Method for preparing anode slurry for solid-state battery

Abstract

The present invention relates to a method for preparing an anode slurry for a solid-state battery and, more specifically, the method for preparing an anode slurry for a solid-state battery comprises the steps of: mixing an anode material and a binder solution so as to prepare a first mixture containing 30-50 wt% of solids; kneading the first mixture; additionally mixing the first mixture with the binder solution so as to prepare a second mixture containing 25-35 wt% of solids; and additionally mixing the second mixture with a solvent so as to prepare a third mixture.

Description

Method for manufacturing a cathode slurry for an all-solid-state battery

[0001] The present invention relates to a method for producing a negative electrode slurry for an all-solid-state battery.

[0002] Recent industrial demands have led to the active development of batteries with high energy density and safety. For example, lithium-ion batteries are being used not only in information and communication devices, but also in the automotive sector. Safety is particularly important in the automotive sector, as it is directly related to life.

[0003] All-solid-state batteries are being proposed, replacing the electrolyte with a solid electrolyte. By eliminating the use of flammable organic dispersion media, all-solid-state batteries can significantly reduce the risk of fire or explosion in the event of a short circuit.

[0004] The problem to be solved by the present invention is to provide a method for manufacturing a cathode slurry having improved dispersion characteristics of a cathode material.

[0005] The problem to be solved by the present invention is to provide a method for manufacturing a cathode slurry having excellent viscosity maintenance properties.

[0006] According to the concept of the present invention, a method for producing a negative electrode slurry for an all-solid-state battery may include the steps of: mixing a negative electrode material and a binder solution to produce a first mixture having a solid content of 30 wt% to 50 wt%; kneading the first mixture; further mixing the binder solution into the kneaded first mixture to produce a second mixture having a solid content of 25 wt% to 35 wt%; and further mixing a solvent into the second mixture to produce a third mixture. The binder solution may include a solvent and a first binder. The kneading may be performed by applying an instantaneous maximum power load of 1.5 W to 3 W per 1 g of the first mixture to a kneader.

[0007] According to another concept of the present invention, a method for manufacturing an anode for an all-solid-state battery may include the above-described method for manufacturing an anode slurry. Specifically, the method may include the steps of: mixing an anode material and a binder solution to manufacture a first mixture having a solid content of 30 wt% to 50 wt%; kneading the first mixture; further mixing the binder solution into the kneaded first mixture to manufacture a second mixture having a solid content of 25 wt% to 35 wt%; and further mixing a solvent into the second mixture to manufacture a third mixture. The binder solution may include a solvent and a first binder. The kneading may be performed by applying an instantaneous maximum power load of 1.5 W to 3 W per 1 g of the first mixture to a kneader. The method for manufacturing an anode for an all-solid-state battery may include the steps of: applying the manufactured anode slurry onto a current collector; drying; and may further include a pressing step.

[0008] According to another concept of the present invention, an anode slurry for an all-solid-state battery can be manufactured according to the above-described method for manufacturing an anode slurry for an all-solid-state battery.

[0009]

[0010] The present invention can realize an all-solid-state battery negative electrode slurry having improved dispersibility of carbon materials and metal particles contained in the negative electrode material.

[0011] The present invention can realize a cathode slurry having excellent dispersion stability and viscosity retention rate.

[0012] The present invention can manufacture an electrode with excellent performance by applying the above-described negative electrode slurry. An all-solid-state battery using the electrode can have improved stability and cell characteristics.

[0013]

[0014] Figures 1 to 3 are flowcharts showing a method for manufacturing a cathode slurry for an all-solid-state battery according to one embodiment of the present invention.

[0015] Figure 4 is a cross-sectional view of an all-solid-state battery according to one embodiment of the present invention.

[0016]

[0017] To fully understand the structure and effects of the present invention, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various forms and subject to various modifications. However, the description of these embodiments is provided solely to ensure a complete disclosure of the present invention and to fully inform those skilled in the art of the invention of the scope of the invention.

[0018] In this specification, when a component is referred to as being on another component, it means that it can be formed directly on the other component, or a third component may be interposed between them. Furthermore, in the drawings, the thicknesses of the components are exaggerated for the sake of clarity. Parts designated by the same reference numerals throughout the specification represent the same components.

[0019] The embodiments described herein will be described with reference to cross-sectional views, plan views, and / or perspective views, which are ideal illustrations of the present invention. Although terms such as "first," "second," and "third" are used to describe various components in various embodiments of this specification, these components should not be limited by these terms. These terms are used merely to distinguish one component from another. The embodiments described and illustrated herein also include complementary embodiments.

[0020] The terminology used herein is for the purpose of describing embodiments and is not intended to limit the present invention. In this specification, the singular also includes the plural unless specifically stated otherwise. As used herein, the words "comprises" and / or "comprising" do not exclude the presence or addition of one or more other components.

[0021] Method for manufacturing cathode slurry

[0022] FIG. 1 is a flowchart showing a method for manufacturing a cathode slurry for an all-solid-state battery according to one embodiment of the present invention.

[0023] Referring to FIG. 1, a method for manufacturing an anode slurry for an all-solid-state battery according to an embodiment of the present invention includes a step of mixing an anode material and a binder solution to manufacture a first mixture (S200); a step of kneading the first mixture (S300); a step of additionally mixing the binder solution into the kneaded first mixture to manufacture a second mixture (S400); and a step of additionally mixing a solvent into the second mixture to manufacture a third mixture (S500). The method for manufacturing an anode slurry for an all-solid-state battery according to an embodiment of the present invention may further include a step of preparing the binder solution (S100).

[0024]

[0025] The step (S100) of preparing the above binder solution includes adding a first binder to a solvent. The solvent may be an aqueous solvent or a non-aqueous solvent. In one embodiment, the solvent may include water.

[0026] As used herein, "aqueous solvent" refers to solvents containing water as a main component. For example, the aqueous solvent may include water. In addition, the aqueous solvent may further include at least one selected from the group consisting of methanol, ethanol, ethylene glycol, diethylene glycol, and glycerol.

[0027] The first binder may include at least one binder selected from the group consisting of an acrylate binder, a polyvinylidene fluoride binder, a polyvinylpyrrolidone binder, a polyvinyl alcohol binder, and a cellulose binder. In one embodiment, the first binder may be an aqueous binder.

[0028] The above acrylate binder may be, for example, polyacrylic acid (PAA), polymethylmethacrylate, polyisobutylmethacrylate, polyethylacrylate, polybutyl acrylate, or poly(2-ethylhexyl acrylate).

