Cathode for all-solid-state battery, and all-solid-state battery comprising same

Abstract

The present invention relates to a cathode for an all-solid-state battery, and an all-solid-state battery comprising same. More specifically, the present invention exhibits physical properties in which the ratio of electronic conductivity to ionic conductivity of a cathode active material layer included in a cathode is in the range of 0.5 to 1.5, and thus an all-solid-state battery including the cathode can have improved battery performance such as that for lifespan characteristics and high-rate characteristics.

Description

Cathode for all-solid-state battery and all-solid-state battery containing same

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2023-0104628, filed August 10, 2023, Korean Patent Application No. 10-2023-0147408, filed October 31, 2023, and Korean Patent Application No. 10-2024-0107332, filed August 12, 2024, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a positive electrode for an all-solid-state battery and an all-solid-state battery including the same.

[0003] Various batteries are being studied to overcome the limitations of current lithium secondary batteries in terms of battery capacity, safety, output, large-scale development, and miniaturization.

[0004] In terms of capacity, continuous research is being conducted in academia and industry on metal-air batteries, which have a much larger theoretical capacity than lithium secondary batteries; all-solid-state batteries, which have no risk of explosion in terms of safety; supercapacitors, which have a higher output; NaS batteries or RFBs (redox flow batteries), which have a larger capacity; and thin film batteries, which have a smaller size.

[0005] All-solid-state batteries are batteries that replace the liquid electrolytes used in conventional lithium secondary batteries with solid electrolytes. Because they do not use flammable solvents, they are completely free of ignition or explosion caused by decomposition reactions of conventional electrolytes, significantly improving safety. Furthermore, among all-solid-state batteries, technological development is ongoing for sulfide-based all-solid-state batteries, which boast high ionic conductivity of solid electrolytes and theoretically capable of achieving high energy densities of over 900 Wh / L. Here, the term "sulfide-based all-solid-state battery" refers to an all-solid-state battery containing a sulfide-based solid electrolyte.

[0006] In all-solid-state battery systems, lithium ion conduction is not achieved by the liquid electrolyte contained in conventional lithium-ion batteries (LIBs). Therefore, when manufacturing a cathode for a sulfide-based all-solid-state battery, small-diameter sulfide-based solid electrolyte particles must be added to the cathode to increase the contact interface between the cathode active material and the sulfide-based solid electrolyte particles, thereby enhancing lithium ion conductivity.

[0007] Additionally, in the positive electrode for a sulfide-based all-solid-state battery, a conductive material is added to improve electronic conductivity so that an electronic conduction path is formed by the conductive material.

[0008] However, when a high content of positive electrode active material is included in the positive electrode of a sulfide-based all-solid-state battery to improve energy density, the positive electrode may not contain enough sulfide-based solid electrolyte and conductive material to secure ionic and electronic conductivity, and thus the high-rate characteristics and life characteristics may deteriorate.

[0009] Accordingly, there is a need for the development of a technology that can not only improve energy density by including a high content of positive electrode active material in the positive electrode of a sulfide-based all-solid-state battery, but also secure both ionic conductivity and electronic conductivity to improve high-rate characteristics and lifespan characteristics.

[0010] [Prior Art Literature]

[0011] [Patent Document]

[0012] (Patent Document 1) U.S. Patent No. 10,333,171

[0013] The inventors of the present invention have conducted various studies to solve the above problems and have confirmed that when the composition inside the positive electrode active material layer is controlled so that the ratio of ionic conductivity and electronic conductivity of the positive electrode active material layer becomes equivalent in an all-solid-state battery positive electrode having a positive electrode active material layer containing a high content of positive electrode active material, the performance of the battery, such as high-rate characteristics and life characteristics, is improved.

[0014] Accordingly, the purpose of the present invention is to provide a positive electrode having a positive electrode active material layer having ionic conductivity and electronic conductivity at equivalent levels.

[0015] Another object of the present invention is to provide an all-solid-state battery having improved battery performance, such as high-rate characteristics and life characteristics, including a positive electrode having a positive electrode active material layer having ionic and electronic conductivity at equivalent levels.

[0016] In order to achieve the above purpose, the present invention provides a positive electrode for an all-solid-state battery including a positive electrode active material layer,

[0017] The above positive electrode active material layer includes a positive electrode active material, a sulfide-based solid electrolyte, a conductive material, and a binder,

[0018] The ratio (R) of the ionic conductivity (IC) and electronic conductivity (EC) of the positive electrode active material layer, as defined by the following equation 1 IC / EC ) provides a positive electrode for an all-solid-state battery, wherein the ratio of the positive electrode is 0.5 to 1.5:

[0019] <Formula 1>

[0020] R IC / EC = Ionic conductivity / electronic conductivity.

[0021] In one embodiment of the present invention, a positive electrode for an all-solid-state battery is provided, wherein the ratio of the ionic conductivity to the electronic conductivity is calculated from a Nyquist plot obtained by electrochemical impedance spectroscopy (EIS) analysis.

[0022] In one embodiment of the present invention, the positive electrode active material is lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), Li[Ni x Co y Mn z M v ]O2 (wherein M is one or two or more elements selected from the group consisting of Al, Ga, and In; 0.3≤x<1.0, 0≤y, z≤0.5, 0≤v≤0.1, x+y+z+v=1), Li(Li a M b-a-b' M' b' )O 2-c A c (In the above formula, 0≤a≤0.2, 0.6≤b≤1, 0≤b'≤0.2, 0≤c≤0.2; M includes at least one selected from the group consisting of Mn and Ni, Co, Fe, Cr, V, Cu, Zn and Ti; M' is at least one selected from the group consisting of Al, Mg and B, and A is at least one selected from the group consisting of P, F, S and N.) layered compounds or compounds substituted with one or more transition metals; chemical formula Li 1+y Mn 2-y Lithium manganese oxides such as O4 (where y is 0 to 0.33), LiMnO3, LiMn2O3, LiMnO2; lithium copper oxide (Li2CuO2); vanadium oxides such as LiV3O8, LiFe3O4, V2O5, Cu2V2O7; chemical formula LiNi 1-y Ni-site type lithium nickel oxide represented by MyO2 (wherein, M=Co, Mn, Al, Cu, Fe, Mg, B or Ga, and y is 0.01 to 0.3); chemical formula LiMn2-y M y A positive electrode for an all-solid-state battery is provided, which comprises a lithium manganese composite oxide represented by O2 (wherein M is Co, Ni, Fe, Cr, Zn or Ta, and y is 0.01 to 0.1) or Li2Mn3MO8 (wherein M is Fe, Co, Ni, Cu or Zn); a disulfide compound; LiMn2O4 in which a portion of Li in the chemical formula is replaced with an alkaline earth metal ion; Fe2(MoO4)3.

