPL, the first metal layer MEL1, and the second metal layer MEL2 can each have the same characteristics as the reference layer. Figure 8A and Figure 8B The support layer SPL, the first metal layer MEL1, and the second metal layer MEL2 discussed have the same structure.

[0128] Each of the first functional layer FCL1 and the second functional layer FCL2 may include a first region FCR1 embedded in a corresponding one of the first terminal block TAB1 and the second terminal block TAB2, and may also include a second region FCR2 in addition to the first region FCR1.

[0129] The first region FCR1 can correspond to the embedded portion EMP of the first connector TAB1 and the second connector TAB2.

[0130] Each or one of the first functional layer FCL1 and the second functional layer FCL2 may include an adhesive material. Because the first functional layer FCL1 and the second functional layer FCL2 include their adhesive material, the retention force of the first terminal block TAB1 and the second terminal block TAB2 embedded between the first functional layer FCL1 and the second functional layer FCL2 can be improved. There are no limitations on the type of adhesive material. For example, each or one of the first functional layer FCL1 and the second functional layer FCL2 may include an adhesive conductive polymer or an adhesive bonding agent.

[0131] In an example embodiment, each or one of the first functional layer FCL1 and the second functional layer FCL2 may include at least one of cellulose-based adhesives, rubber-based adhesives, acrylate-based adhesives, imide-based adhesives, polyvinylidene fluoride-based adhesives, polyvinylpyrrolidone-based adhesives, polyvinyl alcohol-based adhesives, nitrile-based adhesives, acetate-based adhesives, and cyano-based adhesives.

[0132] Cellulose binders may include at least one of, for example, carboxymethyl cellulose (CMC), methyl cellulose (MC), hydroxypropyl cellulose (HPC), methyl hydroxypropyl cellulose (MHPC), ethyl hydroxyethyl cellulose (EHEC), methyl ethyl hydroxyethyl cellulose (MEHEC), or cellulose gum.

[0133] Rubber adhesives may include at least one of, for example, styrene-butadiene rubber (SBR), nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), or ethylene propylene diene monomer rubber (EPDM).

[0134] Acrylic adhesives may include at least one of, for example, polyacrylic acid (PAA), polymethyl methacrylate, polyisobutyl methacrylate, polyethyl acrylate, polybutyl acrylate, or poly(2-ethylhexyl acrylate).

[0135] Polyvinylidene fluoride adhesives may include at least one of, for example, poly(vinylidene fluoride) (PVDF), poly(vinylidene fluoride-co-hexafluoropropylene), poly(vinylidene fluoride-co-trichloroethylene), poly(vinylidene fluoride-co-tetrafluoroethylene), poly(vinylidene fluoride-co-trifluoroethylene), poly(vinylidene fluoride-co-trifluorochloroethylene), poly(vinylidene fluoride-co-fluoroethylene-hexafluoropropylene), or poly(vinylidene fluoride-co-trichloroethylene).

[0136] Polyvinylpyrrolidone adhesives may include, for example, polyvinylpyrrolidone.

[0137] Polyvinyl alcohol adhesives can be, for example, polyvinyl alcohol.

[0138] Imide adhesives may include, for example, polyimides or polyamide-imides.

[0139] Nitrile adhesives may include, for example, polyacrylonitrile or acrylonitrile-styrene-butadiene copolymer.

[0140] Acetate-based adhesives may include at least one of, for example, polyvinyl acetate, polyethylene-covinyl acetate, cellulose acetate, cellulose acetate butyrate, or cellulose acetate propionate.

[0141] Cyano-based binders may include, for example, cyanoethyl sucrose.

[0142] Each or one of the first functional layer FCL1 and the second functional layer FCL2 may include a carbon material configured to increase conductivity.

[0143] In an example embodiment, each or one of the first functional layer FCL1 and the second functional layer FCL2 may include a carbon material, which includes at least one of natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, carbon nanofiber, and carbon nanotube. Each or one of the first functional layer FCL1 and the second functional layer FCL2 may further include the aforementioned binder.

[0144] In another example, each or one of the first functional layer FCL1 and the second functional layer FCL2 may include carbon material and a binder. The amount of binder in each or one of the first functional layer FCL1 and the second functional layer FCL2 may be in the range of about 30 wt% to about 70 wt%, for example, in the range of about 40 wt% to about 60 wt%.

