Positive electrode for all-solid-state battery and all-solid-state battery comprising same

Abstract

The present invention relates to a positive electrode for an all-solid-state battery and an all-solid-state battery comprising the same. More specifically, the present invention is characterized in that the ratio of the ionic conductivity to the electronic conductivity of the positive electrode active material layer contained in the positive electrode is in the range of 0.5 to 1.5. By this characteristic, an all-solid-state battery comprising such a positive electrode can exhibit improved battery performance, such as enhanced lifespan characteristics and high rate characteristics.

Description

Technical Field

[0001] This application claims priority to Korean Patent Application No. 10-2023-0104628 filed on August 10, 2023, Korean Patent Application No. 10-2023-0147408 filed on October 31, 2023, and Korean Patent Application No. 10-2024-0107332 filed on August 12, 2024, the disclosures of which are hereby incorporated by reference in their entirety.

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

[0003] In order to overcome the current limitations of lithium secondary batteries in terms of capacity, safety, power, size and miniaturization, various batteries are being studied.

[0004] As representative examples, compared to lithium-ion secondary batteries, academia and industry are continuously researching metal-air batteries with very large theoretical capacity, all-solid-state batteries with no explosion risk in terms of safety, supercapacitors in terms of output, NaS batteries or redox flow batteries (RFB) in terms of large-scale development, and thin-film batteries in terms of miniaturization.

[0005] All-solid-state batteries refer to batteries that replace the liquid electrolyte used in conventional lithium secondary batteries with solid electrolytes. Since no flammable solvents are used in the battery, fire or explosion caused by the decomposition reaction of conventional electrolytes will not occur, which can significantly improve safety. In addition, among all-solid-state batteries, sulfide all-solid-state batteries are still being developed. The ionic conductivity of their solid electrolytes is high, and theoretically, a high energy density of more than 900Wh / L can be achieved. The term "sulfide all-solid-state battery" refers to an all-solid-state battery containing a sulfide solid electrolyte.

[0006] In an all-solid-state battery system, lithium ions are not conducted through the liquid electrolyte in conventional lithium-ion batteries (LIBs). Therefore, when manufacturing a positive electrode for a sulfide-based all-solid-state battery, it is necessary to add fine sulfide-based solid electrolyte particles to the positive electrode to increase the contact interface between the positive electrode active material and the sulfide-based solid electrolyte particles, thereby improving the ionic conductivity of lithium ions.

[0007] In addition, conductive materials are added to the positive electrode for sulfide-based all-solid-state batteries to form an electron conduction path, thereby enhancing the electron conductivity.

[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 in order to improve energy density, the content of the sulfide-based solid electrolyte and the conductive material may be insufficient to simultaneously ensure ionic conductivity and electronic conductivity, which may reduce high-rate characteristics and life characteristics.

[0009] Therefore, it is necessary to develop a technology that enables a sulfide-based all-solid-state battery cathode to contain a high content of cathode active material to increase energy density while ensuring ion conductivity and electronic conductivity to improve high rate characteristics and life characteristics.

[0010] [Prior art literature]

[0011] [Patent Document]

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

[0013] [Technical issues]

[0014] The inventors of the present invention have conducted in-depth research to solve the above-mentioned problems, and have confirmed that when the composition within the positive electrode active material layer in a positive electrode for an all-solid-state battery having a positive electrode active material layer with a high content of positive electrode active material is adjusted, if the ratio of the ionic conductivity to the electronic conductivity in the positive electrode active material layer is comparable, the performance of the battery, such as high-rate characteristics and life characteristics, can be improved.

[0015] Therefore, an object of the present invention is to provide a positive electrode having a positive electrode active material layer having ion conductivity and electronic conductivity at comparable levels.

[0016] 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), which includes a positive electrode having a positive electrode active material layer having ionic conductivity comparable to electronic conductivity.

[0017] [Technical solution]

[0018] In order to achieve the above object, the present invention provides a positive electrode for an all-solid-state battery comprising a positive electrode active material layer, wherein: the positive electrode active material layer comprises a positive electrode active material, a sulfide solid electrolyte, a conductive material and a binder; and the ratio (R) of the ionic conductivity (IC) to the electronic conductivity (EC) of the positive electrode active material layer defined by the following equation 1 is IC / EC ) is 0.5 to 1.5:

[0019] <Equation 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 ionic conductivity to 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 one or more selected from the group consisting of: layered compounds, such as lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), Li[Ni x Co y Mn z M v ]O2 (wherein M is one or more elements selected from 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' ) 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 selected from Ni, Co, Fe, Cr, V, Cu, Zn, Ti; M' is one or more selected from Al, Mg, B; A is one or more selected from P, F, S, N) or a compound obtained by replacing part of the metal elements in the layered compound with one or more transition metals; lithium manganese oxide, such as formula Li 1+y Mn 2-y O4 (where y is 0 to 0.33), LiMnO3, LiMn2O3 and LiMnO2; lithium copper oxide (Li2CuO2); vanadium oxides such as LiV3O8, LiFe3O4, V2O5 and Cu2V2O7; 1-y M y O2 (wherein, M = Co, Mn, Al, Cu, Fe, Mg, B or Ga, y is 0.01 to 0.3) represented by Ni-type lithium nickel oxide; represented by the formula LiMn 2-y M y Lithium manganese composite oxides represented by Li2Mn3MO8 (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, wherein part of the Li in the formula is replaced by alkaline earth metal ions; disulfide; and Fe2(MoO4)3.

