Dry electrode, method of manufacturing same, and apparatus for manufacturing same

Abstract

Disclosed are a dry electrode, a manufacturing method thereof, and a manufacturing apparatus therefor. The manufacturing method includes: mixing an electrode active material, a first binder, and a first conductive material to form a dry mixture; allowing the dry mixture to form a film to form an electrode active material layer; forming a composite layer on the electrode active material layer; and laminating the electrode active material layer on which the composite layer is formed on the electrode current collector. The step of forming the composite layer includes: applying an adhesive solution including a second adhesive, a second conductive material, and an organic solvent on the electrode active material layer; and drying the adhesive solution.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2024-0040231, filed on March 25, 2024, in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference. Technical Field

[0003] One or more embodiments of the present disclosure relate to a dry electrode, a method of manufacturing the dry electrode, and an apparatus for manufacturing the dry electrode. Background Art

[0004] Driven by industrial demand, batteries with relatively high energy density and high safety have recently received active development (and / or attention). For example, lithium-ion batteries are being commercialized not only in information-related and / or communication-related devices, but also in the automotive industry. In the automotive industry, safety is particularly emphasized due to its direct impact on human health.

[0005] Recently, all-solid-state batteries in which the electrolyte solution is replaced by a solid electrolyte have been proposed. Because all-solid-state batteries do not use flammable organic dispersion media (e.g., organic solvents and / or electrolyte solutions), the possibility of fire or explosion can be significantly reduced even in the event of a short circuit. Therefore, compared to lithium-ion batteries using electrolyte solutions (e.g., organic solvents and / or electrolyte solutions), such all-solid-state batteries (which do not use organic solvents and / or electrolyte solutions) can have greatly increased safety. Summary of the Invention

[0006] One or more aspects of embodiments of the present disclosure relate to a method of manufacturing a dry electrode, by which the dry electrode can be easily and efficiently manufactured, and / or to an apparatus for manufacturing the dry electrode.

[0007] One or more aspects of embodiments of the present disclosure relate to a dry electrode having reduced resistance.

[0008] Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments of the disclosure.

[0009] According to one or more embodiments of the present disclosure, a method for manufacturing a dry electrode may include: mixing an electrode active material, a first binder, and a first conductive material to form a dry mixture; allowing the dry mixture to form a film to form an electrode active material layer; forming a composite layer (composite material layer) on the electrode active material layer; and laminating the electrode active material layer on an electrode current collector, the composite layer being formed on the electrode active material layer. The step (e.g., action or task) of forming the composite layer may include: applying an adhesive solution to the electrode active material layer, the adhesive solution including a second binder, a second conductive material, and an organic solvent; and drying the adhesive solution.

[0010] According to one or more embodiments of the present disclosure, an apparatus for manufacturing a dry electrode may include: a roller for transferring an electrode active material layer; an adhesive solution supplier for supplying an adhesive solution on the electrode active material layer; a distance sensor for identifying a travel distance of the electrode active material layer; a dryer for drying the adhesive solution; and a laminator for laminating an electrode current collector and the electrode active material layer.

[0011] According to one or more embodiments of the present disclosure, a dry electrode may include: an electrode current collector; an electrode active material layer on the electrode current collector, the electrode active material layer including an electrode active material, a first binder, and a first conductive material; and a composite layer between the electrode current collector and the electrode active material layer. The composite layer includes the electrode active material, the first binder, the first conductive material, a second binder, and a second conductive material. The concentration of the second binder may vary in the composite layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The above and other aspects, features, and advantages of some embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings.

[0013] Figure 1 A simplified conceptual diagram showing a rechargeable lithium battery according to one or more embodiments of the present disclosure is shown.

[0014] Figures 2 to 5 Each shows a simplified cross-sectional view showing a rechargeable lithium battery according to one or more embodiments of the present disclosure.

[0015] Figure 6 A cross-sectional view showing an all-solid-state battery according to one or more embodiments of the present disclosure is shown.

[0016] Figure 7A cross-sectional view showing a dry electrode according to one or more embodiments of the present disclosure is shown.

[0017] Figure 8 A graph showing the concentration distribution of the second binder in a cross section of a dry electrode according to one or more embodiments of the present disclosure is shown.

[0018] Figure 9 Shown is a graph showing the concentration distribution of the second binder in the cross section of a dry electrode according to a comparative example of the present disclosure.

[0019] Figure 10 A perspective view showing a pattern-coated dry electrode according to one or more embodiments of the present disclosure is shown.

[0020] Figure 11 A flow chart showing a method of manufacturing a dry electrode according to one or more embodiments of the present disclosure is shown.

[0021] Figure 12 、 13 , 14, 15, and 16 each illustrate a perspective view showing a method of manufacturing a dry electrode according to one or more embodiments of the present disclosure.

[0022] Figure 17 A schematic diagram showing an apparatus for manufacturing a dry electrode according to one or more embodiments of the present disclosure is shown.

[0023] Figure 18 A schematic diagram showing a dryer according to one or more embodiments of the present disclosure is shown. DETAILED DESCRIPTION

[0024] In order to fully understand the configuration and aspects of the present disclosure, one or more embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be noted that the present disclosure is not limited to the following example embodiments and can be implemented in one or more suitable forms. On the contrary, the example embodiments are provided only to illustrate the present disclosure and enable those skilled in the art to fully understand the scope of the present disclosure.

[0025] In the present disclosure, it will be understood that if an element is referred to as being on another element (e.g., when an element is referred to as being on another element), the element may be directly on the other element or there may be an intervening element therebetween. Conversely, if an element is referred to as being "directly on" another element (e.g., when an element is referred to as being "directly on" another element), there are no intervening elements. In the accompanying drawings, the thickness of some components may be exaggerated in order to effectively illustrate the technical content. Throughout the present disclosure, the same reference numerals refer to the same elements, and for the sake of brevity, repeated descriptions thereof may not be provided.

[0026] Unless otherwise specifically indicated in the present disclosure, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. In addition, the use of "may" when describing embodiments of the present disclosure relates to "one or more embodiments of the present disclosure". In addition, unless otherwise specifically indicated, the phrases "A or B", or "A and / or B", or "A / B" may refer to "A but not B", "B but not A", and "A and B". The term "comprising / including" as used in the present disclosure does not exclude the presence or addition of one or more other components (parts).

[0027] As used herein, the term "combination thereof" may refer to a mixture, stack, composite, copolymer, alloy, blend, or reaction product of ingredients (components).

[0028] Unless otherwise specifically defined in the present disclosure, the particle diameter may be an average particle diameter. In addition, the particle diameter represents an average particle diameter (D) in which the cumulative volume in the particle size distribution is about 50% by volume. 50 ). Average particle diameter (D 50 ) can be measured as follows: by a method widely suitable for those skilled in the art, for example, by a particle size analyzer, such as HORIBA, LA-950 laser particle size analyzer, transmission electron microscope (TEM), or scanning electron microscope (SEM). In one or more embodiments, a dynamic light scattering measurement device is used to perform data analysis, the number of particles in each particle size range is counted, and then the average particle diameter (D) can be calculated from the data. 50 In some embodiments, the average particle diameter (D 50 In the laser scattering method, target particles are distributed in a distribution solvent, introduced into a laser scattering particle measuring device (e.g., MT3000 commercially available from Microtrac, Inc), irradiated with 28 kHz ultrasonic waves at a power of 60 W, and then the average particle diameter (D) is calculated based on the 50% standard of the particle diameter distribution in the measuring device. 50 ). D 50 The term "diameter" refers to the average diameter (or size) of particles whose cumulative volume corresponds to 50% by volume in a particle size distribution (e.g., cumulative distribution), and refers to the value of the particle size corresponding to 50% from the smallest particle when the total number of particles in a distribution curve accumulated in order from the smallest particle size to the largest particle size is 100%. In the present disclosure, when the particles are spherical, "diameter" refers to the average particle diameter, and when the particles are non-spherical, "diameter" refers to the length of the major axis.

[0029] As used herein, the term "dry electrode" or "dry electrode film" refers to an electrode or electrode film comprising an electrode active material layer that intentionally does not use, or does not include, a solvent during the electrode preparation process. Solvents include process solvents, process solvent residues, process solvent impurities, and / or the like.

[0030] Figure 1 A simplified conceptual diagram showing a rechargeable lithium battery according to one or more embodiments of the present disclosure is shown. Figure 1 , a rechargeable lithium battery may include a positive electrode 10, a negative electrode 20, a separator 30, and an electrolyte solution (electrolyte) ELL.