[0029] The above polyvinylidene fluoride-based binder is, for example, polyvinylidene fluoride (PVDF), polyvinylidene fluoride-co-hexafluoropropylene, polyvinylidene fluoride-co-trichloroethylene, polyvinylidene fluoride-co-tetrafluoroethylene, polyvinylidene fluoride-co-trifluoroethylene, polyvinylidene fluoride-co-trifluorochloroethylene, polyvinylidene fluoride-co-hexafluoropropylene. It may be poly(vinylidene fluoride-co-ethylenefluoride-hexafluoropropylene) or polyvinylidene fluoride-co-trichloroethylene.

[0030] The above polyvinylpyrrolidone-based binder may be, for example, polyvinylpyrrolidone.

[0031] The above polyvinyl alcohol-based binder may be, for example, polyvinyl alcohol.

[0032]

[0033] The above-mentioned cellulose-based binder may include, for example, at least one selected from the group consisting of carboxymethyl cellulose (CMC), methyl cellulose (MC), hydroxypropyl cellulose (HPC), methyl hydroxypropyl cellulose (MHPC), ethyl hydroxyethyl cellulose (EHEC), methyl ethyl hydroxyethyl cellulose (MEHEC), and cellulose gum.

[0034] In one embodiment, the first binder may comprise carboxymethylcellulose (CMC).

[0035] The first binder may be added so that the content of the first binder in the first mixture is 0.5 to 5 wt%. If the content of the first binder is less than the above range, the dispersion effect of the negative electrode material particles may be reduced in the dispersion process described below. If the content of the first binder exceeds the above range, the first binder may be excessively adsorbed on the surface of the carbon or metal particles, thereby hindering the movement of lithium ions. This may increase the internal resistance of the battery. In addition, the high viscosity of the binder may reduce the processability.

[0036] The step (S100) of preparing the above binder solution may further include adding the first binder to a solvent and then mixing the same. The solvent is the same as that described above in the binder solution preparation step (S100). In one embodiment, the solvent may be an aqueous solvent. For example, the solvent may include water. The mixing method is not limited and may be, for example, stirring. In one embodiment, the mixing of water and the first binder may be performed by a stirrer.

[0037] The viscosity of the binder solution may be 500 cps to 3000 cps. For example, it may be 1000 cps to 3000 cps, 1200 to 2800 cps, or 1500 cps to 2500 cps. The binder solution having the above viscosity may be used in the step (S200) of preparing a first mixture; and the step (S400) of further mixing the binder solution into the kneaded first mixture to prepare a second mixture. By using the binder solution having the above viscosity, an appropriate viscosity can be formed in the first mixture and the second mixture, thereby improving the dispersion characteristics and viscosity retention rate through mixing or kneading.

[0038]

[0039] The step (S200) of preparing a first mixture by mixing the above-mentioned negative electrode material and the above-mentioned binder solution includes adding the above-mentioned binder solution to the negative electrode material.

[0040] The above negative electrode material may include carbon material and metal.

[0041] The above carbon material may include at least one selected from the group consisting of carbon black, acetylene black, furnace black, ketjen black, and graphene.

[0042] The specific surface area (BET) of the above carbon material is 30 m 2 / g to 60 m 2 / g. For example, the specific surface area (BET) of the above carbon material is 30 m 2 / g to 50 m 2 / g, 35 m 2 / g to 50 m 2 / g, 40 m 2 / g to 50 m 2 / g, 30 m 2 / g to 45 m 2 / g, 35 m 2 / g to 45 m 2 / g or 40 m 2 / g to 50 m 2 / g. In one embodiment, the specific surface area of ​​the carbon material is 35 m 2 / g to 50 m 2 / g may be.

[0043] The metal may include at least one selected from the group consisting of gold (Au), indium (In), germanium (Ge), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), and zinc (Zn).

[0044] The weight ratio of the metal and the carbon material may be 1:2 to 20. For example, the weight ratio of the metal and the carbon material may be 1:3 to 20, 1:3 to 15, or 1:3 to 10. By having the above weight ratio of the metal and the carbon material, the catalytic activity of the metal can be smoothly achieved, thereby securing excellent output characteristics and capacity of the battery.

[0045] The above-described negative electrode material may further include additives. For example, the above-described negative electrode material may further include at least one selected from the group consisting of fillers, coating agents, dispersants, and ion-conducting aids.

[0046] The step (S200) of preparing a first mixture by mixing the above-mentioned negative electrode material and the binder solution may further include adding the binder solution to the negative electrode material and then mixing. The mixing method is not limited, and may be, for example, stirring. In one embodiment, the mixing of the negative electrode material and the binder solution may be performed by a stirrer. In another embodiment, the mixing of the negative electrode material and the binder solution may be performed by a kneader, which will be described in the subsequent kneading step (S300).

[0047] The addition and mixing of the binder solution to the cathode material may be repeated one or more times. For example, the process may be repeated one to five times. Depending on the number of repetitions, the amount of binder solution added per repetition may be appropriately adjusted.

[0048] The solid content of the first mixture manufactured in the step of manufacturing the first mixture (S200) may be 30 wt% to 50 wt%. For example, the solid content of the first mixture may be 30 wt% to 50 wt%, 35 wt% to 50 wt%, 40 wt% to 48 wt%, 42 wt% to 48 wt%, or 42 wt% to 46 wt%. In one embodiment, the solid content of the first mixture manufactured in the step of manufacturing the first mixture (S200) may be 40 wt% to 50 wt%.

[0049] If the solid content exceeds the above range, the binder solution may not sufficiently permeate the negative electrode material, and thus the effect of improving dispersion characteristics and viscosity retention rate due to the subsequent kneading process may be reduced.

[0050] If the solids content falls below the above range, the viscosity of the first mixture may become too low, making it difficult to apply sufficient shear force to the first mixture during the subsequent kneading process. This may result in a reduction in the dispersion characteristics and viscosity retention effect resulting from the kneading process.

[0051] In order to further increase the effect of improving the dispersion characteristics and viscosity retention rate, the solid content of the first mixture can be adjusted according to the specific surface area (BET) of the carbon material. More specifically, the smaller the specific surface area of ​​the carbon material, the more the solid content of the first mixture required for the kneading step can be increased. For example, if the specific surface area (BET) of the carbon material is 30 m 2 / g to 60 m 2 / g, and the solid content of the first mixture before kneading may be 30 wt% to 50 wt%. In one embodiment, the specific surface area (BET) of the carbon material is 35 m 2 / g to 50 m 2 / g, and the solid content of the first mixture before kneading may be 40 wt% to 50 wt%. Within this range, the effect of improving dispersion stability and viscosity retention by kneading can be further increased.

