Electrode and secondary battery

Abstract

Disclosed are an electrode and a secondary battery. An electrode includes: a substrate; and a coating layer coated on at least one side of the substrate, and including: a first layer; and a second layer on the first layer and defining a step with the first layer.

Description

[0001] This application claims priority and benefit to Korean Patent Application No. 10-2024-0124172, filed on September 11, 2024, with the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference. Technical Field

[0002] An aspect of the embodiments of this disclosure relates to an electrode and a secondary battery. Background Technology

[0003] Unlike primary batteries, which cannot be recharged, secondary batteries are batteries that can be charged and discharged. For example, low-capacity secondary batteries can be used in small portable electronic devices such as smartphones, feature phones, laptops, digital cameras, and camcorders, while high-capacity secondary batteries are widely used in hybrid vehicles, electric vehicles, and other applications as motor drive power sources and energy storage batteries. These secondary batteries include an electrode assembly comprising electrodes (e.g., positive and negative electrodes), a housing containing the electrode assembly, and electrode terminals connected to the electrode assembly.

[0004] With technological advancements, there is a need for high-capacity rechargeable batteries. Therefore, multiple rechargeable batteries can be used by being electrically connected. For example, rechargeable batteries can be applied to electronic devices in the form of rechargeable battery modules comprising multiple rechargeable batteries and / or rechargeable battery packs comprising multiple battery modules. In this case, the electronic devices require high output and / or high capacity, and include, for example, electric vehicles.

[0005] The electrode includes a substrate and a coating formed on the substrate. Typically, the coating is formed as a single layer.

[0006] However, with technological advancements, there is a need for high-capacity rechargeable batteries. Therefore, the coating in the electrodes needs to be thicker. However, if the coating is formed as a single layer, problems may arise such as difficulties in coating application and / or uneven electrode fabrication.

[0007] The information disclosed above in the background section of this disclosure is provided to enhance understanding of the background of this disclosure, and therefore may include information that does not constitute related technology. Summary of the Invention

[0008] According to one or more embodiments of the present disclosure, an electrode and / or a secondary battery having a coating comprising two or more layers is provided.

[0009] According to another aspect of one or more embodiments of the present disclosure, an electrode and / or secondary battery is provided having a coating having two or more layers in which the rising portions do not overlap.

[0010] According to another aspect of one or more embodiments of the present disclosure, an electrode and / or secondary battery is provided having a coating having two or more layers of non-overlapping drag or sloping portions therein.

[0011] According to another aspect of one or more embodiments of the present disclosure, an electrode and / or secondary battery is provided with improved electrode plate resistance (e.g., resistance of the substrate is avoided from being increased).

[0012] However, the aspects and technical problems to be solved by this disclosure are not limited to those described above, and those skilled in the art will clearly understand other aspects and problems not mentioned by means of the following description of the invention.

[0013] According to one or more embodiments, an electrode includes: a substrate; and a coating applied to at least one side of the substrate, wherein the coating includes: a first layer; and a second layer located on the first layer and defining a step with respect to the first layer.

[0014] According to one or more embodiments, a secondary battery includes: an electrode assembly including stacked electrodes and a separator; and a housing housing the electrode assembly, wherein at least one of the electrodes includes: a substrate; and a coating applied to at least one side of the substrate, the coating including: a first layer; and a second layer located on the first layer and defining a step with respect to the first layer. Attached Figure Description

[0015] The following drawings included in this specification illustrate some embodiments of the invention and, together with the detailed description of the invention described below, provide for understanding the technical concept of the invention; however, the invention should not be construed as limited to the matters described in these drawings, wherein:

[0016] Figures 1 to 4 This is a schematic view of a secondary battery according to some embodiments of the present disclosure;

[0017] Figure 5 This is a schematic view of a coating apparatus according to an embodiment of the present disclosure;

[0018] Figure 6 It is a schematic view showing the electrodes;

[0019] Figure 7 This is a schematic view of electrodes according to an embodiment of the present disclosure;

[0020] Figure 8 This is a schematic view of electrodes according to an embodiment of the present disclosure;

[0021] Figure 9 This is a schematic view of electrodes according to an embodiment of the present disclosure;

[0022] Figure 10 This is a schematic view illustrating the first and second electrodes according to embodiments of the present disclosure; and

[0023] Figure 11 It is a schematic representation based on Figure 10 A view of an electrode according to an embodiment of the present disclosure. Detailed Implementation

[0024] In this document, some embodiments of the present disclosure will be described in further detail. However, these embodiments are presented by way of example only and are not intended to limit the present disclosure, which will be defined by the scope of the claims.

[0025] Unless otherwise stated in this specification, the term "on" another component, such as a layer, film, region, plate, etc., includes not only the case where the component is "directly" on another component, but also the case where another component is present between them.

[0026] Unless otherwise stated in this specification, the singular form may also include the plural form. Furthermore, unless otherwise stated, “A or B” may mean “including A, including B, or including both A and B”.

[0027] In this specification, "combinations thereof" may refer to mixtures, laminates, compounds, copolymers, alloys, blends, and reaction products of compositions.

[0028] Figures 1 to 4 This is a schematic view of a battery cell according to some embodiments of the present disclosure.

[0029] Secondary battery 100

[0030] Secondary batteries can be classified according to their shape, such as cylindrical, prismatic, pouch, and coin-shaped. Figures 1 to 4 This is a schematic diagram illustrating a secondary battery according to some embodiments, wherein Figure 1 A cylindrical secondary battery is shown. Figure 2 A prismatic secondary battery is shown, and Figure 3 and Figure 4 A pouch-type secondary battery is shown. (Reference) Figures 1 to 4 The secondary battery 100 may include an electrode assembly 40 and a housing 50. A separator 30 in the electrode assembly 40 is located between the positive electrode 10 and the 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 (not shown). Figure 1 As shown, the secondary battery 100 may include a sealing member 60 of the sealed housing 50. Further, in Figure 2In this secondary battery 100, a positive electrode lead connector 11, a positive electrode terminal 12, a negative electrode lead connector 21, and a negative electrode terminal 22 may be included. For example... Figure 3 and Figure 4 As shown, the secondary battery 100 may include electrode terminals 70, namely positive electrode terminal 71 and negative electrode terminal 72, which serve as electrical paths to guide the current generated in the electrode assembly 40 to the outside.