[0031] The positive electrode 10 and the negative electrode 20 may be separated and / or separated (e.g., spaced apart or separated) from each other across a separator 30. The separator 30 may be disposed between the positive electrode 10 and the negative electrode 20. The positive electrode 10, the negative electrode 20, and the separator 30 may be in contact with the electrolyte solution ELL. In one or more embodiments, the positive electrode 10, the negative electrode 20, and the separator 30 may be immersed in (and / or impregnated with) the electrolyte solution ELL.

[0032] The electrolyte solution ELL may be a medium in which lithium ions migrate and transfer between the positive electrode 10 and the negative electrode 20. In the electrolyte solution ELL, lithium ions may move toward one of the positive electrode 10 and the negative electrode 20 (eg, one selected from the positive electrode 10 and the negative electrode 20) through the separator 30.

[0033] Positive electrode 10

[0034] The positive electrode 10 for a rechargeable lithium battery may include a current collector COL1 and a positive active material layer AML1 formed on the current collector COL1. The positive active material layer AML1 may include a positive active material (eg, in the form of particles) and may further include a binder and / or a conductive material.

[0035] For example, in some embodiments, the positive electrode 10 may further include an additive that may serve as a sacrificial positive electrode.

[0036] The amount of the positive electrode active material may be in a range of about 90 wt % to about 99.5 wt % relative to 100 wt % of the total weight of the positive electrode active material layer AML1. The amount of the binder and the conductive material may each be in a range of about 0.5 wt % to about 5 wt % relative to 100 wt % of the total weight of the positive electrode active material layer AML1.

[0037] The binder can be used to improve the adhesion of the positive electrode active material particles to each other and also to improve the adhesion of the positive electrode active material to the current collector COL1. The binder may include, for example, one or more selected from the group consisting of polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene oxide (ethylene oxide)-containing polymers, polyvinyl pyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, epoxy resin, (meth)acrylic resin, polyester resin, and nylon, but embodiments of the present disclosure are not limited thereto.

[0038] The conductive material (e.g., an electrically conductive material or an electron conductor) can be used to provide conductivity to the electrode, and any suitable conductive material that does not cause chemical changes in the battery can be used as the conductive material constituting the battery. The conductive material may include, for example, carbon-based materials such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fibers, carbon nanofibers, and / or carbon nanotubes; metal powders or metal fibers containing one or more of the following (e.g., selected from the following): copper, nickel, aluminum, and silver; conductive polymers such as polyphenylene derivatives; and / or (e.g., any suitable) mixtures thereof.

[0039] In one or more embodiments, aluminum (Al) may be used as the current collector COL1 , but embodiments of the present disclosure are not limited thereto.

[0040] positive electrode active material

[0041] The positive electrode active material in the positive electrode active material layer AML1 may include a compound that can reversibly intercalate and deintercalate lithium (e.g., a lithiated intercalation compound). For example, in one or more embodiments, the positive electrode active material may include at least one composite oxide including lithium and a metal selected from cobalt, manganese, nickel, and / or (e.g., any suitable) combination thereof.

[0042] The composite oxide may include a lithium transition metal composite oxide, for example, a lithium nickel-based oxide, a lithium cobalt-based oxide, a lithium manganese-based oxide, a lithium iron phosphate-based compound, a cobalt-free nickel manganese-based oxide, and / or (for example, any suitable) combinations thereof.

[0043] For example, in one or more embodiments, the positive electrode active material may include a compound represented by one selected from 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); Li a 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); and Li a FePO4 (where 0.90≤a≤1.8).

[0044] In the aforementioned chemical formula, A may be nickel (Ni), cobalt (Co), manganese (Mn), or (e.g., any suitable) combination thereof, X may be Al, Ni, Co, Mn, chromium (Cr), iron (Fe), magnesium (Mg), strontium (Sr), vanadium (V), a rare earth element, or (e.g., any suitable) combination thereof, D may be oxygen (O), fluorine (F), sulfur (S), phosphorus (P), or (e.g., any suitable) combination thereof, G may be Al, Cr, Mn, Fe, Mg, lanthanum (La), cerium (Ce), Sr, V, or (e.g., any suitable) combination thereof, and L 1 It may be Mn, Al, or (eg, any suitable) combination thereof.

[0045] For example, in one or more embodiments, the positive electrode active material may be a high nickel-based positive electrode active material having a nickel content (e.g., amount) of about 80 mol% or more, about 85 mol% or more, about 90 mol% or more, about 91 mol% or more, or about 94 mol% or more and about 99 mol% or less, relative to 100 mol% of the total metal excluding lithium in the lithium transition metal composite oxide. The high nickel-based positive electrode active material can achieve high capacity and, therefore, can be applied to high-capacity and high-density rechargeable lithium batteries.

[0046] Negative electrode 20

[0047] The negative electrode 20 of the rechargeable lithium battery may include a current collector COL2 and a negative active material layer AML2 on the current collector COL2. The negative active material layer AML2 may include a negative active material (eg, in the form of particles) and may further include a binder and / or a conductive material.

[0048] For example, in one or more embodiments, the negative active material layer AML2 may include about 90 wt % to about 99 wt % of the negative active material, about 0.5 wt % to about 5 wt % of the binder, and about 0 wt % to about 5 wt % of the conductive material, based on 100 wt % of the total weight of the negative active material layer.

[0049] The binder can be used to improve the adhesion of the negative electrode active material particles to each other and also to improve the adhesion of the negative electrode active material to the current collector COL2. The binder can include a non-aqueous (e.g., water-insoluble) binder, an aqueous (e.g., water-soluble) binder, a dry binder, and / or (e.g., any suitable) combination thereof.

[0050] The non-aqueous binder can include polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, ethylene propylene copolymer, polystyrene, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamideimide, polyimide, and / or (e.g., any suitable) combinations thereof.

[0051] The aqueous binder may include styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, (meth)acrylonitrile-butadiene rubber, (meth)acrylic rubber, butyl rubber, fluoroelastomer, polyethylene oxide, polyvinyl pyrrolidone, polyepichlorohydrin, polyphosphazene, poly(meth)acrylonitrile, ethylene-propylene-diene copolymer (EPDM), polyvinyl pyridine, chlorosulfonated polyethylene, latex, polyester resin, (meth)acrylic resin, phenolic resin, epoxy resin, polyvinyl alcohol, and / or (e.g., any suitable) combination thereof.

[0052] When an aqueous binder is used as a binder for the negative electrode, a cellulose-based compound capable of providing viscosity may be further included. The cellulose-based compound may include one or more selected from the group consisting of carboxymethyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, and alkali metal salts thereof. The alkali metal may include Na, K, or Li.

[0053] The dry binder can include a fibrillizable polymeric material, such as polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polyethylene oxide, and / or (eg, any suitable) combinations thereof.

[0054] The conductive material (e.g., an electrically conductive material or an electron conductor) can be used to provide conductivity to the electrode, and any suitable conductive material that does not cause chemical changes in the battery can be used as the conductive material constituting the battery. For example, in one or more embodiments, the conductive material may include a carbon-based material such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, carbon nanofiber, and / or carbon nanotube; a metal powder or metal fiber comprising one or more selected from the group consisting of copper, nickel, aluminum, and silver; a conductive polymer such as a polyphenylene derivative; and / or (e.g., any suitable) mixture thereof.

[0055] The current collector COL2 may include copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, a polymer substrate coated with a conductive metal, and / or (eg, any suitable) combinations thereof.

[0056] negative electrode active material

[0057] The negative active material in the negative active material layer AML2 may include a material that can reversibly intercalate and deintercalate lithium ions, lithium metal, a lithium metal alloy, a material that can be doped and dedoped with lithium, or a transition metal oxide.

[0058] The material capable of reversibly embedding and de-embedding lithium ions may include carbon-based negative electrode active materials, such as crystalline carbon, amorphous carbon, and / or (for example, any suitable) combinations thereof. For example, the crystalline carbon may include graphite, such as non-shaped (for example, irregularly shaped), sheet-shaped, flake-shaped, spherical, or fibrous natural graphite and / or artificial graphite, and the amorphous carbon may include soft carbon, hard carbon, mesophase pitch carbon, and / or calcined coke.

[0059] The lithium metal alloy may include an alloy of lithium and a metal selected from the following: sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), francium (Fr), beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), silicon (Si), antimony (Sb), lead (Pb), indium (In), zinc (Zn), barium (Ba), radium (Ra), germanium (Ge), aluminum (Al), and tin (Sn).

[0060] The material capable of doping and de-doping 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, alkaline earth metal, group 13 element, group 14 element (except Si), group 15 element, group 16 element, transition metal, rare earth element, or (for example, any suitable) combinations thereof), and / or (for example, any suitable) combinations thereof. The Sn-based negative electrode active materials may include Sn, SnO k (0 < k ≤ 2) (for example, SnO2), Sn-based alloys, or (for example, any suitable) combinations thereof.