[0052]

[0053] The step of kneading the first mixture (S300) includes applying a shear force to the first mixture.

[0054] The above kneading may be performed by a kneader. The kneader is a general term for a device capable of applying a shear force to a material. As long as it can apply a shear force to a material, a device called a “mixer” may also be included in the kneader in the present specification. For example, the kneader may be at least one selected from the group consisting of a paddle mixer, a ribbon mixer, a planetary mixer, a dual shaft mixer mixer, a high-speed impeller mixer, a propeller mixer, and a PD mixer (planetary disperser mixer). In one embodiment, the kneader may be a PD mixer.

[0055] The kneading may be performed by applying an instantaneous maximum power load of 1.5 W to 3 W per 1 g of the first mixture to the kneader. For example, the kneading may be performed by applying an instantaneous maximum power load of 1.5 W to 3 W, 1.5 W to 2.8 W, 1.8 W to 3 W, 1.8 W to 2.8 W, 1.5 W to 2.5 W, 1.8 W to 2.5 W, or 2.0 W to 2.5 W per 1 g of the first mixture to the kneader. In the above range, the first binder can be uniformly attached to the carbon material and the metal without being destroyed. In addition, in the above range, the carbon material and the metal can be uniformly dispersed. In one embodiment of the present invention, the kneading may be performed by the PD mixer.

[0056] More specifically, the kneading may be performed by a planetary blade and a high-speed disperser blade constituting the PD mixer. The rotation speed of the planetary blade may be 50 rpm to 100 rpm. For example, the rotation speed of the planetary blade may be 50 rpm to 90 rpm, 50 rpm to 80 rpm, 60 rpm to 90 rpm, or 60 rpm to 80 rpm. The rotation speed of the high-speed disperser blade may be 700 rpm to 2500 rpm. For example, the rotation speed of the high-speed dispersing blade may be 800 rpm to 2500 rpm, 800 rpm to 2000 rpm, 900 rpm to 1500 rpm, 800 rpm to 1200 rpm, or 900 rpm to 1100 rpm. The first binder can be uniformly attached to the carbon material and the metal by the low-speed rotating planetary blade and the high-speed rotating high-speed dispersing blade, and the carbon material and the metal can be uniformly dispersed in the first mixture.

[0057] The above kneading execution time can be appropriately selected depending on the power applied to the kneader. For example, the kneading can be performed for 20 to 120 minutes, 30 to 90 minutes, 40 to 80 minutes, or 50 to 60 minutes.

[0058] The cathode slurry manufactured by performing the above kneading step (S300) has excellent dispersibility and excellent slurry viscosity retention over time.

[0059]

[0060] The step (S400) of preparing the second mixture includes additionally adding the binder solution to the kneaded first mixture.

[0061] By adding the binder solution to the first mixture, the solid content in the first mixture can be reduced while replenishing the first binder. This allows the viscosity of the first mixture to be controlled and the first binder to be more uniformly attached to the carbon material and the metal.

[0062] By adding the binder solution to the first mixture, the solid content in the first mixture can be made less than 42 wt%. For example, the solid content in the first mixture can be made between 30 wt% and 40 wt%.

[0063] The step (S400) of preparing the second mixture may further include adding the binder solution to the kneaded first mixture and then mixing. The method of mixing the kneaded first mixture and the binder solution is not limited, and may be, for example, stirring. In one embodiment, the mixing of the kneaded first mixture and the binder solution may be performed using a stirrer.

[0064] In another embodiment, the mixing of the first mixture and the binder solution may be performed by the kneader described above in the kneading step (S300).

[0065] The mixing of the first mixture and the binder solution may be performed by applying an instantaneous maximum power load of less than 1.5 W per 1 g of the first mixture to the kneader. For example, the kneading may be performed by applying an instantaneous maximum power load of 0.2 W to 1.2 W, 0.4 W to 1.2 W, or 0.5 W to 1.2 W per 1 g of the first mixture to the kneader.

[0066] In one embodiment of the present invention, mixing of the first mixture and the binder solution may be performed by a planetary blade and a high-speed disperser blade constituting the PD mixer. The rotation speed of the planetary blade may be 50 rpm to 100 rpm. For example, the rotation speed of the planetary blade may be 50 rpm to 90 rpm, 50 rpm to 80 rpm, 60 rpm to 90 rpm, or 60 rpm to 80 rpm. The rotation speed of the high-speed disperser blade may be 1500 rpm to 2500 rpm. For example, the rotation speed of the high-speed dispersion blade may be 1300 rpm to 2200 rpm, 1400 rpm to 2000 rpm, or 1500 rpm to 1900 rpm. By providing a rotation speed higher than the high-speed dispersion blade rotation speed in the kneading step (S300), the constituent materials can be more uniformly dispersed in the mixture with reduced solid content.

[0067] In the second mixture preparation step (S400), the mixing of the first mixture and the binder solution may be repeated one or more times. For example, the mixing may be repeated one to five times.

[0068] Referring to FIG. 2, in one embodiment of the present invention, the step of preparing the second mixture (S400) may include a step of first mixing the binder solution into the first mixture (S410); and a step of second mixing the binder solution into the first mixture (S420).

[0069] Referring to FIG. 3, in another embodiment of the present invention, the step of preparing the second mixture (S400) may include a step of first mixing the binder solution into the first mixture (S410); a step of second mixing the binder solution into the first mixture (S420); and a step of third mixing the binder solution into the first mixture (S430).

[0070] Depending on the number of times the above binder solution is mixed, the weight of the binder solution added per time may vary.

[0071] Even if the number of times the binder solution is mixed changes, the total weight of the binder solution mixed into the first mixture may be the same.

[0072] In the second mixture manufacturing step (S400), a second mixture having a final solid content of 25 wt% to 35 wt% can be manufactured.

[0073]

[0074] The step (S500) of preparing a third mixture by adding a solvent to the second mixture includes adding a solvent to the second mixture.

