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

Abstract

Disclosed are a composite substrate for a rechargeable lithium battery and a rechargeable lithium battery including the same, the composite substrate comprising: a support layer having a first surface and a second surface facing away from each other; a first metal layer on the first surface; and a second metal layer on the second surface. The support layer includes: a plurality of first through portions penetrating the first surface and spaced apart from each other along the first direction; and a plurality of second through portions penetrating the second surface and spaced apart from each other along the first direction. The plurality of first through portions and the plurality of second through portions are alternately disposed along a first direction, and the first direction is substantially parallel to the first surface.

Description

[0001] This application claims priority to Korean Patent Application No. 10-2024-0124646, filed on September 12, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This disclosure relates herein to a composite substrate for a rechargeable lithium battery and a rechargeable lithium battery including the composite substrate. Background Technology

[0003] With the increasing prevalence of battery-powered electronic devices (such as mobile phones, laptops, and electric vehicles), the demand for rechargeable batteries with high energy density and high capacity has increased. Therefore, improving the performance of rechargeable lithium batteries may be advantageous.

[0004] A rechargeable lithium battery includes a positive electrode, a negative electrode, and an electrolyte solution. Both the positive and negative electrodes contain active materials capable of inserting and deintercalating lithium ions. When lithium ions are inserted into or deintercalated from the positive and negative electrodes, electrical energy is generated through oxidation and reduction reactions. Summary of the Invention

[0005] Examples of this disclosure include composite substrates with improved tensile strength.

[0006] Examples disclosed herein also include rechargeable lithium batteries incorporating the composite substrate.

[0007] Example embodiments of this disclosure include a composite substrate for a rechargeable lithium battery, the composite substrate comprising: a support layer having a first surface and a second surface facing away from each other; a first metal layer disposed on the first surface; and a second metal layer disposed on the second surface. The support layer includes: a plurality of first through-portions penetrating the first surface and spaced apart from each other along a first direction; and a plurality of second through-portions penetrating the second surface and spaced apart from each other along the first direction. The plurality of first through-portions and the plurality of second through-portions are alternately disposed along the first direction, and the first direction is substantially parallel to the first surface.

[0008] In an exemplary embodiment of this disclosure, a rechargeable lithium battery includes: a composite substrate; and a battery cell. The composite substrate includes: a support layer having a first surface and a second surface facing away from each other; a first metal layer disposed on the first surface; and a second metal layer disposed on the second surface. The support layer includes: a plurality of first through-portions penetrating the first surface and spaced apart from each other along a first direction; and a plurality of second through-portions penetrating the second surface and spaced apart from each other along the first direction. The plurality of first through-portions and the plurality of second through-portions are alternately arranged along the first direction, and the first direction is substantially parallel to the first surface. Attached Figure Description

[0009] The accompanying drawings, which are incorporated in and constitute a part of this specification, are included to provide a further understanding of this disclosure. The drawings illustrate exemplary embodiments of the present disclosure and, together with the specification, are configured to help explain the principles of the disclosure. In the drawings: Figure 1 This is a simplified conceptual diagram illustrating a rechargeable lithium battery according to an example embodiment of the present disclosure; Figures 2 to 5 Each of these is a schematic diagram illustrating a rechargeable lithium battery according to an example embodiment; Figure 6 This is a cross-sectional view showing a rechargeable lithium battery including a composite substrate according to an exemplary embodiment of the present disclosure; Figure 7 yes Figure 6 A plan view of the composite substrate; Figure 8 It is based on Figure 7 A sectional view of line A-A'; Figure 9 yes Figure 8 A magnified view of region M; Figure 10 This is a plan view of a composite substrate according to an exemplary embodiment of the present disclosure; Figure 11 It is according to the exemplary embodiments of this disclosure along Figure 7 A cross-sectional view of the composite substrate taken along line A-A'; Figure 12 It is according to the exemplary embodiments of this disclosure along Figure 7 A cross-sectional view of the composite substrate taken along line A-A'; and Figure 13 It is according to the exemplary embodiments of this disclosure along Figure 7 A cross-sectional view of the composite substrate taken along line A-A'. Detailed Implementation

[0010] To fully understand the structure and effects of this disclosure, exemplary embodiments of the disclosure are described in more detail below with reference to the accompanying drawings. However, this disclosure can be implemented in various forms and should not be construed as limited to the exemplary embodiments set forth herein, and various changes and modifications can be made. Rather, these exemplary embodiments are provided so that this disclosure is thorough and complete, and fully conveys the scope of this disclosure to those skilled in the art to which this disclosure pertains.

[0011] In this specification, it is 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 the components may be exaggerated for the purpose of effectively explaining the technical content. Throughout the specification, the same reference numerals or symbols denote the same elements.

[0012] Unless the context clearly indicates otherwise, the singular form is intended to include the plural form as well. Furthermore, unless otherwise specifically stated, the phrase "A or B" can mean "including A but not B," "including B but not A," or "including both A and B." The term "including / contains" and / or variations thereof as used in this specification do not exclude the presence or addition of one or more other components.

[0013] In this specification, “combinations thereof” can refer to mixtures, stacks, complexes, copolymers, alloys, blends and reaction products of the components.

[0014] Unless otherwise defined in this specification, particle size may refer to average particle size. Furthermore, particle size refers to average particle size (D50), which is the diameter of particles that constitute approximately 50% of the total volume in a particle size distribution. Average particle size (D50) can be measured by methods widely known to those skilled in the art, for example, by a particle size analyzer, or also using transmission electron microscopy (TEM) images or scanning electron microscopy (SEM) images. Optionally, average particle size can be measured using a dynamic light scattering measuring device, wherein the number of particles in each particle size range is counted by performing data analysis, and the average particle size (D50) value can then be calculated from it. Additionally, average particle size can be measured using laser diffraction. When measured by laser diffraction, for example, after dispersing the particles to be measured in a dispersion medium, the dispersion medium is introduced into a commercially available laser diffraction particle size analyzer (e.g., Microtrac MT 3000) and irradiated with ultrasound at an output of about 60W at about 28kHz, and then the average particle size (D50) based on about 50% of the particle size distribution in the analyzer can be calculated.

[0015] When the terms “about” or “substantially” are used in conjunction with numerical values ​​in this specification, it is intended that the relevant numerical value include 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%.