[0031] Positive electrode active material

[0032] Compounds capable of reversibly inserting and deintercalating lithium (lithiation intercalation compounds) can be used as positive electrode active materials. In embodiments, one or more composite oxides of lithium with metals selected from cobalt, manganese, nickel, and combinations thereof can be used.

[0033] In the embodiments, the composite oxide may be a lithium transition metal composite oxide, and examples of composite oxides may include lithium nickel oxides, lithium cobalt oxides, lithium manganese oxides, lithium iron phosphate compounds, cobalt-free nickel manganese oxides, or combinations thereof.

[0034] For example, compounds represented by any of the following chemical formulas can be used. Li a A 1-b X b O 2-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); Li a Mn 2-b X b O 4-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); Li a Ni 1-b-c Co b X c O 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2); Li a Ni 1-b- c Mn b X c O 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2); Li a Ni b Co c L 1 d G eO2 (0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, 0≤e≤0.1); Li a NiG b O2(0.90≤a≤1.8, 0.001≤b≤0.1); Li a CoG b O2(0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn 1-b G b O2(0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn2G b O4(0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn 1-g G g PO4(0.90≤a≤1.8, 0≤g≤0.5); Li (3-f) Fe2(PO4)3 (0≤f≤2); and Li a FePO4 (0.90≤a≤1.8).

[0035] In the above chemical formulas, A is Ni, Co, Mn, or a combination thereof; X is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, rare earth elements, or a combination thereof; D is O, F, S, P, or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; and L... 1 It is Mn, Al, or a combination thereof.

[0036] For example, the positive electrode active material can be a high-nickel positive electrode active material, based on 100 mol% of lithium-excluding metals in a lithium transition metal complex oxide, with a nickel content of 80 mol% or more, 85 mol% or more, 90 mol% or more, 91 mol% or more, or 94 mol% or more and 99 mol% or less. High-nickel positive electrode active materials can achieve high capacity and therefore can be used in high-capacity and high-density secondary batteries.

[0037] Positive electrode 10

[0038] The positive electrode 10 for the secondary battery 100 may include a current collector and a positive electrode active material layer formed on the current collector. The positive electrode active material layer may include a positive electrode active material and may further include a binder and / or a conductive material.

[0039] For example, the positive electrode may further include additives that can be used as a sacrificial positive electrode.

[0040] In the embodiments, based on 100% by weight of the positive electrode active material layer, the content of the positive electrode active material can be from 90% by weight to 99.5% by weight, and based on 100% by weight of the positive electrode active material layer, the content of the binder and the conductive material can both be from 0.5% by weight to 5% by weight.

[0041] The binder can effectively adhere the particles constituting the positive electrode active material to each other, and also effectively adhere the positive electrode active material to the current collector. Representative examples of binders may include, but are not limited to, polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, polymers containing ethane oxide, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, epoxy resin, (meth)acrylate resin, polyester resin, nylon, etc.

[0042] Conductive materials impart conductivity to electrodes, and any suitable material that does not cause chemical changes and conducts electricity can be used. Examples of conductive materials can include: carbon-based materials, such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fibers, carbon nanofibers, carbon nanotubes, etc.; metallic materials in the form of metal powders or metal fibers containing copper, nickel, aluminum, silver, etc.; conductive polymers, such as polyphenylene derivatives, etc.; or mixtures thereof.

[0043] In the embodiments, Al can be used as a current collector, but the current collector is not limited to this.

[0044] Negative electrode active material

[0045] Negative electrode active materials include materials capable of reversibly inserting and de-intercalating lithium ions, lithium metal, lithium metal alloys, materials capable of doping and de-doping lithium, or transition metal oxides.

[0046] Materials capable of reversibly inserting and deintercalating lithium ions can include carbon-based negative electrode active materials, such as crystalline carbon, amorphous carbon, or combinations thereof. Examples of crystalline carbon can include graphite, such as amorphous, plate-like, flake-like, spherical, or fibrous natural or artificial graphite, and examples of amorphous carbon can include soft or hard carbon, mesophase pitch carbides, calcined coke, etc.

[0047] Alloys of lithium and metals selected from Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Ra, Ge, Al, and Sn can be used as lithium-metal alloys.

[0048] In an embodiment, a Si-based negative electrode active material or a Sn-based negative electrode active material can be used as a material capable of doping and de-doping lithium. The Si-based negative electrode active material can include silicon, a silicon-carbon composite, SiO x (0 < x ≤ 2), a Si-Q alloy (Q is an alkali metal, an alkaline earth metal, a Group 13 element, a Group 14 element (except Si), a Group 15 element, a Group 16 element, a transition metal, a rare earth element, and combinations thereof), or a combination thereof. The Sn-based negative electrode active material can be Sn, SiO2, a Sn-based alloy, or a combination thereof.

[0049] The silicon-carbon composite material can be a composite of silicon and amorphous carbon. According to an embodiment, the silicon-carbon composite can be in the form of silicon particles whose surfaces are coated with amorphous carbon. For example, the silicon-carbon composite material can include secondary particles (cores) in which primary silicon particles are aggregated and an amorphous carbon coating (shells) located on the surfaces of the silicon secondary particles. Amorphous carbon can also be located between the silicon primary silicon particles, and for example, the silicon primary silicon particles can be coated with amorphous carbon. The secondary particles can be dispersed in an amorphous carbon matrix.

[0050] The silicon-carbon composite material can further include crystalline carbon. For example, the silicon-carbon composite material can include a core containing crystalline carbon and silicon particles and an amorphous carbon coating located on the surface of the core.

[0051] The Si-based negative electrode active material or the Sn-based negative electrode active material can be used in combination with a carbon-based negative electrode active material.

[0052] Negative electrode 20

[0053] The negative electrode 20 of the secondary battery 100 can include a current collector and a negative electrode active material layer located on the current collector. The negative electrode active material layer can include a negative electrode active material and can further include an adhesive and / or a conductive material.

[0054] In an embodiment, for example, the negative electrode active material layer can include 90% to 99.5% by weight of the negative electrode active material amount, 0.5% to 5% by weight of the adhesive amount, and 0% to 5% by weight of the conductive material amount.

[0055] The adhesive can well adhere the particles constituting the negative electrode active material to each other and also well adhere the negative electrode active material to the current collector. The binder can be a non-aqueous binder, an aqueous binder, a dry binder, or a combination thereof.

[0056] 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, or a combination thereof.