[0145] Each or one of the first functional layer FCL1 and the second functional layer FCL2 may have a thickness of about 1 nm to about 500 nm, for example, about 10 nm to about 100 nm.

[0146] The composite substrate CPS may include at least one first terminal block TAB1 embedded between the first functional layer FCL1 and the support layer SPL. The first terminal block TAB1 may contact the first functional layer FCL1. The first terminal block TAB1 may contact the support layer SPL.

[0147] The first terminal block TAB1 can be configured to apply a voltage to the first functional layer FCL1. The first terminal block TAB1 can be configured to apply a voltage to the first metal layer MEL1 through the first functional layer FCL1.

[0148] The composite substrate CPS may include at least one second terminal block TAB2 embedded between the second functional layer FCL2 and the support layer SPL. The second terminal block TAB2 may contact the second functional layer FCL2. The second terminal block TAB2 may contact the support layer SPL.

[0149] The second terminal block TAB2 can be configured to apply voltage to the second functional layer FCL2. The second terminal block TAB2 can also be configured to apply voltage to the second metal layer MEL2 through the second functional layer FCL2.

[0150] Return to reference Figure 16 The first terminal block TAB1 and the second terminal block TAB2 can have the same characteristics as those mentioned above. Figures 6 to 8B The first connector TAB1 and the second connector TAB2 discussed have the same or similar construction.

[0151] Although not shown, but Figure 15 and Figure 16 The first terminal block TAB1 and the second terminal block TAB2 can have the same characteristics as those mentioned above. Figures 9 to 14 The construction of one of the first terminals TAB1 discussed is the same as or similar to that of the other terminals.

[0152] The composite substrate CPS according to an example embodiment of this disclosure can be prepared by the following method. First, the support layer SPL can be prepared as an organic polymer film. Electrode tabs can be disposed on the support layer SPL. For example, a first tab TAB1 can be disposed on one surface of the support layer SPL.

[0153] A vacuum deposition process or a plating process can be performed to form a metal layer on one surface of the support layer SPL where the first terminal piece TAB1 is disposed. For example, a first metal layer MEL1 can be formed on the surface of the support layer SPL where the first terminal piece TAB1 is disposed.

[0154] The second terminal block TAB2 can be placed on the other surface of the support layer SPL using the same or similar method, and a metal layer can be formed on the other surface of the support layer SPL where the second terminal block TAB2 is located. For example, a second metal layer MEL2 can be formed on the other surface of the support layer SPL where the second terminal block TAB2 is located.

[0155] Thus, the first connector TAB1 and the second connector TAB2 can be embedded between the support layer SPL and the first metal layer MEL1 and between the support layer SPL and the second metal layer MEL2, respectively.

[0156] In an example embodiment, a vacuum deposition process will be described. A support layer SPL with attached tabs can be loaded into a vacuum deposition chamber. Metal wires in a metal evaporation chamber can be melted and evaporated at a temperature of about 1,300°C to about 2,000°C. The evaporated metal can pass through a cooling system in the vacuum deposition chamber and can ultimately be deposited on the surface of the support layer SPL. In the case of a plating process, the support layer SPL can be placed in a plating solution to form a metal layer on the surface of the support layer SPL.

[0157] The composite substrate CPS according to an example embodiment of this disclosure can be prepared by the following method. First, the support layer SPL can be prepared as an organic polymer film. Electrode tabs can be fixed to the support layer SPL. The first tab TAB1 and the second tab TAB2 can be correspondingly fixed to two opposite surfaces of the support layer SPL.

[0158] In an example embodiment, a conductive adhesive can be used to secure the electrode tabs to the support layer SPL.

[0159] A paste coating method can be performed to form functional layers on a support layer SPL to which the terminal pieces are fixed. For example, a first functional layer FCL1 and a second functional layer FCL2 can be formed correspondingly on two opposite surfaces of the support layer SPL to which the terminal pieces are fixed.

[0160] In an example embodiment, a slurry containing carbon materials and a binder can be coated onto the support layer SPL and dried to form a functional layer on the surface of the support layer SPL.

[0161] Vacuum deposition or plating processes can be performed to form metal layers on the first functional layer FCL1 and the second functional layer FCL2. For example, a first metal layer MEL1 can be formed on the first functional layer FCL1, and a second metal layer MEL2 can be formed on the second functional layer FCL2.