[0016] Figure 1 This is a simplified conceptual diagram illustrating a rechargeable lithium battery according to an example embodiment of the present disclosure. (Refer to...) Figure 1 A rechargeable lithium battery may include a positive electrode 10, a negative electrode 20, a separator 30, and an electrolyte solution ELL.

[0017] The positive electrode 10 and the negative electrode 20 may be spaced apart from each other, with a diaphragm 30 located between them. The diaphragm 30 may be disposed between the positive electrode 10 and the negative electrode 20. The positive electrode 10, the negative electrode 20, and the diaphragm 30 may be in contact with the electrolyte solution ELL. The positive electrode 10, the negative electrode 20, and the diaphragm 30 may be immersed in the electrolyte solution ELL.

[0018] The electrolyte solution ELL may be or include a medium for transporting lithium ions between the positive electrode 10 and the negative electrode 20. In the electrolyte solution ELL, lithium ions can move toward the positive electrode 10 or the negative electrode 20 through the membrane 30.

[0019] 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 may also include a binder and / or a conductive material (e.g., an electrically conductive material).

[0020] For example, the positive electrode 10 may also include additives that can be configured as a sacrificial positive electrode.

[0021] Based on a 100 wt% positive electrode active material layer AML1, the amount of positive electrode active material in the positive electrode active material layer AML1 can range from about 90 wt% to about 99 wt%. Based on a 100 wt% positive electrode active material layer AML1, the amounts of binder and conductive material can each range from about 0.5 wt% to about 5 wt%.

[0022] The binder is configured to adhere the positive electrode active material particles to each other and also to the positive electrode active material to the current collector COL1. As a non-limiting example, examples of the binder may include at least one of polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, polymers including ethylene oxide, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, epoxy resin, (meth)acrylate resin, polyester resin, and nylon.

[0023] Conductive materials may be included to impart conductivity (e.g., electrical conductivity) to the electrodes. The battery may include any material that does not cause chemical changes (e.g., does not cause undesirable chemical changes in a rechargeable lithium battery) and conducts electrons. Examples of conductive materials may include: carbon-based materials, such as at least one of natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fibers, carbon nanofibers, and carbon nanotubes; metallic materials, including at least one of copper, nickel, aluminum, silver, etc., in the form of metal powder or metal fibers; conductive polymers, such as polyphenylene derivatives; or mixtures thereof.

[0024] Al can be included as the current collector COL1, but the material is not limited to this.

[0025] Positive electrode active material The positive electrode active material in the positive electrode active material layer AML1 may include compounds capable of reversibly inserting and deintercalating lithium (lithiation intercalation compounds). For example, it may include at least one of a composite oxide of lithium and a metal (such as or including at least one of cobalt, manganese, nickel and combinations thereof).

[0026] The composite oxide can be or includes lithium transition metal composite oxides. Examples of composite oxides may include at least one of lithium nickel oxides, lithium cobalt oxides, lithium manganese oxides, lithium iron phosphate compounds, cobalt-free lithium nickel manganese oxides, and combinations thereof.

[0027] As an example, it may include the following compounds represented by any of the following chemical formulas. Li a A 1-b X b O 2-c D c (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 (0.90≤a≤1.8, 0≤b≤0.5 and 0≤c≤0.05); Li a Ni 1-b-c Co b X c O 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5 and 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 and 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 and 0≤e≤0.1); Li a NiG b O2 (0.90≤a≤1.8 and 0.001≤b≤0.1); Li a CoG b O2 (0.90≤a≤1.8 and 0.001≤b≤0.1); Li a Mn 1-b G b O2 (0.90≤a≤1.8 and 0.001≤b≤0.1); Li a Mn2G b O4 (0.90≤a≤1.8 and 0.001≤b≤0.1); Li a Mn 1-g G g PO4 (0.90≤a≤1.8 and 0≤g≤0.5); Li (3-f) Fe2(PO4)3 (0≤f≤2); and Li a FePO4 (0.90≤a≤1.8).

[0028] In the above chemical formula, A is or includes at least one of Ni, Co, Mn, and combinations thereof; X is or includes at least one of Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, rare earth elements, and combinations thereof; D is or includes at least one of O, F, S, P, and combinations thereof; G is or includes at least one of Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, and combinations thereof; and L 1 It is or includes at least one of Mn, Al and combinations thereof.

[0029] The positive electrode active material can be, or includes, for example, a high-nickel positive electrode active material, based on 100 mol% of metals other than lithium in a lithium transition metal complex oxide. The nickel content of the high-nickel positive electrode active material is greater than or equal to about 80 mol%, greater than or equal to about 85 mol%, greater than or equal to about 90 mol%, greater than or equal to about 91 mol%, or greater than or equal to about 94 mol% and less than or equal to about 99 mol%. High-nickel positive electrode active materials can achieve high capacity and can be applied to high-capacity, high-density rechargeable lithium batteries.

[0030] 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 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 (e.g., an electrically conductive material).

[0031] For example, the negative electrode active material layer AML2 may include about 90 wt% to about 99.5 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.

[0032] The binder can be configured to adhere the negative electrode active material particles to each other and to adhere the negative electrode active material to the current collector COL2. The binder may include at least one of non-aqueous binders, aqueous binders, dry binders, and combinations thereof.

[0033] 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, and combinations thereof.

[0034] The waterborne adhesive may be or include at least one of the following: styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, (meth)acrylonitrile-butadiene rubber, (meth)acrylic rubber, butyl rubber, fluororubber, polyethylene oxide, polyvinylpyrrolidone, polyepoxygenated alcohol, 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.

[0035] When an aqueous binder is included as the negative electrode binder, a cellulose compound capable of imparting viscosity may also be included. The cellulose compound may include at least one of carboxymethyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, and their alkali metal salts. The alkali metal may include at least one of Na, K, and Li.

[0036] Dry adhesives can be fibrous polymeric materials. For example, dry adhesives can be or include at least one of polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polyethylene oxide, and combinations thereof.

[0037] It may include a conductive material to impart conductivity (e.g., electrical conductivity) to the electrode. Any material that does not cause a chemical change (e.g., does not cause an undesired chemical change in a rechargeable lithium battery) and conducts electrons may be included in the battery. Non-limiting examples of 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; metallic materials, including at least one of copper, nickel, aluminum, silver, etc., in the form of metal powder or metal fiber; conductive polymers, such as polyphenylene derivatives; or mixtures thereof.

[0038] 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, and combinations thereof.