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

[0024] In one example 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 size (D50) of 0.1 μm to 1.5 μm.

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

[0026] In one example of the present invention, the binder includes one or more selected from the group consisting of polytetrafluoroethylene (PTFE), polyethylene, polypropylene, ethylene / propylene copolymer, polybutadiene, polyethylene oxide, chlorosulfonated polyethylene, polyvinyl pyrrolidone, polyvinyl pyridine, polyvinyl alcohol, polyvinyl acetate, polyepichlorohydrin, polyphosphazene, polyacrylonitrile, polystyrene, latex, acrylic resin, phenol 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-co-hexafluoropropylene).

[0027] In one example of the present invention, the positive electrode active material layer includes: 69 wt % to 94 wt % of the positive electrode active material; 5 wt % to 30 wt % of the sulfide solid electrolyte; 0.01 wt % to 10 wt % of the conductive material; and 0.01 wt % to 10 wt % of the binder.

[0028] The present invention also provides an all-solid-state battery, which comprises a positive electrode, a negative electrode, and a sulfide solid electrolyte membrane arranged between the positive electrode and the negative electrode.

[0029] In one example of the present invention, an all-solid-state battery is provided, wherein the negative electrode comprises a negative electrode active material layer containing lithium or no anode coating.

[0030] [Beneficial Effects]

[0031] According to the positive electrode for an all-solid-state battery of the present invention, by adjusting the composition of the sulfide solid electrolyte and the conductive material in the positive electrode active material layer, the ratio of the ionic conductivity to the electronic conductivity is made equal, and a positive electrode with balanced ionic conductivity and electronic conductivity can be designed. Therefore, the high-rate charge and discharge characteristics and life characteristics of the all-solid-state battery can be ensured.

[0032] In addition, the ratio of the ionic conductivity to the electronic conductivity of the cathode can be used to predict battery performance. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0034] Figure 2 FIG. 1 is an example of a Nyquist plot shown by electrochemical impedance analysis according to an embodiment of the present invention.

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

[0036] Hereinafter, the present invention will be described in more detail for better understanding of the present invention.

[0037] The terms and words used in this specification and claims should not be interpreted according to their ordinary meanings or dictionary meanings, but should be interpreted based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention, with the principle of meanings and concepts consistent with the technical ideas of the present invention.

[0038] The terms "ionic conductivity" and "electronic conductivity" used in this specification refer to measures indicating the tendency of ions and electrons to conduct, respectively. The sum of ionic conductivity and electronic conductivity can be regarded as "conductivity".

[0039] Positive electrode for all-solid-state battery

[0040] The invention relates to a positive electrode for an all-solid-state battery.

[0041] The positive electrode for the all-solid-state battery of the present invention contains a high content of positive electrode active materials to improve the energy density. Although the content of the sulfide solid electrolyte and the conductive material that can be included is limited, by adjusting the ratio of the sulfide solid electrolyte and the conductive material to make the ionic conductivity equivalent to the electronic conductivity, it is possible to achieve not only the effect of improving the energy density, but also to ensure high rate characteristics and life characteristics. In the positive electrode for the all-solid-state battery of the present invention, the high content of positive electrode active materials can refer to more than 69 weight % based on the total weight of the positive electrode active material layer.

[0042] The positive electrode for an all-solid-state battery of the present invention comprises a positive electrode active material layer, wherein the positive electrode active material layer comprises a positive electrode active material, a sulfide-based solid electrolyte, a conductive material, and a binder. The ratio (R) of the ionic conductivity (IC) to the electronic conductivity (EC) of the positive electrode active material layer defined by the following equation 1 is: IC / EC ) is 0.5 to 1.5:

[0043] <Equation 1>

[0044] R IC / EC = ionic conductivity / electronic conductivity

[0045] R IC / EC It 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 When it is in the range of 0.5 to 1.5, it indicates that the ionic conductivity and electronic conductivity of the positive electrode are balanced and not biased towards either side, which can improve the overall performance of the battery.

[0046] The positive electrode active material layer can be self-supporting, so that it is self-standing and does not require a separate current collector. For example, the self-supporting positive electrode active material layer can be manufactured by a solvent-free dry process.

[0047] 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 collector.

[0048] In one embodiment of the present invention, the ratio of ionic conductivity to electronic conductivity (R IC / EC ) can be calculated by the Nyquist plot obtained by electrochemical impedance spectroscopy (EIS) analysis. However, the analysis method is not limited thereto, and the ratio of ionic conductivity to electronic conductivity (R) known in the art can be used. IC / EC ) by any method.

[0049] The ionic conductivity can be 1.0x 10 -6 S / cm to 1.0x 10 -1 S / cm.

[0050] The electronic conductivity can be 1.0x 10 -6 S / cm to 1.0x 10 -1 S / cm.

[0051] Figure 1 Schematic diagram of a cross section of an electrochemical cell for electrochemical impedance analysis according to an embodiment of the present invention.

[0052] Reference Figure 1In electrochemical impedance spectroscopy, an electrochemical cell can be manufactured so that the positive electrode active material layer 12 is disposed between two positive electrode current collectors 11 to analyze ionic conductivity and electronic conductivity (Journal of power sources, 2016, 316, 215-223).