[0162] The following description will focus on some exemplary embodiments of this disclosure. These exemplary embodiments are provided to aid in understanding this disclosure and are not intended to limit its scope.

[0163] Example 1 A polyethylene terephthalate (PET) film with a thickness of 5 μm was prepared. Figure 7 As shown, a connector with a length of 84 mm, a width of 15 mm, and a thickness of 2 μm is disposed on one surface of a PET film. The connector is configured to partially extend beyond the PET film, achieving a length ratio of 1:1 between the exposed and embedded portions of the connector. Copper plating is then performed. The same method is performed to place the connector on the other surface of the PET film, and copper plating is subsequently performed. A first metal layer and a second metal layer are each formed to have a thickness of 3 μm. Thus, a composite substrate comprising a connector partially embedded between the metal layers and the PET film is manufactured.

[0164] Example 2 The composite substrate was manufactured using the same method as in Example 1, except that a portion of the terminal block was embedded to achieve a length ratio of 10:1 between the exposed portion and the embedded portion of the terminal block.

[0165] Example 3 The composite substrate was manufactured using the same method as in Example 1, except that a portion of the terminal block was embedded to achieve a length ratio of 1:10 between the exposed portion and the embedded portion of the terminal block.

[0166] Example 4 The composite substrate was manufactured using the same method as in Example 1, except that a portion of the terminal block was embedded to achieve a length ratio of 2:1 between the exposed portion and the embedded portion of the terminal block.

[0167] Example 5 The composite substrate was manufactured using the same method as in Example 1, except that a portion of the terminal block was embedded to achieve a length ratio of 1:2 between the exposed portion and the embedded portion of the terminal block.

[0168] Example 6 A polyethylene terephthalate (PET) film with a thickness of 5 μm was prepared. Figure 7 As shown, a FET film has a tab with a length of 84 mm, a width of 15 mm, and a thickness of 2 μm disposed on one surface of it. The tab is configured to allow partial extension beyond the PET film, such that the length ratio between the exposed portion and the embedded portion of the tab is 1:1. 2.5 wt% of conductive material or double-walled carbon nanotubes (average length: 50 μm, average diameter: 1 nm to 1 μm, specific surface area: 250 m²) are used. 2 / g to 300m 2 Hydrogenated nitrile butadiene rubber (HNBR) of 0.3 wt% was added to 97.2 wt% N-methylpyrrolidone (NMP) solvent and dispersed for 12 hours to prepare a 2.8 wt% adhesive slurry. The prepared adhesive slurry was coated onto the surface of a PET film containing the connecting tabs and dried to form a first functional layer. The same method was performed to place the connecting tabs on another surface of the PET film, and then a second functional layer was formed. Each of the first and second functional layers was formed to have a thickness of approximately 300 nm. Subsequently, copper plating was performed on the top surface of each of the first and second functional layers to form a first metal layer on the first functional layer and a second metal layer on the second functional layer. Each of the first and second metal layers was formed to have a thickness of approximately 3 μm. Thus, a composite substrate comprising connecting tabs partially embedded between the functional layers and the PET film was manufactured.

[0169] Comparison Example 1 A polyethylene terephthalate (PET) film with a thickness of 5 μm was prepared. A copper plating process was performed on both opposite surfaces of the PET film to create a composite substrate. A first metal layer of uniform thickness was formed on the top surface of the PET film, and a second metal layer of uniform thickness was formed on the bottom surface of the PET film. Each of the first and second metal layers was formed to have a thickness of 1 μm. Subsequently, a connector identical to the connector used in Example 1 was soldered to the end of each of the first and second metal layers. For example, the connector was not embedded but soldered to the top surface of each of the first and second metal layers.

[0170] Comparison Example 2 The composite substrate was manufactured using the same method as in Example 1, except that the length ratio between the exposed portion and the embedded portion of the terminal block was achieved to be 11:1.

[0171] The properties of the embodiments and comparative examples are summarized and listed in Table 1.

[0172] [Table 1]

[0173] After manufacturing cells with composite substrates including Examples 1 to 6 and Comparative Examples 1 to 2, the battery DC-IR and discharge efficiency according to the battery's C-rate were measured.