[0039] 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 reversibly intercalates / deintercalates lithium ions, lithium metal, a lithium metal alloy, a material capable of doping / dedoping lithium, and a transition metal oxide.

[0040] The material that reversibly intercalates / deintercalates lithium ions may include carbonaceous negative electrode active materials, such as crystalline carbon, amorphous carbon, or a combination thereof as an example. The crystalline carbon may be or include graphite, such as natural graphite or artificial graphite in an amorphous shape, sheet shape, flake shape, spherical shape, or fibrous shape. The amorphous carbon may be or include at least one of soft carbon, hard carbon, mesophase pitch carbonized product, calcined coke, etc.

[0041] The lithium metal alloy includes an alloy of lithium and a metal (such as or including at least one of Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Ra, Ge, Al, and Sn).

[0042] The material capable of doping / dedoping lithium may be or include a Si-based negative electrode active material or a Sn-based negative electrode active material. The Si-based negative electrode active material may include silicon, a silicon-carbon composite, SiO x (0 < x ≤ 2), a Si-Q alloy (where Q is or includes at least one of an alkali metal, an alkaline earth metal, a Group 13 element, a Group 14 element (excluding Si), a Group 15 element, a Group 16 element, a transition metal, a rare earth element, and combinations thereof), and combinations thereof. The Sn-based negative electrode active material may include at least one of Sn, SnO2, Sn-based alloys, and combinations thereof.

[0043] Silicon-carbon composites can be or include composites of silicon and amorphous carbon. According to example embodiments, the silicon-carbon composite can be in the form of silicon particles having amorphous carbon coated on the surface of the silicon particles. For example, the silicon-carbon composite can include secondary particles (cores) formed by the aggregation of primary silicon particles and an amorphous carbon coating (shell) on the surface of the secondary particles. Amorphous carbon can also be located between the primary silicon particles, and, for example, the primary silicon particles can be coated with amorphous carbon. The secondary particles can be dispersed within an amorphous carbon matrix.

[0044] Silicon-carbon composites may also include crystalline carbon. For example, a silicon-carbon composite may include a core comprising crystalline carbon and silicon particles, and an amorphous carbon coating layer on the surface of the core.

[0045] Si-type or Sn-type negative electrode active materials can be combined with carbon-type negative electrode active materials.

[0046] 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 at least one of polyethylene, polypropylene, polyvinylidene fluoride, multilayer membranes of two or more layers thereof, and mixed multilayer membranes (such as polyethylene / polypropylene bilayer membranes, polyethylene / polypropylene / polyethylene trilayer membranes, polypropylene / polypropylene / polypropylene trilayer membranes, etc.).

[0047] The diaphragm 30 may include a porous substrate and a coating layer on one or both surfaces of the porous substrate, comprising organic materials, inorganic materials or combinations thereof.

[0048] The porous substrate may be or include a polymer membrane formed or comprising at least one of the following polymers or a copolymer or mixture of two or more of these polymers, or comprising at least one of the following polymers or a copolymer or mixture of two or more of these polymers, said polymers being: polyolefins (such as polyethylene and polypropylene), polyesters (such as polyethylene terephthalate and polybutylene terephthalate), polyacetal, polyamide, polyimide, polycarbonate, polyetherketone, polyaryletherketone, polyetherimide, polyamideimide, polybenzimidazole, polyethersulfone, polyphenylene ether, cyclic olefin copolymers, polyphenylene sulfide, polyethylene naphthalate, glass fiber, Teflon, and polytetrafluoroethylene.

[0049] Organic materials may include polymers such as polyvinylidene fluoride or (meth)acrylic acid polymers.

[0050] Inorganic materials may include inorganic particles, such as or including at least one of Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, SrTiO3, BaTiO3, Mg(OH)2, boehmite and combinations thereof, but are not limited thereto.

[0051] Organic and inorganic materials can be mixed in a coating layer, or a coating layer containing organic materials and a coating layer containing inorganic materials can be stacked together.

[0052] Electrolyte solution ELL Electrolyte solutions (ELLs) used in rechargeable lithium batteries may include non-aqueous organic solvents and lithium salts.

[0053] Non-aqueous organic solvents can be constructed as media for transporting ions that participate in the electrochemical reactions of a battery.

[0054] Non-aqueous organic solvents may be or include at least one of carbonate solvents, ester solvents, ether solvents, ketone solvents, alcohol solvents, aprotic solvents, and combinations thereof.

[0055] 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), and butyl carbonate (BC).

[0056] Ester solvents may include at least one of the following: methyl acetate, ethyl acetate, n-propyl acetate, dimethyl acetate, methyl propionate, ethyl propionate, decanoic acid lactone, mevalonate lactone, caprolactone, etc.

[0057] Ether solvents may include at least one of dibutyl ether, tetraethylene glycol dimethyl ether, diethylene glycol dimethyl ether, dimethoxyethane, 2-methyltetrahydrofuran, 2,5-dimethyltetrahydrofuran, tetrahydrofuran, etc. Additionally, ketone solvents may include cyclohexanone, etc. Alcohol solvents may include at least one of ethanol, isopropanol, etc., and aprotic solvents may include: nitriles, such as R-CN (wherein R is a C2 to C20 straight-chain, branched, or cyclic hydrocarbon group, and includes double bonds, aromatic rings, or ether bonds, etc.); amides, such as dimethylformamide; dioxolane, such as 1,3-dioxolane, 1,4-dioxolane, etc.; sulfolane, etc.

[0058] Non-aqueous organic solvents may be included alone or in combination of two or more.

[0059] For example, when using carbonate solvents, cyclic carbonates and chain carbonates can be mixed and included, and the cyclic carbonates and chain carbonates can be mixed in a volume ratio ranging from about 1:1 to about 1:9.

[0060] Lithium salts dissolved in organic solvents are configured to supply lithium ions in batteries to enable basic operation of rechargeable lithium batteries and improve lithium ion transport between the positive and negative electrodes. Examples of lithium salts may include LiPF6, LiBF4, LiSbF6, LiAsF6, LiClO4, LiAlO2, LiAlCl4, LiPO2F2, LiCl, LiI, LiN(SO3C2F5)2, Li(FSO2)2N (lithium bis(fluorosulfonyl)imide, LiFSI), LiC4F9SO3, LiN(C x F 2x+1 SO2)(C y F 2y+1 At least one of the following: (SO2) (where x and y are integers from 1 to 20), lithium trifluoromethanesulfonate, lithium tetrafluoroethanesulfonate, lithium difluorobis(oxalate)phosphate (LiDFBOP), and lithium bis(oxalate)borate (LiBOB).