[0061] The silicon-carbon composite may be a composite of silicon and amorphous carbon (for example, in the form of particles). According to one or more embodiments, the silicon-carbon composite may have a structure in which the amorphous carbon coats the respective surfaces of the silicon particles. For example, in one or more embodiments, the silicon-carbon composite may include secondary particles (cores) that aggregate primary silicon particles, and an amorphous carbon coating layer (shell) on the surface of the secondary particles (for example, located on the surface). The amorphous carbon may also be located between the primary silicon particles, and for example, the primary silicon particles may be coated with the amorphous carbon. The secondary particles may be dispersed in an amorphous carbon matrix.

[0062] In one or more embodiments, the silicon-carbon composite may further include crystalline carbon. For example, the silicon-carbon composite may include a core containing crystalline carbon and silicon particles, and may also include an amorphous carbon coating layer on the surface of the core.

[0063] In one or more embodiments, the Si-based negative electrode active material and / or the Sn-based negative electrode active material may be used in combination with a carbon-based negative electrode active material.

[0064] Partition 30

[0065] Depending on the type or kind 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 selected from polyethylene, polypropylene, and polyvinylidene fluoride, or may have a multilayer separator thereof such as a polyethylene / polypropylene double-layer separator, a polyethylene / polypropylene / polyethylene three-layer separator, or a polypropylene / polyethylene / polypropylene three-layer separator.

[0066] The separator 30 may include a porous substrate and a coating on a surface (eg, one surface or two opposing surfaces) of the porous substrate, and the coating may include an organic material, an inorganic material, and / or (eg, any suitable) combination thereof.

[0067] The porous substrate may be a material selected from the group consisting of polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyacetals, polyamides, polyimides, polycarbonates, polyetherketones, polyaryletherketones, polyetherimides, polyamideimides, polybenzimidazoles, polyethersulfones, polyphenylene oxides, cyclic olefin copolymers, polyphenylene sulfide, polyethylene naphthalate, glass fibers, and polytetrafluoroethylene (e.g., Teflon). TM ), or may be a copolymer or mixture comprising two or more thereof.

[0068] The organic material may include a polyvinylidene fluoride-based copolymer and / or a (meth)acrylic copolymer.

[0069] The inorganic material may include inorganic particles selected from the group consisting of Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, SrTiO3, BaTiO3, Mg(OH)2, boehmite, and / or (e.g., any suitable) combinations thereof, but embodiments of the present disclosure are not limited thereto.

[0070] In one or more embodiments, the organic material and the inorganic material may be present in the form of being mixed in one coating layer, or may be present as a stack of a coating layer including the organic material and a coating layer including the inorganic material.

[0071] Electrolyte solution ELL

[0072] The electrolyte solution ELL for a rechargeable lithium battery may include a non-aqueous organic solvent and a lithium salt.

[0073] The nonaqueous organic solvent may serve as a medium for transporting ions participating in an electrochemical reaction of a battery.

[0074] The non-aqueous organic solvent may include a carbonate-based solvent, an ester-based solvent, an ether-based solvent, a ketone-based solvent, an alcohol-based solvent, an aprotic solvent, and / or (eg, any suitable) combinations thereof.

[0075] The carbonate-based solvent may include dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methylpropyl carbonate (MPC), ethylpropyl carbonate (EPC), ethylmethyl carbonate (MEC), ethylene carbonate (EC), propylene carbonate (PC), and / or butylene carbonate (BC).

[0076] The ester-based solvent may include methyl acetate, ethyl acetate, n-propyl acetate, dimethyl acetate, methyl propionate, ethyl propionate, decanoic acid lactone, mevalonolactone, valerolactone, and / or caprolactone.

[0077] The ether-based solvent may include dibutyl ether, tetraglyme, diglyme, dimethoxyethane, 2-methyltetrahydrofuran, 2.5-dimethyltetrahydrofuran, and / or tetrahydrofuran. The ketone-based solvent may include cyclohexanone. The alcohol-based solvent may include ethanol and / or isopropanol. The aprotic solvent may include a nitrile such as R-CN (wherein R is a hydrocarbon group having a C2 to C20 linear, branched or cyclic structure and may include a double bond, an aromatic ring, or an ether group); an amide such as dimethylformamide; a dioxolane such as 1,3-dioxolane and / or 1,4-dioxolane; and / or sulfolane.

[0078] The nonaqueous organic solvent may be used alone or as a mixture of two or more thereof.

[0079] In addition, if a carbonate-based solvent is used (for example, when a carbonate-based solvent is used), cyclic carbonate and chain carbonate may be mixed and used, and the cyclic carbonate and the chain carbonate may be mixed in a volume ratio of about 1:1 to about 1:9.

[0080] The lithium salt may be a material that dissolves in the non-aqueous organic solvent to serve as a lithium ion supply source in a rechargeable lithium battery and plays a role in enabling basic operations of the rechargeable lithium battery and promoting the movement of lithium ions between the positive electrode and the negative electrode. The lithium salt may include, for example, at least one selected from the group consisting of 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 SO2) (wherein x and y are integers between 1 and 20), lithium trifluoromethanesulfonate, lithium tetrafluoroethanesulfonate, lithium difluorobis(oxalato)phosphate (LiDFBOP), and lithium bis(oxalato)borate (LiBOB)

[0081] Rechargeable lithium battery

[0082] Based on the shape of the rechargeable lithium battery, the rechargeable lithium battery can be classified into cylindrical, prismatic, pouch, or coin types (categories). Figures 2 to 5 middle, Figure 2 Showing cylindrical batteries, Figure 3 Display prismatic cells, and Figure 4 and 5 Each shows the type or kind of battery in the bag. Figures 2 to 5 , the rechargeable lithium battery 100 may include an electrode assembly 40 in which a separator 30 is inserted between a positive electrode 10 and a negative electrode 20, and may further include a case 50 in which the electrode assembly 40 is housed. The positive electrode 10, the negative electrode 20, and the separator 30 may be immersed in an electrolyte solution. In some embodiments, the rechargeable lithium battery 100 may include a sealing member 60 that seals the case 50, such as Figure 2 In some embodiments, as shown in Figure 3 As shown in FIG, the rechargeable lithium battery 100 may include a positive electrode lead tab 11, a positive electrode terminal 12, a negative electrode lead tab 21, and a negative electrode terminal 22. In some embodiments, as shown in FIG. Figure 4 and 5 As shown in , the rechargeable lithium battery 100 may include electrode tabs 70 , or positive and negative electrode tabs 71 and 72 , which serve as electrical paths for externally inducing current generated in the electrode assembly 40 .

[0083] The rechargeable lithium battery according to one or more embodiments of the present disclosure may be applied to a motor vehicle, a mobile phone, and / or any other electrical equipment, but the embodiments of the present disclosure are not limited thereto.

[0084] All-solid-state batteries

[0085] Figure 6 A cross-sectional view showing an all-solid-state battery according to one or more embodiments of the present disclosure is shown. In one or more embodiments of the present disclosure, the rechargeable lithium battery may be an all-solid-state battery.

[0086] In one or more embodiments, the positive electrode active material layer AML1 may further include a solid electrolyte. The solid electrolyte may include a sulfide-based solid electrolyte having excellent or suitable lithium ion conductivity characteristics. The sulfide-based solid electrolyte may include, for example, at least one selected from the following: Li2S-P2S5, Li2S-P2S5-LiX (wherein X is a halogen element), Li2S-P2S5-Li2O, Li2S-P2S5-Li2O-LiI, Li2S-SiS2, Li2S-SiS2-LiI, Li2S-SiS2-LiBr, Li2S-SiS2-LiCl, Li2S-SiS2-B2S3-LiI, Li2S-SiS2-P2S5-LiI, Li2S-B2S3, Li2S-P2S5-Z m S n (wherein m and n are each a positive integer, and Z is at least one selected from Ge, Zn, and Ga), Li2S-GeS2, Li2S-SiS2-Li3PO4, Li2S-SiS2-Li p MO q (wherein p and q are each a positive integer, and M is at least one selected from P, Si, Ge, B, Al, Ga, and In), Li 7-x PS 6-x Cl x (where 0≤x≤2), Li 7-x PS 6-x Br x (where 0≤x≤2), and Li 7-x PS 6-x I x (where 0≤x≤2).

[0087] In one or more embodiments, the sulfide-based solid electrolyte may include, for example, a material selected from Li 7-x PS 6-x Cl x (where 0≤x≤2), Li 7-x PS6-x Br x (where 0≤x≤2), and Li 7-x PS 6-x I x (where 0≤x≤2). For example, in one or more embodiments, the sulfide-based solid electrolyte may be an argyrodite-type or species compound including at least one selected from Li6PS5Cl, Li6PS5Br, and Li6PS5I.