[0174] 1) 0.2C discharge efficiency Charge the battery at a constant current of 0.2C until the battery voltage reaches 4.2V. Then measure the amount of charge. Discharge the battery at a constant current of 0.2C until the battery voltage reaches 2.0V. Then measure the amount of discharge. Calculate the discharge efficiency (%) by dividing the measured amount of discharge by the amount of charge, and the values ​​are shown in Table 2.

[0175] 2) 1.0C discharge efficiency Charge the battery at a constant current of 1.0C until the battery voltage reaches 4.2V. Then measure the charge amount. Discharge the battery at a constant current of 1.0C until the battery voltage reaches 2.0V. Then measure the discharge amount. Calculate the discharge efficiency (%) by dividing the measured discharge amount by the charge amount, and the values ​​are shown in Table 2.

[0176] 3) 2.0C discharge efficiency Charge the battery at a constant current of 2.0C until the battery voltage reaches 4.2V. Then measure the charge amount. Discharge the battery at a constant current of 2.0C until the battery voltage reaches 2.0V. Then measure the discharge amount. Calculate the discharge efficiency (%) by dividing the measured discharge amount by the charge amount, and the values ​​are shown in Table 2.

[0177] 4) Measure the DC internal resistance (battery DC-IR) The voltage drop (V) was measured while current flowed at 1C for 1 second at SOC50 (charged to 50% of the charge capacity (relative to 50% of the discharge capacity of a 100% fully charged battery)). The DC internal resistance (DC-IR) was calculated from the results and is listed in Table 2.

[0178] Evaluation: Connector joint strength The clamp holds the terminals of the composite substrate according to the embodiments and comparative examples, and then measures the maximum shear stress when the terminals separate or break. The maximum shear stress is defined as the terminal joint strength, and the terminal joint strengths are listed in Table 2.

[0179] [Table 2]

[0180] Referring to Table 2, it can be observed that when the terminal block is embedded between the metal layer and the support layer without being soldered to the metal layer, the desired or improved discharge efficiency at each rate and the reduced DC-IR are achieved to improve battery performance (see Example 1 and Comparative Example 1). For example, referring to Examples 1 and 5, it can be observed that when the length ratio of the embedded portion to the exposed portion of the terminal block is 1 to 2, the discharge efficiency and DC-IR are significantly improved, and the terminal block bonding strength is significantly increased, exceeding 1.8 kgf or greater. Additionally, it can be observed that when the length ratio of the embedded portion to the exposed portion of the terminal block is greater than 2, the internal resistance slightly increases and the discharge efficiency decreases, and the most desired or improved battery performance is achieved in Examples 1 and 5, where the length ratio of the embedded portion to the exposed portion of the terminal block is 1 to 2 (see Examples 1, 3, and 5). Furthermore, referring to Table 2, it can be observed that in the composite substrate of Comparative Example 2, where the length ratio of the embedded portion to the exposed portion of the terminal block is less than 0.1, the embedded terminal block has a significantly reduced bonding strength. In this case, it can be determined that the battery performance is significantly reduced.

[0181] In the composite substrate according to this disclosure, terminals can be embedded to achieve reduced contact resistance. Rechargeable lithium batteries incorporating the composite substrate of this disclosure can have desired or improved battery performance.

[0182] Although some exemplary embodiments of the present disclosure have been discussed with reference to the accompanying drawings, it will be understood that various changes in form and detail may be made therein without departing from the spirit and scope of the present disclosure. It will be apparent to those skilled in the art that various substitutions, modifications, and alterations may be made therein without departing from the scope and spirit of the present disclosure.

Claims

1. A composite substrate for a rechargeable lithium battery, the composite substrate comprising: Support layer; A first metal layer is on the first surface of the support layer; A second metal layer is disposed on the second surface of the support layer; as well as At least one terminal block is embedded between the support layer and at least one of the first metal layer and the second metal layer. The at least one connector includes an embedded portion and an exposed portion.

2. The composite substrate according to claim 1, wherein, The ratio of the length of the embedded portion in the first direction to the length of the exposed portion in the first direction is in the range of 0.1 to 10.

3. The composite substrate according to claim 1, wherein, The thickness of the at least one terminal piece is in the range of 1 μm to 5 μm.

4. The composite substrate according to claim 1, wherein, The support layer includes at least one of polyethylene terephthalate film, polyimide film, polyethylene film, polypropylene film, polyvinylidene chloride film, polystyrene film, polyethylene naphthalate film, polytetrafluoroethylene film, polycarbonate film, polyamide film, and multiple films including combinations thereof.