[0057] Waterborne adhesives can be selected from styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, (meth)acrylonitrile-butadiene rubber, (meth)acrylic rubber, butyl rubber, fluororubber, polyethylene oxide, polyvinylpyrrolidone, polyepoxychloropropane, polyphosphazene, poly(meth)acrylonitrile, ethylene propylene diene copolymer, polyvinylpyridine, chlorosulfonated polyethylene, latex, polyester resin, (meth)acrylic resin, phenolic resin, epoxy resin, polyvinyl alcohol, and combinations thereof.

[0058] If an aqueous binder is used as the negative electrode binder, it may further include a cellulose-based compound capable of imparting viscosity. As a cellulose-based compound, one or more of carboxymethyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, and their alkali metal salts may be used in combination. In the embodiments, Na, K, or Li may be used as the alkali metal.

[0059] Dry adhesives are fibrous polymeric materials and can be, for example, polytetrafluoroethylene, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polyethylene oxide, or combinations thereof.

[0060] Conductive materials impart conductivity to electrodes, and any suitable material that does not cause chemical changes and conducts electricity can be used. Examples of conductive materials can include: carbon-based materials, such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fibers, carbon nanofibers, carbon nanotubes, etc.; metallic materials in the form of metal powders or metal fibers containing copper, nickel, aluminum, silver, etc.; conductive polymers, such as polyphenylene derivatives, etc.; or mixtures thereof.

[0061] The negative electrode current collector can be selected from copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, polymer substrate coated with conductive metal, and combinations thereof.

[0062] Electrolyte (not shown)

[0063] The electrolyte of the secondary battery 100 includes a non-aqueous organic solvent and a lithium salt.

[0064] Non-aqueous organic solvents serve as a medium through which ions participating in the electrochemical reactions of the battery can move.

[0065] In the embodiments, the non-aqueous organic solvent may be a carbonate solvent, an ester solvent, an ether solvent, a ketone solvent, an alcohol solvent, an aprotic solvent, or a combination thereof.

[0066] As carbonate solvents, dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC), methyl ethyl carbonate (MEC), ethylene carbonate (EC), propylene carbonate (PC), butyl carbonate (BC), etc. can be used.

[0067] As ester solvents, methyl acetate, ethyl acetate, n-propyl acetate, dimethyl acetate, methyl propionate, ethyl propionate, decanoic acid lactone, mevalonate lactone, caprolactone, etc. can be used.

[0068] As ether solvents, dibutyl ether, tetraethylene glycol dimethyl ether, diethylene glycol dimethyl ester, dimethoxyethane, 2-methyltetrahydrofuran, 2,5-dimethyltetrahydrofuran, tetrahydrofuran, etc., can be used. Furthermore, as ketone solvents, cyclohexanone can be used. As alcohol solvents, ethanol, isopropanol, etc., can be used, and as aprotic solvents, nitriles such as R-CN (R is a straight-chain, branched, or cyclic hydrocarbon group having C2 to C20, and may include double bonds, aromatic rings, or ether groups) can be used; amides such as dimethylformamide; dioxolane such as 1,3-dioxolane or 1,4-dioxolane; sulfolane, etc.

[0069] Non-aqueous organic solvents can be used alone or in combination of two or more.

[0070] Furthermore, if carbonate solvents are used, a mixture of cyclic carbonates and chain carbonates can be used, and the cyclic carbonates and chain carbonates can be mixed in a volume ratio of 1:1 to 1:9.

[0071] Lithium salts can be materials dissolved in organic solvents and used as lithium-ion sources in batteries to enable basic operation of secondary batteries and facilitate the movement of lithium ions between the positive and negative electrodes. Representative examples of lithium salts can include those from LiPF6, LiBF4, LiSbF6, LiAsF6, LiClO4, LiAlO2, LiAlCl4, LiPO2F2, LiCl, LiI, LiN(SO3C2F5)2, Li(FSO2)2N (lithium bis(fluorosulfonyl)imide, LiFSI), LiC4F9SO3, and LiN(C x F 2x+1 SO2)(C y F 2y+1 One or more of the following: SO2 (where x and y are integers from 1 to 20), lithium trifluoromethane sulfonate, lithium tetrafluoroethane sulfonate, lithium difluorobis(oxalate)phosphate (LiDFOB), and lithium bis(oxalate)borate (LiBOB).

[0072] Diaphragm 30

[0073] The separator 30 may be present between the positive electrode 10 and the negative electrode 20, depending on the type of secondary battery 100. As the separator 30, a multilayer membrane of polyethylene, polypropylene, polyvinylidene fluoride, or two or more layers thereof may be used, and a mixed multilayer membrane such as a polyethylene / polypropylene two-layer separator, a polyethylene / polypropylene / polyethylene three-layer separator, or a polyethylene / polypropylene / polypropylene three-layer separator may be used.

[0074] The diaphragm 30 may include a porous substrate and a coating comprising an organic material, an inorganic material, or a combination thereof located on one or both or opposite sides of the porous substrate.

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

[0076] Organic materials may include polymers such as polyvinylidene fluoride or (meth)acrylic acid polymers.

[0077] Inorganic materials may include, but are not limited to, inorganic particles selected from Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, SrTiO3, BaTiO3, Mg(OH)2, boehmite and combinations thereof.

[0078] Organic and inorganic materials can exist as a mixture in a coating, or as a coating containing organic materials and a coating containing inorganic materials stacked together.

[0079] As described above, the secondary battery 100 according to embodiments of the present disclosure may include an electrode assembly 40 and a housing 50 for accommodating the electrode assembly 40. Further, the electrode assembly 40 is formed by stacking electrodes (e.g., including a positive electrode 10 and / or a negative electrode 20) and a separator (e.g., including a separator 30).

[0080] In this paper, the method by which the electrode can be formed as a thick film electrode will be described in further detail.

[0081] Figure 5 This is a schematic view of a coating apparatus according to an embodiment of the present disclosure.

[0082] exist Figure 5In the diagram, 1100 represents a coating apparatus according to an embodiment of the present disclosure. The coating apparatus 1100 manufactures the electrode 200 by coating the substrate 210 with a slurry for forming the coating 220 (see [link to documentation]). Figure 7 ).

[0083] In an embodiment, for example, electrode 200 includes a reference. Figures 1 to 4 The positive electrode 10 and / or negative electrode 20 are described.

[0084] The substrate 210 may include a reference Figures 1 to 4 The current collector is described. For example, if electrode 200 is a positive electrode, then substrate 210 is a positive electrode current collector. In an embodiment, for example, the positive electrode current collector includes aluminum (Al). For example, if the electrode is a negative electrode, then substrate 210 is a negative electrode current collector. In an embodiment, for example, the negative electrode current collector includes copper (Cu).