[0075] The step (S500) of preparing the third mixture may further include adding a solvent to the second mixture and then mixing. In one embodiment, the solvent may be an aqueous solvent. For example, the solvent may include water. The mixing method is not limited and may be, for example, stirring. In one embodiment, the mixing may be performed using a stirrer. In another embodiment, the mixing may be performed using the kneader described above.

[0076] In the step (S500) of preparing the third mixture, a third mixture having a solid content of 15 wt% to 23 wt% may be prepared.

[0077]

[0078] Referring to FIG. 2, the method for manufacturing a negative electrode slurry for an all-solid-state battery according to one embodiment of the present invention may further include a step (S600) of adding a second binder to the third mixture.

[0079] By adding a second binder after the above-described kneading, the second binder can be prevented from being destroyed in the above-described kneading step (S300).

[0080] The second binder may include at least one binder selected from the group consisting of a rubber-based binder, an imide-based binder, a nitrile-based binder, an acetate-based binder, and a cyano-based binder. In one embodiment, the second binder may be an aqueous binder.

[0081] The above imide binder may be, for example, polyimide or polyamide imide.

[0082] The above nitrile-based binder may be, for example, polyacrylonitrile or an acrylonitrile-styrene-butadiene copolymer.

[0083] The acetate-based binder may be, for example, polyvinylacetate, polyethylene-co-vinyl acetate, cellulose acetate, cellulose acetate butyrate, or cellulose acetate propionate.

[0084] The above cyano-based binder may be, for example, cyanoethyl sucrose.

[0085] The rubber-based binder may be, for example, styrene butadiene rubber (SBR), nitrile butadiene rubber (NBR), hydrogenated nitrile butadiene rubber (HNBR), or ethylene propylene diene monomer rubber (EPDM).

[0086] In one embodiment, the second binder may include a rubber-based binder. For example, the second binder may include at least one rubber-based binder selected from the group consisting of styrene butadiene rubber (SBR), nitrile butadiene rubber (NBR), hydrogenated nitrile butadiene rubber (HNBR), and ethylene propylene diene monomer rubber (EPDM).

[0087] The second binder may be added in an amount of 0.5 to 2 wt% based on the total weight of the third mixture. For example, it may be added in an amount of 0.5 to 1.8 wt% or 0.8 to 1.5 wt%.

[0088] After the addition of the second binder, the sum of the weights of the first binder and the second binder included in the third mixture may be 0.5 wt% to 5 wt% with respect to the total weight of the third mixture. For example, it may be 1 wt% to 5 wt%, 1 wt% to 3 wt%, or 1.5 wt% to 2.0 wt%.

[0089] The weight ratio of the first binder and the second binder included in the third mixture may be 1:1 to 1:3. For example, the weight ratio of the first binder and the second binder may be 1:1.5 to 1:2.5 or 1:1.8 to 1:2.2. In one embodiment, the weight ratio of the CMC binder and the SBR binder included in the third mixture may be 1:2.

[0090]

[0091] The present invention can uniformly disperse constituent materials within a first mixture by performing a kneading process on a first mixture having a predetermined solid content. Thereafter, by reducing the solid content and adding a first binder, a second mixture in which constituent materials within the mixture are more uniformly dispersed can be prepared. In addition, a third mixture having an adjusted concentration can be prepared by further adding a solvent to the second mixture. After the third mixture preparation step (S500), a second binder can be added to the third mixture. The second binder can have excellent adhesive properties. The present invention can prevent the second binder from being destroyed and modified by the kneading process, thereby reducing adhesive properties. Consequently, according to the present invention, an anode slurry for an all-solid-state battery with improved dispersibility, dispersion stability, and adhesive strength can be prepared.

[0092]

[0093] cathode slurry

[0094] An anode slurry for an all-solid-state battery according to one embodiment of the present invention can be manufactured by the anode slurry manufacturing method described above.

[0095] The cathode slurry of the present invention may include the carbon material, metal, first binder, and second binder described above in the cathode slurry manufacturing method.

[0096] The dispersibility of carbon material and metal in the cathode slurry of the present invention is excellent.

[0097] The first binder in the negative electrode slurry of the present invention can be uniformly attached to the carbon material and the metal.

[0098] The cathode slurry of the present invention has excellent dispersion stability and viscosity retention.

[0099] The negative electrode slurry of the present invention has excellent adhesive strength due to the second binder added later.

[0100]

[0101] All-solid-state batteries

[0102] FIG. 4 is a cross-sectional view illustrating an all-solid-state battery according to embodiments of the present invention. Referring to FIG. 4, the all-solid-state battery (10) may include a positive electrode layer (100), a negative electrode layer (200) facing the positive electrode layer (100), and a solid electrolyte layer (300) disposed between the positive electrode layer (100) and the negative electrode layer (200). However, the present invention is not limited thereto, and the all-solid-state battery (10) may further include an additional functional layer, such as an adhesion enhancing layer, disposed between the positive electrode layer (100) and the solid electrolyte layer (300) or between the negative electrode layer (200) and the solid electrolyte layer (300).

[0103] The positive electrode layer (100) may include a positive electrode current collector (110) and a positive electrode active material layer (120) disposed on the positive electrode current collector (110). The positive electrode active material layer (120) may include a positive electrode active material, a solid electrolyte, a conductive material, and a binder.

[0104] The positive electrode current collector (110) can provide a reference surface on which the positive electrode active material layer (120) is arranged. The positive electrode current collector (110) can have a plate or foil shape. For example, the positive electrode current collector (110) can include indium (In), copper (Cu), magnesium (Mg), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), aluminum (Al), germanium (Ge), lithium (Li), or an alloy thereof.

[0105] Unlike the one illustrated in FIG. 4, in one embodiment of the present invention, the positive electrode current collector (110) may be omitted. Although not illustrated, a carbon layer having a thickness of 0.1 μm to 4 μm may be additionally disposed between the positive electrode current collector (110) and the positive electrode active material layer (120) to increase the bonding strength between the positive electrode current collector (110) and the positive electrode active material layer (120).

[0106] The cathode active material may be a material that can reversibly absorb and desorb lithium ions. For example, the cathode active material may include, but is not limited to, lithium transition metal oxides such as lithium cobalt oxide (LCO), lithium nickel oxide, lithium nickel cobalt oxide, lithium nickel cobalt aluminum oxide (NCA), lithium nickel cobalt manganese oxide (NCM), lithium manganate, and lithium iron phosphate, nickel sulfide, copper sulfide, lithium sulfide, iron oxide, or vanadium oxide. The cathode active materials may be used alone or as a mixture of two or more thereof.