5. The composite substrate according to claim 1, wherein, At least one of the first metal layer and the second metal layer includes at least one of aluminum, aluminum alloy, copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, iron, iron alloy, silver, and silver alloy.

6. The composite substrate according to claim 1, wherein, The thickness of at least one of the first metal layer and the second metal layer is in the range of 200 nm or more and 5 μm or less.

7. The composite substrate according to claim 1, wherein, The thickness of the support layer is in the range of 3 μm to 10 μm.

8. The composite substrate according to claim 1, wherein: The at least one terminal block includes at least two terminal blocks parallel to the second direction, and The spacing between the at least two terminals is in the range of 20mm to 50mm.

9. A composite substrate for a rechargeable lithium battery, the composite substrate comprising: Support layer; A first functional layer is located on the first surface of the support layer; A first metal layer is disposed on the surface of the first functional layer; A second functional layer is located on the second surface of the support layer; A second metal layer is disposed on the surface of the second functional layer; as well as At least one terminal block is embedded between the support layer and at least one of the first functional layer and the second functional layer. The at least one connector includes an embedded portion and an exposed portion.

10. The composite substrate according to claim 9, wherein, The ratio of the length of the embedded portion in the first direction to the length of the exposed portion in the first direction is in the range of 0.1 to 10.

11. The composite substrate according to claim 9, wherein: The at least one terminal block includes at least two terminal blocks parallel to the second direction, and The spacing between the at least two terminals is in the range of 20mm to 50mm.

12. The composite substrate according to claim 9, wherein: The support layer includes at least one of polyethylene terephthalate film, polyimide film, polyethylene film, polypropylene film, polyvinylidene chloride film, polystyrene film, polyethylene naphthalate film, polytetrafluoroethylene film, polycarbonate film, polyamide film, and multiple films including combinations thereof. At least one of the first metal layer and the second metal layer includes at least one of aluminum, aluminum alloy, copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, iron, iron alloy, silver, and silver alloy.

13. The composite substrate according to claim 9, wherein, At least one of the first functional layer and the second functional layer includes at least one of cellulose-based adhesives, rubber-based adhesives, acrylate-based adhesives, imide-based adhesives, polyvinylidene fluoride-based adhesives, polyvinylpyrrolidone-based adhesives, polyvinyl alcohol-based adhesives, nitrile-based adhesives, acetate-based adhesives, and cyano-based adhesives.

14. The composite substrate according to claim 9, wherein, At least one of the first functional layer and the second functional layer includes a carbon material, which includes at least one of natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, carbon nanofiber, and carbon nanotube.

15. A rechargeable lithium battery, said rechargeable lithium battery comprising: A composite substrate, comprising a support layer and a metal layer on the support layer; Battery cells are located on the metal layer; as well as At least one terminal block is located between the metal layer and the support layer.

16. The rechargeable lithium battery according to claim 15, further comprising a functional layer between the metal layer and the support layer. in, The at least one terminal block is located between the functional layer and the support layer.

17. The rechargeable lithium battery according to claim 16, wherein, The functional layer includes at least one of cellulose-based adhesives, rubber-based adhesives, acrylate-based adhesives, imide-based adhesives, polyvinylidene fluoride-based adhesives, polyvinylpyrrolidone-based adhesives, polyvinyl alcohol-based adhesives, nitrile-based adhesives, acetate-based adhesives, and cyano-based adhesives.

18. The rechargeable lithium battery according to claim 16, wherein, The functional layer includes at least one of natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, carbon nanofiber, and carbon nanotube.

19. The rechargeable lithium battery according to claim 15, wherein, The battery cell includes: A first active material layer is disposed on the metal layer; A diaphragm is formed on the first active material layer; A second active material layer is disposed on the diaphragm; and A metal substrate is placed on the second active material layer.

20. The rechargeable lithium battery according to claim 15, wherein: The supporting layer is at least one of polyethylene terephthalate film, polyimide film, polyethylene film, polypropylene film, polyvinylidene chloride film, polystyrene film, polyethylene naphthalate film, polytetrafluoroethylene film, polycarbonate film, polyamide film, and multiple films including combinations thereof. The metal layer includes at least one of aluminum, aluminum alloy, copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, iron, iron alloy, silver, and silver alloy.

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