Positive electrode for all-solid-state battery and all-solid-state battery including the same

Abstract

The present invention relates to a positive electrode for an all-solid-state battery and an all-solid-state battery including the same. More specifically, the present invention relates to a positive electrode having a ratio of ionic conductivity to electronic conductivity of a positive electrode active material layer in the range of 0.5 to 1.5, and an all-solid-state battery including such a positive electrode may exhibit improved battery performance, such as lifespan characteristics and high-rate characteristics.

Description

[Technical Field]

[0001] This application claims the benefit of priority based on 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, and all contents disclosed in the documents of these Korean patent applications 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. [Background technology]

[0003] Currently, various batteries that can overcome the limitations of lithium secondary batteries are being researched from the viewpoints of battery capacity, safety, output, size increase, and miniaturization.

[0004] Typically, metal-air batteries, which have a much larger theoretical capacity than lithium secondary batteries, all-solid-state batteries, which are safe and do not pose a risk of explosion, supercapacitors, which have higher output, NaS batteries or RFBs (redox flow batteries), which are larger, and thin film batteries, which are smaller, are being continuously researched in both academia and industry.

[0005] All-solid-state batteries are batteries that replace the liquid electrolyte used in conventional lithium secondary batteries with a solid. Because they do not use flammable solvents, they are completely free of fires and explosions caused by decomposition reactions of conventional electrolytes, significantly improving safety. Furthermore, among all-solid-state batteries, technological development is progressing on sulfide-based all-solid-state batteries, which have high ionic conductivity in the solid electrolyte and can theoretically achieve a high energy density of over 900 Wh / L. In this context, sulfide-based all-solid-state batteries refer to all-solid-state batteries that contain a sulfide-based solid electrolyte.

[0006] In an all-solid-state battery system, lithium ion conduction does not occur due to the liquid electrolyte contained in conventional lithium-ion batteries (LIBs). Therefore, when manufacturing a cathode for a sulfide-based all-solid-state battery, it is necessary to add small sulfide-based solid electrolyte particles inside the cathode to increase the contact surface between the cathode active material and the sulfide-based solid electrolyte particles, thereby increasing the ionic conductivity of lithium ions.

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

[0008] However, when the positive electrode of a sulfide-based all-solid-state battery contains a high content of positive electrode active material to improve energy density, the sulfide-based solid electrolyte and conductive material may not be contained in an amount sufficient to ensure ionic conductivity and electronic conductivity, which may result in a decrease in high-rate characteristics and life characteristics.

[0009] For this reason, there is a need for technological development that will not only improve energy density by incorporating a high content of positive electrode active material into the positive electrode of sulfide-based all-solid-state batteries, but will also ensure both ionic and electronic conductivity, thereby improving high-rate characteristics and lifespan characteristics. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] U.S. Patent No. 10333171 Summary of the Invention [Problem to be solved by the invention]

[0011] As a result of extensive research to solve the above problems, the present inventors have found that in a positive electrode for an all-solid-state battery having a positive electrode active material layer containing a high content of positive electrode active material, when the composition inside the positive electrode active material layer is controlled so that the ratio of ionic conductivity to electronic conductivity of the positive electrode active material layer is at an equivalent level, battery performance such as high rate characteristics and life characteristics can be improved.

[0012] SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a positive electrode having a positive electrode active material layer formed thereon, the ionic conductivity and the electronic conductivity of which are at the same level.

[0013] Another object of the present invention is to provide an all-solid-state battery including a cathode in which a cathode active material layer having the same level of ionic conductivity and electronic conductivity is formed, and which has improved battery performance such as high rate characteristics and life characteristics.

[0014] In order to achieve the above object, the present invention provides a positive electrode for an all-solid-state battery including 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 is defined by the following formula 1: IC / EC ) is 0.5 to 1.5: [Formula 1] R IC / EC = ionic conductivity / electronic conductivity

[0015] In one embodiment of the present invention, there is provided a positive electrode for an all-solid-state battery, wherein the ratio of ionic conductivity to electronic conductivity is calculated from a Nyquist plot obtained by electrochemical impedance spectroscopy (EIS) analysis.

[0016] 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 any one 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, and x+y+z+v=1), Li (Li a M b-a-b’ M' b’ )O 2-c A c (wherein 0≦a≦0.2, 0.6≦b≦1, 0≦b'≦0.2, 0≦c≦0.2; M comprises Mn and one or more elements selected from the group consisting of Ni, Co, Fe, Cr, V, Cu, Zn, and Ti; M' is one or more elements selected from the group consisting of Al, Mg, and B; and A is one or more elements selected from the group consisting of P, F, S, and N), or compounds substituted with one or more transition metals; 1+y Mn 2-y Vanadium oxides such as LiV3O8, LiFe3O4, V2O5, and Cu2V2O7; with the chemical formula LiNi 1-y Ni-site lithium nickel oxide represented by MyO2 (where 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 The present invention provides a positive electrode for an all-solid-state battery, which comprises a lithium manganese composite oxide represented by LiMnO2 (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; or a positive electrode for an all-solid-state battery, which comprises a lithium manganese composite oxide represented by LiMnO4 (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). The positive electrode is a disulfide compound; or a positive electrode is a disulfide compound;

[0017] In one embodiment of the present invention, there is provided a positive electrode for an all-solid-state battery, wherein the sulfide-based solid electrolyte includes one or more selected from the group consisting of LiPSX (X = Cl, Br, or I), LiGePS, and LiPS.