[0107] Lithium transition metal oxides include, for example, Li a A 1-b B b D2(0.90≤a≤1, 0≤b≤0.5), Li a E 1-b B b O 2-c D c (0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05), LiE 2-b B b O 4-c D c (0≤b≤0.5, 0≤c≤0.05), Li a Ni 1-b-c Co b B c D α (0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α<2), Li a Ni 1-b-c Co b B c O 2-α F α (0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α<2), Li a Ni 1-b-c Mn b B c D α(0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α≤2), Li a Nor 1-b-c Mn b B c O 2-α F α (0.90≤a≤1, 0≤b≤0.5, 0≤c≤0.05, 0<α<2), Li a Nor b E c G d O2(0.90≤a≤1, 0≤b≤0.9, 0≤c≤0.5, 0.001≤d≤0.1), Li a Nor b Co c Mn d GeO2(0.90≤a≤1, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, 0.001≤e≤0.1), Li a NiG b O2(0.9≤a≤1, 0.001≤b≤0.1), Li a CoG b O2(0.90≤a≤1, 0.001≤b≤0.1), Li a MnG b O2(0.90≤a≤1, 0.001≤b≤0.1), Li a Mn2GbO4(0.90≤a≤1, 0.001≤b≤0.1), QO2, QS2, LiQS2, V2O5, LiV2O5, LiIO2, LiNiVO4, Li 3-f J2(PO4)3(0≤f≤2), Li 3-fIt may be a compound represented by any one of Fe2(PO4)3(0≤f≤2), LiFePO4. In these compounds, the capital letter “A” is Ni, Co, Mn, or a combination thereof, the capital letter “B” is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element, or a combination thereof, the capital letter “D” is O, F, S, P, or a combination thereof, the capital letter “E” is Co, Mn, or a combination thereof, the capital letter “F” is F, S, P, or a combination thereof, the capital letter “G” is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof, the capital letter “Q” is Ti, Mo, Mn, or a combination thereof, the capital letter “I” is Cr, V, Fe, Sc, Y, or a combination thereof, and the capital letter “J” is V, Cr, Mn, Co, Ni, Cu, or a combination thereof.

[0108] The cathode active material may include, for example, a lithium salt of a transition metal oxide having a layered rock salt type structure among the lithium transition metal oxides described above. The "layered rock salt type structure" is, for example, a cubic rock salt type structure. <111> It is a structure in which oxygen atomic layers and metal atomic layers are alternately and regularly arranged in a direction, and thereby each atomic layer forms a two-dimensional plane. The "cubic rock salt structure" refers to the sodium chloride type (NaCl type) structure, which is a type of crystal structure, and specifically refers to a structure in which the face-centered cubic lattice (fcc) formed by each cation and anion is arranged with a displacement of half of the ridge of the unit lattice. Lithium transition metal oxides having this layered rock salt structure include, for example, LiNi x Co y Al z O2(NCA) or LiNi x Co y Mnz O2(NCM) (0 <x<1,0<y<1, 0<z<1, x+y+z=1) 등의 삼원계 리튬전이금속산화물일 수 있다. 양극 활물질이 층상암염형 구조를 갖는 삼원계 리튬전이금속산화물을 포함하는 경우, 전고체 전지(10)의 에너지 밀도가 커지고 열안정성이 향상될 수 있다.

[0109] The above-described compound included in the positive electrode active material may be covered by a coating layer (not shown). The positive electrode active material may also be a mixture of the above-described compound and a compound to which a coating layer is added. Meanwhile, the coating layer added to the surface of the positive electrode active material may include, for example, an oxide, a hydroxide, an oxyhydroxide, an oxycarbonate, or a hydroxycarbonate of the coating elements below. The compound forming the coating layer may be amorphous or crystalline. The coating elements included in the coating layer may include Mg, Al, Co, K, Na, Ca, Si, Ti, V, Sn, Ge, Ga, B, As, Zr, or mixtures thereof. The coating layer may include, for example, Li2O-ZrO2 (LZO). The method for forming the coating layer may be selected within a range that does not adversely affect the physical properties of the positive electrode active material. The method for forming the coating layer may include, for example, a spray coating method or an immersion method.

[0110] When the positive electrode active material includes nickel (Ni) as a ternary lithium transition metal oxide such as NCA or NCM, for example, the capacity density of the all-solid-state battery (10) can be increased, and metal dissolution of the positive electrode active material in a charged state can be reduced. As a result, the cycle characteristics of the all-solid-state battery (10) in a charged state can be improved. Meanwhile, the “cycle characteristics” are characteristics indicating the degree to which the all-solid-state battery (10) is deteriorated due to charge / discharge of the all-solid-state battery (10). An all-solid-state battery (10) with high cycle characteristics can have a small degree of deterioration of the all-solid-state battery (10) due to charge / discharge, and an all-solid-state battery (10) with low cycle characteristics can have a large degree of deterioration of the all-solid-state battery (10) due to charge / discharge.

[0111] The shape of the positive electrode active material may include particle shapes such as a sphere or an ellipsoid, for example. The particle size and content of the positive electrode active material are not particularly limited.

[0112] The solid electrolyte may include a sulfide-based solid electrolyte having excellent lithium ion conductivity characteristics. Examples of the sulfide-based solid electrolyte include Li2S-P2S5, Li2S-P2S5-LiX (X is a halogen element), Li2S-P2S5-Li2O, Li2S-P2S5-Li2O-LiI, Li2S-SiS2, Li2S-SiS2-LiI, Li2S-SiS2-LiBr, Li2S-SiS2-LiCl, Li2S-SiS2-B2S3-LiI, Li2S-SiS2-P2S5-LiI, Li2S-B2S3, Li2S-P2S5-Z. m S n (m, n are positive numbers, capital letter “Z” represents Ge, Zn or Ga), Li2S-GeS2, Li2S-SiS2-Li3PO4, Li2S-SiS2-Li p MO q (p, q are positive numbers, capital letter “M” is one of P, Si, Ge, B, Al, Ga In), Li 7-x PS 6-x Cl x(0≤x≤2), Li 7-x PS 6-x Br x (0≤x≤2), and Li 7-x PS 6-x I x It may include at least one selected from (0≤x≤2).