[0023] In one embodiment of the present invention, a positive electrode for an all-solid-state battery is provided, wherein the sulfide-based solid electrolyte includes at least one selected from the group consisting of LiPSX (X = Cl, Br or I), LiGePS, and LiPS.

[0024] In one embodiment of the present invention, a positive electrode for an all-solid-state battery is provided, wherein the sulfide-based solid electrolyte is in the form of particles having a particle diameter (D50) of 0.1 ㎛ to 1.5 ㎛.

[0025] In one embodiment of the present invention, an all-solid-state battery positive electrode is provided, wherein the conductive material includes at least one selected from the group consisting of carbon nanotubes (CNTs) and carbon nanofibers (CNFs).

[0026] In one embodiment of the present invention, the binder is polytetrafluoroethylene (PTFE), polyethylene, polypropylene, ethylene / propylene copolymer, polybutadiene, polyethylene oxide, chlorosulfonated polyethylene, polyvinylpyrrolidone, polyvinylpyridine, polyvinyl alcohol, polyvinyl acetate, polyepichlorohydrin, polyphosphazene, polyacrylonitrile, polystyrene, latex, acrylic resin, phenol resin, epoxy resin, carboxymethylcellulose, hydroxypropyl cellulose, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethylcellulose, cyanoethylsucrose, polyester, polyamide, polyether, polyimide, polycarboxylate, polycarboxylic acid, polyacrylic acid, polyacrylate, lithium polyacrylate, polymethacrylic acid, A positive electrode for an all-solid-state battery is provided, comprising at least one selected from the group consisting of polymethacrylate, polyacrylamide, polyurethane, polyvinylidene fluoride, and poly(vinylidene fluoride)-hexafluoropropene.

[0027] In one embodiment of the present invention, an all-solid-state battery positive electrode is provided, wherein the positive electrode active material layer comprises 69 to 94 wt% of a positive electrode active material, 5 to 30 wt% of a sulfide-based solid electrolyte, 0.01 to 10 wt% of a conductive material, and 0.01 to 10 wt% of a binder.

[0028]

[0029] The present invention also provides an all-solid-state battery comprising the positive electrode, the negative electrode, and a sulfide-based solid electrolyte membrane interposed therebetween.

[0030] In one embodiment of the present invention, an all-solid-state battery is provided, wherein the negative electrode includes a lithium-containing negative electrode active material layer or an anodeless coating layer.

[0031] According to the positive electrode for an all-solid-state battery of the present invention, by controlling the composition of a sulfide-based solid electrolyte and a conductive material within the positive electrode active material layer so that the ratio of ionic conductivity and electronic conductivity becomes equal, the positive electrode can be designed so that ionic conductivity and electronic conductivity are balanced, and accordingly, high-rate charge / discharge characteristics and life characteristics of the all-solid-state battery can be secured.

[0032] Additionally, the performance of the battery can be predicted through the ratio of ionic conductivity and electronic conductivity at the anode.

[0033] FIG. 1 is a schematic diagram showing a cross-section of an electrochemical cell used for electrochemical impedance analysis according to one embodiment of the present invention.

[0034] FIG. 2 illustrates an example of a Nyquist plot shown during electrochemical impedance analysis according to one embodiment of the present invention.

[0035] Figure 3 is a schematic diagram showing a longitudinal cross-section of an all-solid-state battery according to one embodiment of the present invention.

[0036] Hereinafter, the present invention will be described in more detail to help understand the present invention.

[0037] The terms and words used in this specification and claims should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted as meanings and concepts that conform to the technical idea of ​​the present invention, based on the principle that the inventor can appropriately define the concept of the term to explain his or her own invention in the best way.

[0038] The terms ionic conductivity and electronic conductivity used in this specification are measures of the conduction tendencies of ions and electrons, respectively, and the concept of adding ionic conductivity and electronic conductivity may be “electrical conductivity.”

[0039]

[0040] Cathode for all-solid-state batteries

[0041] The present invention relates to a positive electrode for an all-solid-state battery.

[0042] The positive electrode for an all-solid-state battery of the present invention contains a high content of positive electrode active material for the effect of improving energy density, and thus, although the content that can be included in the sulfide-based solid electrolyte and the conductive material is limited, by controlling the ratio of the sulfide-based solid electrolyte and the conductive material so that the ratio of ionic conductivity and electronic conductivity becomes equivalent, not only the effect of improving energy density but also high-rate characteristics and lifespan characteristics can be secured. In the positive electrode for an all-solid-state battery according to the present invention, the high content of the positive electrode active material may mean 69 wt% or more based on the total weight of the positive electrode active material layer.

[0043] The positive electrode for an all-solid-state battery according to the present invention includes a positive electrode active material layer. The positive electrode active material layer includes a positive electrode active material, a sulfide-based solid electrolyte, a conductive material, and a binder. The ratio (R) of the ionic conductivity (IC) and electronic conductivity (EC) of the positive electrode active material layer IC / EC ) is 0.5 to 1.5 and is defined by the following equation 1:

[0044] <Formula 1>

[0045] R IC / EC = Ionic conductivity / electronic conductivity.

[0046] The above R IC / EC may be 0.5 or more, 0.7 or more, or 0.9 or more, may be 1.1 or less, 1.3 or less, or 1.5 or less, or may be 1. The R IC / EC When it falls within the range of 0.5 to 1.5, it means that the ionic and electronic conductivity characteristics of the positive electrode are balanced without being biased to either side, which can improve the overall performance of the battery.

[0047] The above-mentioned positive electrode active material layer may be self-standing and may not require a separate current collector. For example, the above-mentioned self-standing positive electrode active material layer may be manufactured using a dry process that does not use a solvent.

[0048] Alternatively, the positive electrode active material layer may be manufactured by a wet process using a solvent, and the positive electrode active material layer manufactured by the wet process may be formed on one surface of the positive electrode current collector.

[0049]

[0050] In one embodiment of the present invention, the ratio of ionic conductivity and electronic conductivity (R IC / EC ) can be calculated from the Nyquist plot obtained by electrochemical impedance spectroscopy (EIS) analysis. However, in the art, the ratio of ionic conductivity to electronic conductivity (R IC / EC ) is not limited to the method used to calculate it.

[0051] The above ionic conductivity is 1.0 x 10 -6 S / cm to 1.0 x 10 -1 It can be S / cm.

[0052] The above electronic conductivity is 1.0 x 10 -6 S / cm to 1.0 x 10 -1 It can be S / cm.

[0053]

[0054] FIG. 1 is a schematic diagram showing a cross-section of an electrochemical cell used for electrochemical impedance analysis according to one embodiment of the present invention.

[0055] Referring to Fig. 1, when conducting electrochemical impedance analysis, an electrochemical cell is manufactured so that a positive electrode active material layer (12) is placed between two positive electrode current collectors (11), and ionic conductivity and electronic conductivity can be analyzed (Journal of power sources, 2016, 316, 215-223).