[0018] In one embodiment of the present invention, there is provided a positive electrode for an all-solid-state battery, wherein the sulfide-based solid electrolyte is in the form of particles having a particle size (D50) of 0.1 μm to 1.5 μm.

[0019] In one embodiment of the present invention, there is provided a positive electrode for an all-solid-state battery, wherein the conductive material comprises at least one material selected from the group consisting of carbon nanotubes (CNTs) and carbon nanofibers (CNFs).

[0020] 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, phenolic resin, epoxy resin, carboxymethyl cellulose, hydroxypropyl Provided is a positive electrode for an all-solid-state battery, which contains one or more materials selected from the group consisting of cellulose, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethyl cellulose, cyanoethyl sucrose, polyester, polyamide, polyether, polyimide, polycarboxylate, polycarboxylic acid, polyacrylic acid, polyacrylate, lithium polyacrylate, polymethacrylic acid, polymethacrylate, polyacrylamide, polyurethane, polyvinylidene fluoride, and poly(vinylidene fluoride)-hexafluoroprofen.

[0021] In one embodiment of the present invention, there is provided a positive electrode for an all-solid-state battery, wherein the positive electrode active material layer contains 69 wt % to 94 wt % of a positive electrode active material, 5 wt % to 30 wt % of a sulfide-based solid electrolyte, 0.01 wt % to 10 wt % of a conductive material, and 0.01 wt % to 10 wt % of a binder.

[0022] 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.

[0023] In one embodiment of the present invention, there is provided an all-solid-state battery, wherein the negative electrode includes a lithium-containing negative electrode active material layer or an anodeless coating layer. [Effects of the Invention]

[0024] According to the positive electrode for an all-solid-state battery of the present invention, the ratio of ionic conductivity to electronic conductivity is set to an equal level by adjusting the composition of the sulfide-based solid electrolyte and the conductive material in the positive electrode active material layer, so that the positive electrode can be designed to have a good balance between ionic conductivity and electronic conductivity, thereby ensuring high-rate charge / discharge characteristics and life characteristics of the all-solid-state battery.

[0025] Furthermore, the ratio of ionic conductivity to electronic conductivity in the positive electrode can be used to predict the performance of the battery. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a schematic diagram showing a longitudinal cross section of an electrochemical cell used for electrochemical impedance analysis according to one embodiment of the present invention. [Figure 2] FIG. 2 is a diagram showing an example of a Nyquist plot displayed during electrochemical impedance analysis according to an embodiment of the present invention. [Figure 3] FIG. 1 is a schematic diagram showing a vertical cross section of an all-solid-state battery according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0027] The present invention will now be described in further detail to aid in its understanding.

[0028] The terms and words used in this specification and claims should not be construed as being limited to their ordinary or dictionary meanings, but should be construed in a meaning and concept that is consistent with the technical idea of ​​the present invention, based on the principle that an inventor can appropriately define the concept of a term in order to best describe his or her invention.

[0029] The terms ionic conductivity and electronic conductivity used in this specification are measures that indicate the tendency of ions and electrons to conduct, respectively, and the combined concept of ionic conductivity and electronic conductivity is sometimes referred to as electrical conductivity.

[0030] Positive electrode for all-solid-state batteries The present invention relates to a positive electrode for an all-solid-state battery.

[0031] The positive electrode for an all-solid-state battery according to the present invention includes a high content of a positive electrode active material for improving energy density. Although the sulfide-based solid electrolyte and conductive material may be included in limited amounts, the ratio of the sulfide-based solid electrolyte to the conductive material can be controlled to achieve an equal ratio between ionic conductivity and electronic conductivity, thereby ensuring not only improved energy density but also high rate characteristics and life characteristics. 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.

[0032] 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 ionic conductivity (IC) to electronic conductivity (EC) of the positive electrode active material layer is IC / EC) is 0.5 to 1.5 and is defined by the following formula 1: [Formula 1] R IC / EC = ionic conductivity / electronic conductivity

[0033] R IC / EC may be 0.5 or more, 0.7 or more, or 0.9 or more, and may be 1.1 or less, 1.3 or less, or 1.5 or less, or may be 1. IC / EC If the ratio is in the range of 0.5 to 1.5, it means that the ionic conductivity and electronic conductivity characteristics of the positive electrode are well balanced without being biased towards either one, and the overall performance of the battery can be improved.

[0034] The positive electrode active material layer may be a self-standing type that does not require a separate current collector. For example, the self-standing positive electrode active material layer may be manufactured by a dry process that does not use a solvent.

[0035] 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 a positive electrode current collector.

[0036] In one embodiment of the present invention, the ratio of the ionic conductivity to the electronic conductivity (R IC / EC ) may be calculated from a 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 this.

[0037] The ionic conductivity is 1.0×10 -6 S / cm~1.0×10 -1 It may be S / cm.

[0038] The electronic conductivity is 1.0×10 -6S / cm~1.0×10 -1 It may be S / cm.