[0085] The coating 220 is formed by applying it to one or both (or opposite) sides of the substrate 210. The coating 220 includes, for example, reference... Figures 1 to 4 The active substance, binder, and conductive material are described. Coating 220 includes, for example, an active substance layer.

[0086] The coating apparatus 1100 includes a roller 1140 for conveying a substrate 210 and an outlet port 1120 for discharging slurry onto the substrate 210 to form a coating 220.

[0087] Roller 1140 is positioned in front of discharge port 1120. For example, roller 1140 is positioned on the side from which slurry is discharged from discharge port 1120. Roller 1140 conveys substrate 210 while rotating. For example, roller 1140 can convey substrate 210 to the front of discharge port 1120 while rotating counterclockwise (“r”). However, compared with… Figure 5 Unlike the example shown, roller 1140 can convey substrate 210 to the front of discharge port 1120 while rotating clockwise.

[0088] Discharge port 1120 discharges slurry onto substrate 210 conveyed by roller 1140. In an embodiment, for example, coating apparatus 1100 further includes a manifold (not shown) for receiving slurry for forming coating 220. The manifold allows slurry contained therein to be supplied toward discharge port 1120. Discharge port 1120 discharges the slurry supplied from the manifold onto substrate 210.

[0089] For example, discharge port 1120 discharges slurry onto substrate 210 located in front of discharge port 1120. For example, at the point where slurry is discharged onto substrate 210, the direction of slurry discharge and the direction of substrate 210 transport can be perpendicular to each other. For example, at the point where slurry is discharged onto substrate 210, the angle between the direction of slurry discharge and the direction of substrate 210 transport can be 90° ± 10°.

[0090] The discharge port 1120 may have a coating 220 formed on the substrate 210, and the coating 220 may be formed to be thick. For example, the discharge port 1120 may have a thick coating 220 formed on the substrate 210 by forming a coating 220 comprising two or more layers (e.g., including a first layer 221 and a second layer 222).

[0091] Therefore, emission port 1120 includes a first emission port 1121 and a second emission port 1122.

[0092] In an embodiment, for example, the coating apparatus 1100 includes a plurality of mold blocks 1110. For example, the coating apparatus 1100 includes a number of mold blocks 1110 that exceeds the number of discharge ports 1120. For example, if the coating apparatus 1100 includes n discharge ports 1120, then the coating apparatus 1100 may include n+1 mold blocks 1110. In this case, n is an integer greater than or equal to 2.

[0093] The plurality of mold blocks 1110 include, for example, a first mold block 1111, a second mold block 1112, and a third mold block 1113.

[0094] The first mold block 1111 and the second mold block 1112 are positioned adjacent to each other. The first mold block 1111 and the second mold block 1112 may be formed spaced apart from each other. For example, the second mold block 1112 is provided to be spaced apart from the first mold block 1111 on its upper side. Therefore, the first discharge port 1121 may be formed by the space between the first mold block 1111 and the second mold block 1112.

[0095] The second mold block 1112 and the third mold block 1113 are positioned adjacent to each other. In this case, the second mold block 1112 and the third mold block 1113 can be formed spaced apart from each other. For example, the third mold block 1113 is provided to be spaced apart from the second mold block 1112 on its upper side. Therefore, the second discharge port 1122 can be formed by the space between the second mold block 1112 and the third mold block 1113.

[0096] Furthermore, utilizing this structure, the second discharge port 1122 can be provided to be spaced apart from the first discharge port 1121 by the thickness of the second mold block 1112. The second discharge port 1122 can also be provided to be spaced apart from the first discharge port 1121 in the height direction.

[0097] In an embodiment, the first discharge port 1121 and the second discharge port 1122 may be formed at an angle to each other. For example, the second discharge port 1122 may be formed to have an inclination relative to the first discharge port 1121. Therefore, the discharge port 1120 can prevent or substantially prevent the coating 220 from flowing downward from the substrate 210.

[0098] The first discharge port 1121 discharges the first slurry onto the substrate 210. For example, the first discharge port 1121 discharges the first slurry contained in a first manifold (not shown) connected to the first discharge port 1121 onto the substrate 210. The first slurry is discharged onto the substrate 210 to form a first layer 221.

[0099] The second discharge port 1122 discharges the second slurry onto the substrate 210. In an embodiment, the second slurry may be the same as the first slurry. However, the second slurry may be different from the first slurry. For example, the second discharge port 1122 discharges the second slurry contained in a second manifold (not shown) connected to the second discharge port 1122 onto the substrate 210.

[0100] In this configuration, the second discharge port 1122 can discharge the second slurry onto the first slurry already discharged onto the substrate 210. In an embodiment, the second discharge port 1122 may be located adjacent to the first discharge port 1121, but may be located behind the first discharge port 1121. The second slurry is discharged onto the first layer 221 to form the second layer 222.

[0101] In one embodiment, for example, roller 1140 is located in front of discharge port 1120. In another embodiment, the first discharge port 1121 and the second discharge port 1122 may be positioned at different heights to sequentially discharge the slurry for forming coating 220 onto the substrate 210 conveyed by roller 1140.

[0102] For example, if roller 1140 rotates counterclockwise (“r”), the first discharge port 1121 can be located on the lower side, and the second discharge port 1122 can be located on the upper side. However, with Figure 5As shown in the diagram, for example, if roller 1140 rotates clockwise, the first discharge port 1121 can be located on the upper side and the second discharge port 1122 can be located on the lower side. With this structure, the second discharge port 1122 can apply the second slurry after the first slurry has been applied to the substrate 210 at the first discharge port 1121.

[0103] However, Figure 5 The components of the coating apparatus 1100 shown are provided only as examples, and the components included in the coating apparatus 1100 according to embodiments of this disclosure are not limited thereto. For example, the discharge port 1120 may include two or more discharge ports, and may include, for example, three discharge ports. Thus, the coating apparatus 1100 can fabricate an electrode 200 in the form of a thick film.

[0104] The coating apparatus 1100 according to embodiments of the present disclosure can form an electrode 200 including an active material layer formed as a thick film through this configuration. Furthermore, the coating apparatus 1100 can manufacture a high-capacity secondary battery 100.

[0105] Figure 6 This is a schematic view showing the electrodes.

[0106] exist Figure 6 In this context, 200 represents the electrode manufactured by the coating apparatus 1100. For example... Figure 5 As described, electrode 200 includes substrate 210 and coating 220 formed on substrate 210. Further, coating 220 may include a first layer 221 and a second layer 222.