[0056] For example, if a Nyquist plot is drawn with the impedance measured by applying an AC impedance of 10 mHz to 1 mHz frequency to the electrochemical cell, a number of curves similar to a semicircle shape can be drawn continuously, and for example, in FIG. 2, three large and small curves are drawn continuously from the high-frequency region (left side of the X-axis) to the low-frequency region (right side of the X-axis), and by fitting the low-frequency region to the equivalent circuit, the resistance values ​​R1 and R2 can be used to calculate the electronic resistance RE = R1 + R2 and the ionic resistance RI = (R1 + R2) * R1 / R2. Each resistance can be converted to the conductivity of the electrode by considering the thickness and area of ​​the electrode. At this time, the equivalent circuit can be an R1 + Q2 / R2 model (R: Resister, Q: Constant Phase Element).

[0057]

[0058] In one embodiment of the present invention, the weight ratio of the sulfide-based solid electrolyte and the conductive material may be appropriately adjusted and selected so that the ratio of the ionic conductivity and electronic conductivity of the positive electrode active material layer can be as defined in Equation 1. At this time, the weight ratio of the sulfide-based solid electrolyte and the conductive material may be adjusted in consideration of the inherent ionic conductivity and electronic conductivity of each of the positive electrode active material, the sulfide-based solid electrolyte, and the conductive material used to manufacture the positive electrode active material layer. For example, the weight ratio of the sulfide-based solid electrolyte and the conductive material may be, but is not limited to, 14.1 to 14.8 : 0.2 to 0.9 or 14.3 to 14.7 : 0.3 to 0.7, and as described above, the weight ratio may be adjusted in consideration of the inherent physical properties of the components of the positive electrode active material layer.

[0059]

[0060] In one embodiment of the present invention, the positive electrode active material is not particularly limited as long as it is a material capable of reversibly absorbing and releasing lithium ions, and examples thereof include lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), Li[Ni x Co y Mn z M v ]O2 (wherein M is one or two or more elements selected from the group consisting of Al, Ga, and In; 0.3≤x<1.0, 0≤y, z≤0.5, 0≤v≤0.1, x+y+z+v=1), Li(Li a M b-a-b' M' b' )O 2-c A c(In the above formula, 0≤a≤0.2, 0.6≤b≤1, 0≤b'≤0.2, 0≤c≤0.2; M includes at least one selected from the group consisting of Mn and Ni, Co, Fe, Cr, V, Cu, Zn and Ti; M' is at least one selected from the group consisting of Al, Mg and B, and A is at least one selected from the group consisting of P, F, S and N.) layered compounds or compounds substituted with one or more transition metals; chemical formula Li 1+y Mn 2-y Lithium manganese oxides such as O4 (where y is 0 to 0.33), LiMnO3, LiMn2O3, LiMnO2; lithium copper oxide (Li2CuO2); vanadium oxides such as LiV3O8, LiFe3O4, V2O5, Cu2V2O7; chemical formula LiNi 1-y Ni-site type lithium nickel oxide represented by MyO2 (wherein, M=Co, Mn, Al, Cu, Fe, Mg, B or Ga, and y is 0.01 to 0.3); chemical formula LiMn 2-y M y Lithium manganese composite oxides represented by O2 (wherein M is Co, Ni, Fe, Cr, Zn or Ta, and y is 0.01 to 0.1) or Li2Mn3MO8 (wherein M is Fe, Co, Ni, Cu or Zn); LiMn2O4 in which a portion of Li in the chemical formula is replaced by an alkaline earth metal ion; disulfide compounds; Fe2(MoO4)3, etc., but are not limited thereto.

[0061] In addition, the positive electrode active material may be included in an amount of 69 to 94 wt% based on the total weight of the positive electrode active material layer. Specifically, the content of the positive electrode active material may be 69 wt% or more, 70 wt% or more, 71 wt% or more, 72 wt% or more, 73 wt% or more, 74 wt% or more, 75 wt% or more, 76 wt% or more, 77 wt% or more, 78 wt% or more, 79 wt% or more, or 80 wt% or more, and may be 94 wt% or less, 93 wt% or less, 92 wt% or less, 91 wt% or less, 90 wt% or less, 89 wt% or less, 88 wt% or less, 87 wt% or less, 86 wt% or less, or 85 wt% or less. If the content of the above-mentioned positive electrode active material is less than 69 wt%, the proportion of components that do not participate in the reaction among the battery components increases, which may lower the energy density, and if it exceeds 94 wt%, the ionic conductivity and electronic conductivity required for battery operation may not be secured.

[0062] Additionally, the positive electrode active material may be coated with an insulating material. As the positive electrode active material is coated with an insulating material, the reaction between the positive electrode active material and the solid electrolyte can be limited, thereby reducing resistance.

[0063] The above insulating material may include at least one selected from the group consisting of oxides and fluorides. The oxide may include at least one metal oxide selected from the group consisting of Al2O3, Cr2O3, TiO2, SiO2, ZrO2, and Fe2O3. In addition, the fluoride may include at least one selected from the group consisting of polyvinylidene fluoride (PVdF) and polyvinylidene fluoride copolymers.

[0064] In addition, the thickness of the insulating material coating layer may be 20 nm or less. If the thickness exceeds 20 nm, it may act as resistance when the battery is operated. Specifically, the thickness may be 20 nm or less, 19 nm or less, 18 nm or less, 17 nm or less, 16 nm or less, 15 nm or less, 14 nm or less, 13 nm or less, 12 nm or less, 11 nm or less, 10 nm or less, 9 nm or less, 8 nm or less, 7 nm or less, 6 nm or less, or 5 nm or less. The lower limit of the thickness is not particularly limited, but may be, for example, 1 nm or more or 2 nm or more.

[0065]

[0066] In one embodiment of the present invention, the sulfide-based solid electrolyte is a solid electrolyte containing sulfur among solid electrolytes, and can be added to a positive electrode active material layer to improve ionic conductivity.

[0067] The above sulfide-based solid electrolyte may include at least one selected from the group consisting of LiPSX (X = Cl, Br or I), LiGePS, and LiPS. However, the sulfide-based solid electrolyte is not limited to these, and a wide range of sulfide-based solid electrolytes commonly used in the art may be used.

[0068] In addition, the particle size (D50) of the sulfide-based solid electrolyte may be in the form of particles having a size of 0.1 ㎛ to 1.5 ㎛. Specifically, the particle size (D50) of the sulfide-based solid electrolyte may be 0.1 ㎛ or more, 0.3 ㎛ or more, or 0.5 ㎛ or more, and may be 0.9 ㎛ or less, 1.0 ㎛ or less, 1.2 ㎛ or less, or 1.5 ㎛ or less. If the particle size (D50) of the sulfide-based solid electrolyte is less than 0.1 ㎛, the ultrafine sulfide-based solid electrolyte particles may not be sufficiently dispersed within the positive electrode active material layer and may aggregate, and if it exceeds 1.5 ㎛, dispersion may be somewhat easy, but the contact surface with the positive electrode active material particles may decrease, thereby increasing the positive electrode porosity.