[0053] For example, when an AC impedance with a frequency range of 10 mHz to 1 mHz is applied to an electrochemical cell and a Nyquist plot of the measured impedance is plotted, a curve with a plurality of continuous semicircles may be displayed. Figure 2 As shown, three curves of different sizes are continuously shown from the high frequency region (left part of the X-axis) to the low frequency region (right part of the X-axis). By fitting the low frequency region of the figure to the equivalent circuit, the resistance values ​​R1 and R2 can be obtained. Then, these R1 and R2 values ​​can be used to calculate the electronic resistance RE = R1 + R2 and the ionic resistance RI = (R1 + R2) * R1 / R2. Considering the thickness and area of ​​the electrode, each resistance can be converted into the conductivity of the electrode. In this case, the equivalent circuit can be the R1 + Q2 / R2 model (R: resistor, Q: constant phase element).

[0054] In one example of the present invention, the weight ratio of the sulfide solid electrolyte to the conductive material is selected by appropriately adjusting the ratio of the ionic conductivity to the electronic conductivity of the positive electrode active material layer, so that the ratio of the ionic conductivity to the electronic conductivity of the positive electrode active material layer can be as shown in Equation 1. At this time, the weight ratio of the positive electrode active material, the sulfide solid electrolyte and the conductive material used to manufacture the positive electrode active material layer can be adjusted considering the inherent ionic conductivity and electronic conductivity of the positive electrode active material, the sulfide solid electrolyte and the conductive material. For example, the weight ratio of the sulfide solid electrolyte to the conductive material can be 14.1 to 14.8: 0.2 to 0.9, or 14.3 to 14.7: 0.3 to 0.7, but is not limited thereto. As described above, the weight ratio can be adjusted considering the inherent properties of each constituent component of the positive electrode active material layer.

[0055] In one embodiment of the present invention, the positive electrode active material is not particularly limited as long as it can reversibly absorb and release lithium ions, and can be one or more selected from the group consisting of: layered compounds such as lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), Li[Ni x Co y Mn z M v ]O2 (wherein M is one or more elements selected from 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' ) 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 selected from Ni, Co, Fe, Cr, V, Cu, Zn, Ti; M' is one or more selected from Al, Mg, B; A is one or more selected from P, F, S, N) or a compound obtained by replacing part of the metal elements in the layered compound with one or more transition metals; lithium manganese oxide, such as formula Li 1+y Mn 2-y O4 (where y is 0 to 0.33), LiMnO3, LiMn2O3 and LiMnO2; lithium copper oxide (Li2CuO2); vanadium oxides such as LiV3O8, LiFe3O4, V2O5 and Cu2V2O7; 1-y M y O2 (wherein, M = Co, Mn, Al, Cu, Fe, Mg, B or Ga, y is 0.01 to 0.3) represented by Ni-type lithium nickel oxide; represented by the formula LiMn 2-y M y Lithium manganese composite oxides represented by Li2Mn3MO8 (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, wherein part of the Li in the formula is replaced by alkaline earth metal ions; disulfide; and Fe2(MoO4)3.

[0056] In addition, based on the total weight of the positive electrode active material layer, the positive electrode active material can be 69% to 94% by weight. Specifically, the content of the positive electrode active material can be more than 69% by weight, more than 70% by weight, more than 71% by weight, more than 72% by weight, more than 73% by weight, more than 74% by weight, more than 75% by weight, more than 76% by weight, more than 77% by weight, more than 78% by weight, more than 79% by weight, or more than 80% by weight, and can be less than 94% by weight, less than 93% by weight, less than 92% by weight, less than 91% by weight, less than 90% by weight, less than 89% by weight, less than 88% by weight, less than 87% by weight, less than 86% by weight, or less than 85% by weight. If the content of the positive electrode active material is less than 69% by weight, the proportion of components that do not participate in the reaction in the battery can be increased, resulting in a decrease in energy density, and if its content exceeds 94% by weight, the ionic conductivity and electronic conductivity required for driving the battery may not be obtained.

[0057] In addition, the positive electrode active material may be coated with an insulating material. When the positive electrode active material is coated with an insulating material, the reaction of the positive electrode active material with the solid electrolyte may be limited, thereby reducing resistance.

[0058] The insulating material may include one or more selected from oxides and fluorides, and the oxide may include one or more metal oxides selected from the group consisting of: Al2O3, Cr2O3, TiO2, SiO2, ZrO2, and Fe2O3. In addition, the fluoride may include one or more selected from polyvinylidene fluoride (PVdF) and polyvinylidene fluoride copolymers.

[0059] In addition, the thickness of the insulating material coating may be less than 20 nm. If the thickness is greater than 20 nm, it may act as a resistor when driving the battery. Specifically, the thickness may be less than 20 nm, less than 19 nm, less than 18 nm, less than 17 nm, less than 16 nm, less than 15 nm, less than 14 nm, less than 13 nm, less than 12 nm, less than 11 nm, less than 10 nm, less than 9 nm, less than 8 nm, less than 7 nm, less than 6 nm, or less than 5 nm. The lower limit of the thickness is not particularly limited, but may be, for example, more than 1 nm or more than 2 nm.

[0060] In one embodiment of the present invention, the sulfide-based solid electrolyte is a solid electrolyte containing sulfur in the solid electrolyte, which can be added to the positive electrode active material layer to improve ion conductivity.

[0061] The sulfide-based solid electrolyte may include one or more 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 any sulfide-based solid electrolyte conventionally used in the art may be used.