[0107] The coating 220 is applied to the substrate 210, for example, in the first direction (X). That is, the coating 220 is formed by applying a paste in the first direction (X) from the point where the coating begins to the point where the coating ends.

[0108] The coating 220 may have a raised portion formed at the point where coating begins. For example, the slurry may be excessively discharged from the discharge port 1120 when it begins to be discharged from the coating apparatus 1100. Therefore, the coating 220 may have a raised portion formed at the point where coating begins, and the raised portion of the coating 220 is formed to be higher than the initial expected height of the coating 220 (or thicker than the initial expected thickness of the coating 220).

[0109] In this configuration, coating 220 comprises multiple layers (e.g., a first layer 221 and a second layer 222). Therefore, each of the multiple layers (e.g., the first layer 221 and the second layer 222) may have a raised portion. For example, the first layer 221 may have a raised portion 221t at the point where coating begins due to over-discharge of the first slurry from the first discharge port 1121. Similarly, the second layer 222 may have a raised portion 222t at the point where coating begins due to over-discharge of the second slurry from the second discharge port 1122.

[0110] In this scenario, when multiple layers (e.g., the first layer 221 and the second layer 222) have the same coating start point, the rising portions may overlap. For example, the first layer 221 and the second layer 222 may be formed at the same point on the substrate 210. In this case, the rising portion 222t of the second layer 222 can be formed on the rising portion 221t of the first layer 221. Therefore, the rising portions 221t of the first layer 221 and the rising portions 222t of the second layer 222 can be formed in an overlapping manner.

[0111] When multiple layers (e.g., first layer 221 and second layer 222) overlap and thus form an elevated portion (e.g., including 221t and 222t), the height of coating 220 at the point where coating begins may be too high.

[0112] In this case, there may be a problem that the electrode 200 may be formed unevenly. However, in order to manufacture a high-capacity electrode 200 and / or a secondary battery 100, a coating 220 comprising multiple layers is required. Therefore, a method for providing an electrode 200 including a coating 220 that is formed relatively uniformly (e.g., uniformly or substantially uniformly) while comprising multiple layers will be described herein.

[0113] Figure 7 This is a schematic view of an electrode according to an embodiment of the present disclosure.

[0114] exist Figure 7 In the diagram, 200 represents an electrode according to an embodiment of the present disclosure. Electrode 200 may, for example, be made of... Figure 5 The coating apparatus 1100 described herein is manufactured.

[0115] Electrode 200 includes substrate 210 and coating 220 formed on at least one side of substrate 210, and coating 220 includes a first layer 221 and a second layer 222 located on the first layer 221 and forming or defining a step with the first layer 221.

[0116] For example, coating 220 is applied to substrate 210 in a first direction (X). For example, the first direction (X) is a direction parallel to the longitudinal direction of substrate 210. Coating 220 is formed by applying slurry to substrate 210 along the first direction (X) from a point where coating begins.

[0117] In the first direction (X), the first layer 221 is formed to be longer than the second layer 222. That is, the coating 220 can be formed by gradually narrowing or step-narrowing from the lower side in contact with the substrate 210 toward a direction away from the substrate 210. Therefore, when viewed in a cross section parallel to the first direction (X), the first layer 221 and the second layer 222 can form a step. In this case, the step can be formed at at least one end portion of the coating 220.

[0118] For example, the step includes a first step formed at the coating start point in the coating direction of the coating layer 220.

[0119] In one embodiment, for example, the second layer 222 is formed after the first layer 221 is coated. In this case, the second layer 222 begins to form at a distance from the point where the first layer 221 was first coated. When viewed from above, the second layer 222 may have a different coating start point than the first layer 221 when it was coated on top of the first layer 221. Therefore, the second layer 222 forms a first step with the first layer 221.

[0120] For reference Figure 6 As described, coating 220 may have a raised portion formed on the side where coating begins. For example, the first layer 221 has a raised portion 221t. For example, the second layer 222 has a raised portion 222t.

[0121] In this embodiment, the second layer 222 has a different coating start point than the first layer 221. Therefore, the rising portion 222t of the second layer 222 can be formed on the first layer 221 without overlapping with the rising portion 221t of the first layer 221.

[0122] For example, such as Figure 7 As shown, the rising portion 221t of the first layer 221 can be formed on a line "A" (or a plane A perpendicular to the first direction (X)) perpendicular to the first direction (X). In this case, the line "A" is a line drawn perpendicular to the first direction (X) from the top of the rising portion 221t of the first layer 221.

[0123] For example, such as Figure 7As shown, the rising portion 222t of the second layer 222 can be formed on a line "B" (or a plane B perpendicular to the first direction (X)) perpendicular to the first direction (X). In this case, the line "B" is a line drawn perpendicular to the first direction (X) from the top of the rising portion 222t of the second layer 222.

[0124] In this configuration, lines "A" and "B" can be spaced apart with a width equal to that of the first step. In this case, when viewed from above, the width of the first step is the shortest interval in the first direction (X) between the coating start points of the first layer 221 and the second layer 222. In embodiments, the width of the first step is typically determined based on the section where excessive paste is discharged when the paste is coated onto the substrate 210. For example, in an embodiment, the first step can be formed with a width of 2 μm to 4 μm in the first direction (X).

[0125] Therefore, lines “A” and “B” can be separated by the width W1 of the first step. That is, the rising portion 221t of the first layer 221 and the rising portion 222t of the second layer 222 can be formed without overlapping each other. For example, when viewed from above, the top of the rising portion 221t of the first layer 221 and the top of the rising portion 222t of the second layer 222 can be formed without overlapping each other.

[0126] Therefore, since the tops of the rising portions of multiple layers (e.g., the first layer 221 and the second layer 222) are formed without overlapping each other, the height h2 (or thickness) of the coating 220 can be formed to be lower than (or less than) that of the other layers. Figure 6 The height h1 (or thickness) of the coating 220 described herein.

[0127] Therefore, the electrode 200 according to embodiments of the present disclosure can avoid excessive rising portions on the electrode 200 by forming multiple layers of steps (e.g., a first layer 221 and a second layer 222). For example, the electrode 200 can avoid overlapping of rising portions of the coating 220 by forming steps at the end portion corresponding to the coating start point of the coating 220.

[0128] Figure 8 This is a schematic view of an electrode according to an embodiment of the present disclosure.