[0069] Additionally, the sulfide-based solid electrolyte may be included in an amount of 5 to 30 wt% based on the total weight of the positive electrode active material layer. Specifically, the content of the sulfide-based solid electrolyte may be 5 wt% or more, 6 wt% or more, 7 wt% or more, 8 wt% or more, 9 wt% or more, 10 wt% or more, 11 wt% or more, 12 wt% or more, 13 wt% or more, 14 wt% or more, 14.1 wt% or more, or 14.3 wt% or more, and may be 30 wt% or less, 29 wt% or less, 28 wt% or less, 27 wt% or less, 26 wt% or less, 25 wt% or less, 24 wt% or less, 23 wt% or less, 22 wt% or less, 21 wt% or less, 20 wt% or less, 19 wt% or less, 18 wt% or less, 17 wt% or less, 16 wt% or less, 15 wt% or less, 14.9 wt% or less, 14.8 wt% or less, or 14.7 wt% or less. If the content of the above sulfide-based solid electrolyte is less than 5 wt%, ionic conductivity may decrease, and if it exceeds 30 wt%, the content of the positive electrode active material and conductive material may relatively decrease, resulting in deterioration of battery performance.

[0070]

[0071] In one embodiment of the present invention, the conductive material can form a path that can conduct electrons, thereby improving electronic conductivity.

[0072] The above conductive material may be a linear conductive material, and the linear conductive material may be at least one selected from the group consisting of carbon nanotubes (CNTs) and carbon nanofibers (CNFs). The linear conductive material may improve electronic conductivity due to its morphological characteristics. For example, the aspect ratio (length / diameter) of the linear conductive material may be 2 or more, and specifically, the aspect ratio may be 2 or more, 5 or more, 10 or more, 20 or more, 30 or more, 40 or more, 50 or more, or 100 or more. If the aspect ratio is less than 2, it may be difficult to form an electronic conduction path, and thus electronic conductivity may be reduced. In addition, the upper limit of the aspect ratio is not particularly limited, but may be 300 or less, 400 or less, 500 or less, 600 or less, or 700 or less in consideration of the ease of forming an electronic conduction path.

[0073] In addition, the conductive agent may be included in an amount of 0.01 to 10 wt% based on the total weight of the positive electrode active material layer. Specifically, the content of the conductive agent may be 0.01 wt% or more, 0.1 wt% or more, 0.2 wt% or more, or 0.3 wt% or more, and may be 10 wt% or less, 9 wt% or less, 8 wt% or less, 7 wt% or less, 6 wt% or less, 5 wt% or less, 4 wt% or less, 3 wt% or less, 2 wt% or less, 1 wt% or less, 0.9 wt% or less, 0.8 wt% or less, or 0.7 wt% or less. If the content of the conductive agent is less than 0.01 wt%, the electronic conductivity of the positive electrode may be lowered, and if it exceeds 10 wt%, the resistance may be increased as the side reaction of the solid electrolyte increases, and also the content of the positive electrode active material and the sulfide-based solid electrolyte may be relatively reduced, thereby deteriorating battery performance.

[0074]

[0075] In one embodiment of the present invention, the binder may be included to assist bonding between materials included in the positive electrode active material layer and bonding between the positive electrode active material layer and the positive electrode current collector.

[0076] The above binder may be a fibrous binder. During the mixing process of manufacturing the positive electrode, the binder may undergo fiberization and be incorporated into the positive electrode active material layer in a fibrous form. Therefore, it is preferable that the binder have physical properties that can be easily modified.

[0077] In addition, the binder is polytetrafluoroethylene (PTFE), polyethylene, polypropylene, ethylene / propylene copolymer, polybutadiene, polyethylene oxide, chlorosulfonated polyethylene, polyvinylpyrrolidone, polyvinylpyridine, polyvinyl alcohol, polyvinyl acetate, polyepichlorohydrin, polyphosphazene, polyacrylonitrile, polystyrene, latex, acrylic resin, phenol resin, epoxy resin, carboxymethylcellulose, hydroxypropyl cellulose, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethylcellulose, cyanoethylsucrose, polyester, polyamide, polyether, polyimide, polycarboxylate, polycarboxylic acid, polyacrylic acid, polyacrylate, lithium polyacrylate, polymethacrylic acid, It may include at least one selected from the group consisting of polymethacrylate, polyacrylamide, polyurethane, polyvinylidene fluoride, and poly(vinylidene fluoride)-hexafluoropropene. Preferably, the binder may include polytetrafluoroethylene (PTFE).

[0078] In addition, the binder may be included in an amount of 0.01 to 10 wt% based on the total weight of the positive electrode active material layer. Specifically, the content of the binder may be 0.01 wt% or more, 1 wt% or more, or 2 wt% or more, and may be 10 wt% or less, 9 wt% or less, 8 wt% or less, 7 wt% or less, 6 wt% or less, 5 wt% or less, 4 wt% or less, or 3 wt% or less. If the content of the binder is less than 0.01 wt%, the effect of improving the bonding strength between materials included in the positive electrode active material layer may be insignificant, and thus the electrode sheet may not be properly formed. If the content of the binder is more than 10 wt%, ionic conductivity or electronic conductivity may be reduced.

[0079]

[0080] In one embodiment of the present invention, the thickness of the positive electrode active material layer may be 100 ㎛ to 300 ㎛, specifically, may be 100 ㎛ or more, 110 ㎛ or more, or 120 ㎛ or more, and may be 200 ㎛ or less, 250 ㎛ or less, or 300 ㎛ or less. However, the thickness of the positive electrode active material layer is not limited thereto, and the ratio of the solid electrolyte and the conductive material may be adjusted so that the ratio of ionic conductivity and electronic conductivity becomes 0.5 to 1.5 depending on the target loading of the positive electrode active material layer.

[0081]

[0082] In one embodiment of the present invention, the positive electrode current collector supports the positive electrode active material layer and serves to transfer electrons between the external conductor and the positive electrode active material layer.

[0083] The positive electrode current collector is not particularly limited as long as it has high electronic conductivity without causing chemical changes in the all-solid-state battery. For example, stainless steel, aluminum, nickel, titanium, palladium, calcined carbon, stainless steel surface-treated with carbon, nickel, silver, etc., aluminum-cadmium alloy, etc. can be used as the positive electrode current collector.

[0084] The positive electrode current collector may have a finely irregular structure on its surface or may employ a three-dimensional porous structure to strengthen the bonding strength with the positive electrode active material layer. Accordingly, the positive electrode current collector may include various forms such as a film, sheet, foil, mesh, net, porous body, foam, or non-woven fabric.