[0039] FIG. 1 is a schematic diagram showing a vertical cross section of an electrochemical cell used for electrochemical impedance analysis according to one embodiment of the present invention.

[0040] Referring to FIG. 1, in electrochemical impedance analysis, an electrochemical cell can be manufactured so that a positive electrode active material layer (12) is disposed between two positive electrode current collectors (11), and ionic conductivity and electronic conductivity can be analyzed (Journal of Power Sources, 2016, 316, 215-223).

[0041] For example, when an AC impedance of 10 mHz to 1 mHz is applied to the electrochemical cell and a Nyquist plot of the measured impedance is drawn, multiple curves resembling semicircles are often plotted in succession. For example, in FIG. 2, three curves of varying magnitude are plotted in succession from the high-frequency region (left side of the X-axis) to the low-frequency region (right side of the X-axis). Among these, the low-frequency region is fitted to an equivalent circuit to obtain resistance values ​​R1 and R2, which can be used to calculate electronic resistance RE = R1 + R2 and ionic resistance RI = (R1 + R2) * R1 / R2. Each resistance can be converted to the electrode conductivity, taking into account the electrode thickness and area. In this case, the equivalent circuit may be an R1 + Q2 / R2 model (R: resistor, Q: constant phase element).

[0042] In one embodiment of the present invention, the weight ratio of the sulfide-based solid electrolyte to the conductive material may be appropriately adjusted and selected so that the ratio of the ionic conductivity to the electronic conductivity of the positive electrode active material layer satisfies Equation 1. The weight ratio of the sulfide-based solid electrolyte to the conductive material may be adjusted taking into account the inherent ionic conductivity and electronic conductivity of the positive electrode active material, sulfide-based solid electrolyte, and conductive material used to manufacture the positive electrode active material layer. For example, the weight ratio of the sulfide-based solid electrolyte to the conductive material may be, but is not limited to, 14.1-14.8:0.2-0.9 or 14.3-14.7:0.3-0.7. As described above, the weight ratio may be adjusted taking into account the inherent physical properties of the components of the positive electrode active material layer.

[0043] 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. For example, lithium cobalt oxide (LiCoO), lithium nickel oxide (LiNiO), Li[Ni x Co y Mn z M v ]O2 (wherein M is any one 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, and x+y+z+z+v=1), Li (Li a M b-a-b’ M' b’ )O 2-c A c (wherein 0≦a≦0.2, 0.6≦b≦1, 0≦b'≦0.2, 0≦c≦0.2; M includes Mn and one or more elements selected from the group consisting of Ni, Co, Fe, Cr, V, Cu, Zn, and Ti; M' is one or more elements selected from the group consisting of Al, Mg, and B; and A is one or more elements selected from the group consisting of P, F, S, and N), and other layered compounds and compounds substituted with one or more transition metals; 1+y Mn 2-yLithium manganese oxides such as LiMnO4 (where y is 0 to 0.33), LiMnO3, LiMn2O3, and LiMnO2; lithium copper oxide (Li2CuO2); vanadium oxides such as LiV3O8, LiFe3O4, V2O5, and Cu2V2O7; and the chemical formula LiNi 1-y Ni-site lithium nickel oxide represented by MyO2 (where 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 Examples of such compounds include, but are not limited to, lithium manganese composite oxides represented by Li2Mn3MO8 (where M is Co, Ni, Fe, Cr, Zn, or Ta, and y is 0.01 to 0.1) or Li2Mn3MO8 (where M is Fe, Co, Ni, Cu, or Zn); LiMn2O4, in which part of the Li in the chemical formula is replaced with an alkaline earth metal ion; disulfide compounds; and Fe2(MoO4)3.

[0044] The positive electrode active material may be included in an amount of 69 wt% 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, or 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 positive electrode active material is less than 69 wt%, the proportion of components that do not participate in the reaction among the battery components may increase, resulting in a decrease in energy density. If the content of the positive electrode active material is more than 94 wt%, the ionic conductivity and electronic conductivity required for battery operation may not be ensured.

[0045] In addition, the positive electrode active material may be coated with an insulating material, which may limit the reaction between the positive electrode active material and the solid electrolyte, thereby reducing resistance.

[0046] The 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. The fluorides may include at least one selected from the group consisting of polyvinylidene fluoride (PVdF) and polyvinylidene fluoride copolymers.

[0047] The thickness of the insulating material coating layer may be 20 nm or less. If the thickness exceeds 20 nm, it may act as a resistor when the battery is powered. 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.

[0048] In one embodiment of the present invention, the sulfide-based solid electrolyte is a solid electrolyte containing sulfur among solid electrolytes, and may be added to a positive electrode active material layer to improve ion conductivity.

[0049] The 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 thereto, and a wide range of sulfide-based solid electrolytes commonly used in the art can be used.