[0062] In addition, the sulfide solid electrolyte can be in the form of particles with a particle size (D50) of 0.1 μm to 1.5 μm. Specifically, the median particle size (D50) of the sulfide solid electrolyte can be 0.1 μm or more, 0.3 μm or more, 0.5 μm or more, and can be 0.9 μm or less, 1.0 μm or less, 1.2 μm or less, or 1.5 μm or less. If the median particle size (D50) of the sulfide solid electrolyte is less than 0.1 μm, the ultrafine sulfide solid electrolyte particles cannot be fully dispersed in the positive electrode active material layer and may agglomerate. In addition, if it exceeds 1.5 μm, dispersion can be relatively easy, but the contact area with the positive electrode active material particles can be reduced, resulting in an increase in the porosity of the positive electrode.

[0063] In addition, based on the total weight of the positive electrode active material layer, the content of the sulfide solid electrolyte may be 5 to 30 wt %. Specifically, the content of the sulfide 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 sulfide-based solid electrolyte is less than 5 wt %, ion conductivity may decrease, and if greater than 30 wt %, the contents of the positive electrode active material and the conductive material may be relatively reduced, resulting in deterioration of battery performance.

[0064] In one embodiment of the present invention, the conductive material can enhance electronic conductivity by forming a path for conducting electrons.

[0065] The conductive material may be a linear conductive material, wherein the linear conductive material may be one or more selected from the group consisting of carbon nanotubes (CNTs) and carbon nanofibers (CNFs). The linear conductive material may enhance conductivity due to its morphological characteristics. For example, the aspect ratio (length / diameter) of the linear conductive material may be more than 2, more specifically, the aspect ratio may be more than 2, more than 5, more than 10, more than 20, more than 30, more than 40, more than 50 or more than 100. If the aspect ratio is less than 2, it may be difficult to form an electronic conduction path, resulting in a decrease in electronic conductivity. In addition, the upper limit of the aspect ratio is not particularly limited, but considering the convenience of forming an electronic conduction path, it may be less than 300, less than 400, less than 500, less than 600 or less than 700.

[0066] In addition, based on the total weight of the positive electrode active material layer, the content of the conductive material can be 0.01 wt % to 10 wt %. Specifically, the content of the conductive material can 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 can be reduced, and if its content is greater than 10 wt %, the resistance can be increased due to the increase in the side reaction of the solid electrolyte, and the content of the positive electrode active material and the sulfide solid electrolyte can be relatively reduced, resulting in a decrease in the performance of the battery.

[0067] In one example of the present invention, a binder may be present to promote binding between the materials contained in the positive electrode active material layer and binding between the positive electrode active material layer and the positive electrode current collector.

[0068] The binder may be a fibrous binder. The binder may be fibrillated during mixing during the positive electrode manufacturing process and may be present in the positive electrode active material layer in a fibrous form. Therefore, it is preferred that the binder has a physical property that is easily deformable.

[0069] In addition, the binder can include one or more selected from the group consisting of: polytetrafluoroethylene (PTFE), polyethylene, polypropylene, ethylene / propylene copolymer, polybutadiene, polyethylene oxide, chlorosulfonated polyethylene, polyvinyl pyrrolidone, polyvinyl pyridine, polyvinyl alcohol, polyvinyl acetate, polyepichlorohydrin, polyphosphazene, polyacrylonitrile, polystyrene, latex, acrylic resin, phenol 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-co-hexafluoropropylene). Preferably, the binder can include polytetrafluoroethylene (PTFE).

[0070] In addition, based on the total weight of the positive electrode active material layer, the content of the binder can be 0.01 wt % to 10 wt %. Specifically, the content of the binder can be more than 0.01 wt %, more than 1 wt % or more than 2 wt %, and can be less than 10 wt %, less than 9 wt %, less than 8 wt %, less than 7 wt %, less than 6 wt %, less than 5 wt %, less than 4 wt % or less than 3 wt %. If the content of the binder is less than 0.01 wt %, the effect of improving the cohesion between the materials contained in the positive electrode active material layer is not significant, and the electrode sheet cannot be properly formed, and if its content is greater than 10 wt %, the ionic conductivity or electronic conductivity may be reduced.

[0071] In one example of the present invention, the thickness of the positive electrode active material layer may be 100 μm to 300 μm, more specifically, may be 100 μm or more, 110 μm or more, or 120 μm or more, and may be 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 according to the target loading amount of the positive electrode active material layer, so that the ratio of ionic conductivity to electronic conductivity is between 0.5 and 1.5.

[0072] In one example of the present invention, the positive electrode current collector supports the positive electrode active material layer and is used to transfer electrons between the external conductor and the positive electrode active material layer.

[0073] There is no particular limitation on the positive electrode current collector, as long as it has high electronic conductivity and does not cause chemical changes in the all-solid-state battery. For example, as the positive electrode current collector, stainless steel, aluminum, nickel, titanium, palladium, calcined carbon, stainless steel whose surface is treated with carbon, nickel or silver, aluminum-cadmium alloy, etc. can be used.

[0074] The positive electrode current collector may have a microscopic uneven structure or a three-dimensional porous structure on the surface of the positive electrode current collector to strengthen the bonding force with the positive electrode active material layer. Therefore, the positive electrode current collector may include a film, a sheet, a foil, a screen, a net, a porous body, a foam, a non-woven fabric, etc.

[0075] Method for manufacturing positive electrode for all-solid-state battery

[0076] The invention relates to a method for manufacturing a positive electrode for an all-solid-state battery.