[0088] In one or more embodiments, the sulfide-based solid electrolyte may include Li 7-a M a PS 6-c X c (where 0≤a≤2 and 0≤c≤2) is a compound of the argyrodite type or species. In the above chemical formula, X can be F, Br, Cl, or (for example, any suitable) combination thereof. In addition, M can be scandium (Sc), yttrium (Y), titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten (W), manganese (Mn), technetium (Tc), rhenium (Re), iron (Fe), ruthenium (Ru), osmium (Os), cobalt (Co), rhodium (Rh), iridium (Ir), nickel (Ni), palladium (Pd), platinum (Pt), copper (Cu), silver (Ag), gold (Au), zinc (Zn), cadmium (Cd), mercury (Hg), aluminum (Al), gallium (Ga), indium (In), thallium (Tl), silicon (Si), germanium (Ge), tin (Sn), lead (Pb), arsenic (As), antimony (Sb), bismuth (Bi), or any combination thereof.

[0089] The argyrodite-type or species solid electrolyte may have a density of about 1.5 g / cc to about 2.0 g / cc. Because the argyrodite-type or species solid electrolyte has a density equal to or greater than about 1.5 g / cc, it can reduce the internal resistance of the all-solid-state battery and prevent or reduce short circuits and penetration of the solid electrolyte layer due to the formation of lithium dendrites. The solid electrolyte may have, for example, an elastic modulus of about 15 GPa to about 35 GPa.

[0090] The solid electrolyte included in the positive electrode active material layer AML1 may have an average particle diameter (D 50 ) average particle diameter (D 50 For example, in one or more embodiments, the average particle diameter (D 50) may be an average particle diameter (D 50 ) is equal to or less than about 90%, equal to or less than about 80%, equal to or less than about 70%, equal to or less than about 60%, equal to or less than about 50%, equal to or less than about 40%, equal to or less than about 30%, or equal to or less than about 20%. The average particle diameter (D 50 ) may be a median diameter measured by a laser particle size distribution analyzer.

[0091] In one or more embodiments of the present disclosure, the all-solid-state battery may include a solid electrolyte layer SEL instead of the electrolyte solution ELL as described in more detail above. The solid electrolyte layer SEL may include a solid electrolyte, for example, a sulfide-based solid electrolyte. The sulfide-based solid electrolyte may be prepared, for example, by melting and quenching starting materials such as Li2S and / or P2S5 or mechanically grinding them. In addition, after the above treatment, the resultant may be heat-treated. The solid electrolyte may be in an amorphous state, a crystalline state, or a mixed state of an amorphous state and a crystalline state. The solid electrolyte may include at least sulfur (S), phosphorus (P), and lithium (Li) among the component elements in the sulfide-based solid electrolyte described above. For example, the solid electrolyte may be a material including Li2S-P2S5. When a material including Li2S-P2S5 is used as the sulfide-based solid electrolyte material of the solid electrolyte, a mixing molar ratio of Li2S to P2S5 may be in the range of about 50:50 to about 90:10 (or Li2S:P2S5=50:50 to 90:10).

[0092] The sulfide-based solid electrolyte may include, for example, a material selected from Li 7-x PS 6-x Cl x (where 0≤x≤2), Li 7-x PS 6-x Br x (where 0 ≤ x ≤ 2), and Li 7-x PS 6-x I x (where 0 ≤ x ≤ 2). For example, in one or more embodiments, the sulfide-based solid electrolyte may be an argyrodite-type or species compound including at least one selected from Li6PS5Cl, Li6PS5Br, and Li6PS5I.

[0093] In one or more embodiments, the sulfide-based solid electrolyte may include Li 7-a M a PS6-c X c (where 0≤a≤2 and 0≤c≤2) is a compound of the argyrodite type or species. In the aforementioned chemical formula, X can be F, Br, Cl, or (eg, any suitable) combination thereof. In addition, M can be scandium (Sc), yttrium (Y), titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten (W), manganese (Mn), technetium (Tc), rhenium (Re), iron (Fe), ruthenium (Ru), osmium (Os), cobalt (Co), rhodium (Rh), iridium (Ir), nickel (Ni), palladium (Pd), platinum (Pt), copper (Cu), silver (Ag), gold (Au), zinc (Zn), cadmium (Cd), mercury (Hg), aluminum (Al), gallium (Ga), indium (In), thallium (Tl), silicon (Si), germanium (Ge), tin (Sn), lead (Pb), arsenic (As), antimony (Sb), bismuth (Bi), or any combination thereof.

[0094] The argyrodite-type or species solid electrolyte may have a density of about 1.5 g / cc to about 2.0 g / cc. Because the argyrodite-type or species solid electrolyte has a density equal to or greater than about 1.5 g / cc, it can reduce the internal resistance of the all-solid-state battery and prevent or reduce short circuits and penetration of the solid electrolyte layer (SEL) due to the formation of lithium dendrites. The solid electrolyte may have, for example, an elastic modulus of about 15 GPa to about 35 GPa.

[0095] In one or more embodiments, the solid electrolyte layer SEL may further include a binder. The binder included in the solid electrolyte layer SEL may include styrene-butadiene rubber (SBR), polytetrafluoroethylene (PTFE), polyvinylidene fluoride, and / or polyethylene, but the embodiments of the present disclosure are not limited thereto. The binder of the solid electrolyte layer SEL may be the same as or similar to the binder of the positive electrode active material layer AML1 or the binder of the negative electrode active material layer AML2.

[0096] dry electrode

[0097] Figure 7 A cross-sectional view showing a dry electrode (positive electrode or negative electrode) according to one or more embodiments of the present disclosure is shown. Figure 8 and 9 Shown are graphs each showing a concentration distribution of a second binder in a cross section of a dry electrode according to one or more embodiments of the present disclosure. Figure 10 A perspective view showing a pattern-coated dry electrode according to one or more embodiments of the present disclosure is shown. Figure 1A description of those components that are the same as discussed above will be provided, and the differences will be discussed in more detail.

[0098] Reference Figure 7 , a dry electrode according to one or more embodiments of the present disclosure may include an electrode current collector COL, an electrode active material layer AML, and a composite layer CPL.

[0099] The electrode current collector COL may include the positive electrode current collector COL1 or the negative electrode current collector COL2 discussed above.

[0100] The electrode active material layer AML may include the positive electrode active material layer AML1 or the negative electrode active material layer AML2 discussed above. The electrode active material layer AML may include an electrode active material, a first binder, and a first conductive material. The electrode active material may include the positive electrode active material or the negative electrode active material discussed above. In one or more embodiments, the electrode active material layer AML may further include a solid electrolyte.

[0101] The first binder can be used to improve the adhesion of the positive (or negative) electrode active material particles to each other and also to improve the adhesion of the positive (or negative) electrode active material to the electrode current collector COL. The first binder may include, for example, polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, a polymer containing ethylene oxide (ethylene oxide), polyvinyl pyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, epoxy resin, (meth)acrylic resin, polyester resin and / or nylon, but embodiments of the present disclosure are not limited thereto.

[0102] For example, in one or more embodiments, the first adhesive may be a dry adhesive. The dry adhesive may be defined as an adhesive that is not impregnated, dissolved, or dispersed in a solvent. For example, the dry adhesive may be an adhesive that does not include a solvent or is not in contact with a solvent.

[0103] The dry binder may be, for example, a fibrillated binder. The fibrillated binder may serve as a matrix for supporting and binding the electrode active material and other components included in the electrode active material layer (AML). For example, a scanning electron microscope image of an electrode cross-section may be used to confirm that the fibrillated binder has a fibrous morphology. The fibrillated binder may have an aspect ratio of about 10 or greater, about 20 or greater, about 50 or greater, or about 100 or greater.

[0104] In one or more embodiments, the first binder may include at least one selected from polytetrafluoroethylene (PTFE), polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) copolymer, polyvinylidene fluoride (PVDF), polyvinyl alcohol (PVA), polyacrylonitrile (PAN), carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, cellulose, polyvinyl pyrrolidone (PVP), polyethylene (PE), polypropylene (PP), ethylene-propylene-diene polymer (EPDM), sulfonated EPDM, styrene-butadiene rubber (SBR), fluororubber, and copolymers thereof, but the embodiments of the present disclosure are not limited thereto, and any binder may be used as long as the dry electrode can be manufactured.

[0105] In one or more embodiments, the dry binder may include a fluorine-based binder. The fluorine-based binder may include, for example, at least one selected from polytetrafluoroethylene (PTFE), polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) copolymer, and polyvinylidene fluoride (PVDF).