[0113] Sulfide-based solid electrolytes include, for example, Li 7-x PS 6-x Cl x (0≤x≤2), Li 7-x PS 6-x Br x (0≤x≤2), and Li 7-x PS 6-x I x It may be an argyrodite-type compound including at least one selected from (0≤x≤2). In particular, the sulfide-based solid electrolyte may be an argyrodite-type compound including at least one selected from Li6PS5Cl, Li6PS5Br, and Li6PS5I.

[0114] Alternatively, the sulfide-based solid electrolyte is Li 7-a M a PS 6-c X cIt may be an argyrodite-type compound containing X, wherein X may be F, Br, Cl, or a combination thereof. M is candium (Sc), yttrium (Y), titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten (W), manganese (Mn), technetium (Tc), rhenium (Re), iron (Fe), ruthenium (Ru), osmium (Os), cobalt (Co), rhodium (Rh), iridium (Ir), nickel (Ni), palladium (Pd), platinum (Pt), copper (Cu), silver (Ag), gold (Au), zinc (Zn), cadmium (Cd), mercury (Hg), aluminum (Al), gallium (Ga), indium (In), thallium (Tl), silicon (Si), germanium (Ge), tin (Sn), lead (Pb), arsenic (As), antimony (Sb), bismuth (Bi), or a combination thereof. Can be.

[0115] The density of the argyrodite-type solid electrolyte may be 1.5 g / cc to 2.0 g / cc. Since the argyrodite-type solid electrolyte has a density of 1.5 g / cc or more, the internal resistance of the all-solid-state battery is reduced, and the defect of the solid electrolyte membrane being penetrated and short-circuited due to the formation of lithium dendrites can be prevented. The elastic modulus of the solid electrolyte may be, for example, 15 GPa to 35 GPa.

[0116] The solid electrolyte included in the positive electrode active material layer (120) may have a smaller median particle size (D50) than the solid electrolyte included in the solid electrolyte layer (300). For example, the median particle size (D50) of the solid electrolyte included in the positive electrode active material layer (120) may be 90% or less, 80% or less, 70% or less, 60% or less, 50% or less, 40% or less, 30% or less, or 20% or less of the median particle size (D50) of the solid electrolyte included in the solid electrolyte layer (300). Meanwhile, the median particle size (D50) may be a median diameter measured using a laser particle size distribution meter.

[0117] The positive electrode active material layer (120) may include a conductive material. The conductive material may have conductivity without causing a chemical change in the all-solid-state battery (10), thereby increasing the conductivity of the positive electrode active material and the solid electrolyte. The conductive material may include a carbon-based material. The conductive material may include, for example, one or more selected from graphite, carbon black, acetylene black, carbon nanofibers, and carbon nanotubes.

[0118] The positive electrode active material layer (120) may further include a binder. The binder may include a material for binding the positive electrode active material, solid electrolyte, and conductive material included in the positive electrode active material layer (120) and improving bonding strength with the positive electrode current collector (110). For example, the binder may include polyvinylidene fluoride, styrene butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, vinylidene fluoride / hexafluoropropylene copolymer, polyacrylonitrile, or polymethyl methacrylate.

[0119] When the total amount of the positive electrode active material, the solid electrolyte, the conductive material, and the binder is 100 parts by weight, the positive electrode active material layer (120) may include 85 parts by weight to 92 parts by weight of the positive electrode active material. The positive electrode active material layer (120) may include 0.5 parts by weight to 1.5 parts by weight of the binder.

[0120] Within the positive electrode active material layer (120), the conductive material may be present in an amount of 1 to 50 parts by weight relative to 100 parts by weight of the solid electrolyte. If the conductive material is present in an amount less than 1 part by weight relative to 100 parts by weight of the solid electrolyte, the electrical conductivity of the positive electrode active material layer (120) may be reduced. If the conductive material is present in an amount greater than 50 parts by weight relative to 100 parts by weight of the solid electrolyte, the conductive material ratio may be excessively high, and thus a covering layer covering the surface of the solid electrolyte may not be properly formed.

[0121] According to embodiments, the positive electrode active material layer (120) may further include at least one additive selected from the group consisting of a filler, a coating agent, a dispersant, and an ion conductive auxiliary agent in addition to the above-described positive electrode active material, solid electrolyte, conductive agent, and binder.

[0122] The solid electrolyte layer (300) is disposed between the positive electrode layer (100) and the negative electrode layer (200) and may include a sulfide-based solid electrolyte having excellent lithium ion conductivity characteristics. The solid electrolyte included in the solid electrolyte layer (300) may be the same as or different from any one of the materials that may be included in the solid electrolyte included in the positive electrode active material layer (120) described above.

[0123] The solid electrolyte layer (300) of one embodiment may include a sulfide-based solid electrolyte. The sulfide-based solid electrolyte may be manufactured by treating starting materials such as Li2S and P2S5 by a melting rapid cooling method or a mechanical milling method. In addition, a heat treatment may be performed after the treatment. The solid electrolyte may be amorphous, crystalline, or a mixture thereof. In addition, the solid electrolyte may include, for example, at least sulfur (S), phosphorus (P), and lithium (Li) as constituent elements among the above-described sulfide-based solid electrolyte materials. For example, the solid electrolyte may be a material including Li2S-P2S5. When using a sulfide-based solid electrolyte material including Li2S-P2S5 to form the solid electrolyte, the mixing molar ratio of Li2S and P2S5 is, for example, in the range of Li2S:P2S5=50:50 to 90:10.

[0124] Sulfide-based solid electrolytes include, for example, Li 7-x PS 6-x Cl x (0≤x≤2), Li 7-x PS 6-x Br x (0≤x≤2), and Li 7-x PS 6-x I x It may be an argyrodite-type compound including at least one selected from (0≤x≤2). In particular, the sulfide-based solid electrolyte may be an argyrodite-type compound including at least one selected from Li6PS5Cl, Li6PS5Br, and Li6PS5I.

[0125] Alternatively, the sulfide-based solid electrolyte is Li 7-a M a PS 6-c X cIt may be an argyrodite-type compound containing X, wherein X may be F, Br, Cl, or a combination thereof. M is candium (Sc), yttrium (Y), titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten (W), manganese (Mn), technetium (Tc), rhenium (Re), iron (Fe), ruthenium (Ru), osmium (Os), cobalt (Co), rhodium (Rh), iridium (Ir), nickel (Ni), palladium (Pd), platinum (Pt), copper (Cu), silver (Ag), gold (Au), zinc (Zn), cadmium (Cd), mercury (Hg), aluminum (Al), gallium (Ga), indium (In), thallium (Tl), silicon (Si), germanium (Ge), tin (Sn), lead (Pb), arsenic (As), antimony (Sb), bismuth (Bi), or a combination thereof. Can be.