[0077] The method for manufacturing the positive electrode for an all-solid-state battery of the present invention can be a dry method or a wet method, with or without a solvent. The specific substances, properties and contents of the positive electrode active material, sulfide solid electrolyte, conductive material and binder used in the method for manufacturing the positive electrode for an all-solid-state battery of the present invention are as described above.

[0078] The method for manufacturing a positive electrode for an all-solid-state battery of the present invention includes a wet process comprising the following steps: (A1) a step of adding a positive electrode active material, a sulfide 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 step (A1) on a positive electrode current collector; (A3) a step of drying the coating formed in step (A2).

[0079] Hereinafter, each step of the wet process of the method for manufacturing the positive electrode for an all-solid-state battery will be described in more detail.

[0080] In one embodiment of the present invention, in the above step (A1), the positive electrode active material, the sulfide-based solid electrolyte, the conductive material, and the binder may be added to an organic solvent to form a slurry.

[0081] The organic solvent can uniformly disperse the positive electrode active material, the sulfide-based solid electrolyte, the conductive material and the binder, and is preferably easily volatilized. Specific examples include acetonitrile, methanol, ethanol, tetrahydrofuran, water, isopropanol and the like.

[0082] In addition, the concentration of the slurry is not particularly limited as long as the coating process can be smoothly performed. For example, the concentration of the slurry may be 30 wt % to 50 wt % based on the solid content.

[0083] In one embodiment of the present invention, in the step (A2), the slurry formed in the step (A1) may be coated on the positive electrode current collector.

[0084] The coating method is not particularly limited as long as a coating layer can be formed using a slurry. For example, the coating in step (A2) can be performed by roll coating, gravure coating, doctor blade coating, slot die coating, slurry coating or extrusion coating.

[0085] In one example of the present invention, in step (A3), the coating layer formed in step (A2) may be dried.

[0086] In addition, the drying is not particularly limited as long as the method dries sufficiently to remove the organic solvent in the coating. For example, the drying can be performed at a temperature of 80°C to 130°C.

[0087] In the manufacturing method of the positive electrode for an all-solid-state battery of the present invention, the dry process includes: (B1) a step of mixing a positive electrode active material, a sulfide solid electrolyte, a conductive material and a binder; and (B2) a step of forming the mixed powder obtained in step (B1) into a film by a calendering process.

[0088] Hereinafter, each step of the dry process of the method for producing the positive electrode for an all-solid-state battery will be described in more detail.

[0089] In one embodiment of the present invention, in the above step (B1), the positive electrode active material, the sulfide solid electrolyte, the conductive material and the binder are mixed to obtain a mixed powder.

[0090] Alternatively, mixing can be physical mixing without using a separate solvent, and the binder can be fibrillated by physical mixing. During physical mixing, the binder can be physically deformed due to shear force when rubbing against the particles in the mixed powder, thereby causing its fibrillation. In order to induce this physical deformation, a binder with very weak physical properties and relatively easy fibrillation is used as a binder, for example, PTFE with a property of easy physical deformation is used as a binder. In addition, physical deformation can be achieved by introducing induction, ball milling or roller pressing during mixing.

[0091] In one embodiment of the present invention, in the above step (B2), the mixed powder obtained in the above step (B1) can be subjected to a calendering process to be formed into a film.

[0092] The conditions of the calendering process may be to apply appropriately adjusted process conditions to form a film. For example, the calendering process may be performed at a temperature of 20° C. to 200° C. for 5 to 50 cycles. However, the calendering process conditions (e.g., temperature, pressure, number of cycles, etc.) may be any of the conditions used in the electrode manufacturing process used in the battery field.

[0093] All-solid-state battery

[0094] The present invention also relates to an all-solid-state battery comprising the aforementioned positive electrode.

[0095] Figure 3 is a schematic diagram showing a cross section of an all-solid-state battery of an example of the present invention.

[0096] Now refer to Figure 3 The all-solid-state battery of the present invention comprises a positive electrode 10, a negative electrode 20, and a sulfide-based solid electrolyte membrane 30 disposed 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, 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 the sulfide-based solid electrolyte membrane 30 is disposed between the positive electrode active material layer 12 and the negative electrode active material layer 22. However, the all-solid-state battery of the present invention is not limited to this structure, and if the positive electrode active material layer 12 can be self-supporting, it may not contain a positive electrode current collector, and the negative electrode active material layer may be free of an anode coating.

[0097] In one example of the present invention, the negative electrode may include a negative electrode active material layer or anode-free coating. In addition, the negative electrode active material layer or anode-free coating may also be formed on one surface of the negative electrode current collector.

[0098] The negative electrode active material layer includes a negative electrode active material, a binder, and a conductive material.

[0099] The negative electrode active material may include a material capable of reversibly inserting or deinserting lithium (Li + ), a material capable of reacting with lithium ions to reversibly form a lithium-containing compound, lithium metal or a lithium alloy.

[0100] Able to reversibly insert or deintercalate lithium ions (Li + ) can be, for example, crystalline carbon, amorphous carbon or a mixture thereof. + ) to reversibly form a lithium-containing compound may be, for example, tin oxide, titanium nitrate or silicon. The lithium alloy may be 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).

[0101] Preferably, the negative electrode active material may be lithium metal or lithium indium alloy (Li-In), and more specifically, it may be in the form of lithium metal or lithium thin film, or lithium indium alloy thin film or powder.