[0050] The sulfide-based solid electrolyte may have a particle size (D50) of 0.1 μm to 1.5 μm. Specifically, the particle size (D50) of the sulfide-based solid electrolyte may be 0.1 μm or more, 0.3 μm or more, or 0.5 μm or more, or 0.9 μm or less, 1.0 μm or less, 1.2 μm or less, or 1.5 μm or less. If the particle size (D50) of the sulfide-based solid electrolyte is less than 0.1 μm, the ultrafine sulfide-based solid electrolyte particles may not be sufficiently dispersed in the positive electrode active material layer and may aggregate. If the particle size (D50) is more than 1.5 μm, dispersion may be somewhat easier, but the contact surface with the positive electrode active material particles may be reduced, resulting in increased positive electrode porosity.

[0051] The sulfide-based solid electrolyte may be included in an amount of 5 wt% 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, or 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 sulfide-based solid electrolyte is less than 5 wt %, the ionic conductivity may decrease, and if it exceeds 30 wt %, the contents of the positive electrode active material and conductive material may be relatively reduced, resulting in a decrease in battery performance.

[0052] In one embodiment of the present invention, the conductive material can improve electron conductivity by forming a path through which electrons can be conducted.

[0053] The conductive material may be a linear conductive material, and the linear conductive material may be one or more selected from the group consisting of carbon nanotubes (CNT) and carbon nanofibers (CNF). The linear conductive material can 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 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, taking into consideration the ease of forming an electronic conduction path.

[0054] The conductive material may be included in an amount of 0.01 wt % to 10 wt % based on the total weight of the positive electrode active material layer. Specifically, the content of the conductive material may be 0.01 wt % or more, 0.1 wt % or more, 0.2 wt % or more, or 0.3 wt % or more, or 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 material is less than 0.01 wt %, the electronic conductivity of the positive electrode may decrease. If the content exceeds 10 wt %, the resistance may increase due to an increase in side reactions of the solid electrolyte. In addition, the content of the positive electrode active material and the sulfide-based solid electrolyte may decrease relatively, resulting in a decrease in battery performance.

[0055] In one embodiment of the present invention, the binder may be included to aid in bonding between materials included in the positive electrode active material layer and between the positive electrode active material layer and the positive electrode current collector.

[0056] The binder may be a fibrous binder. The binder may be fibrous during the mixing process during the preparation of the positive electrode, and may be contained in the positive electrode active material layer in a fibrous form. Therefore, it is preferable that the binder has physical properties that can be easily modified.

[0057] The binder may also include one or more selected from the group consisting of 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, phenolic resin, epoxy resin, carboxymethyl cellulose, hydroxypropyl cellulose, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethyl cellulose, cyanoethyl sucrose, 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).

[0058] The binder may be contained in an amount of 0.01 wt % to 10 wt % based on the total weight of the positive electrode active material layer. Specifically, the binder content may be 0.01 wt % or more, 1 wt % or more, or 2 wt % or more, or 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 binder content is less than 0.01 wt %, the effect of improving the bonding strength between the materials contained in the positive electrode active material layer is insignificant, and the electrode sheet may not be firmly formed. If the binder content exceeds 10 wt %, the ionic conductivity or electronic conductivity may decrease.

[0059] In one embodiment of the present invention, the thickness of the positive electrode active material layer may be 100 μm to 300 μm, specifically, 100 μm or more, 110 μm or more, or 120 μm or more, or 200 μm or less, 250 μm or less, or 300 μm or less. However, the thickness of the positive electrode active material layer is not limited thereto, and the ratio of the solid electrolyte to the conductive material may be adjusted so that the ratio of the ionic conductivity to the electronic conductivity is 0.5 to 1.5 depending on the desired loading of the positive electrode active material layer.

[0060] In one embodiment of the present invention, the positive electrode current collector supports the positive electrode active material layer and transfers electrons between an external conductive wire and the positive electrode active material layer.

[0061] The positive electrode current collector is not particularly limited as long as it does not cause a chemical change in the all-solid-state battery and has high electronic conductivity. For example, the positive electrode current collector can be made of stainless steel, aluminum, nickel, titanium, palladium, baked carbon, stainless steel surface-treated with carbon, nickel, silver, or the like, or an aluminum-cadmium alloy.

[0062] The positive electrode current collector may have a finely textured surface or a three-dimensional porous structure to strengthen the bonding strength with the positive electrode active material layer, and may have various forms such as a film, sheet, foil, mesh, net, porous material, foam, or nonwoven fabric.

[0063] Method for manufacturing positive electrodes of all-solid-state batteries The present invention also relates to a method for producing a positive electrode for an all-solid-state battery.

[0064] The method for manufacturing a positive electrode for an all-solid-state battery according to the present invention may be a wet process or a dry process depending on whether a solvent is used. The specific materials, properties, and contents of the positive electrode active material, sulfide-based solid electrolyte, conductive material, and binder used in the method for manufacturing a positive electrode for an all-solid-state battery according to the present invention are as described above.

[0065] 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 adding a positive electrode active material, a sulfide-based solid electrolyte, a conductive material, and a binder to an organic solvent to form a slurry; (A2) a step of coating the slurry formed in the step (A1) on a positive electrode current collector; and (A3) a step of drying the coating layer formed in the step (A2).

[0066] Hereinafter, the wet process of the method for manufacturing the positive electrode for the all-solid-state battery will be described in more detail for each step.

[0067] In one embodiment of the present invention, in 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.