[0061] Rechargeable lithium batteries Rechargeable lithium batteries can be classified according to their shape into cylindrical batteries, prismatic batteries, pouch batteries, coin-shaped batteries, etc. Figures 2 to 5 This is a schematic diagram illustrating a rechargeable lithium battery according to an embodiment. Figure 2 A cylindrical battery is shown. Figure 3 A prismatic battery is shown, and 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 and a housing 50. The electrode assembly 40 includes a separator 30 between a positive electrode 10 and a negative electrode 20, and the electrode assembly 40 is housed within the housing 50. The positive electrode 10, the negative electrode 20, and the separator 30 may be impregnated with an electrolyte solution (not shown). Figure 2 As shown, the rechargeable lithium battery 100 may include a sealing member 60 of the sealed housing 50. Figure 3 In this context, 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. For example... Figure 4 and Figure 5 As shown, the rechargeable lithium battery 100 may include Figure 5 The electrode terminal 70 shown, or for example Figure 4The positive electrode terminal 71 and negative electrode terminal 72 shown herein form an electrical path for guiding the current formed in the electrode assembly 40 to the outside.

[0062] Figure 6 This is a cross-sectional view illustrating a rechargeable lithium battery including a composite substrate according to an exemplary embodiment of the present disclosure. Figure 7 yes Figure 6 A plan view of the composite substrate. Figure 8 It is based on Figure 7 A sectional view of line A-A'. Figure 9 yes Figure 8 A magnified view of region M. For simplicity, details regarding the reference area are omitted. Figures 1 to 5 The description of the rechargeable lithium battery is a repetitive description.

[0063] Reference Figure 6 It can be configured with 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. Figure 6 The first battery cell CEL1, the second battery cell CEL2, and the composite substrate CPS can form a dual-cell battery. Figure 6 The first battery cell CEL1, the second battery cell CEL2, and the composite substrate CPS can form the above-mentioned reference. Figures 3 to 5 The electrode assembly 40 is described.

[0064] Both 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 second active material layer ACT2 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, with the separator 30 located between them. The metal substrate MES may be disposed on the first active material layer ACT1.

[0065] The first active substance layer ACT1 can be referenced above. Figure 1 The described active material layer is either AML1 (positive electrode) or AML2 (negative electrode). The second active material layer ACT2 can be any one of the above-described active material layers. Figure 1 The first active material layer ACT1 and the second active material layer AML2 are described. According to an exemplary embodiment of this disclosure, the first active material layer ACT1 may be the positive electrode active material layer AML1, and the second active material layer ACT2 may be the negative electrode active material layer AML2. The metal substrate MES may be or correspond to the above-described MES. Figure 1 The described current collectors are COL1 or COL2.

[0066] The composite substrate CPS may include a support layer SPL and a first metal layer MEL1 and a second metal layer MEL2 respectively disposed on a first surface 1a and a second surface 2a opposite to each other of the support layer SPL. Based on 100 wt% of the composite substrate, the content of the support layer SPL in the composite substrate CPS may be in the range of about 20 wt% to about 30 wt%.

[0067] The first metal layer MEL1 of the composite substrate CPS can contact the second active material layer ACT2 of the first battery cell CEL1. The second metal layer MEL2 of the composite substrate CPS can contact the second active material layer ACT2 of the second battery cell CEL2. The first metal layer MEL1 and the second metal layer MEL2 of the composite substrate CPS can respectively correspond to the above reference. Figure 1 The current collectors COL1 and COL2 are described.

[0068] The support layer SPL may comprise a polymer membrane. For example, the support layer SPL may have a thickness ranging from about 3 μm to about 10 μm. The support layer SPL may comprise at least one of, for example, polyethylene membranes, polypropylene membranes, polyvinylidene chloride membranes, and combinations thereof, multilayer membranes. The support layer SPL may have desired or improved ion permeability and desired or improved mechanical strength.

[0069] The first metal layer MEL1 and the second metal layer MEL2 may each include at least one of aluminum, aluminum alloy, copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, iron, iron alloy, silver, and silver alloy.

[0070] According to exemplary embodiments of this disclosure, the thicknesses of both the first metal layer MEL1 and the second metal layer MEL2 can be greater than 0 μm and about 5 μm or less. For example, both the first metal layer MEL1 and the second metal layer MEL2 can have a thickness in the range of about 200 nm to about 5 μm. The support layer SPL can have a thickness in the range of about 2 μm to about 10 μm. The thickness of the support layer SPL can be greater than the thickness of each or at least one of the first metal layer MEL1 and the second metal layer MEL2.

[0071] The composite substrate CPS may include a first end ENP1 at one end. The metal substrate MEL of the first battery cell CEL1 may include a second end ENP2 at one end. The metal substrate MES of the second battery cell CEL2 may include a third end ENP3 at one end.

[0072] A first connector TAB1 can be disposed at a first end ENP1 of the composite substrate CPS. The first connector TAB1 may include a first connecting portion UPP1, a second connecting portion UPP2, and an extension portion EXP. The first connecting portion UPP1 can contact the first metal layer MEL1 of the composite substrate CPS. The second connecting portion UPP2 can contact the second metal layer MEL2 of the composite substrate CPS. The extension portion EXP can connect the first connecting portion UPP1 and the second connecting portion UPP2 to each other. The extension portion EXP can extend substantially horizontally from the first end ENP1 toward a first direction D1.

[0073] The first metal layer MEL1 and the second metal layer MEL2 can be electrically connected to each other via the first terminal block TAB1. The first terminal block TAB1 can be configured to apply a common voltage to the first metal layer MEL1 and the second metal layer MEL2.

[0074] The second connector TAB2 can be disposed at the second end ENP2 of the metal substrate MES of the first battery cell CEL1. The second connector TAB2 can be configured to apply voltage to the metal substrate MES of the first battery cell CEL1. The third connector TAB3 can be disposed at the third end ENP3 of the metal substrate MES of the second battery cell CEL2. The third connector TAB3 can be configured to apply voltage to the metal substrate MES of the second battery cell CEL2.

[0075] The first connector TAB1 can form the above reference. Figures 2 to 4 The positive electrode connector (or positive electrode lead connector) and the negative electrode connector (or negative electrode lead connector) described herein. The second connector TAB2 and the third connector TAB3 can constitute the above-mentioned reference. Figures 2 to 4 The other of the positive electrode terminal block (or positive electrode lead terminal block) and negative electrode terminal block (or negative electrode lead terminal block) described.