[0102] Based on the total weight of the negative electrode active material layer, the negative electrode active material may be 40% to 80% by weight. Specifically, the content of the negative electrode active material may be 40% by weight or more, 50% by weight or more, 70% by weight or less, or 80% by weight or less. If the content of the negative electrode active material is less than 40% by weight, the connectivity between the wet negative electrode active material layer and the dry negative electrode active material layer may be insufficient, and if the content is greater than 80% by weight, the mass transfer resistance may be large.

[0103] In addition, the binder, as a component that helps the negative electrode active material and the conductive material to adhere to the negative electrode current collector, can include one or more selected from the group consisting of: styrene butadiene rubber, acrylate-modified styrene butadiene rubber, acrylonitrile copolymer, acrylonitrile-butadiene rubber, nitrile rubber, acrylonitrile-styrene-butadiene copolymer, acrylic rubber, butyl rubber, fluororubber, polytetrafluoroethylene, polyethylene, polypropylene, ethylene / propylene copolymer, polybutadiene, polyethylene oxide, chlorosulfonated polyethylene, polyvinyl pyrrolidone, polyvinyl pyridine, polyethylene The binder may include polytetrafluoroethylene (PTFE), 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-co-hexafluoropropylene). Preferably, the binder may include polytetrafluoroethylene (PTFE).

[0104] In addition, based on the total weight of the negative electrode active material layer, the content of the binder may be 0.5 wt % to 4 wt %, specifically, the content of the binder may be 0.5 wt % or more, 1 wt % or more, or 1.5 wt % or more, and may be 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 adhesion between the positive electrode active material and the negative electrode current collector may be reduced, and if the binder content is greater than 4 wt %, the adhesion may be improved, but the content of the negative electrode active material may be reduced, thereby causing the battery capacity to become low.

[0105] In addition, the conductive material is not particularly limited, as long as it has excellent electronic conductivity, can prevent side reactions, and does not cause chemical changes in the all-solid-state battery. Graphite or conductive carbon can usually be used. Materials that can be used as conductive materials are: 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 thermal black; carbon materials with graphene or graphite crystal structure; conductive fibers, such as carbon fibers and metal fibers; carbon fluoride; metal powders, such as aluminum powder and nickel powder; conductive whiskers, such as zinc oxide and potassium titanate; conductive oxides, such as titanium oxide; conductive polymers, such as polyphenylene derivatives, which can be used alone or in mixtures of two or more thereof. Preferably, the conductive material may include vapor grown carbon fibers (VGCF).

[0106] Based on the total weight of the negative electrode active material layer, the content of the conductive material can generally be 1% to 5% by weight. Specifically, the content of the conductive material can be more than 1% by weight, more than 1.5% by weight, or more than 2% by weight, and can be less than 4% by weight, less than 4.5% by weight, or less than 5% by weight. If the content of the conductive material is too little, for example, less than 1% by weight, it is difficult to expect the effect of improving the electronic conductivity, or the electrochemical performance of the battery may decrease; if the content of the conductive material is too much, for example, greater than 5% by weight, the amount of the negative electrode active material is relatively small, and the capacity and energy density may decrease. There is basically no limitation on the method of incorporating the conductive material into the negative electrode, and any conventional method known in the art can be used, such as mixing with the negative electrode active material, coating the negative electrode active material, etc.

[0107] In addition, the negative electrode current collector is not particularly limited as long as it has conductivity and does not cause chemical changes in the battery. For example, the negative electrode current collector can be made of copper, stainless steel, aluminum, nickel, titanium, calcined carbon, or a material surface-treated with carbon, nickel, titanium or silver on copper or stainless steel, or an aluminum-cadmium alloy. In addition, like the positive electrode current collector, the negative electrode current collector can be used in various forms, for example, a film, sheet, foil, net, porous material, foam, non-woven fabric, etc., with fine irregularities formed on the surface.

[0108] The manufacturing method of the 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 conventional layer or film formation method in the art. For example, methods such as pressing, coating or deposition can be used. The negative electrode of the present invention also includes the following case: the battery is assembled without a lithium film on the negative electrode current collector, and then a metallic lithium film is formed on the metal plate by initial charging.

[0109] In addition, the non-anode coating layer may refer to a negative electrode active material layer that does not contain a negative electrode active material. The negative electrode active material may be formed on the non-anode coating layer by charging. For example, when the battery is charged, lithium ions may be transferred from the positive electrode and lithium metal may be precipitated from the negative electrode. In other words, the non-anode coating layer may be a film that induces lithium precipitation.

[0110] The non-anodic coating layer may include metal particles and carbon material particles, and more specifically, may include a carbon material-metal composite.

[0111] The 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 amorphous carbon materials include carbon black (eg, acetylene black, furnace black, and Ketjen black), graphene, or a combination thereof.

[0112] In addition, the metal particles may be particles that form an alloy with lithium. The metal particles may be selected from one or more of silver (Ag), gold, platinum, palladium, silicon, aluminum, bismuth, tin, indium and zinc. The anode-free coating may be formed as a very thin film of micrometer-level thickness, for example, it may be formed to a thickness of 10 μm or less.

[0113] Preferably, the anode-free coating layer may include an Ag—C complex as a carbon-metal complex, and lithium may be precipitated between the negative electrode current collector and the coating layer including the Ag—C complex at the time of the first charge.