[0068] The organic solvent is preferably one that can uniformly disperse the positive electrode active material, sulfide-based solid electrolyte, conductive material, and binder and that evaporates easily, such as acetonitrile, methanol, ethanol, tetrahydrofuran, water, and isopropyl alcohol.

[0069] The concentration of the slurry is not particularly limited as long as it allows the coating process to be carried out smoothly. For example, the concentration of the slurry may be 30% by weight to 50% by weight based on the solid content.

[0070] In one embodiment of the present invention, in step (A2), the slurry formed in step (A1) may be coated on a positive electrode current collector.

[0071] The coating method is not particularly limited as long as it can form a coating layer using a slurry, and can be, for example, roll coating, gravure coating, doctor blade coating, slot die coating, slurry coating, or extrusion coating.

[0072] In one embodiment of the present invention, in step (A3), the coating layer formed in step (A2) may be dried.

[0073] The drying method is not particularly limited as long as it is a method that can remove the organic solvent from the coating layer. For example, the drying may be performed at a temperature of 80°C to 130°C.

[0074] In the method for manufacturing a positive electrode for an all-solid-state battery according to the present invention, the dry process includes: (B1) mixing a positive electrode active material, a sulfide-based solid electrolyte, a conductive material, and a binder; and (B2) forming the mixed powder obtained in step (B1) into a film by a calendaring process.

[0075] Hereinafter, the dry process of the method for manufacturing a positive electrode for an all-solid-state battery will be described in more detail for each step.

[0076] In one embodiment of the present invention, in step (B1), a mixed powder is obtained by mixing a positive electrode active material, a sulfide-based solid electrolyte, a conductive material, and a binder.

[0077] Alternatively, the mixing may be physical mixing without using a separate solvent, and the binder may be fiberized through physical mixing. During physical mixing, the binder may undergo physical deformation due to friction with particles in the mixed powder due to shear force, resulting in fiberization. To facilitate this physical deformation, a binder that is physically very weak and relatively susceptible to fiberization may be used. For example, PTFE, which has physical properties that make it susceptible to physical deformation, may be used as the binder. To facilitate physical deformation, mixing may be performed using a mortar, ball mill, or roll pressing.

[0078] In one embodiment of the present invention, in step (B2), the mixed powder obtained in step (B1) may be subjected to a calendaring process to be formed into a film.

[0079] The conditions for the calendering step may be appropriately controlled and applied so as to allow the material to be formed into a film. For example, the calendering step may be performed at a temperature of 20°C to 200°C for 5 to 50 loops. However, the calendering step conditions, such as temperature, pressure, and number of loops, may be any conditions used in electrode manufacturing processes commonly used in the battery field.

[0080] All solid state battery The present invention also relates to an all-solid-state battery including the positive electrode.

[0081] FIG. 3 is a schematic diagram showing a vertical cross section of an all-solid-state battery according to an embodiment of the present invention.

[0082] Referring to FIG. 3, the all-solid-state battery according to the present invention includes the cathode (10), the anode (20), and the sulfide-based solid electrolyte membrane (30) interposed therebetween. As described above, the cathode (10) has a structure in which a cathode active material layer (12) is formed on one side of a cathode current collector (11), and the anode (20) has a structure in which a cathode active material layer (22) is formed on one side of a cathode current collector (21), and the sulfide-based solid electrolyte membrane (30) may be interposed between the cathode active material layer (12) and the anode active material layer (22). However, the all-solid-state battery according to the present invention is not limited to this structure. If the cathode active material layer (12) is self-standing, it may not include a cathode current collector, and the anode active material layer may be an anodeless coating layer.

[0083] In one embodiment of the present invention, the negative electrode may include a negative electrode active material layer or an anodeless coating layer, and the negative electrode active material layer or the anodeless coating layer may be formed on one surface of a negative electrode current collector.

[0084] The negative electrode active material layer includes a negative electrode active material, a binder, and a conductive material.

[0085] The negative electrode active material is lithium (Li + The material may include a material capable of reversible intercalation or deintercalation of . ) , a material capable of reacting with lithium ions to reversibly form a lithium-containing compound, lithium metal, or a lithium alloy.

[0086] The lithium ion (Li + The material capable of reversibly inserting or de-inserting lithium ions (Li) may be, for example, crystalline carbon, amorphous carbon, or a mixture thereof. +The material capable of reacting with lithium (Li) to reversibly form a lithium-containing compound may be, for example, tin oxide, titanium nitride, or silicon. The lithium alloy may 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).

[0087] Preferably, the negative electrode active material may be lithium metal or a lithium-indium alloy (Li-In), specifically, lithium metal, lithium and thin film, lithium-indium alloy thin film, or powder.

[0088] The negative electrode active material may be included in an amount of 40 wt % 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, or 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 mass transfer resistance may be increased.

[0089] The binder is a component that helps bind the negative electrode active material and the conductive material and the like and to the negative electrode current collector, and may be selected from the group consisting of 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, polyacrylic The binder may include one or more selected from the group consisting of fluorocarbon nitrile, polystyrene, latex, acrylic resin, phenolic resin, epoxy resin, carboxymethyl cellulose, hydroxypropyl cellulose, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethyl cellulose, cyanoethyl sucrose, 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).