[0129] exist Figure 8 In the diagram, 200 represents an electrode according to an embodiment of the present disclosure.

[0130] Electrode 200 includes substrate 210 and coating 220 formed on at least one side of substrate 210, and coating 220 includes a first layer 221 and a second layer 222 located on the first layer 221 and formed with or defining a step of the first layer 221.

[0131] For reference Figure 7 Described, the step may include a first step as an end portion corresponding to the coating start point of coating 220. In embodiments, the step that coating 220 may include is not limited to the coating start point. In embodiments, for example, the step may include a second step formed at the coating end point in the coating direction of coating 220.

[0132] The coating 220 may have a downward-sloping portion formed on the side where the coating terminates. For example, the downward-sloping portion may be formed due to a reduction in the amount of slurry discharged from the discharge port 1120, thus terminating the coating. Therefore, for example, the first layer 221 has a downward-sloping portion 221b. For example, the second layer 222 has a downward-sloping portion 222b.

[0133] In this case, when viewed from above, the second layer 222 may have a different coating termination point than the first layer 221. Therefore, the downward slope portion 222b of the second layer 222 may be formed on the first layer 221 without overlapping with the downward slope portion 221b of the first layer 221.

[0134] For example, such as Figure 8 As shown, the downward sloping portion 221b of the first layer 221 can be formed on a line "C" perpendicular to the first direction (X) (or a plane "C" perpendicular to the first position (X)). In this case, the line "C" is a line drawn perpendicular to the first direction (X) from the starting point of the downward sloping portion 221b of the first layer 221.

[0135] For example, such as Figure 8 As shown, the downward sloping portion 222b of the second layer 222 can be formed on a line "D" perpendicular to the first direction (X) (or a plane "D" perpendicular to the first position (X)). In this case, the line "D" is a line drawn perpendicular to the first direction (X) from the starting point of the downward sloping portion 222b of the second layer 222.

[0136] In this configuration, lines "C" and "D" can be spaced apart with a width W2 equal to that of the second step. In this configuration, when viewed from above, the width of the second step is the shortest interval in the first direction (X) between the coating termination points of the first layer 221 and the second layer 222. The width W2 of the second step is typically set based on the section where the amount of paste discharged from the discharge port 1120 decreases when the paste is coated onto the substrate 210.

[0137] Therefore, lines “C” and “D” can be spaced apart by the width W2 of the second step. Thus, the downward-sloping portion 221b of the first layer 221 and the downward-sloping portion 222b of the second layer 222 can be formed without overlapping each other. For example, when viewed from above, the top of the downward-sloping portion 221b of the first layer 221 and the top of the downward-sloping portion 222b of the second layer 222 can be formed without overlapping each other.

[0138] In an embodiment, at the coating termination point, the downward-sloping portion 221b of the first layer 221 is formed with a first tilt angle, and the downward-sloping portion 222b of the second layer 222 is formed with a second tilt angle. The first tilt angle and the second tilt angle may have the same or different tilt angles. The first tilt angle and the second tilt angle may be formed in the first layer 221 and / or the second layer 222 due to the downward-sloping portion.

[0139] In an embodiment, such as Figure 8 As shown, the second step can be formed when the downwardly sloping portion 221b of the first layer 221 with a first inclination and the downwardly sloping portion 222b of the second layer 222 with a second inclination are continuously connected. That is, the second step can be formed with a width as wide as the section where the downwardly sloping portion 221b of the first layer 221 appears. Therefore, since the first layer 221 and the second layer 222 have a minimum or reduced second step, the high capacity effect obtained from the electrode 200 formed as a thick film can be maximized or increased.

[0140] In the embodiment, with Figure 8 Unlike the previous example, the second step can be formed when the downward sloping portion 221b of the first layer 221 with a first inclination and the downward sloping portion 222b of the second layer 222 with a second inclination are discontinuously connected. That is, the second step can be formed with a wider section than the section where the downward sloping portion 221b of the first layer 221 appears. Therefore, it is possible to prevent or substantially prevent the first layer 221 and the second layer 222 from stably overlapping and descending.

[0141] Figure 9 This is a schematic view of an electrode according to an embodiment of the present disclosure.

[0142] exist Figure 9 In the diagram, 200 represents an electrode according to an embodiment of this disclosure. Figure 7 and Figure 8 An example is described where the coating is formed on one side of the substrate 210. Figure 9 In this section, an example of forming a coating on both sides or opposite sides of the substrate 210 will be described. For ease of description, in Figure 9 In the diagram, 220 is shown to represent the first coating.

[0143] Electrode 200 includes substrate 210 and coating, which includes a first coating 220 coated on one side of substrate 210 in a first direction (X) and a second coating 220' coated on the other side of substrate 210 in a second direction (X'). That is, the coating can be coated in the first direction (X) or the second direction (X'), and the coating (e.g., the first coating 220 or the second coating 220') includes a first layer 221 or 221' and a second layer 222 or 222' located on the first layer 221 or 221' and forming or defining a step with the first layer 221 or 221'.

[0144] The coating includes a first coating 220 applied to one side of the substrate 210. In this case, the first coating 220 is applied to the substrate 210 along a first direction (X). In this case, the first direction (X) is, for example, parallel to the longitudinal direction of the substrate 210.

[0145] The coating may further include a second coating 220' applied to the other side of the substrate 210. In this case, the second coating 220' is applied to the substrate 210 along a second direction (X'). In this case, for example, the second direction (X') is the opposite direction to the first direction (X). That is, the second direction (X') may be parallel to the longitudinal direction of the substrate 210 and may be the opposite direction to the first direction (X).

[0146] The coating includes two coatings (e.g., first coating 220 and second coating 220') applied in different directions to both sides or opposite sides of the substrate 210.

[0147] The starting point of the coating of the first coating 220 can face the ending point of the coating of the second coating 220' when the substrate 210 is between the first coating 220 and the second coating 220'. For example, the rising portion 220t of the first coating 220 can face the descending portion 220b' of the second coating 220' when the substrate 210 is between the first coating 220 and the second coating 220'.

[0148] Furthermore, the coating termination point of the first coating 220 can face the coating start point of the second coating 220' when the substrate 210 is between the first coating 220 and the second coating 220'. For example, the downward slope portion 220b of the first coating can face the upward slope portion 220t' of the second coating when the substrate 210 is between the first coating 220 and the second coating 220'.