[0114] In one example of the present invention, the sulfide solid electrolyte contained in the sulfide solid electrolyte membrane may include one or more selected from the group consisting of: LiPSX (X = Cl, Br or I), LiGePS and LiPS. However, the sulfide solid electrolyte is not limited to these, and any sulfide solid electrolyte conventionally used in the art can be used.

[0115] Battery Module

[0116] The present invention also relates to a battery module comprising the all-solid-state battery as a unit cell, a battery pack comprising the battery module, and a device comprising the battery pack as a power source.

[0117] In this case, specific examples of devices that can use the battery include power tools driven by a battery-powered motor, electric vehicles (EV), hybrid electric vehicles (HEV) and plug-in hybrid electric vehicles (PHEV), electric two-wheeled vehicles such as electric bicycles (E-bikes) and electric scooters (E-scooters), electric golf carts, and energy storage systems, but the examples are not limited thereto. Preferred embodiments of the present invention are described below to illustrate the present invention, but it is obvious to those skilled in the art that various changes and modifications can be made within the scope and technical concept of the present invention, and such changes and modifications also fall within the scope of the attached patent claims.

[0118] Hereinafter, preferred embodiments of the present invention are described to illustrate the present invention, but it is obvious to those skilled in the art that various changes and modifications can be made within the scope of the present invention and technical ideas, and such changes and modifications also fall within the scope of the appended patent claims.

[0119] In the following Examples and Comparative Examples, a positive electrode and an all-solid-state battery including the positive electrode were manufactured according to the composition of the positive electrode active material layer shown in Table 1 below.

[0120] [Table 1]

[0121]

[0122] Example 1

[0123] 1-1. Fabrication of positive electrode active material layer

[0124] The positive electrode was prepared as follows: LiN 0.8 Co 0.1 Mn 0.1 O2 (NCM 811) as the positive electrode active material, Li6PS5Cl as the sulfide-based solid electrolyte, CNF as the linear conductive material and polytetrafluoroethylene (PTFE) as the binder.

[0125] The positive electrode active material, sulfide 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 solid electrolyte and conductive material were weighed in powder form, and then mixed for 30 minutes using a blade mixer in a dry indoor environment without using any separate solvent to obtain a mixture. Subsequently, PTFE (polytetrafluoroethylene) powder as a binder was weighed and further mixed to obtain a mixed powder.

[0126] The mixed powder was added to a mortar, fiberized in the mortar, and then rolled on a roller press to form a 150 μm thick, R IC / EC The positive electrode has a ratio of 1.04.

[0127] R IC / EC The Nyquist plot was obtained by electrochemical impedance spectroscopy (EIS) analysis using BioLogic's SP-50e instrument, and the ionic conductivity and electronic conductivity were extracted from the plot for calculation. IC / EC The calculated value is rounded to two decimal places.

[0128] 1-2. Manufacturing of all-solid-state batteries

[0129] An all-solid-state battery is manufactured by sequentially stacking a negative electrode current collector (copper, Cu), lithium metal, a sulfide-based solid electrolyte membrane composed of Li6PS5Cl, the aforementioned positive electrode, and a positive electrode current collector (aluminum, Al).

[0130] Example 2

[0131] The same method as in Example 1 was used to prepare R IC / EC =1.41, except that the weight ratio of the positive electrode active material, the sulfide solid electrolyte, the conductive material and the binder is 84:14.7:0.3:1.

[0132] Example 3

[0133] The same method as in Example 1 was used to prepare R IC / EC=0.69, except that the weight ratio of the positive electrode active material, the sulfide solid electrolyte, the conductive material and the binder is 84:14.3:0.7:1.

[0134] Example 4

[0135] The same method as in Example 1 was used to prepare R IC / EC =1.38, except that the weight ratio of the positive electrode active material, the sulfide solid electrolyte, the conductive material and the binder is 80:18:1:1.

[0136] Example 5

[0137] The same method as in Example 1 was used to prepare R IC / EC =0.86, except that the weight ratio of the positive electrode active material, the sulfide solid electrolyte, the conductive material and the binder is 88:10.9:0.1:1.

[0138] Comparative Example 1

[0139] The same method as in Example 1 was used to prepare R IC / EC =0.01, except that the weight ratio of the positive electrode active material, the sulfide solid electrolyte, the conductive material and the binder is 84:13.5:1.5:1.

[0140] Comparative Example 2

[0141] The same method as in Example 1 was used to prepare R IC / EC =0.01, except that the weight ratio of the positive electrode active material, the sulfide solid electrolyte, the conductive material and the binder is 80:16:3:1.

[0142] Comparative Example 3

[0143] The same method as in Example 1 was used to prepare R IC / EC =0.03, except that the weight ratio of the positive electrode active material, the sulfide solid electrolyte, the conductive material and the binder is 90:8:1:1.

[0144] Test Example 1: Evaluation of All-Solid-State Battery Performance

[0145] According to the ratio of ionic conductivity to electronic conductivity (R IC / EC ) to evaluate the performance of the all-solid-state battery. Examples 1 to 5 and Comparative Examples 1 to 3 were evaluated.