[0085]

[0086] Method for manufacturing a cathode for an all-solid-state battery

[0087] The present invention also relates to a method for manufacturing a positive electrode for an all-solid-state battery.

[0088] The method for manufacturing an all-solid-state battery positive electrode according to the present invention may be a wet process or a dry process, depending on whether a solvent is used. The specific materials, physical properties, and contents of the positive electrode active material, sulfide-based solid electrolyte, conductive agent, and binder used in the method for manufacturing an all-solid-state battery positive electrode according to the present invention are as described above.

[0089]

[0090] In the method for manufacturing a positive electrode for an all-solid-state battery according to the present invention, the wet process includes: (A1) a step of forming a slurry by adding a positive electrode active material, a sulfide-based solid electrolyte, a conductive material, and a binder to an organic solvent; (A2) a step of coating the slurry formed in step (A1) onto a positive electrode current collector; and (A3) a step of drying the coating layer formed in step (A2).

[0091]

[0092] Hereinafter, the wet process among the methods for manufacturing the positive electrode for the all-solid-state battery is described in more detail for each step.

[0093]

[0094] In one embodiment of the present invention, in the step (A1), a positive electrode active material, a sulfide-based solid electrolyte, a conductive material, and a binder may be added to an organic solvent to form a slurry.

[0095] The organic solvent described above is capable of uniformly dispersing the positive electrode active material, sulfide-based solid electrolyte, conductive material, and binder, and it is preferable to use one that evaporates easily. Specific examples include acetonitrile, methanol, ethanol, tetrahydrofuran, water, and isopropyl alcohol.

[0096] Additionally, the concentration of the slurry is not particularly limited as long as it allows for smooth coating fixation. For example, the concentration of the slurry may be 30 to 50 wt% based on the solid content.

[0097]

[0098] In one embodiment of the present invention, in the step (A2), the slurry formed in the step (A1) can be coated on the positive electrode current collector.

[0099] The above coating method is not particularly limited as long as it is a method capable of forming a coating layer using slurry. For example, the coating may be performed by roll coating, gravure coating, doctor blade coating, slot die coating, slurry coating, or extrusion coating.

[0100]

[0101] In one embodiment of the present invention, in the step (A3), the coating layer formed in the step (A2) can be dried.

[0102] In addition, the drying is not particularly limited as long as it is a method of drying to a degree capable of removing the organic solvent from the coating layer. For example, the drying may be performed at a temperature of 80 to 130°C.

[0103]

[0104] In the method for manufacturing a positive electrode for an all-solid-state battery according to the present invention, the dry process includes (B1) a step of mixing a positive electrode active material, a sulfide-based solid electrolyte, a conductive material, and a binder; and (B2) a step of applying the mixed powder obtained in step (B1) to a calendaring process to form it into a film shape.

[0105]

[0106] Hereinafter, the dry process among the methods for manufacturing the positive electrode for the all-solid-state battery is described in more detail for each step.

[0107]

[0108] In one embodiment of the present invention, in the step (B1), a positive electrode active material, a sulfide-based solid electrolyte, a conductive material, and a binder are mixed to obtain a mixed powder.

[0109] Alternatively, the mixing may be physical mixing without using a separate solvent, and the binder may be fiberized by physical mixing. During the physical mixing, the binder may be physically deformed by friction with the particles in the mixed powder due to shear force, thereby fiberizing. In order to induce such physical deformation, a binder that is physically very weak and thus relatively prone to fiberization may be used. For example, PTFE, which has properties that facilitate physical deformation, may be used as a binder. In addition, the mixing may be performed by introducing an induction furnace, ball milling, or roll press to facilitate physical deformation.

[0110]

[0111] In one embodiment of the present invention, in the step (B2), the mixed powder obtained in the step (B1) can be formed into a film shape by applying a calendaring process.

[0112] The conditions for the above-mentioned calendering process may be applied by appropriately controlling process conditions that allow for film-forming. For example, the calendering process may be performed at a temperature of 20°C to 200°C for 5 to 50 loops. However, any of the calendering process conditions, such as temperature, pressure, and number of loops, that are used in electrode manufacturing processes commonly used in the battery field may be used.

[0113]

[0114] All-solid-state batteries

[0115] The present invention also relates to an all-solid-state battery including the positive electrode.

[0116] Figure 3 is a schematic diagram showing a longitudinal cross-section of an all-solid-state battery according to one embodiment of the present invention.

[0117] Referring to FIG. 3, the all-solid-state battery according to the present invention includes the positive electrode (10), the negative electrode (20), and the sulfide-based solid electrolyte membrane (30) interposed therebetween. The positive electrode (10) has a structure in which a positive electrode active material layer (12) is formed on one surface of a positive electrode current collector (11), as described above, and the negative electrode (20) has a structure in which a negative electrode active material layer (22) is formed on one surface of a negative electrode current collector (21), and a sulfide-based solid electrolyte membrane (30) may be interposed between the positive electrode active material layer (12) and the negative electrode active material layer (22). However, the all-solid-state battery according to the present invention is not limited to this structure, and if the positive electrode active material layer (12) is capable of self-standing, the positive electrode current collector may not be included, and the negative electrode active material layer may be a non-cathode coating layer.

[0118]

[0119] In one embodiment of the present invention, the negative electrode may include an negative electrode active material layer or an anodeless coating layer. In addition, the negative electrode active material layer or the anodeless coating layer may be formed on one surface of the negative electrode current collector.

[0120]

[0121] The above negative electrode active material layer includes a negative electrode active material, a binder, and a conductive material.

[0122] The above negative active material is lithium (Li + ) can be reversibly intercalated or deintercalated, a material that can react with lithium ions to form a reversibly lithium-containing compound, or a lithium metal or a lithium alloy.

[0123] The above lithium ion (Li +) can be reversibly inserted or de-inserted, for example, crystalline carbon, amorphous carbon, or a mixture thereof. The lithium ion (Li + ) can be, for example, tin oxide, titanium nitrate or silicon. The lithium alloy can be, for example, an alloy of lithium (Li) and a metal selected from the group consisting of indium (In), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), francium (Fr), beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), radium (Ra), aluminum (Al) and tin (Sn).

[0124] Preferably, the negative electrode active material may be lithium metal or a lithium-indium alloy (Li-In), and specifically, may be in the form of a lithium metal or lithium and a thin film or a lithium-indium alloy thin film or powder.

[0125] The negative electrode active material may be included in an amount of 40 to 80 wt% based on the total weight of the negative electrode active material layer. Specifically, the content of the negative electrode active material may be 40 wt% or more or 50 wt% or more, and 70 wt% or less or 80 wt% or less. If the content of the negative electrode active material is less than 40 wt%, the connectivity between the wet negative electrode active material layer and the dry negative electrode active material layer may be insufficient, and if it exceeds 80 wt%, the material transfer resistance may increase.