[0106] The first binder may be present in an amount of about 0.5% to about 5% by weight relative to 100% by weight of the total weight of the electrode active material layer AML. When the amount of the first binder satisfies the above range, electrode bonding strength may be increased and high electrode energy density may be maintained.

[0107] The first conductive material, which is an electrically conductive material (e.g., an electron conductor), can be used to provide conductivity to the electrode, and any suitable conductive material that does not cause chemical changes in the battery can be used as the first conductive material constituting the battery. The first conductive material may include, for example, carbon-based materials such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fibers, carbon nanofibers, and / or carbon nanotubes; metal powders or metal fibers containing one or more selected from the group consisting of copper, nickel, aluminum, and silver; conductive polymers such as polyphenylene derivatives; and / or (e.g., any suitable) mixtures thereof. For example, the first conductive material may include at least one selected from the group consisting of: a carbon-based material, a metal-based material, a conductive polymer, and / or (e.g., any suitable) mixtures thereof.

[0108] The first conductive material may be a dry conductive material. The dry conductive material may be defined as a conductive material that is not immersed, dissolved, or dispersed in a solvent. For example, the dry conductive material may be a conductive material that does not include a solvent or is not in contact with a solvent.

[0109] The dry conductive material may include, for example, the carbon-based material, the metal-based material discussed above, and / or (e.g., any suitable) combination thereof. The carbon-based material may include carbon black, graphite particles, natural graphite, artificial graphite, acetylene black, Ketjen black, carbon fiber, and / or carbon nanotubes, but the embodiments of the present disclosure are not limited thereto, and any suitable material may be used as the carbon-based material as long as it is used in the art.

[0110] The amount of the first conductive material may be in an amount of about 0.5 wt % to about 5 wt % relative to 100 wt % of the total weight of the electrode active material layer AML. When the amount of the first conductive material satisfies the above range, electrode conductivity may be increased and high electrode energy density may be maintained.

[0111] The composite layer CPL may be arranged between the electrode current collector COL and the electrode active material layer AML. The composite layer CPL may be configured to combine the electrode active material layer AML with the electrode current collector COL. The composite layer CPL may include components substantially the same as those of the electrode active material layer AML, and may include, for example, an electrode active material, a first binder, and a first conductive material. Furthermore, the composite layer CPL may further include other components that are excluded from (not included in) the electrode active material layer AML, and, for example, in one or more embodiments, may further include a second binder and a second conductive material. For example, the composite layer CPL may be a layer in which the components of the electrode active material layer AML and the components of the adhesive layer ADL are present together.

[0112] Because the composite layer CPL includes the second binder, the bonding strength between the electrode current collector COL and the electrode active material layer AML can be increased. The second binder in the composite layer CPL can be, for example, a conductive binder or a non-conductive binder. The conductive binder can be, for example, an ion conductive binder and / or an electron conductive binder. Adhesives having both ion conductivity and electron conductivity (e.g., having both ion conductivity and electron conductivity) can be classified as both ion conductive binders and electron conductive binders (e.g., simultaneously classified as both ion conductive binders and electron conductive binders).

[0113] The ion conductive binder may include, for example, one or more selected from the group consisting of polystyrene sulfonate (polystyrene sulfonate) (PSS), polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-HFP), polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), poly(methyl methacrylate) (PMMA), polyethylene oxide (PEO), polyethylene glycol (PEG), polyacrylonitrile (PAN), polytetrafluoroethylene (PTFE), polyethylenedioxythiophene (PEDOT), polypyrrole (PPy), polyacrylonitrile (PAN), polyaniline, and polyacetylene. The ion conductive binder may include a polar functional group. The ion conductive binder containing a polar functional group may include, for example, one or more selected from the group consisting of Nafion TM 、Aquivion TM 、Flemion TM 、Gore TM 、Aciplex TM Morgane ADP TM , sulfonated poly(etheretherketone) (SPEEK), sulfonated poly(aryleneetherketoneketonesulfone) (SPAEKKS), sulfonated poly(aryleneetherketone) (SPAEK), poly[bis(benzimidazolobenzoisoquinolinone)] (SPBIBI), poly(styrenesulfonate) (PSS), and lithium 9,10-diphenylanthracene-2-sulfonate (DPASLi + ).

[0114] The electron conductive binder may include, for example, one or more selected from the group consisting of polyacetylene, polythiophene, polypyrrole, poly(p-phenylene), poly(phenylene vinylene), poly(phenylene sulfide), and polyaniline. The composite layer CPL may be, for example, a conductive layer including a conductive polymer.

[0115] In one or more embodiments, the second binder included in the composite layer CPL may be selected from the first binder included in the electrode active material layer AML. The second binder of the composite layer CPL may be the same as the first binder of the electrode active material layer AML. The second binder of the composite layer CPL may be, for example, a fluorine-based binder. The fluorine-based binder of the composite layer CPL may include, for example, polyvinylidene fluoride (PVDF). The composite layer CPL may be, for example, a bonding layer (adhesive layer) including the second binder.

[0116] In one or more embodiments, the first binder and the second binder may be different from each other. For example, in some embodiments, the first binder may include polytetrafluoroethylene (PTFE), and the second binder may include at least one selected from polyvinylidene fluoride (PVDF) and styrene-butadiene rubber (SBR).

[0117] The second binder may be present in an amount of about 5 wt % to about 20 wt % relative to 100 wt % of the total weight of the composite layer CPL. When the amount of the second binder satisfies the above range, the bonding force between the electrode current collector COL and the electrode active material layer AML may be increased.

[0118] The total thickness w of the composite layer CPL may be in the range of about 1 micrometer (μm) to about 3 μm. For example, the total thickness w of the composite layer CPL may be defined to refer to a region in which the second adhesive exists.

[0119] Reference Figure 8 The concentration of the second binder may vary within the composite layer CPL. For example, in one or more embodiments, the concentration of the second binder in the composite layer CPL may gradually decrease in a direction from the top surface of the electrode current collector COL (i.e., the surface facing the electrode active material layer AML) toward the electrode active material layer AML (e.g., the concentration of the binder changes slowly or gradually, rather than abruptly, e.g., a gentle slope rather than a sudden (sharp) drop). In other words, the gradual decrease in the concentration of the second binder within the composite layer means that there is a concentration gradient from the top surface of the electrode current collector (the surface facing the electrode active material layer) toward the electrode active material layer itself. By varying the binder concentration in this manner (e.g., slowly and incrementally), the dry electrode can achieve improved performance and reliability. Furthermore, the concentration of the second binder in the composite layer CPL may have a maximum value at the interface between the top surface of the electrode current collector COL and the bottom surface of the composite layer CPL (i.e., the surface adjacent to the top surface of the electrode current collector COL). The concentration of the second binder may have a minimum value (e.g., zero) at the interface between the composite layer CPL and the electrode active material layer AML. By including the composite layer CPL having the above-described characteristics, the binding force between the electrode current collector COL and the electrode active material layer AML may be increased.

[0120] According to a comparative example of the present disclosure, a dry electrode may include an electrode current collector COL, an electrode active material layer AML, and an adhesive layer ADL. Figure 7 and 8 The composite layer CPL according to one or more embodiments of the present disclosure depicted in may be a layer in which the electrode active material layer AML and the adhesive layer ADL are blended (mixed) with each other. In contrast, the adhesive layer ADL according to the comparative example may be a separate (separate) layer that is significantly different from the electrode active material layer AML.

[0121] The adhesive layer ADL may include a second adhesive and a second conductive material. The adhesive layer ADL may not include (e.g., may exclude) the components of the electrode active material layer AML, and for example, may not include (e.g., may exclude) any of the electrode active material, the first adhesive, and / or the first conductive material. The adhesive layer ADL may be arranged between the electrode current collector COL and the electrode active material layer AML. Figure 9 , the second adhesive may be present only in the adhesive layer ADL. The concentration of the second adhesive in the adhesive layer ADL may be substantially uniform between the electrode current collector COL and the electrode active material layer AML. For example, the concentration of the second adhesive in the adhesive layer ADL may be constant without substantially changing in the direction from the bottom surface of the adhesive layer ADL (i.e., the surface adjacent to the electrode current collector COL) toward the top surface of the adhesive layer ADL (i.e., the surface adjacent to the electrode active material layer). The dry electrode according to the comparative example of the present invention does not include the composite layer CPL, but includes an adhesive layer ADL that is clearly (unambiguously) distinguished from the electrode active material layer AML. As a result, the bonding force between the electrode current collector COL and the electrode active material layer AML may be relatively weak, and the resistance of the dry electrode may be relatively high.