[0076] Reference Figure 7 and Figure 8 The support layer SPL may include a plurality of first through portions PWP1 that penetrate the first surface 1a and are spaced apart from each other along a first direction D1. Each or at least one of the plurality of first through portions PWP1 may have a generally strip-shaped shape extending in a third direction D3. The third direction D3 may be a direction that is substantially parallel to the first surface 1a and intersects the first direction D1.

[0077] The support layer SPL may include a plurality of second through portions PWP2 that penetrate the second surface 2a and are spaced apart from each other along a first direction D1. Each or at least one of the plurality of second through portions PWP2 may have a generally strip-shaped form extending in a third direction D3. Unlike those shown in the figures, each or at least one of the plurality of first through portions PWP1 and the plurality of second through portions PWP2 may have various shapes, such as a conical shape, a square shape, etc.

[0078] Multiple first through portions PWP1 and multiple second through portions PWP2 may be alternately arranged along a first direction D1 that is substantially parallel to the first surface 1a.

[0079] The lowest surface PWP1_L of each of the plurality of first through-hole portions PWP1 may be located at a level higher than the second surface 2a. The length PWP1_T of each of the plurality of first through-hole portions PWP1 in the second direction D2 may be greater than half the thickness SPL_T of the support layer SPL in the second direction D2. The length PWP1_T of each or at least one of the plurality of first through-hole portions PWP1 in the second direction D2 may, for example, be in the range of about 1 μm to about 3 μm. The second direction D2 may be a direction substantially perpendicular to the first surface 1a.

[0080] Multiple first through portions PWP1 may be spaced apart from each other along a first direction D1 by a first pitch P1. The first pitch P1 may be, for example, in the range of about 3 μm to about 12 μm. The width PWP1_W of the multiple first through portions PWP1 in the first direction D1 may be, for example, in the range of about 1.5 μm to about 4 μm.

[0081] The uppermost surface PWP2_U of each of the plurality of second through portions PWP2 may be located at a level lower than that of the first surface 1a. The length PWP2_T of each or at least one of the plurality of second through portions PWP2 in the second direction D2 may be greater than half the thickness SPL_T of the support layer SPL in the second direction D2. The length PWP2_T of each of the plurality of second through portions PWP2 in the second direction D2 may, for example, be in the range of about 1 μm to about 3 μm.

[0082] Multiple second through portions PWP2 may be spaced apart from each other along a first direction D1 by a second pitch P2. The second pitch P2 may, for example, be in the range of about 3 μm to about 12 μm. The second pitch P2 may be the same as or different from the first pitch P1. The width PWP2_W of the multiple second through portions PWP2 in the first direction D1 may, for example, be in the range of about 1.5 μm to about 4 μm.

[0083] Each or at least one of the plurality of first through portions PWP1 may be spaced apart from an adjacent second through portion PWP2 along a first direction D1 by a third pitch P3. The third pitch P3 may, for example, be in the range of about 2 μm to about 6 μm.

[0084] Reference Figure 7 and Figure 9 The first metal layer MEL1 may be disposed on the first surface 1a of the support layer SPL. The first metal layer MEL1 may include a plurality of first protrusions MEP1 that substantially fill a plurality of first through portions PWP1. Each or at least one of the plurality of first protrusions MEP1 may have a generally strip shape, for example, extending in a third direction D3.

[0085] The lowest surface of each or at least one of the plurality of first protrusions MEP1 may be located at a level lower than the first surface 1a. The width MEP1_W of the plurality of first protrusions MEP1 in the first direction D1 may, for example, range from about 1.5 μm to about 4 μm. The length MEP1_T of the plurality of first protrusions MEP1 in the second direction D2 may, for example, range from about 1 μm to about 3 μm.

[0086] A second metal layer MEL2 may be disposed on the second surface 2a of the support layer SPL. The second metal layer MEL2 may include a plurality of second protrusions MEP2 that substantially fill a plurality of second through portions PWP2. Each or at least one of the plurality of second protrusions MEP2 may have a generally strip shape, for example, extending in a third direction D3.

[0087] The uppermost surface of each or at least one of the plurality of second protrusions MEP2 may be located at a level higher than the second surface 2a. The width MEP2_W of each of the plurality of second protrusions MEP2 in the first direction D1 may, for example, range from about 1.5 μm to about 4 μm. The length MEP2_T of each of the plurality of second protrusions MEP2 in the second direction D2 may, for example, range from about 1 μm to about 3 μm.

[0088] According to an exemplary embodiment of this disclosure, the support layer SPL may include a plurality of through portions PWP1, PWP2, and a plurality of protrusions MEP1, MEP2 may substantially fill the corresponding through portions PWP1, PWP2. The content of the metal layer in the composite substrate may be increased. When an external force is applied to the composite substrate, the plurality of protrusions MEP1, MEP2 may constitute a support. The composite substrate may provide desired or improved tensile strength, and the rechargeable lithium battery including the composite substrate may have improved stability. For example, according to an exemplary embodiment of this disclosure, the composite substrate may have a tensile strength in the range of about 250 MPa to about 500 MPa.

[0089] Figure 10 This is a plan view of a composite substrate according to some exemplary embodiments of the present disclosure. For the sake of simplicity, references to the image are omitted. Figures 6 to 9 The description of the composite substrate is repeated.

[0090] Reference Figure 10 The support layer SPL may include a plurality of first through portions PWP1 that penetrate the first surface 1a and are spaced apart from each other along a first direction D1. The plurality of first through portions PWP1 may be spaced apart from each other along the first direction D1 with a first pitch P1. The first pitch P1 may be in the range of, for example, about 3 μm to about 12 μm.

[0091] Multiple first through-sections PWP1 may be spaced apart from each other along a third direction D3. Multiple first through-sections PWP1 may be spaced apart from each other along a third direction D3 with a fourth pitch P4. The first pitch P1 and the fourth pitch P4 may be different from each other. The fourth pitch P4 may, for example, be in the range of about 2 μm to about 6 μm.

[0092] like Figure 10 As shown, each or at least one of the plurality of first through portions PWP1 may have a generally circular shape in a plane. The shapes of the plurality of first through portions are not limited thereto and may have various shapes different from those shown in the figures.