[0090] 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. Specifically, the binder content 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 binder content is less than 0.5 wt %, the adhesive strength between the positive electrode active material and the negative electrode current collector may be reduced. If the binder content exceeds 4 wt %, the adhesive strength is improved, but the content of the negative electrode active material may be reduced accordingly, resulting in a reduced battery capacity.

[0091] 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. Typical examples include graphite or conductive carbon, such as graphite (e.g., natural graphite, artificial graphite, etc.); carbon black (e.g., carbon black, acetylene black, ketjen black, denka black, thermal black, channel black, furnace black, lamp black, summer black, etc.); carbon-based materials with a graphene or graphite crystalline structure; conductive fibers (e.g., carbon fiber, metal fiber, etc.); carbon fluoride; metal powders (e.g., aluminum powder, nickel powder, etc.); conductive whiskey (e.g., zinc oxide, potassium titanate, etc.); conductive oxides (e.g., titanium oxide, etc.); and conductive polymers (e.g., polyphenylene derivatives). These may be used alone or in combination, but are not necessarily limited to these. Preferably, the conductive material may include vapor-grown carbon fiber (VGCF).

[0092] 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. 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, such as less than 1 wt %, the effect of improving electronic conductivity may not be expected or the electrochemical properties of the battery may be reduced. If the content is too high, such as more than 5 wt %, the amount of negative electrode active material may be relatively small, resulting in reduced capacity and energy density. The method for incorporating the conductive material into the negative electrode is not particularly limited, and may be a conventional method known in the art, such as mixing or coating with the negative electrode active material.

[0093] The negative electrode current collector is not particularly limited as long as it does not cause chemical changes in the battery and is conductive. For example, the negative electrode current collector can be made of copper, stainless steel, aluminum, nickel, titanium, baked carbon, copper or stainless steel surface-treated with carbon, nickel, titanium, silver, or the like, or an aluminum-cadmium alloy. Similarly to the positive electrode current collector, the negative electrode current collector can be in various forms, such as a film, sheet, foil, net, porous material, foam, or nonwoven fabric, each having a finely textured surface.

[0094] The method for manufacturing the anode is not particularly limited, and the anode may be manufactured by forming an anode active material layer on an anode current collector using a layer or film formation method commonly used in the art, such as compression bonding, coating, or vapor deposition. The anode may also be manufactured by assembling a battery without a lithium thin film on the anode current collector, and then forming a metallic lithium thin film on the metal plate by initial charging.

[0095] The anodeless coating layer may also refer to a negative electrode active material layer that does not contain a negative electrode active material. A negative electrode active material may be formed in the anodeless coating layer upon charging. For example, during charging of the battery, lithium ions may migrate from the positive electrode, causing lithium metal to deposit from the negative electrode. In other words, the anodeless coating layer may be a film that induces lithium deposition.

[0096] The anode-less coating layer may contain metal particles and carbon material particles, and specifically may contain a carbon material-metal composite.

[0097] The carbon particles may be, for example, amorphous carbon particles. However, the carbon 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 a combination thereof.

[0098] The metal particles may be particles that form an alloy with lithium, and may be particles of one or more types selected from silver (Ag), gold, platinum, palladium, silicon, aluminum, bismuth, tin, indium, and zinc. The anode-less coating layer may be formed as a very thin film having a micron thickness, for example, a thickness of 10 μm or less.

[0099] Preferably, the anode-less coating layer may contain an Ag-C composite as the carbon material-metal composite, and lithium may be deposited between the negative electrode current collector and the coating layer containing the Ag-C composite during the first charge.

[0100] 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 thereto, and a wide range of sulfide-based solid electrolytes commonly used in the art can be used.

[0101] Battery module The present invention also relates to a battery module including the all-solid-state battery as a unit cell, a battery pack including the battery module, and a device including the battery pack as a power source.

[0102] Specific examples of the device include, but are not limited to, power tools powered by a battery-powered motor; electric vehicles including electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (PHEVs); electric two-wheeled vehicles including electric bicycles (E-bikes) and electric scooters; electric golf carts; and power storage systems. Preferred embodiments of the present invention will be described below to aid in understanding the present invention. However, the following embodiments are merely illustrative of the present invention, and it will be apparent to those skilled in the art that various changes and modifications can be made within the scope and technical spirit of the present invention. Such changes and modifications are also intended to fall within the scope of the accompanying claims.

[0103] Preferred examples will be described below to aid in understanding the present invention. However, the following examples are merely 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 of the scope and technical idea of ​​the present invention. Naturally, such changes and modifications also fall within the scope of the appended claims.

[0104] In the following examples and comparative examples, positive electrodes and all-solid-state batteries including the same were manufactured according to the compositions of the positive electrode active material layers as shown in Table 1 below.

[0105] [Table 1]

[0106] Example 1 1-1. Manufacturing of the positive electrode active material layer LiN as the positive electrode active material 0.8 Co 0.1 Mn 0.1A positive electrode was fabricated 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.