[0122] Return to reference Figure 7 The composite layer CPL may include a second conductive material that is an electrically conductive material (e.g., an electron conductor). The second conductive material included in the composite layer CPL may be selected from the first conductive material included in the electrode active material layer AML. The second conductive material of the composite layer CPL may include the same carbon-based conductive material as the first conductive material of the electrode active material layer AML. Because the composite layer CPL includes the carbon-based conductive material, the composite layer CPL may be a conductive layer (i.e., an electrical conductor). In one or more embodiments, the composite layer CPL may be a conductive layer including, for example, the second binder and a carbon-based conductive material (the second conductive material).

[0123] The amount of the second conductive material may be about 10 wt % to about 50 wt % relative to 100 wt % of the total weight of the composite layer CPL. When the amount of the second conductive material satisfies the above range, electrode conductivity may be increased and high electrode energy density may be maintained.

[0124] In one or more embodiments, the composite layer CPL may be provided on opposite sides of the electrode current collector COL. For example, the composite layer CPL may include multiple composite layers, and the electrode current collector COL may be arranged between the multiple composite layers. The electrode active material layer AML may be correspondingly arranged on the multiple composite layers.

[0125] Reference Figure 10 According to one or more embodiments of the present disclosure, the dry electrode may be configured such that the composite layer CPL is pattern-coated on the electrode current collector COL. For example, the composite layer CPL may include multiple composite layers, and each of the multiple composite layers may be intermittently distributed on the electrode current collector COL. The electrode active material layer AML may include multiple electrode active material layers, and the multiple electrode active material layers may be arranged accordingly on the multiple composite layers. Therefore, the dry electrode in which the composite layer CPL and the electrode active material layer AML are pattern-coated on the electrode current collector COL may be suitable for rechargeable batteries having a cylindrical shape or any other suitable shape.

[0126] The dry electrode according to one or more embodiments may be manufactured by the following manufacturing method.

[0127] Method for manufacturing dry electrodes

[0128] Figure 11 A flow chart showing a method of manufacturing a dry electrode according to one or more embodiments of the present disclosure is shown. Figures 12 to 16 Each shows a perspective view showing a method of manufacturing a dry electrode according to one or more embodiments of the present disclosure.

[0129] Reference Figure 11 The method for manufacturing a dry electrode may include: mixing an electrode active material, a first binder, and a first conductive material to form a dry mixture (S200), allowing the dry mixture to form a film to form an electrode active material layer (S400), forming a composite layer on the electrode active material layer (S500), and laminating the electrode active material layer on which the composite layer is formed on an electrode current collector (S600). The composite layer forming step (e.g., action or task) step (S500) may include: coating the electrode active material layer with an adhesive solution including a second binder, a second conductive material, and an organic solvent (S520), and drying the adhesive solution (S540).

[0130] Reference Figure 12 , the electrode active material AM, the conductive material CDM, and the binder BND may be dry-mixed to form a dry mixture S200. Dry mixing may refer to mixing without using a process solvent (process solvent). The process solvent may be, for example, a solvent used in preparing an electrode slurry. The process solvent may be water or N-methyl-2-pyrrolidone (NMP), but embodiments of the present disclosure are not limited thereto, and the process solvent may be any solvent as long as it can be used in manufacturing an electrode slurry.

[0131] The conductive material CDM and the binder BND may correspond to a first conductive material and a first binder, respectively, and the first conductive material and the first binder may be a dry conductive material and a dry binder, respectively. The electrode active material AM may be a dry electrode active material.

[0132] The stirrer KND can be used to perform dry mixing at a temperature of about 25° C. to about 65° C. For example, the stirrer KND can be used to perform dry mixing at a rotation speed ranging from about 10 rpm to about 10,000 rpm, or from about 100 rpm to about 10,000 rpm. The stirrer KND can be used to perform dry mixing for about 1 minute to about 200 minutes, or from about 1 minute to about 150 minutes.

[0133] The dry mixing may be performed one or more times. First, the electrode active material AM, the first conductive material, and the first binder may be dry mixed for the first time to prepare a first mixture. The first dry mixing may be performed for about 15 minutes or less at a temperature of about 25°C to about 65°C at a rotation speed of about 2,000 rpm or less. For example, in one or more embodiments, the first dry mixing may be performed for about 5 minutes to about 15 minutes at a temperature of about 25°C to about 65°C at a rotation speed of about 500 rpm to about 2,000 rpm. In the first dry mixing, the electrode active material AM, the first conductive material, and the first binder may be uniformly (e.g., substantially uniformly) mixed with each other.

[0134] Next, the electrode active material AM, the first conductive material, and the first binder may be dry-mixed a second time to prepare a second mixture. The second dry-mixing may be performed at a temperature of about 25° C. to about 65° C. and a rotation speed of about 4,000 rpm or greater for about 10 minutes or more. For example, in one or more embodiments, the second dry-mixing may be performed at a temperature of about 25° C. to about 65° C. and a rotation speed of about 4,000 rpm to about 9,000 rpm for about 10 minutes to about 60 minutes. The second dry-mixing may produce a dry mixture including the fibrillated first binder.

[0135] In one or more embodiments, a plasticizer or a pore former may be further added to the dry mixture to form pores in the electrode plate.

[0136] The kinds / types and amounts of the electrode active material AM, the first conductive material, and the first binder used in the dry mixture may be as discussed above.

[0137] Reference Figure 13The dry mixture MXR can be thinned to form an electrode active material layer AML S400. The dry mixture MXR can be introduced from the feeder FDR into an extrusion device and extruded into a sheet or film. For example, in one or more embodiments, the extrusion device may include a pair of rollers R. The dry mixture MXR can be introduced into the gap between the pair of rollers R.

[0138] For example, the step (eg, action or task) may be performed at a temperature of about 25° C. to about 150° C. and a pressure of about 500 kPa to about 3 MPa. Thus, a film-shaped electrode active material layer AML may be formed.

[0139] Reference Figure 14 , an adhesive solution ALQ may be coated on the electrode active material layer AML S520. The adhesive solution ALQ may include a second binder, a second conductive material, and an organic solvent.

[0140] In one or more embodiments, the organic solvent may include, for example, at least one selected from the group consisting of ethanol, methanol, and isopropyl alcohol. By including the organic solvent, the adhesive solution ALQ can be applied to the electrode active material layer AML in a liquid form. The organic solvent may be any solvent that allows the adhesive solution ALQ to form an adhesive layer (i.e., in a liquid form), and is not limited to the examples described.

[0141] For example, in one or more embodiments, in addition to the above materials, the adhesive solution ALQ may further include an additive, such as a dispersant, which may assist in dispersing the second binder and the second conductive material in the adhesive solution ALQ.

[0142] The adhesive solution ALQ can be applied using methods widely available in the art. For example, in one or more embodiments, the adhesive solution ALQ can be applied by at least one method selected from the group consisting of spray coating, dispensing, gravure coating, and inkjet coating. For example, spray coating can apply the adhesive solution ALQ thinly and evenly (e.g., substantially evenly) without directly contacting the electrode active material layer AML.

[0143] The electrode active material layer AML may include a plurality of pores. The adhesive solution ALQ may enter the plurality of pores. Therefore, if the adhesive solution ALQ is applied to the electrode active material layer AML (for example, when the adhesive solution ALQ is applied to the electrode active material layer AML), a layer ALQ+AML may be formed in which the adhesive solution ALQ and the electrode active material layer AML coexist.

[0144] Reference Figure 15, the adhesive solution ALQ may be dried S540. For example, in one or more embodiments, the adhesive solution ALQ may be dried on the electrode current collector (see Figure 16 Since the organic solvent included in the adhesive solution ALQ has strong volatility, the organic solvent can be removed before lamination on the electrode current collector COL.

[0145] Drying the adhesive solution ALQ may include drying by air, drying by light, or drying by a combination of air and light. For example, air drying may include at least one selected from the group consisting of hot air drying and cold air drying. For example, light drying may include at least one selected from the group consisting of infrared drying and ultraviolet drying.

[0146] When the adhesive solution ALQ is dried, a composite layer CPL may be formed on the electrode active material layer AML. As discussed above, the composite layer CPL may include the electrode active material AM, the first binder, the first conductive material, the second binder, and the second conductive material. The concentration of the second binder may vary within the composite layer CPL.

[0147] The composite layer forming step (e.g., action or task) step S500 may include forming a patterned composite layer CPL on the electrode active material layer AML. For example, in one or more embodiments, in steps (e.g., actions or tasks) S520 and S540, the adhesive solution ALQ may be intermittently coated and dried on the electrode active material layer AML. Thus, a plurality of composite layers CPL may be formed on the electrode active material layer AML in the shape of a pattern, and the electrode current collector (see Figure 16 The electrode active material layer AML can be laminated on a plurality of composite layers CPL, and as a result, the electrode active material layer AML can be attached to the electrode current collector COL in a pattern. The portion of the electrode active material layer AML that is not attached to the electrode current collector COL, that is, the portion where the composite layer CPL is not formed, can be removed. Thus, a dry electrode can be obtained in which the composite layer CPL and the electrode active material layer AML are coated on the electrode current collector COL in a pattern (see Figure 10 ).