[0149] In the embodiments, the description of the rising portion 220t or 220t' and the descending portion 220b or 220b' of each of the first coating 220 and the second coating 220' is consistent with... Figures 7 to 8The descriptions of the ascending and / or descending portions are the same or similar.

[0150] For example, if the first direction and the second direction are formed to be the same (e.g., identical), the rising portion 220t of the first coating and the rising portion 220t' of the second coating may be located on one side of the substrate 210 when the substrate 210 is between the first coating 220 and the second coating 220'. In this case, one side of the substrate 210 may become too thick. For example, if the first direction and the second direction are formed to be the same (e.g., identical), the descending portion 220b of the first coating and the descending portion 220b' of the second coating may be located on one side of the substrate 210 when the substrate 210 is between the first coating 220 and the second coating 220'. In this case, the other side of the substrate 210 may become too thin. Therefore, the electrode 200 may be formed unevenly, and the charging / discharging efficiency may be reduced.

[0151] On the other hand, according to embodiments of the present disclosure, the first direction (X) and the second direction (X') of the electrode 200 are arranged oppositely to avoid the above-mentioned problems and to allow the electrode 200 to be formed uniformly.

[0152] In an embodiment, for example, in a first direction (X) (or in a second direction (X')), the first coating 220 is formed to be longer than the second coating 220'. For example, the first coating 220 is formed with a first length d, and the second coating 220' is formed with a second length d' that is shorter than the first length d.

[0153] Figure 10 This is a schematic view of the first and second electrodes according to an embodiment of the present disclosure.

[0154] Figure 11 It is a schematic representation based on Figure 10 A view of an electrode according to an embodiment of the present disclosure is shown.

[0155] A secondary battery 100 according to an embodiment of the present disclosure includes an electrode 200. The electrode 200 may include, for example, a first electrode 200p and a second electrode 200n. In an embodiment, the first electrode 200p includes, for example, a reference electrode. Figures 1 to 4 The positive electrode 10 is described, and the second electrode 200n includes, for example, reference... Figures 1 to 4 The negative electrode 20 is described. In another embodiment, the first electrode 200p includes, for example, a reference electrode. Figures 1 to 4 The negative electrode 20 is described, and the second electrode 200n includes, for example, reference... Figures 1 to 4 The positive electrode 10 is described.

[0156] The electrode 200 according to embodiments of the present disclosure may include a contact piece 230 and a protective layer 240. As described above, the electrode 200 includes a substrate 210 and a coating 220 coated on the substrate 210. For example, a first electrode 200p includes a substrate 210p and a coating 220p coated on the substrate 210p. For example, a second electrode 200n includes a substrate 210n and a coating 220n coated on the substrate 210n.

[0157] In this case, the area where the coating 220 is applied to the substrate 210 can be referred to as the "coated portion". Further, the area where the coating 220 is not applied to the substrate 210 and the substrate 210 is exposed to the outside can be referred to as the "uncoated portion".

[0158] The connector 230 may be located on an uncoated portion. The connector 230 may be attached to and extend outward from the substrate 210. For example, in the connector 230, one side is attached to the substrate 210, and the other side extends to the outside of the substrate 210. For example, the connector 230 is attached to an uncoated portion. In an embodiment, for example, the connector 230 may be secured to the substrate 210 by soldering one side to the uncoated portion.

[0159] For example, the first contact 230p may be located on the uncoated portion of the first electrode 200p. The first contact 230p may be formed such that one side is bonded to the substrate 210p of the first electrode 200p, and the other side extends to the outside of the substrate 210p.

[0160] Furthermore, for example, the second terminal 230n may be located on the uncoated portion of the second electrode 200n.

[0161] The terminal block 230 allows the electrode 200 to be electrically connected to the outside. Therefore, the terminal block 230 can be used as an electron movement path through which electrons are introduced into the electrode 200 or released from the electrode plate.

[0162] For example, if the secondary battery 100 is formed in a cylindrical shape, the terminal piece 230 can be connected to the current collector plate. For example, if electrode 200 is a positive electrode, the terminal piece 230 can be connected to the positive electrode current collector plate. For example, if electrode 200 is a negative electrode, the terminal piece 230 can be connected to the negative electrode current collector plate. For example, if the secondary battery 100 is formed in a pouch shape, the terminal piece 230 can be electrically connected to the lead terminal piece.

[0163] With repeated charging / discharging, the electrode 200 may repeatedly expand or shrink. In this situation, the terminal block 230 may contact the electrode adjacent to it. For example, the terminal block 230 may apply pressure to the substrate 210 to which it is attached and / or to the electrode adjacent to it. Therefore, the terminal block 230 may cause a short circuit. For example, the terminal block 230 may cause cracks in the substrate 210. In this case, the resistance of the secondary battery 100 increases, leading to reduced charging / discharging efficiency and / or reduced stability of the secondary battery 200.

[0164] To avoid this problem, the electrode 200 according to an embodiment of the present disclosure may further include a protective layer 240.

[0165] A protective layer 240 is provided on the substrate 210 and covers the terminal block 230. For example, the protective layer 240 is attached to the substrate 210 and covers the terminal block 230. That is, the protective layer 240 can be attached to uncoated portions. The protective layer 240 can not only be provided on the substrate 210 and cover the terminal block 230, but can also be provided on the coating 220 by extending from the substrate 210. That is, the protective layer 240 can be attached to uncoated portions and coated portions adjacent to the uncoated portions. Figure 10 For ease of description, only the protective layer 240 for the first electrode 200p is shown. In this document, the protective layer 240 included in the first electrode 200p will be described as an example. However, the second electrode 200n may also include a protective layer covering the terminal piece 230n, and the description of the protective layer included in the second electrode 200n may be the same as or similar to the description of the protective layer 240 included in the first electrode 200p.

[0166] For example, the first electrode 200p includes a protective layer 240. The protective layer 240 is provided on at least a portion of the substrate 210p of the first electrode 200p and the coating 220p of the first electrode 200p, while also covering the first terminal piece 230p.

[0167] In an embodiment, such as Figure 10 As shown, the first electrode 200p and the second electrode 200n can be located in the diaphragm ( Figure 10 (Not shown) The electrodes are stacked between the first electrode 200p and the second electrode 200n.

[0168] In this case, the protective layer 240 may be located on a portion of the coating 220n of the second electrode 200n in the stacking direction. For example, the protective layer 240 may be located on a portion of the second layer of the second electrode 200n.