[0126] In addition, the binder is a component that assists in the bonding of the negative electrode active material and the conductive material and the bonding to the negative electrode current collector, and includes styrene-butadiene rubber, acrylated styrene-butadiene rubber, acrylonitrile copolymer, acrylonitrile-butadiene rubber, nitrile butadiene rubber, acrylonitrile-styrene-butadiene copolymer, acrylic rubber, butyl rubber, fluorine rubber, polytetrafluoroethylene, polyethylene, polypropylene, ethylene / propylene copolymer, polybutadiene, polyethylene oxide, chlorosulfonated polyethylene, polyvinylpyrrolidone, polyvinylpyridine, polyvinyl alcohol, polyvinyl acetate, polyepichlorohydrin, polyphosphazene, polyacrylonitrile, polystyrene, latex, acrylic resin, phenol resin, epoxy resin, carboxymethylcellulose, hydroxypropyl cellulose, cellulose acetate, cellulose It may include at least one selected from the group consisting of acetate butyrate, cellulose acetate propionate, cyanoethylcellulose, cyanoethylsucrose, polyester, polyamide, polyether, polyimide, polycarboxylate, polycarboxylic acid, polyacrylic acid, polyacrylate, lithium polyacrylate, polymethacrylic acid, polymethacrylate, polyacrylamide, polyurethane, polyvinylidene fluoride, and poly(vinylidene fluoride)-hexafluoropropene. Preferably, the binder may include polytetrafluoroethylene (PTFE).

[0127] In addition, the binder may be included in an amount of 0.5 wt% to 4 wt% based on the total weight of the negative electrode active material layer, and specifically, the content of the binder may be 0.5 wt% or more, 1 wt% or more, or 1.5 wt% or more, and 3 wt% or less, 3.5 wt% or less, or 4 wt% or less. If the content of the binder is less than 0.5 wt%, the adhesive strength between the positive electrode active material and the negative electrode current collector may be reduced, and if it exceeds 4 wt%, the adhesive strength may be improved, but the content of the negative electrode active material may be reduced, which may lower the battery capacity.

[0128]

[0129] In addition, the conductive material is not particularly limited as long as it prevents side reactions in the internal environment of the all-solid-state battery, does not cause chemical changes in the battery, and has excellent electronic conductivity. Representative examples thereof include graphite or conductive carbon, and examples thereof include graphite such as natural graphite and artificial graphite; carbon black such as carbon black, acetylene black, Ketjen black, Denka black, thermal black, channel black, furnace black, lamp black, and summer black; carbon-based materials having a crystal structure of graphene or graphite; conductive fibers such as carbon fiber and metal fiber; fluorinated carbon; metal powder such as aluminum powder and nickel powder; conductive whiskey such as zinc oxide and potassium titanate; conductive oxides such as titanium oxide; and conductive polymers such as polyphenylene derivatives; which may be used alone or in combination of two or more thereof, but are not necessarily limited thereto. Preferably, the conductive material may include vapor-grown carbon fiber (VGCF).

[0130] The conductive material may typically be included in an amount of 1 wt% to 5 wt% based on the total weight of the negative electrode active material layer, and specifically, the content of the conductive material may be 1 wt% or more, 1.5 wt% or more, or 2 wt% or more, and 4 wt% or less, 4.5 wt% or less, or 5 wt% or less. If the content of the conductive material is too low, less than 1 wt%, it may be difficult to expect the effect of improving electronic conductivity or the electrochemical characteristics of the battery may deteriorate, and if it exceeds 5 wt%, the amount of the negative electrode active material may be relatively small, which may lower the capacity and energy density. The method of including the conductive material in the negative electrode is not particularly limited, and conventional methods known in the art, such as mixing with the negative electrode active material or coating, may be used.

[0131] In addition, the negative electrode current collector is not particularly limited as long as it is conductive and does not cause a chemical change in the battery. For example, the negative electrode current collector may be made of copper, stainless steel, aluminum, nickel, titanium, calcined carbon, copper or stainless steel surface-treated with carbon, nickel, titanium, silver, etc., an aluminum-cadmium alloy, etc. In addition, the negative electrode current collector, like the positive electrode current collector, may be made of various forms such as a film, sheet, foil, net, porous body, foam, non-woven fabric, etc. having fine irregularities formed on the surface.

[0132] The method for manufacturing the above negative electrode is not particularly limited, and can be manufactured by forming a negative electrode active material layer on the negative electrode current collector using a method for forming a layer or film commonly used in the art. For example, methods such as compression, coating, and deposition can be used. In addition, a case in which a battery is assembled on the negative electrode current collector without a lithium thin film and then a metallic lithium thin film is formed on the metal plate through initial charging is also included in the negative electrode of the present invention.

[0133]

[0134] Additionally, the non-cathode coating layer may refer to a negative active material layer that does not include a negative active material. The negative active material may be formed in the non-cathode coating layer by charging. For example, when the battery is charged, lithium ions may migrate from the positive electrode, causing lithium metal to be precipitated from the negative electrode. In other words, the non-cathode coating layer may be a film that induces lithium precipitation.

[0135] The above-mentioned cathode-free coating layer may include metal particles and carbon material particles, and specifically, may include a carbon material-metal composite.

[0136] The above carbon material particles may be, for example, amorphous carbon material particles. However, the carbon material particles are not limited to amorphous particles. Specific examples of the amorphous carbon material include carbon black such as acetylene black, furnace black, and Ketjen black, graphene, or combinations thereof.

[0137] In addition, the metal particles may be particles that form an alloy with lithium, and the metal particles may be at least one particle selected from silver (Ag), gold, platinum, palladium, silicon, aluminum, bismuth, tin, indium, and zinc. The non-cathode coating layer may be formed as a very thin film with a micro-thickness, and may be formed with a thickness of, for example, 10 μm or less.

[0138] Preferably, the non-cathode coating layer may include an Ag-C composite as a carbon material-metal composite, and upon first charging, lithium may be precipitated between the negative electrode current collector and the coating layer including the Ag-C composite.

[0139]

[0140] In one embodiment of the present invention, the sulfide-based solid electrolyte included in the sulfide-based solid electrolyte membrane may include at least one selected from the group consisting of LiPSX (X = Cl, Br or I), LiGePS, and LiPS. However, the sulfide-based solid electrolyte is not limited to these, and a sulfide-based solid electrolyte commonly used in the art can be widely used.

[0141]

[0142] battery module

[0143] The present invention also relates to a battery module including the all-solid-state battery as a unit battery, a battery pack including the battery module, and a device including the battery pack as a power source.