[0148] Reference Figure 16 The electrode active material layer AML may be laminated on the electrode current collector COL S600. This step (eg, action or task) may include providing the electrode current collector COL. The material of the electrode current collector COL may be as discussed above.

[0149] The electrode active material layer AML may be disposed on a side or surface (eg, one side (see Figure 16 ), or two opposite sides (see Figure 17)) on, thereby manufacturing an electrode. For example, the electrode can be manufactured by laminating the electrode active material layer AML on the electrode current collector COL. The lamination can use a roller press or a plate press, but the embodiments of the present disclosure are not limited thereto.

[0150] For example, in one or more embodiments, the lamination may be performed at a temperature of about 25° C. to about 180° C. under a pressure of about 500 kPa to about 15 MPa. Thus, the electrode active material layer AML may be closely and firmly adhered to the electrode current collector COL.

[0151] The method of manufacturing a dry electrode according to one or more embodiments of the present disclosure may have the following effects.

[0152] Because the adhesive solution ALQ is directly coated on the electrode active material layer AML, the width of the electrode active material layer AML can be freely adjusted to adhere to the electrode current collector COL.

[0153] In addition, in the present disclosure, the adhesive layer ADL may not be formed on the electrode current collector COL, so that there is no need to uniformly (e.g., substantially uniformly) coat the adhesive layer ADL on the electrode current collector COL and align the electrode active material layer AML with the electrode current collector COL on which the adhesive layer ADL is coated, which can lead to a reduction in the scale of equipment required for manufacturing the dry electrode and the ease of manufacturing the dry electrode.

[0154] Since the adhesive solution ALQ enters the plurality of pores in the electrode active material layer AML, the bonding force between the electrode current collector COL and the electrode active material layer AML can be increased, and the contact area between the first conductive material and the second conductive material can be increased and the electrode resistance can be reduced. Since the adhesive solution ALQ enters the plurality of pores in the electrode active material layer AML, a composite layer in which the components of the electrode active material layer AML and the components of the adhesive solution ALQ are blended can be formed (see Figure 7 of CPL).

[0155] When the adhesive layer ADL is coated on the electrode current collector COL in the form of a pattern, the starting point of the pattern coating is set or predetermined. Differently, according to one or more embodiments of the present disclosure, the adhesive solution ALQ can be intermittently coated on the electrode active material layer AML to manufacture a dry electrode on which the composite layer CPL is coated in the form of a pattern, thereby increasing the manufacturing yield (finished product rate) of the dry electrode.

[0156] Dry electrode manufacturing device DEV

[0157] Figure 17 A schematic diagram showing an apparatus for manufacturing a dry electrode according to one or more embodiments of the present disclosure is shown. Figure 18 A schematic diagram showing a dryer according to one or more embodiments of the present disclosure is shown.

[0158] refer to Figure 12 、 13 , and 17, the dry electrode manufacturing device DEV of the present disclosure may include an agitator KND, a feeder FDR, a roller R, an adhesive solution supplier SP, a distance sensor DS, a dryer DP, and a laminator.

[0159] Roller R may include a plurality of rollers (see Figure 12 、 13 , and 17). The roller R can transfer the electrode active material layer AML, the composite layer CPL, and the electrode current collector COL, which will be discussed later. The roller R can continuously perform the above-mentioned method of manufacturing a dry electrode.

[0160] In one or more embodiments, the agitator KND may be, for example, a kneader (see Figure 12 ). The agitator KND may include, for example, a chamber, one or more rotating shafts arranged in the chamber, and blades rotatably coupled to the rotating shafts and arranged in the longitudinal direction of the rotating shafts. The blades may be, for example, at least one selected from the group consisting of a ribbon blade, a sigma (σ) blade, a Z blade, a dispersion blade, and a spiral blade. Because the blades are included, the electrode active material AM, the dry conductive material, and the dry binder can be effectively mixed with each other even in the absence of any solvent. For example, in one or more embodiments, a dough-like dry mixture can be prepared.

[0161] The prepared dry mix can be introduced into the extrusion equipment via the feeder FDR (see Figure 13 ). For example, the extrusion device may include a pair of rollers R. The extrusion device may extrude the dry mixture in the form of a sheet or film. For example, in one or more embodiments, the electrode active material layer AML may be formed by a feeder FDR.

[0162] For example, the extrusion apparatus can cause the dry mixture to form a film at a temperature of about 25°C to about 150°C and a pressure of about 500 kPa to about 3 MPa.

[0163] The adhesive solution supplier SP can apply the adhesive solution ALQ on the electrode active material layer AML (see Figure 14 and 17). The adhesive solution supplier SP can apply the adhesive solution ALQ using a coating method widely applicable in the art. For example, the adhesive solution supplier SP may include at least one selected from the group consisting of a spray coater, a dispenser, a gravure roll coater, and an inkjet coater. For example, in some embodiments, the spray coater can apply the adhesive solution ALQ thinly and evenly (e.g., substantially evenly) without directly contacting the electrode active material layer AML.

[0164] The dryer DP dries the adhesive solution ALQ (see Figure 15 and 17 ). A dryer DP may be arranged between the adhesive solution supplier SP and the laminator.

[0165] The dryer DP may include at least one selected from the group consisting of: an air dryer that uses air for drying, a light dryer that uses light for drying, and / or (e.g., any suitable) combination thereof. The air dryer may include at least one selected from the group consisting of: a hot air dryer and a cold air dryer. The light dryer may include at least one selected from the group consisting of: an infrared dryer and a UV dryer.

[0166] refer to Figure 18 In one or more embodiments of the present disclosure, the dryer DP may include both an air dryer and a light dryer (e.g., simultaneously). The dryer DP may include a heat source SRC and a lamp LMP that provides light. The heat source SRC may supply temperature and / or wind WND. The lamp LMP may provide light LGT, ultraviolet rays, or infrared rays. The temperature and wind WND supplied from the heat source SRC may reach the adhesive solution ALQ after passing through a plurality of holes formed in the lamp LMP.

[0167] The wind WND or light LGT of the dryer DP may be used to uniformly (eg, substantially uniformly) spread the adhesive solution ALQ on the electrode active material layer AML. The wind WND or light LGT of the dryer DP may propagate in a radial direction or a linear direction.

[0168] The dryer DP can be configured to adjust its angle (e.g., the angle of drying and / or drying output) (e.g., relative to the composite layer CPL). Thus, it can evenly (e.g., substantially evenly) spread the adhesive solution ALQ over the electrode active material layer AML and can also prevent or reduce unintentional spreading of the adhesive solution ALQ. The dryer DP can form a flat composite layer CPL. Furthermore, dry electrode production can be performed continuously without interruption.

[0169] The distance sensor DS may identify the travel distance of the electrode active material layer AML. The distance sensor DS may be located on the electrode active material layer AML. The distance sensor DS may be disposed between the feeder FDR and the adhesive solution supplier SP.

[0170] For example, the distance sensor DS may detect a first point on the electrode active material layer AML, and after the electrode active material layer AML is transferred by the roller R, the distance sensor DS may detect a second point on the electrode active material layer AML, thereby identifying the travel distance of the electrode active material layer using the difference in distance between the first point and the second point.

[0171] The distance sensor DS may identify the travel distance of the electrode active material layer AML using a method widely applicable in the art. For example, the distance sensor DS may irradiate light to identify the travel distance of the electrode active material layer AML.

[0172] The dry electrode manufacturing device DEV of the present invention may include a controller. The controller may include multiple controllers.

[0173] The controller may control the operation of the adhesive solution supplier SP. The controller may receive a signal SGN from the distance sensor DS. For example, the controller may receive a signal detecting a first point on the electrode active material layer AML to control the adhesive solution supplier SP to apply the adhesive solution ALQ. The controller may receive a signal detecting a second point on the electrode active material layer AML to control the adhesive solution supplier SP to stop applying the adhesive solution ALQ.

[0174] The controller may control the operation of the dryer DP. The controller may adjust the angle of the dryer DP.

[0175] The laminator (eg, laminating unit) may bond the transferred electrode active material layer AML and the composite layer CPL to the electrode current collector COL (see Figure 16 and 17 ). The laminator may include a roller press or a plate press. When the laminator includes a roller press, the laminator may include a plurality of rollers.