[0107] The positive electrode active material, sulfide-based solid electrolyte, conductive material, and binder were powder mixed in a weight ratio of 84:14.5:0.5:1. Specifically, the positive electrode active material, sulfide-based solid electrolyte, and conductive material were measured in powder form, and then mixed in a blade mixer in a dry room environment for 30 minutes without the use of a separate solvent to obtain a mixture. Then, PTFE (Polytetrafluoroethylene) powder, which serves as the binder, was measured and added to the mixture to obtain a mixed powder.

[0108] The mixed powder was put into a mortar (mortar), and then fiberized in the mortar, calendered with a roller to a thickness of 150 μm, and R IC / EC =1.04 positive electrodes were produced.

[0109] R IC / EC was calculated by extracting ionic conductivity and electronic conductivity from a Nyquist plot obtained by electrochemical impedance spectroscopy (EIS) analysis using a SP-50e device manufactured by BioLogic. IC / EC The calculated value is rounded to three decimal places.

[0110] 1-2. Manufacturing all-solid-state batteries An all-solid-state battery was fabricated by sequentially stacking a negative electrode current collector (copper, Cu), lithium metal, a sulfide-based solid electrolyte membrane made of Li6PS5Cl, the positive electrode, and a positive electrode current collector (aluminum, Al).

[0111] Example 2 The same procedure as in Example 1 was carried out, 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. IC / EC =1.41 positive electrodes were produced.

[0112] Example 3 The same procedure as in Example 1 was carried out, except that the weight ratio of the positive electrode active material, sulfide-based solid electrolyte, conductive material, and binder was 84:14.3:0.7:1. IC / EC =0.69 positive electrodes were produced.

[0113] Example 4 The same procedure as in Example 1 was carried out, except that the weight ratio of the positive electrode active material, sulfide-based solid electrolyte, conductive material, and binder was 80:18:1:1. IC / EC =1.38 positive electrodes were produced.

[0114] Example 5 The same procedure as in Example 1 was carried out, except that the weight ratio of the positive electrode active material, the sulfide-based solid electrolyte, the conductive material, and the binder was 88:10.9:0.1:1. IC / EC =0.86 positive electrodes were produced.

[0115] Comparative Example 1 The same procedure as in Example 1 was carried out, 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. IC / EC =0.01 positive electrode was produced.

[0116] Comparative Example 2 The same procedure as in Example 1 was carried out, except that the weight ratio of the positive electrode active material, sulfide-based solid electrolyte, conductive material, and binder was 80:16:3:1. IC / EC =0.01 positive electrode was produced.

[0117] Comparative Example 3 The same procedure as in Example 1 was carried out, except that the weight ratio of the positive electrode active material, sulfide-based solid electrolyte, conductive material, and binder was 90:8:1:1. IC / EC A positive electrode with a Cr content of 0.03 was produced.

[0118] Experimental example 1: Performance evaluation of all-solid-state batteries The ratio of ionic conductivity to electronic conductivity of the positive electrode active material layer formed on the positive electrode (R IC / EC The performance of the all-solid-state battery was evaluated by the following method. Examples 1 to 5 and Comparative Examples 1 to 3 were evaluated.

[0119] To evaluate the performance of the all-solid-state battery, the voltage was 4.25V (vs. Li / Li) at a current of 0.1C. + ) and then charge to 4.25V (vs. Li / Li + The battery was charged at a current cut-off of 0.05C while maintaining a voltage of 3V (vs. Li / Li + ) until the discharge capacity reached 0.1C. This process was repeated for two cycles, and the discharge capacity of the second cycle was used as the initial 0.1C discharge capacity. Next, the rate capability was evaluated using a protocol for discharging up to 1C. Specifically, the rate capability was observed using a protocol for CC discharge at 0.1C / 0.33C / 0.5C / 1C while maintaining a 0.1C / 0.05C CC / CV (Constant Current / Constant Voltage) charging process. The 1C capacity retention calculated by dividing the 1C discharge capacity obtained through this evaluation process by the initial 0.1C discharge capacity was used as a result of high-rate capability. The 0.1C initial discharge capacities and 1C capacity retention rates measured in Examples 1 to 5 and Comparative Examples 1 to 3 are listed in Table 2 below.

[0120] [Table 2]

[0121] As shown in Table 2, Examples 1 to 5 are superior in discharge capacity and high-rate characteristics to Comparative Examples 1 to 3. Examples 1 to 5 have a high ionic conductivity to electronic conductivity ratio (R IC / EC ) was in the range of 0.5 to 1.5, and it was confirmed that when this range was exceeded, the discharge capacity and high rate characteristics rapidly decreased. Furthermore, among Examples 1 to 5, the ratio of ionic conductivity to electronic conductivity (R IC / EC It was confirmed that Example 1, in which the ratio of the discharge capacity to the high rate characteristic was close to 1, was the most excellent. [Explanation of symbols]

[0122] 10: Positive electrode 11: Positive electrode current collector 12: Positive electrode active material layer 20: Negative electrode 21: Negative electrode current collector 22: Negative electrode active material layer 30: Sulfide solid electrolyte membrane

Claims

1. In a positive electrode for an all-solid-state battery including 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 (Ratio, R) of the ionic conductivity (Ionic Conductivity, IC) to the electronic conductivity (Electronic Conductivity, EC) of the positive electrode active material layer is defined by the following formula 1: ＩＣ／ＥＣ ) is 0.5 or more and 1.5 or less: [Formula 1] R ＩＣ／ＥＣ = ionic conductivity / electronic conductivity

2. 2. The positive electrode for an all-solid-state battery according to claim 1, wherein the ratio of ionic conductivity to electronic conductivity is calculated from a Nyquist plot obtained by electrochemical impedance spectroscopy (EIS) analysis.