[0126] The density of the argyrodite-type solid electrolyte may be 1.5 g / cc to 2.0 g / cc. When the argyrodite-type solid electrolyte has a density of 1.5 g / cc or more, the internal resistance of the all-solid-state battery is reduced, and the defect of the solid electrolyte membrane being penetrated and short-circuited due to the formation of lithium dendrites can be prevented. The elastic modulus of the solid electrolyte is, for example, 15 GPa to 35 GPa.

[0127] The solid electrolyte layer (300) may further include a binder. The binder in the solid electrolyte layer (300) may be, for example, styrene butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, etc., but is not limited thereto. The binder of the solid electrolyte layer (300) may be the same as or different from the binder included in the positive electrode active material layer (120) or the binder included in the negative electrode coating layer (220).

[0128] The negative electrode layer (200) may include a negative electrode current collector (210) and a negative electrode coating layer (220) on the negative electrode current collector (210). The negative electrode current collector (210) may provide a reference surface on which the negative electrode coating layer (220) is disposed. The negative electrode current collector (210) may include, for example, a material that does not react with lithium, i.e., does not form an alloy or a compound with lithium. For example, the negative electrode current collector (210) may include at least one metal selected from the group consisting of copper (Cu), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), and nickel (Ni). The thickness of the negative electrode current collector (210) may be 1 μm to 20 μm, more specifically 5 μm to 15 μm, and more specifically 7 μm to 10 μm.

[0129] The negative electrode current collector (210) may be composed of one of the above-described metals, or may include an alloy or coating material of two or more metals. The negative electrode current collector (210) may have, for example, a plate shape or a foil shape. Meanwhile, in one embodiment, the negative electrode current collector (210) may be omitted.

[0130] The negative electrode coating layer (220) can allow lithium metal to grow between it and the negative electrode current collector (210) when the all-solid-state battery (10) is charged. The negative electrode coating layer (220) can act as a protective layer for the lithium metal and simultaneously suppress the precipitation and growth of lithium dendrites.

[0131] The cathode coating layer (220) may include a metal and carbon. For example, the cathode coating layer (220) may include at least one metal selected from the group consisting of gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), and zinc (Zn). The cathode coating layer (220) may include at least one carbon selected from the group consisting of carbon black, acetylene black, furnace black, ketjen black, and graphene.

[0132] The cathode coating layer (220) may further include additives other than metal and carbon. The cathode coating layer (220) may further include, for example, at least one additive selected from the group consisting of a binder, a filler, a coating agent, a dispersant, and an ion conductive additive.

[0133] The negative electrode coating layer (220) may have a smaller thickness than the positive electrode active material layer (120). The thickness of the negative electrode coating layer (220) may be, for example, 50% or less, 40% or less, 30% or less, 20% or less, 10% or less, or 5% or less of the thickness of the positive electrode active material layer (120). The thickness of the negative electrode coating layer (220) may be, for example, 1 um to 20 um, 2 um to 10 um, or 3 um to 7 um. If the thickness of the negative electrode coating layer (220) is too thin, lithium dendrites formed between the negative electrode coating layer (220) and the negative electrode current collector (210) may cause the negative electrode coating layer (220) to collapse, thereby deteriorating the cycle characteristics of the all-solid-state battery (10). If the thickness of the cathode coating layer (220) increases excessively, the energy density of the all-solid-state battery (10) may decrease and the internal resistance of the all-solid-state battery (10) due to the cathode coating layer (220) may increase, thereby deteriorating the cycle characteristics of the all-solid-state battery (10).

[0134] Meanwhile, although not shown, a carbon layer may be further included to improve adhesion between the cathode coating layer (220) and the solid electrolyte layer (300).

[0135] The negative electrode layer (200) of the all-solid-state battery according to the present embodiment can be manufactured using the above-described negative electrode slurry. The negative electrode layer (200) can be manufactured using a conventional technique for manufacturing an electrode, and is not particularly limited. Specifically, the above-described negative electrode slurry can be applied and dried on a negative electrode current collector (210) using a doctor blade, spray, bar coating, slot die coating, or the like, and then pressed to manufacture an electrode. An negative electrode coating layer (220) can be formed from the negative electrode slurry.

[0136]

[0137] While embodiments of the present invention have been described with reference to the attached drawings, the present invention may be implemented in other specific forms without altering the technical spirit or essential features thereof. Therefore, it should be understood that the embodiments described above are exemplary in all respects and are not limiting.

[0138]

[0139] Example 1

[0140] 1) Preparation of binder solution: Water and carboxymethyl cellulose (CMC) binder were mixed to prepare a binder solution (hereinafter referred to as “1.3 wt% CMC”) having a CMC binder content of 1.3 wt% and a viscosity of 2000 cps.

[0141] 2) Preparation of the first mixture: Specific surface area (BET) of 50 m 2 / g of carbon black and silver (Ag) having an average particle diameter (D50) of 60 nm were mixed in a weight ratio of 3:1, and a total of 1.3 wt% CMC solution was further mixed to prepare a first mixture having a solid content of 45.61 wt% and a viscosity of 2000 cps.

[0142] 3) Kneading: The first mixture was placed in a PD mixer and kneading was performed. The specific method is described in Table 1.

[0143] 4) Preparation of a second mixture: A 1.3 wt% CMC solution was added to the kneaded first mixture to prepare a second mixture having a solids content of 31.14 wt%. The specific method is described in Table 2.

[0144] 5) Preparation of the third mixture: Water was added to the second mixture to prepare a third mixture having a solid content of 20.55 wt%.

[0145] 6) Second binder mixing: An SBR solution containing 60 wt% of water and 40 wt% of SBR binder was mixed with the third mixture and then defoamed to prepare a cathode slurry having a solid content of 21.11 wt%.

[0146]

[0147] Example 2

[0148] 1) Preparation of binder solution: Water and carboxymethyl cellulose (CMC) binder were mixed to prepare a binder solution (hereinafter referred to as “1.0 wt% CMC”) having a CMC binder content of 1.0 wt% and a viscosity of 1000 cps.

[0149] 2) Preparation of the first mixture: Specific surface area (BET) of 50 m 2 / g of carbon black and silver (Ag) having an average particle diameter (D50) of 60 nm were mixed in a weight ratio of 3:1, and a 1.0 wt% CMC solution was further mixed to prepare a first mixture having a solid content of 43.50 wt%.