[0176] For example, in one or more embodiments, the laminator may bond the electrode active material layer AML and the composite layer CPL to the electrode current collector COL at a temperature of about 25° C. to about 180° C. under a pressure of about 500 kPa to about 15 MPa.

[0177] When the method for manufacturing a dry electrode and / or the apparatus for manufacturing a dry electrode according to one or more embodiments of the present disclosure is used, a dry electrode can be easily and efficiently manufactured. In addition, a dry electrode with reduced resistance can be manufactured.

[0178] In this disclosure, expressions such as "at least one of," "one of," and "selected from," when preceding or following a list of elements, modify the entire list of elements and do not modify the individual elements of that list. For example, "at least one of a, b, or c," "at least one selected from a, b, and c," "at least one selected from a through c," and the like may indicate only a, only b, only c, both a and b (e.g., simultaneously), both a and c (e.g., simultaneously), both b and c (e.g., simultaneously), all of a, b, and c, or variations thereof. As used herein, " / " may be interpreted as either "and" or "or," depending on the context.

[0179] In the context of the present disclosure and unless defined otherwise, the terms "use" and "utilize" may be considered synonymous with the terms "utilize," respectively.

[0180] In the present disclosure, the term "Group" as used herein refers to a Group of the Periodic Table of the Elements according to the 1 to 18 classification system of the International Union of Pure and Applied Chemistry ("IUPAC").

[0181] As used herein, the terms "substantially," "about," and similar terms are used as terms of approximation and not as terms of degree, and are intended to account for the inherent deviations in measured or calculated values ​​that will be recognized by one of ordinary skill in the art. As used herein, "about" or "approximately" also includes the stated value and means within an acceptable range of deviation for that particular value as determined by one of ordinary skill in the art taking into account the measurement in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system). For example, "about" can mean within one or more standard deviations, or within ± 30%, 20%, 10%, or 5% relative to the stated value.

[0182] Any numerical range listed herein is intended to include all subranges of the same numerical precision contained within the listed range. For example, the range of "1.0 to 10.0" is intended to be included between the listed minimum value 1.0 and the listed maximum value 10.0 (and including them), that is, all subranges with a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0, such as 2.4 to 7.6. Any maximum numerical limit listed herein is intended to include all lower numerical limits contained therein, and any minimum numerical limit listed in this specification is intended to include all higher numerical limits contained therein. Therefore, the applicant reserves the right to amend this specification (including claims) to explicitly list any subranges contained within the ranges explicitly listed herein.

[0183] The apparatus for manufacturing dry electrodes according to the embodiments of the present disclosure described herein and / or any other related equipment or components can be further implemented using any suitable hardware, firmware (e.g., application specific integrated circuits), software, or a combination of software, firmware, and hardware. For example, the various components of the device can be formed on an integrated circuit (IC) chip or on separate IC chips. In addition, the various components of the device can be implemented on a flexible printed circuit film, a carrier package (TCP), a printed circuit board (PCB), or formed on a substrate. In addition, the various components of the device can be processes or threads, running on one or more processors in one or more computing devices, executing computer program instructions and interacting with other system components to perform the various functions described herein. Computer program instructions are stored in a memory, which can be implemented in a computing device using a standard memory device such as a random access memory (RAM). The computer program instructions can also be stored in other non-temporary computer-readable media such as a CD-ROM, a flash drive, etc. Moreover, those skilled in the art will recognize that, without departing from the scope of the present disclosure, the functions of each computing device can be combined or integrated into a single computing device, or the functions of a particular computing device can be distributed across one or more other computing devices.

[0184] Those skilled in the art will understand that, in view of the entire content of the present disclosure, each suitable feature of the various embodiments of the present disclosure may be partially or fully combined with each other, and may be technically interlocked and operated in various suitable ways, and the various embodiments may be implemented independently of each other or in combination with each other in any suitable manner, unless otherwise stated or implied.

[0185] Although one or more embodiments of the present disclosure have been discussed with reference to the accompanying drawings, it will be understood that one or more suitable changes in form and details may be made therein without departing from the spirit and scope of the present disclosure and its equivalents. Therefore, it will be understood that the above one or more embodiments are illustrative in all aspects and not restrictive.

Claims

1. A method for manufacturing a dry electrode, comprising: mixing an electrode active material, a first binder, and a first conductive material to form a dry mixture; allowing the dry mixture to form a film to form an electrode active material layer; forming a composite layer on the electrode active material layer; and laminating the electrode active material layer on an electrode current collector, wherein the composite layer is formed on the electrode active material layer; The forming of the composite layer comprises: applying an adhesive solution on the electrode active material layer, the adhesive solution comprising a second binder, a second conductive material, and an organic solvent; as well as The adhesive solution is dried.

2. The method of claim 1 , wherein the first binder and the second binder each independently comprise at least one selected from the group consisting of polytetrafluoroethylene, polyvinylidene fluoride-hexafluoropropylene copolymer, polyvinylidene fluoride, polyvinyl alcohol, polyacrylonitrile, carboxymethyl cellulose, starch, hydroxypropyl cellulose, cellulose, polyvinyl pyrrolidone, polyethylene, polypropylene, ethylene-propylene-diene polymer (EPDM), sulfonated EPDM, styrene-butadiene rubber, fluororubber, and copolymers thereof.

3. The method of claim 1, wherein the first adhesive and the second adhesive are different from each other. 4 . The method of claim 1 , wherein the first conductive material and the second conductive material each independently comprise at least one selected from the group consisting of a carbon-based material, a metal-based material, a conductive polymer, and mixtures thereof.

5. The method according to claim 1, wherein the organic solvent comprises at least one selected from the group consisting of ethanol, methanol, and isopropanol. The method according to claim 1 , wherein the adhesive solution further comprises a dispersant.

7. The method according to claim 1, wherein the applying of the adhesive solution comprises performing at least one selected from the group consisting of spraying, dispensing, gravure coating, and inkjet coating. 8 . The method according to claim 1 , wherein the drying of the adhesive solution comprises performing at least one selected from the group consisting of hot air drying, cold air drying, infrared drying, ultraviolet drying, and combinations thereof. 9 . The method according to claim 1 , wherein the forming of the composite layer comprises forming a patterned composite layer on the electrode active material layer.

10. An apparatus for manufacturing a dry electrode, comprising: a roller configured to transfer the electrode active material layer; an adhesive solution supplier configured to supply an adhesive solution onto the electrode active material layer; a distance sensor configured to identify a travel distance of the electrode active material layer; a dryer configured to dry the adhesive solution; as well as a laminator configured to laminate the electrode current collector and the electrode active material layer.

11. The apparatus according to claim 10, wherein the adhesive solution supplier comprises at least one selected from the group consisting of a sprayer, a dispenser, a gravure roll coater, and an inkjet coater.

12. The apparatus of claim 10, further comprising a controller configured to control the operation of the adhesive solution supplier, Wherein the controller is configured to receive a signal from the distance sensor.

13. The apparatus of claim 10, wherein the dryer comprises at least one selected from the group consisting of a hot air dryer, a cold air dryer, an infrared dryer, an ultraviolet dryer, and combinations thereof.

14. The apparatus of claim 10, wherein the dryer is further configured to adjust its angle.

15. Dry electrode, including: electrode current collector; an electrode active material layer on the electrode current collector, the electrode active material layer comprising an electrode active material, a first binder, and a first conductive material; as well as a composite layer between the electrode current collector and the electrode active material layer, wherein the composite layer comprises the electrode active material, the first binder, the first conductive material, a second binder, and a second conductive material, The concentration of the second binder varies within the composite layer.

16. The dry electrode according to claim 15, wherein the concentration of the second binder in the composite layer gradually decreases in a direction from the top surface of the electrode current collector toward the electrode active material layer, the top surface being the surface of the electrode current collector facing the electrode active material layer. 17 . The dry electrode according to claim 15 , wherein the total thickness of the composite layer is in the range of 1 μm to 3 μm.

18. The dry electrode according to claim 15, wherein the composite layer is pattern-coated on the electrode current collector.

19. The dry electrode according to claim 15, wherein the first binder and the second binder each independently comprise at least one selected from the group consisting of polytetrafluoroethylene, polyvinylidene fluoride-hexafluoropropylene copolymer, polyvinylidene fluoride, polyvinyl alcohol, polyacrylonitrile, carboxymethyl cellulose, starch, hydroxypropyl cellulose, cellulose, polyvinyl pyrrolidone, polyethylene, polypropylene, ethylene-propylene-diene polymer (EPDM), sulfonated EPDM, styrene-butadiene rubber, fluororubber, and copolymers thereof.

20. The dry electrode of claim 15, wherein the first conductive material and the second conductive material each independently comprise at least one selected from the group consisting of a carbon-based material, a metal-based material, a conductive polymer, and mixtures thereof.

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