[0093] The support layer SPL may include a plurality of second through portions PWP2 that penetrate the second surface 2a and are spaced apart from each other along a first direction D1. The plurality of second through portions PWP2 may be spaced apart from each other along the first direction D1 at a second pitch P2. The second pitch P2 may, for example, be in the range of about 3 μm to about 12 μm.

[0094] Multiple second through-sections PWP2 may be spaced apart from each other along a third direction D3. Multiple second through-sections PWP2 may be spaced apart from each other along a third direction D3 with a fifth pitch P5. The second pitch P2 and the fifth pitch P5 may be different from each other. The fifth pitch P5 may, for example, be in the range of about 2 μm to about 6 μm.

[0095] like Figure 10 As shown, each or at least one of the plurality of second through portions PWP2 may have a generally circular shape in a plane. The shapes of the plurality of second through portions PWP2 are not limited thereto, and may have various shapes different from those shown in the figures.

[0096] Each or at least one of the plurality of first through portions PWP1 may be spaced apart from an adjacent second through portion PWP2 along a first direction D1 by a third pitch P3. The third pitch P3 may, for example, be in the range of about 2 μm to about 6 μm.

[0097] Other components can be referenced above. Figures 6 to 9 The components of the composite substrates described are essentially the same.

[0098] Figure 11 This is a cross-sectional view of a composite substrate according to some exemplary embodiments of the present disclosure. For simplicity, references to the image are omitted. Figures 6 to 9 The description of the composite substrate is repeated.

[0099] Reference Figure 11 The support layer SPL may include a plurality of first through portions PWP1 penetrating the first surface 1a and a plurality of third through portions PWP3 penetrating the first surface 1a. The plurality of first through portions PWP1 may be disposed on the side surface of the support layer SPL. The plurality of first through portions PWP1 may be disposed adjacent to two ends of the support layer SPL.

[0100] Multiple third through-hole portions PWP3 can be disposed on the central portion (or middle side) of the support layer SPL. Multiple third through-hole portions PWP3 can be disposed between multiple first through-hole portions PWP1 disposed at both ends of the support layer SPL. The length PWP3_T of each of the multiple third through-hole portions PWP3 in the second direction D2 can be less than the length of each of the multiple first through-hole portions PWP1 in the second direction D2. The length PWP3_T of each of the multiple third through-hole portions PWP3 in the second direction D2 can be less than half the thickness SPL_T of the support layer SPL. The length PWP3_T of each of the multiple third through-hole portions PWP3 in the second direction D2 can, for example, be in the range of about 0.5 μm to about 1.5 μm.

[0101] The support layer SPL may include a plurality of second through portions PWP2 penetrating the second surface 2a and a plurality of fourth through portions PWP4 penetrating the second surface 2a. The plurality of second through portions PWP2 may be disposed on the sides of the support layer SPL. The plurality of second through portions PWP2 may be disposed adjacent to the two ends of the support layer SPL. The plurality of fourth through portions PWP4 may be disposed on the central portion (or middle side) of the support layer SPL. The plurality of fourth through portions PWP4 may be disposed between the plurality of second through portions PWP2 disposed at the two ends of the support layer SPL. The length PWP4_T of each of the plurality of fourth through portions PWP4 in the second direction D2 may be less than the length of each of the plurality of second through portions PWP2 in the second direction. The length PWP4_T of each of the plurality of fourth through portions PWP4 in the second direction D2 may be less than half the thickness of the support layer SPL. The length PWP4_T of each of the plurality of fourth through portions PWP4 in the second direction D2 may, for example, be in the range of about 0.5 μm to about 1.5 μm.

[0102] The first metal layer MEL1 may include a plurality of first protrusions MEP1 that fill or substantially fill a plurality of first through portions PWP1 and a plurality of third protrusions MEP3 that fill or substantially fill a plurality of third through portions PWP3. The plurality of first protrusions MEP1 may be disposed on the side surface of the support layer SPL. The plurality of first protrusions MEP1 may be disposed adjacent to two end portions of the support layer SPL.

[0103] Multiple third protrusions MEP3 can be disposed on the central portion (or middle side) of the support layer SPL. Multiple third protrusions MEP3 can be disposed between multiple first protrusions MEP1 disposed at the two ends of the support layer SPL.

[0104] The length MEP3_T of each of the plurality of third protrusions MEP3 in the second direction D2 can be less than the length MEP3_T of each of the plurality of first protrusions MEP1 in the second direction D2. The length MEP3_T of each of the plurality of third protrusions MEP3 in the second direction D2 can be less than half the thickness SPL_T of the support layer SPL. The length MEP3_T of each of the plurality of third protrusions MEP3 in the second direction D2 can, for example, be in the range of about 0.5 μm to about 1.5 μm.

[0105] The second metal layer MEL2 may include a plurality of second protrusions MEP2 that fill or substantially fill a plurality of second through portions PWP2 and a plurality of fourth protrusions MEP4 that fill or substantially fill a plurality of fourth through portions PWP4. The plurality of second protrusions MEP2 may be disposed on the sides of the support layer SPL. The plurality of second protrusions MEP2 may be disposed adjacent to two ends of the support layer SPL.

[0106] Multiple fourth protrusions MEP4 can be disposed on the central portion (or middle side) of the support layer SPL. Multiple fourth protrusions MEP4 can be disposed between multiple second protrusions MEP2 disposed at the two ends of the support layer SPL.

[0107] The length MEP4_T of each of the plurality of fourth protrusions MEP4 in the second direction D2 can be less than the length MEP4_T of each of the plurality of second protrusions MEP2 in the second direction D2. The length MEP4_T of each of the plurality of fourth protrusions MEP2 in the second direction D2 can be less than half the thickness SPL_T of the support layer SPL. The length MEP4_T of each of the plurality of fourth protrusions MEP4 in the second direction D2 can, for example, be in the range of about 0.5 μm to about 1.5 μm.

[0108] Because multiple first protrusions MEP1 and second protrusions MEP2, each having a long length in the second direction D2, are disposed on the side of the support layer SPL, the tensile strength of the composite substrate can be improved. Because multiple third protrusions MEP3 and fourth protrusions MEP4, each having a short length in the second direction D2, are disposed on the central portion (or middle side) of the support layer SPL, the tensile strength of the composite substrate can be improved without significantly increasing the weight of the composite substrate.

[0109] Other components can be referenced above. Figures 6 to 9 The components of the composite substrates described are essentially the same.