3. The positive electrode active material is lithium cobalt oxide (LiCoO ２ ), lithium nickel oxide (LiNiO ２ ), Li[Ni ｘ Co ｙ Mn ｚ M ｖ ]O ２ (wherein M is any one 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, and x+y+z+v=1), Li (Li ａ M ｂ－ａ－ｂ’ M' ｂ’ ) O ２－ｃ A ｃ (wherein, 0≦a≦0.2, 0.6≦b≦1, 0≦b′≦0.2, 0≦c≦0.2; M includes Mn and one or more elements selected from the group consisting of Ni, Co, Fe, Cr, V, Cu, Zn, and Ti; M′ includes one or more elements selected from the group consisting of Al, Mg, and B; and A includes one or more elements selected from the group consisting of P, F, S, and N) and compounds substituted with one or more transition metals; １＋ｙ Mn ２－ｙ O ４ (where y is 0 to 0.33), LiMnO ３ , LiMn ２ O ３ , LiMnO ２ lithium manganese oxides containing lithium copper oxides (Li ２ CuO ２ ); LiV ３ O ８ , LiFe ３ O ４ , V ２ O ５ , Cu ２ V ２ O ７ Vanadium oxide containing the chemical formula LiNi １－ｙ MyO ２ (wherein M=Co, Mn, Al, Cu, Fe, Mg, B, or Ga, and y is 0.01 to 0.3); Ni-site lithium nickel oxide represented by the chemical formula LiMn ２－ｙ M ｙ O ２ (wherein M is Co, Ni, Fe, Cr, Zn or Ta, and y is 0.01 to 0.1) or Li ２ Mn ３ MO ８ Lithium manganese composite oxides represented by the formula (where M is Fe, Co, Ni, Cu, or Zn); LiMn ２ O ４ Disulfide compounds; Fe ２ (MoO ４ ) ３ The positive electrode for an all-solid-state battery according to claim 1 , comprising one or more selected from the group consisting of:

4. 2. The positive electrode for an all-solid-state battery according to claim 1, wherein the sulfide-based solid electrolyte contains one or more selected from the group consisting of LiPSX (X = Cl, Br, or I), LiGePS, and LiPS.

5. 2. The positive electrode for an all-solid-state battery according to claim 1, wherein the sulfide-based solid electrolyte is in the form of particles having a particle size (D50) of 0.1 μm or more and 1.5 μm or less.

6. 2. The positive electrode for an all-solid-state battery according to claim 1, wherein the conductive material comprises at least one material selected from the group consisting of carbon nanotubes (CNTs) and carbon nanofibers (CNFs).

7. The binder may be 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, phenolic resin, epoxy resin, carboxymethyl cellulose, hydroxypropyl cellulose, cellulose 2. The positive electrode for an all-solid-state battery according to claim 1, comprising at least one selected from the group consisting of sucrose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethyl cellulose, cyanoethyl sucrose, polyester, polyamide, polyether, polyimide, polycarboxylate, polycarboxylic acid, polyacrylic acid, polyacrylate, lithium polyacrylate, polymethacrylic acid, polymethacrylate, polyacrylamide, polyurethane, polyvinylidene fluoride, and poly(vinylidene fluoride)-hexafluoroprofen.

8. 2. The positive electrode for an all-solid-state battery according to claim 1, wherein the positive electrode active material layer contains 69% by weight or more and 94% by weight or less of a positive electrode active material, 5% by weight or more and 30% by weight or less of a sulfide-based solid electrolyte, 0.01% by weight or more and 10% by weight or less of a conductive material, and 0.01% by weight or more and 10% by weight or less of a binder.

9. 2. The positive electrode for an all-solid-state battery according to claim 1, wherein the positive electrode active material layer contains 80% by weight or more and 90% by weight or less of a positive electrode active material, 9% by weight or more and 20% by weight or less of a sulfide-based solid electrolyte, 0.1% by weight or more and 1% by weight or less of a conductive material, and 0.01% by weight or more and 3% by weight or less of a binder.

10. The positive electrode for an all-solid-state battery according to claim 1 , wherein the positive electrode active material is coated with an insulating material.

11. The positive electrode for an all-solid-state battery according to claim 10, wherein the insulating material comprises at least one selected from the group consisting of oxides and fluorides.

12. The positive electrode for an all-solid-state battery according to claim 1 , wherein the conductive material is a linear conductive material.

13. The positive electrode for an all-solid-state battery according to claim 1 , wherein the binder is a fibrous binder.

14. An all-solid-state battery comprising the positive electrode, the negative electrode, and a sulfide-based solid electrolyte film interposed between them according to any one of claims 1 to 13.

15. 15. The all-solid-state battery according to claim 14, wherein the negative electrode comprises a lithium-containing negative electrode active material layer or an anodeless coating layer.

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