[0144] Hereinafter, specific examples of the device include, but are not limited to, a power tool that is powered by an electric motor; an electric vehicle including an electric vehicle (EV), a hybrid electric vehicle (HEV), and a plug-in hybrid electric vehicle (PHEV); an electric two-wheeled vehicle including an electric bicycle (E-bike) and an electric scooter (E-scooter); an electric golf cart; and a power storage system. Hereinafter, preferred embodiments are presented to help understand the present invention, but the following embodiments are only illustrative of the present invention and it will be apparent to those skilled in the art that various changes and modifications are possible within the scope and technical idea of ​​the present invention, and it will be apparent that such changes and modifications also fall within the scope of the appended patent claims.

[0145] Hereinafter, preferred examples are presented to help understand the present invention, but the following examples are only illustrative of the present invention, and it is obvious to those skilled in the art that various changes and modifications are possible within the scope and technical idea of ​​the present invention, and it is also natural that such changes and modifications fall within the scope of the appended patent claims.

[0146] In the following examples and comparative examples, a positive electrode and an all-solid-state battery including the same were manufactured according to the composition of the positive electrode active material layer as described in Table 1 below.

[0147]

[0148] Composition of the positive electrode active material layer (weight %) Non-ionic conductivity (S / cm) Electronic conductivity (S / cm) R IC / EC Cathode active material sulfide-based solid electrolyte conductive material binder Example 1 8414.50.5 13.27E-05 3.15E-05 1.04 Example 2 8414.70.3 13.41E-05 2.42E-05 1.41 Example 3 8414.30.7 12.94E-05 4.27E-05 0.69 Example 4 8018116.62E-05 4.80E-05 1.38 Example 5 8810.90.1 11.96E-05 2.27E-05 0.86 Comparative example 18413.51.5 12.16E-05 1.57E-05 0.01 Comparative example 28016316.12E-059.33E-030.01 Comparative example 3908116.44E-062.12E-040.03

[0149]

[0150] Example 1

[0151] 1-1. Manufacturing of positive electrode active material layer

[0152] LiN as a cathode active material 0.8 Co 0.1 Mn 0.1 The positive electrode was manufactured as follows using O2 (NCM 811), Li6PS5Cl as a sulfide-based solid electrolyte, CNF as a linear conductive material, and polytetrafluoroethylene (PTFE) as a binder.

[0153] Powder mixing was performed with a weight ratio of 84:14.5:0.5:1 for the positive electrode active material, sulfide-based solid electrolyte, conductive agent, and binder. Specifically, the positive electrode active material, sulfide-based solid electrolyte, and conductive agent were quantified in powder form, and then mixed for 30 minutes using a blade mixer in a dry room environment without using a separate solvent to obtain a mixture. Thereafter, PTFE (Polytetrafluoroethylene) powder, which is a binder, was quantified and additionally mixed to obtain a mixed powder.

[0154] After the above mixed powder is put into the inducer, fiberization is performed in the inducer and calendaring is performed on the roller to have a thickness of 150 ㎛, and R IC / EC = 1.04 was manufactured.

[0155] The above R IC / EC The ionic conductivity and electronic conductivity were extracted and calculated from the Nyquist plot obtained by electrochemical impedance spectroscopy (EIS) analysis using the SP-50e equipment of BioLogic. The R IC / EC The calculated value is the number rounded to the third decimal place.

[0156]

[0157] 1-2. All-solid-state battery manufacturing

[0158] An all-solid-state battery was manufactured by sequentially stacking a sulfide-based solid electrolyte membrane composed of a negative electrode current collector (copper, Cu), lithium metal, and Li6PS5Cl, and the positive electrode and positive electrode current collector (aluminum, Al).

[0159]

[0160] Example 2

[0161] The same method as Example 1 was performed, except that the weight ratio of the positive electrode active material, sulfide-based solid electrolyte, conductive material, and binder was 84:14.7:0.3:1, and R IC / EC = 1.41 A positive electrode was manufactured.

[0162]

[0163] Example 3

[0164] The same method as Example 1 was performed, except that the weight ratio of the positive electrode active material, sulfide-based solid electrolyte, conductive agent, and binder was 84:14.3:0.7:1, and R IC / EC = 0.69 was manufactured.

[0165]

[0166] Example 4

[0167] The same method as Example 1 was performed, except that the weight ratio of the positive electrode active material, sulfide-based solid electrolyte, conductive material, and binder was 80:18:1:1, and R IC / EC = 1.38 positive electrode was manufactured.

[0168]

[0169] Example 5

[0170] The same method as Example 1 was performed, except that the weight ratio of the positive electrode active material, sulfide-based solid electrolyte, conductive material, and binder was 88:10.9:0.1:1, and R IC / EC = 0.86 was manufactured.

[0171]

[0172] Comparative Example 1

[0173] The same method as Example 1 was performed, except that the weight ratio of the positive electrode active material, sulfide-based solid electrolyte, conductive material, and binder was 84:13.5:1.5:1, and R IC / EC= 0.01 positive electrode was manufactured.

[0174]

[0175] Comparative Example 2

[0176] The same method as Example 1 was performed, except that the weight ratio of the positive electrode active material, sulfide-based solid electrolyte, conductive agent, and binder was 80:16:3:1, and R IC / EC = 0.01 positive electrode was manufactured.

[0177]

[0178] Comparative Example 3

[0179] The same method as Example 1 was performed, except that the weight ratio of the positive electrode active material, sulfide-based solid electrolyte, conductive material, and binder was 90:8:1:1, and R IC / EC = 0.03 was manufactured.

[0180]

[0181] Experimental Example 1: Performance Evaluation of All-Solid-State Battery

[0182] The ratio of ionic conductivity and electronic conductivity of the positive electrode active material layer formed on the positive electrode (R IC / EC ) was used to evaluate the performance of all-solid-state batteries. Examples 1 to 5 and Comparative Examples 1 to 3 were used as the evaluation subjects.

[0183] In order to evaluate the performance of the above all-solid-state battery, the voltage was 4.25 V (vs. Li / Li) at a current of 0.1 C. + ) and then charged until 4.25 V (vs. Li / Li + ) and charged with a current cut-off of 0.05C. The voltage was 3 V (vs. Li / Li +) was discharged at a current of 0.1C until 1000 mAh. This process was performed twice, and the discharge capacity of the second cycle was used as the 0.1C initial discharge capacity. Subsequently, the rate capability was evaluated through a protocol discharging up to 1C. Specifically, the rate capability was observed through a protocol of CC discharging at 0.1C / 0.33C / 0.5C / 1C while maintaining the 0.1C / 0.05C CC / CV (Constant Current / Constant Voltage) charging process. The 1C capacity retention rate, which is calculated by dividing the 1C discharge capacity obtained through the evaluation process by the 0.1C initial discharge capacity, was used as the result of the high rate capability. The 0.1C initial discharge capacity and 1C capacity retention rate measured in Examples 1 to 5 and Comparative Examples 1 to 3 are shown in Table 2 below.