[0110] Figure 12 This is a cross-sectional view of a composite substrate according to some exemplary embodiments of the present disclosure. For simplicity, references to the image are omitted. Figures 6 to 9 The description of the composite substrate is repeated.

[0111] Reference Figure 12 The support layer SPL can have a multi-layer structure. The support layer SPL may include a first support layer SPL1, a second support layer SPL2, and a third support layer SPL3. The first support layer SPL1 may include a second surface 2a, and the third support layer SPL3 may include a first surface 1a. The second support layer SPL2 may be disposed between the first support layer SPL1 and the third support layer SPL3.

[0112] The thickness SPL1_T of the first support layer SPL1 can, for example, be in the range of about 0.5 μm to about 1 μm. The thickness SPL3_T of the third support layer SPL3 can, for example, be in the range of about 0.5 μm to about 1 μm. The thickness SPL2_T of the second support layer SPL2 can, for example, be in the range of about 1 μm to about 9 μm.

[0113] The first support layer SPL1 and the third support layer SPL3 may comprise the same material. The first support layer SPL1 and the third support layer SPL3 may comprise at least one of, for example, polyethylene film and polyethylene terephthalate film. The second support layer SPL2 may comprise, for example, a polypropylene film.

[0114] Because the first support layer SPL1 and the third support layer SPL3 comprise a polyethylene terephthalate film with high durability, the tensile strength of the composite substrate can be further improved. Since the second support layer SPL2 is made of or comprises polypropylene, which is desirable or improved in terms of lightweight properties, the composite substrate can be lightweight.

[0115] Multiple first through-holes PWP1 can penetrate the third support layer SPL3 and can be disposed inside the second support layer SPL2. Multiple second through-holes PWP2 can penetrate the first support layer SPL1 and can be disposed inside the second support layer SPL2.

[0116] Other components can be referenced above. Figures 6 to 9 The components of the composite substrates described are essentially the same.

[0117] Figure 13 This is a cross-sectional view of a composite substrate according to some exemplary embodiments of the present disclosure. For the sake of simplicity, references to the above are omitted. Figures 6 to 9 The description of the composite substrate is repeated.

[0118] Reference Figure 13 The support layer SPL may include a plurality of first support patterns SPP1 and a plurality of second support patterns SPP2. The plurality of first support patterns SPP1 may be spaced apart from each other along a first surface 1a in a first direction D1. The plurality of second support patterns SPP2 may be spaced apart from each other along a second surface 2a in the first direction D1.

[0119] The plurality of first support patterns SPP1 and the plurality of second support patterns SPP2 may comprise at least one of a polyethylene film and a polyethylene terephthalate film. The support layer SPL may comprise a polymer layer PP surrounding the plurality of first support patterns SPP1 and the plurality of second support patterns SPP2. The polymer layer PP may comprise, for example, a polypropylene film.

[0120] Since the multiple first support patterns SPP1 and the multiple second support patterns SPP2 comprise a polyethylene terephthalate film with high durability, the tensile strength of the composite substrate can be further improved. Because the polymer layer is made of or comprises polypropylene, which is desirable or improved in terms of lightweight properties, the composite substrate can be lightweight.

[0121] The plurality of first through portions PWP1 can all penetrate the corresponding first support pattern among the plurality of first support patterns SPP1. The width SPP1_W of each of the plurality of first support patterns SPP1 in the first direction D1 can be greater than the width PWP1_W of each of the plurality of first through portions PWP1 in the first direction D1. The width SPP1_W of each of the plurality of first support patterns SPP1 in the first direction D1 can, for example, be in the range of about 1.6 μm to about 4.2 μm.

[0122] The plurality of second through portions PWP2 can all penetrate the corresponding second support pattern among the plurality of second support patterns SPP2. The width SPP2_W of each of the plurality of second support patterns SPP2 in the first direction D1 can be greater than the width PWP2_W of each of the plurality of second through portions PWP2 in the first direction D1. The width SPP2_W of each of the plurality of second support patterns SPP2 in the first direction D1 can, for example, be in the range of about 1.6 μm to about 4.2 μm.

[0123] Other components can be referenced above. Figures 6 to 9 The components of the composite substrates described are essentially the same.

[0124] Furthermore, it should be understood that, in Figures 6 to 13 In this disclosure, the plan views and sectional views are schematic and are only used to help understand the present disclosure, and do not constitute any limitation on the type, arrangement, size, or scale of the through parts.

[0125] Examples of this disclosure are described in more detail below. However, the following examples are intended only to aid in understanding this disclosure, and the scope of this disclosure is not limited thereto.

[0126] Example 1 A polyethylene film with a thickness of approximately 3 μm is prepared as a support layer. A first through-hole and a second through-hole are formed on both sides of the support layer. Each of the first through-holes has a width of approximately 1.5 μm in a first direction. The length of each first through-hole in the vertical direction (second direction) is approximately 1.7 μm. The first through-holes are formed to be spaced approximately 2 μm apart from each other.

[0127] Each of the second through-holes has a width of approximately 1.5 μm in the first direction. The length of the second through-hole in the vertical direction (second direction) is approximately 1.7 μm. The second through-holes are spaced approximately 2 μm apart from each other. The first and second through-holes are each spaced approximately 0.25 μm apart from each other.

[0128] Subsequently, copper is applied to both sides of the support layer. A first metal layer is formed, comprising a first protrusion filling the first through-hole portion. A second metal layer is formed, comprising a second protrusion filling the second through-hole portion. The thickness of each of the first and second metal layers is approximately 2 μm.

[0129] Example 2 The width of each of the first and second through-hole portions in the first direction is formed to be approximately 2 μm. The length of each of the first and second through-hole portions in the vertical direction (second direction) is formed to be approximately 2 μm. The first through-hole portions are spaced approximately 2.5 μm apart from each other. The second through-hole portions are spaced approximately 2.5 μm apart from each other. The other fabrication processes are performed in the same manner as those in Example 1.

[0130] Example 3 The width of each of the first and second through-hole portions in the first direction is formed to be approximately 3 μm. The length of each of the first and second through-hole portions in the vertical direction (second direction) is formed to be approximately 2.5 μm. The first through-hole portions are spaced approximately 3.5 μm apart from each other. The second through-hole portions are spaced approximately 3.5 μm apart from each other. The other fabrication processes are performed in the same manner as those in Example 1.