[0146] In order to evaluate the performance of the above all-solid-state battery, it was charged at 0.1C current to 4.25V (vs. Li / Li +), then maintain 4.25V (vs.Li / Li + ) while charging at a cut-off current of 0.05C. Discharge the battery at a current of 0.1C until the voltage reaches 3V (vs.Li / Li + ). The process was repeated for 2 cycles, and the discharge capacity of the 2nd cycle was used as the 0.1C initial discharge capacity. The rate performance was then evaluated using a scheme for discharge up to 1C. Specifically, the rate performance was observed by performing CC discharge at 0.1C / 0.33C / 0.5C / 1C and maintaining a 0.1C / 0.05C CC / CV (constant current / constant voltage) charge. The 1C capacity retention rate is calculated by dividing the 1C discharge capacity obtained by this evaluation process by the 0.1C initial discharge capacity, which is used as a result of the high rate characteristics. The 0.1C initial discharge capacity and 1C capacity retention rate measured in Examples 1 to 5 and Comparative Examples 1 to 3 are listed in Table 2 below.

[0147] [Table 2]

[0148] 0.1C initial discharge capacity (mAh / g) 1C discharge capacity (mAh) 1C capacity retention rate (%) Example 1 19.3 17.6 91.4 Example 2 19.3 17.2 89.5 Example 3 19.1 16.7 87.7 Example 4 19.3 17.4 90.5 Example 5 18.6 16.2 87.4 Comparative Example 1 17.6 11.0 62.5 Comparative Example 2 17.8 9.8 54.8 Comparative Example 3 16.8 7.3 43.7

[0149] As shown in Table 2 above, it can be seen that Examples 1 to 5 have more excellent discharge capacity and high rate characteristics than Comparative Examples 1 to 3. In Examples 1 to 5, the ratio of ionic conductivity to electronic conductivity (R IC / EC ) is in the range of 0.5 to 1.5, and it can be confirmed that when the ratio of ionic conductivity to electronic conductivity (R IC / EC ) When it exceeds this range, the discharge capacity and high rate characteristics decrease rapidly. In addition, in Examples 1 to 5, it can be confirmed that the ratio of ionic conductivity to electronic conductivity (R IC / EC ) is close to 1, the discharge capacity and high rate characteristics of Example 1 are the best.

[0150] Reference numerals

[0151] 10: Positive electrode

[0152] 11: Positive electrode current collector

[0153] 12: Positive electrode active material layer

[0154] 20: Negative electrode

[0155] 21: Negative electrode current collector

[0156] 22: Negative electrode active material layer

[0157] 30: Sulfide solid electrolyte membrane

Claims

1. A positive electrode for an all-solid-state battery, comprising a positive electrode active material layer, in, The positive electrode active material layer comprises a positive electrode active material, a sulfide-based solid electrolyte, a conductive material and a binder, and the positive electrode active material layer has a ratio R of ionic conductivity (IC) to electronic conductivity (EC) defined by the following equation 1: IC / EC 0.5 to 1.5: <Equation 1> R IC / EC = ionic conductivity / electronic conductivity.

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 the Nyquist plot obtained by electrochemical impedance spectroscopy (EIS) analysis.

3. The positive electrode for an all-solid-state battery according to claim 1, wherein The positive electrode active material is one or more selected from the group consisting of: Layered compounds, such as lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), Li[Ni x Co y Mn z M v ]O2 (wherein M is one or more elements selected from 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' ) 2-c A c (in, 0≤a≤0.2,0.6≤b≤1,0≤b'≤0.2,0≤c≤0.2; M includes Mn and one or more selected from Ni, Co, Fe, Cr, V, Cu, Zn, Ti; M' is one or more selected from Al, Mg, B; A is one or more selected from P, F, S, N), or a compound obtained by replacing some metal elements in the layered compound with one or more transition metals; Lithium manganese oxide, such as Li 1+y Mn 2-y O4 (wherein y is 0 to 0.33), LiMnO3, LiMn2O3 and LiMnO2; Lithium copper oxide (Li2CuO2); Vanadium oxides, such as LiV3O8, LiFe3O4, V2O5 and Cu2V2O7; LiNi 1-y M y Ni-type lithium nickel oxide represented by O2 (wherein M = Co, Mn, Al, Cu, Fe, Mg, B or Ga, y is 0.01 to 0.3); LiMn 2-y M y A lithium manganese composite oxide represented by Li2Mn3MO8 (wherein M is Fe, Co, Ni, Cu or Zn); Formula LiMn2O4, in which part of Li is replaced by alkaline earth metal ions; disulfides; and Fe2(MoO4)3.

4. The positive electrode for an all-solid-state battery according to claim 1, 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.

5. 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 to 1.5 μm.

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

7. The positive electrode for an all-solid-state battery according to claim 1, wherein: The binder includes one or more selected from the group consisting of polytetrafluoroethylene (PTFE), polyethylene, polypropylene, ethylene / propylene copolymer, polybutadiene, polyethylene oxide, chlorosulfonated polyethylene, polyvinyl pyrrolidone, polyvinyl pyridine, polyvinyl alcohol, polyvinyl acetate, polyepichlorohydrin, polyphosphazene, polyacrylonitrile, polystyrene, latex, acrylic resin, phenol 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-co-hexafluoropropylene).

8. The positive electrode for an all-solid-state battery according to claim 1, wherein: The positive electrode active material layer includes 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. The positive electrode for an all-solid-state battery according to claim 1, wherein: The positive electrode active material layer includes 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. 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 includes one or more 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 adhesive is a fibrous adhesive.

14. An all-solid-state battery comprising the positive electrode according to claim 1, a negative electrode and a sulfide-based solid electrolyte membrane disposed therebetween.

15. The all-solid-state battery according to claim 14, wherein: The negative electrode includes a lithium-containing negative electrode active material layer or an anode-free coating.

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