[0184]

[0185] 0.1C Initial Discharge Capacity (mAh) 1C Discharge Capacity (mAh) 1C Capacity Retention Rate (%) Example 1 19.3 17.6 9 1.4 Example 2 19.3 17.2 8 9.5 Example 3 19.1 16.7 8 7.7 Example 4 19.3 17.4 9 0.5 Example 5 18.6 16.2 8 7.4 Comparative Example 1 17.6 11.0 6 2.5 Comparative Example 2 17.8 9 8 5 4.8 Comparative Example 3 16.8 7.3 4 3.7

[0186]

[0187] As shown in Table 2 above, it can be seen that Examples 1 to 5 have superior discharge capacity and high rate characteristics compared to Comparative Examples 1 to 3. Examples 1 to 5 have a ratio of ionic conductivity to electronic conductivity (R IC / EC ) is within the range of 0.5 to 1.5, and it was confirmed that the discharge capacity and high-rate characteristics were rapidly reduced when it was out of this range. In addition, among Examples 1 to 5, the ratio of ionic conductivity to electronic conductivity (R IC / EC ) was confirmed to have the best discharge capacity and high-rate characteristics of Example 1, which was close to 1.

[0188]

[0189] [Explanation of symbols]

[0190] 10: Bipolar

[0191] 11: Positive current collector

[0192] 12: Positive active material layer

[0193] 20: Cathode

[0194] 21: Negative current collector

[0195] 22: Negative active material layer

[0196] 30: Sulfide-based solid electrolyte membrane

Claims

1. In a positive electrode for an all-solid-state battery including a positive electrode active material layer, The above positive electrode active material layer includes a positive electrode active material, a sulfide-based solid electrolyte, a conductive material, and a binder, The ratio (R) of the ionic conductivity (IC) and electronic conductivity (EC) of the positive electrode active material layer, as defined by the following equation 1 IC / EC ) is 0.5 to 1.5, anode for all-solid-state batteries: <Formula 1> R IC / EC = Ionic conductivity / electronic conductivity.

2. In paragraph 1, An all-solid-state battery positive electrode, wherein the ratio of the above ionic conductivity and electronic conductivity is calculated from a Nyquist plot obtained by electrochemical impedance spectroscopy (EIS) analysis.

3. In paragraph 1, The above positive electrode active material is lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), Li[Ni x Co y Mn z M v ]O2 (wherein M is one or two or more elements selected from the group consisting of Al, Ga, and In; 0.3≤x<1.0, 0≤y, z≤0.5, 0≤v≤0.1, x+y+z+v=1), Li(Li a M b-a-b' M' b' )O 2-c A c (In the above formula, 0≤a≤0.2, 0.6≤b≤1, 0≤b'≤0.2, 0≤c≤0.2; M includes at least one selected from the group consisting of Mn and Ni, Co, Fe, Cr, V, Cu, Zn and Ti; M' is at least one selected from the group consisting of Al, Mg and B, and A is at least one selected from the group consisting of P, F, S and N.) layered compounds or compounds substituted with one or more transition metals; chemical formula Li 1+y Mn 2-y Lithium manganese oxides such as O4 (where y is 0 to 0.33), LiMnO3, LiMn2O3, LiMnO2; lithium copper oxide (Li2CuO2); vanadium oxides such as LiV3O8, LiFe3O4, V2O5, Cu2V2O7; chemical formula LiNi 1-y Ni-site type lithium nickel oxide represented by MyO2 (wherein, M=Co, Mn, Al, Cu, Fe, Mg, B or Ga, and y is 0.01 to 0.3); chemical formula LiMn 2-y M y A positive electrode for an all-solid-state battery, comprising a lithium manganese composite oxide represented by O2 (wherein M is Co, Ni, Fe, Cr, Zn or Ta, and y is 0.01 to 0.1) or Li2Mn3MO8 (wherein M is Fe, Co, Ni, Cu or Zn); a disulfide compound; LiMn2O4 in which a portion of Li in the chemical formula is replaced by an alkaline earth metal ion; Fe2(MoO4)3.

4. In paragraph 1, An all-solid-state battery positive electrode, wherein the above sulfide-based solid electrolyte comprises at least one selected from the group consisting of LiPSX (X = Cl, Br or I), LiGePS, and LiPS.

5. In paragraph 1, An all-solid-state battery positive electrode, wherein the above sulfide-based solid electrolyte is in the form of particles having a particle size (D50) of 0.1 ㎛ to 1.5 ㎛.

6. In paragraph 1, An all-solid-state battery positive electrode, wherein the above-mentioned conductive material comprises at least one selected from the group consisting of carbon nanotubes (CNTs) and carbon nanofibers (CNFs).

7. In paragraph 1, The above binder is polytetrafluoroethylene (PTFE), polyethylene, polypropylene, ethylene / propylene copolymer, polybutadiene, polyethylene oxide, chlorosulfonated polyethylene, polyvinylpyrrolidone, polyvinylpyridine, polyvinyl alcohol, polyvinyl acetate, polyepichlorohydrin, polyphosphazene, polyacrylonitrile, polystyrene, latex, acrylic resin, phenol resin, epoxy resin, carboxymethylcellulose, hydroxypropyl cellulose, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethylcellulose, cyanoethylsucrose, polyester, polyamide, polyether, polyimide, polycarboxylate, polycarboxylic acid, polyacrylic acid, polyacrylate, lithium polyacrylate, polymethacrylic acid, An all-solid-state battery positive electrode comprising at least one selected from the group consisting of polymethacrylate, polyacrylamide, polyurethane, polyvinylidene fluoride, and poly(vinylidene fluoride)-hexafluoropropene.

8. In paragraph 1, An all-solid-state battery positive electrode, wherein the positive electrode active material layer comprises 69 to 94 wt% of a positive electrode active material, 5 to 30 wt% of a sulfide-based solid electrolyte, 0.01 to 10 wt% of a conductive material, and 0.01 to 10 wt% of a binder.

9. In paragraph 1, An all-solid-state battery positive electrode, wherein the positive electrode active material layer comprises 80 to 90 wt% of a positive electrode active material, 9 to 20 wt% of a sulfide-based solid electrolyte, 0.1 to 1 wt% of a conductive material, and 0.01 to 3 wt% of a binder.

10. In paragraph 1, A positive electrode for an all-solid-state battery, wherein the positive electrode active material is coated with an insulating material.

11. In paragraph 10, An all-solid-state battery positive electrode, wherein the insulating material comprises at least one selected from the group consisting of oxides and fluorides.

12. In paragraph 1, A positive electrode for an all-solid-state battery, wherein the above conductive material is a linear conductive material.

13. In paragraph 1, A positive electrode for an all-solid-state battery, wherein the above binder is a fibrous binder.

14. An all-solid-state battery comprising the positive electrode, negative electrode and a sulfide-based solid electrolyte membrane interposed therebetween.

15. In paragraph 14, An all-solid-state battery, wherein the negative electrode comprises a lithium-containing negative electrode active material layer or an anodeless coating layer.

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