[0131] Comparison Examples The composite substrate is formed in the same manner as in the example, except that multiple through-holes are not formed on the support layer. A polyethylene film with a thickness of approximately 3 μm is prepared as the support layer, and then a first metal layer and a second metal layer are formed on both sides of the support layer. The thickness of each of the first metal layer and the second metal layer is approximately 2 μm.

[0132] Evaluation example: Evaluation of tensile strength Tensile tests were performed on the composite substrate according to the example and the composite substrate according to the comparative example. The composite substrates according to the example and the composite substrate according to the comparative example were stretched until they broke to test the tensile strength. The results are shown in Table 1 below.

[0133] Table 1:

[0134] Referring to Table 1 above, it can be seen that the composite substrate according to the example has a more desirable or improved tensile strength than the composite substrate according to the comparative example.

[0135] According to an exemplary embodiment of this disclosure, a support layer comprising a first surface and a second surface facing away from each other can be provided. The support layer may include a plurality of first through-hole portions penetrating the first surface and a plurality of second through-hole portions penetrating the second surface, and a metal layer may include a plurality of protrusions filling the plurality of through-hole portions. Because the metal layer fills the plurality of first through-hole portions and the plurality of second through-hole portions, the content of the metal layer in the composite substrate can be increased.

[0136] When an external force is applied to the composite substrate, the multiple protrusions can be configured as support members. The composite substrate can provide desired or improved tensile strength, and the rechargeable lithium battery including the composite substrate can have improved stability.

[0137] Although exemplary embodiments of the present disclosure have been described with reference to the accompanying drawings, it is understood that the present disclosure may be implemented in other forms without altering the technical concept or essential features of the disclosure. Therefore, the exemplary embodiments described above should be understood in all respects as illustrative rather than restrictive.

Claims

1. A composite substrate for a rechargeable lithium battery, the composite substrate comprising: The support layer includes a first surface and a second surface facing away from each other; A first metal layer is disposed on the first surface; as well as A second metal layer is disposed on the second surface. The support layer includes: a plurality of first through-hole portions penetrating the first surface and spaced apart from each other along a first direction; and a plurality of second through-hole portions penetrating the second surface and spaced apart from each other along the first direction. The plurality of first through-hole portions and the plurality of second through-hole portions are alternately arranged along the first direction, and The first direction is parallel to the first surface.

2. The composite substrate according to claim 1, wherein, The uppermost surface of at least one of the plurality of second through portions is located at a level lower than the first surface, and The lowest surface of at least one of the plurality of first through portions is located at a level higher than the second surface.

3. The composite substrate according to claim 1, wherein, At least one of the plurality of first through portions has a width in the first direction ranging from 1.5 μm to 4 μm, and At least one of the plurality of second through portions has a width in the first direction ranging from 1.5 μm to 4 μm.

4. The composite substrate according to claim 1, wherein, At least one of the plurality of first through portions has a length in the second direction greater than half the thickness of the support layer. At least one of the plurality of second through portions has a length in the second direction greater than half the thickness of the support layer, and The second direction is perpendicular to the first surface.

5. The composite substrate according to claim 1, wherein, The plurality of first through portions are spaced apart from each other along the first direction at a first pitch, and The first pitch is in the range of 3 μm to 12 μm.

6. The composite substrate according to claim 1, wherein, At least one of the plurality of first through portions has a length in the second direction ranging from 1 μm to 3 μm. At least one of the plurality of second through portions has a length in the second direction ranging from 1 μm to 3 μm, and The second direction is perpendicular to the first surface.

7. The composite substrate according to claim 1, wherein, The first metal layer includes a plurality of first protrusions, which respectively fill the plurality of first through-portions, and The second metal layer includes a plurality of second protrusions, which respectively fill the plurality of second through portions.

8. The composite substrate according to claim 1, wherein, Based on 100 wt% of the composite substrate, the content of the support layer in the composite substrate is in the range of 20 wt% to 30 wt%.

9. 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.

10. The composite substrate according to claim 1, wherein, The support layer includes at least one of a multilayer film consisting of a polyethylene film, a polypropylene film, a polyvinylidene chloride film, and combinations thereof.

11. The composite substrate according to claim 1, wherein, At least one of the plurality of first through portions is spaced apart from an adjacent second through portion of the plurality of second through portions along the first direction by a second pitch, and The second pitch is in the range of 2μm to 6μm.

12. The composite substrate according to claim 1, wherein, The tensile strength of the composite substrate is in the range of 250 MPa to 500 MPa.

13. A rechargeable lithium battery, said rechargeable lithium battery comprising: Composite substrate; as well as Battery cells, on the composite substrate, The composite substrate includes: a support layer having a first surface and a second surface facing away from each other; a first metal layer disposed on the first surface; and a second metal layer disposed on the second surface. The support layer includes: a plurality of first through-hole portions penetrating the first surface and spaced apart from each other along a first direction; and a plurality of second through-hole portions penetrating the second surface and spaced apart from each other along the first direction. The plurality of first through-hole portions and the plurality of second through-hole portions are alternately arranged along the first direction, and The first direction is parallel to the first surface.

14. The rechargeable lithium battery according to claim 13, wherein, The battery cell includes: A first active material layer is disposed on either the first metal layer or the second 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.

15. The rechargeable lithium battery according to claim 13, wherein, The uppermost surface of at least one of the plurality of second through portions is located at a level lower than the first surface, and The lowest surface of at least one of the plurality of first through portions is located at a level higher than the second surface.

16. The rechargeable lithium battery according to claim 13, wherein, The first metal layer includes a plurality of first protrusions, which respectively fill the plurality of first through-portions, and The second metal layer includes a plurality of second protrusions, which respectively fill the plurality of second through portions.

17. The rechargeable lithium battery according to claim 13, wherein, At least one of the plurality of first through portions has a length in the second direction greater than half the thickness of the support layer. At least one of the plurality of second through portions has a length in the second direction greater than half the thickness of the support layer, and The second direction is perpendicular to the first surface.

18. The rechargeable lithium battery according to claim 13, wherein, Based on 100 wt% of the composite substrate, the content of the support layer in the composite substrate is in the range of 20 wt% to 30 wt%.

19. The rechargeable lithium battery according to claim 13, wherein, The support layer includes at least one of a multilayer film consisting of a polyethylene film, a polypropylene film, a polyvinylidene chloride film, and combinations thereof.

20. The rechargeable lithium battery according to claim 13, wherein, The composite substrate has a tensile strength in the range of 250 MPa to 500 MPa.

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