[0169] In an embodiment, the protective layer 240 may be located at the start point and / or the coating end point of the coating 220n of the second electrode 200n. Therefore, the protective layer 240 can prevent or substantially prevent the start point and / or the coating end point of the coating 220n of the second electrode 200n from facing the first electrode 200p.

[0170] In this configuration, a portion of the second layer of the second electrode 200n may be formed planarly on or relative to the substrate 210n of the second electrode 200n. That is, the protective layer 240 may prevent, or substantially prevent, the rising and / or falling portions of the coating 220n of the second electrode 200n from facing the first electrode 200p. The protective layer 240 may allow the flat portions of the coating 220n of the second electrode 200n without rising and / or falling portions to face the first electrode 200p.

[0171] Therefore, the protective layer 240 can be attached to the first electrode 200p based on the coating 220n of the second electrode 200n. Figure 11 This is a view of the second electrode 200n, shown to illustrate the location where the protective layer 240 is attached.

[0172] exist Figure 11 In this context, N1 represents the region where the coating of the first electrode 200p does not overlap with the coating of the second electrode 200n in the stacking direction, and specifically represents the region where the rising portion of the coating 220n of the second electrode 200n is locally formed. N2 represents the region where the coating of the first electrode 200p does not overlap with the coating of the second electrode 200n in the stacking direction, and specifically represents the region where the descending portion of the coating 220n of the second electrode 200n is locally formed. N1 and N2 can correspond to, for example... Figure 10 The "n" in the text.

[0173] In this case, Figure 10 In this context, "n" is a portion of the uncoated portion of the first electrode 200p, and "n" is the area of ​​the first electrode 200p where the coating 220p is not formed on the substrate 210p. Further, "n" is a portion of the coated portion of the second electrode 200n, and "n" is the area of ​​the second electrode 200n where the coating 220n is formed on the substrate 210n.

[0174] Therefore, the protective layer 240 is formed on the regions corresponding to n, N1, and N2. However, the end portions of the protective layer 240 are not formed on the regions corresponding to n, N1, and N2.

[0175] exist Figure 11In the diagram, M1 represents the region where the coating of the first electrode 200p overlaps with the coating of the second electrode 200n in the stacking direction, and specifically represents the region where the rising portion of the coating 220n of the second electrode 200n is locally formed. M2 represents the region where the coating of the first electrode 200p overlaps with the coating of the second electrode 200n in the stacking direction, and specifically represents the region where the descending portion of the coating 220n of the second electrode 200n is locally formed. Further, M1 represents the region at the end of the rising portion, and M2 represents the region including the beginning of the descending portion. M1 and M2 can correspond to, for example... Figure 10 The "m" in it.

[0176] In this case, Figure 10 In this context, "m" is a portion of the coated portion of the first electrode 200p, and "m" is the region of the first electrode 200p in which the coating 220p is formed on the substrate 210p. Further, "m" is a portion of the coated portion of the second electrode 200n, and "m" is the region of the second electrode 200n in which the coating 220n is formed on the substrate 210n.

[0177] Therefore, the protective layer 240 is formed on the regions corresponding to m, M1, and M2. The end portions of the protective layer 240 are formed on the regions corresponding to m, M1, and M2.

[0178] With this structure, the protective layer 240 can prevent or substantially prevent the rising and / or falling portions of the second electrode 200n from facing the first electrode 200p.

[0179] In an embodiment, the protective layer 240 may include, for example, an adhesive material. The adhesive material may be at least one selected from the group consisting of, for example, acrylic adhesives, rubber adhesives, silicone adhesives, hot melt adhesives, and combinations thereof. The protective layer 240 may be attached to the first electrode 200p by the adhesive material.

[0180] According to one or more embodiments of this disclosure, a high-capacity electrode and / or secondary battery is provided.

[0181] According to one or more embodiments of this disclosure, an electrode and / or a secondary battery capable of rapid charging is provided.

[0182] However, the aspects and technical effects obtainable through this disclosure are not limited to those described above, and those skilled in the art will clearly understand other aspects and technical effects not mentioned through the description of the invention.

[0183] While the present disclosure has been described above with reference to some embodiments and accompanying drawings, the present disclosure is not limited thereto, and those skilled in the art can make various modifications and variations within the spirit of the present disclosure and the equivalents of the claims.

Claims

1. An electrode, comprising: substrate; as well as A coating is applied to at least one side of the substrate. The coating comprises: First layer; as well as The second layer is located above the first layer and is separated from the first layer by a step.

2. The electrode according to claim 1, wherein the coating comprises a first coating applied on one side of the substrate along a first direction and a second coating applied on the other side of the substrate along a second direction, the first coating and the second coating each comprising a first layer and a second layer, and the second direction being the opposite direction to the first direction.

3. The electrode according to claim 2, wherein the first coating is longer than the second coating.

4. The electrode according to claim 1, wherein the first layer is longer than the second layer.

5. The electrode according to claim 1, wherein the step comprises a first step at the coating start point in the direction of coating application.

6. The electrode according to claim 5, wherein the first step has a width of 2 μm to 4 μm in the direction in which the coating is applied.

7. The electrode according to claim 1, wherein the step includes a second step at the coating termination point in the direction of coating application.

8. The electrode according to claim 7, wherein at the coating termination point, The first layer has a first downward sloping portion formed at a first inclination, and The second layer has a second downward-sloping portion formed at a second inclination.

9. The electrode of claim 8, wherein the second step is formed when the first downward-sloping portion and the second downward-sloping portion are continuously connected.

10. The electrode of claim 8, wherein the second step is formed when the first downward-sloping portion and the second downward-sloping portion are discontinuously connected.

11. A secondary battery, comprising: Electrode assembly, including stacked electrodes and a diaphragm; as well as Housing, housing the electrode assembly At least one of the electrodes is an electrode as described in any one of claims 1 to 10.

12. The secondary battery according to claim 11, wherein The electrode includes a first electrode and a second electrode. The first electrode includes a first electrode contact and a protective layer, and the second electrode includes a second electrode contact. One side of the first terminal block is bonded to the substrate of the first electrode, and the other side of the first terminal block extends outward from the substrate of the first electrode. The protective layer is located on at least a portion of the substrate of the first electrode and the coating of the first electrode, and also covers the first terminal piece.

13. The secondary battery according to claim 12, wherein The first electrode and the second electrode are stacked with the diaphragm therebetween, and In the stacking direction, the protective layer is located on a portion of the second layer of the second electrode.

14. The secondary battery of claim 13, wherein a portion of the second layer of the second electrode is flat relative to the substrate of the second electrode.

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