[0150] 3) Kneading: The first mixture was placed in a PD mixer and kneading was performed. The specific method is described in Table 1.

[0151] 4) Preparation of a second mixture: A 1.0 wt% CMC solution was additionally mixed into the kneaded first mixture to prepare a second mixture having a solid content of 25.75 wt%. The specific method is described in Table 2.

[0152] 5) Preparation of the third mixture: Water was added to the second mixture to prepare a third mixture having a solid content of 20.51 wt%.

[0153] 6) Second binder mixing: An SBR solution containing 60 wt% of water and 40 wt% of SBR binder was mixed with the third mixture and then defoamed to prepare a cathode slurry having a solid content of 21.07 wt%.

[0154]

[0155] Comparative Example 1

[0156] 1) Preparation of binder solution: A binder solution (1.0 wt% CMC) having a CMC binder content of 1.0 wt% and a viscosity of 1000 cps was prepared using the same method as in Example 2.

[0157] 2) Preparation of the first mixture: Specific surface area (BET) of 50 m 2 / g of carbon black and silver (Ag) having an average particle diameter (D50) of 60 nm were mixed in a weight ratio of 3:1, and a 1.0 wt% CMC solution was further mixed to prepare a first mixture having a solid content of 41.15 wt%.

[0158] 3) Preparation of a second mixture: 1.0 wt% CMC was added to the first mixture to prepare a second mixture having a solid content of 25.75 wt%. The detailed process is described in Table 2.

[0159] 4) Preparation of the third mixture: Water was added to the second mixture to prepare a third mixture having a solid content of 20.51 wt%.

[0160] 5) Second binder mixing: An SBR solution containing 60 wt% of water and 40 wt% of SBR binder was mixed with the third mixture and then defoamed to prepare a cathode slurry having a solid content of 21.07 wt%.

[0161]

[0162] In Table 1 below, the step of kneading the first mixture in each example is specifically described.

[0163] Classification Solid content (weight %) PD Mixer Rotation speed (rpm) Instantaneous peak energy consumption rate (W / g) Mixing time (min) PD Example 145.617510002.2W / g60 Example 243.507510002.1W / g55P: Rotation speed of planetary blades D: Rotation speed of high-speed dispersion blades Instantaneous peak energy consumption rate: The magnitude of the instantaneous peak power applied to the PD mixer (Watt) ÷ Total weight of the first mixture (gram)

[0164] In Table 2 below, the steps for preparing the second mixture in each example and comparative example are specifically described.

[0165]

[0166] Classification stepBinder solutionMixing orderAddition amountSolid content after mixing (weight %)PDMixer rotation speed (rpm)Instantaneous maximum energy consumption rate (W / g)Mixing time (min)PDExample 1Second mixture production1st time1.3wt% CMC75.0g37.347517501W / g302nd time1.3wt% CMC83.5g31.147517500.8W / g30Example 2Second mixture production1st time1wt% CMC80.0g35.437517500.9W / g302nd time1wt% CMC80.0g29.947517500.7W / g303rd time1wt% CMC85.0g25.757517500.5W / g30Comparative example 1. Second mixture manufacturing 1st time 1 wt% CMC 20.0g 39.04 75 1750 1.1 W / g 20 2nd time 1 wt% CMC 20.0g 37.15 75 1750 1 W / g 20 3rd time 1 wt% CMC 20.0g 35.43 75 1750 0.9 W / g 20 4th time 1 wt% CMC 20.0g 32.45 75 1750 0.8 W / g 20 5th time 1 wt% CMC 125.0g 25.75 75 1750 0.5 W / g 20 P: Rotation speed of planetary blade D: Rotation speed of high-speed dispersion blade Instantaneous peak energy consumption rate: Size of instantaneous peak power applied to PD mixer (Watt) ÷ Total weight of first mixture (gram)

[0167] Evaluation Example 1: Viscosity change rate The viscosity change rate of the cathode slurry according to each example and comparative example was analyzed.

[0168] Immediately after preparing the negative electrode slurry of Example 1, Example 2 and Comparative Example 1, after 1 day of stirring, after 3 days of stirring and after 1 day of no stirring, at room temperature (25°C, shear rate 10 s -1 The viscosity was measured, and the viscosity change rate was analyzed by dividing each viscosity value by the viscosity immediately after manufacturing. For example, the viscosity change rate after 1 day of stirring was calculated as “Viscosity after 1 day of stirring ÷ Viscosity immediately after manufacturing” (%). The results are shown in Table 3.

[0169] Ball mill stirring (150 rpm) was performed as the stirring method, and in the case of no stirring, the slurry was prepared and left at room temperature.

[0170] As shown in Table 3, it can be confirmed that the viscosity maintenance effect of the slurries according to Examples 1 and 2 is excellent.

[0171] Viscosity (cps) Viscosity change rate (%) After mixing, stirring for 1 day After mixing for 3 days After no mixing for 1 day After mixing for 1 day After mixing for 3 days After no mixing for 1 day After Example 115351536151024960.1-3.162.6 Example 22045172516795219-15.6-17.9155.2 Comparative example 12629186814885238-28.9-42.699.2

[0172] Evaluation Example 2: The particle size distribution of the cathode slurry according to the particle size analysis example and comparative example was measured using a particle size analyzer, and the results are shown in Table 4.

[0173] D10 represents the particle size at 10% of the volume from the largest particle size based on the total volume of the particle size analysis graph, D50 represents the particle size at 50% of the volume from the largest particle size based on the total volume of the graph, and D90 represents the particle size at 90% of the volume from the largest particle size based on the total volume of the graph. In other words, when the graph is divided into 10 equal parts based on the cumulative distribution of particle sizes, the sizes of the particles corresponding to the positions of 1 / 10, 5 / 10, and 9 / 10 are indicated.

[0174] Through this, it can be confirmed that the cathode slurry according to the embodiment of the present invention has superior dispersibility compared to the comparative example.

[0175] D10(μm)D50(μm)D90(μm)Example 10.01880.3192.6Example 20.02230.4383.3Comparative example 10.03210.8285.4

Claims

1. A step of mixing a cathode material and a binder solution to prepare a first mixture having a solid content of 30 wt% to 50 wt%; A step of kneading the first mixture; A step of adding the binder solution to the first mixture to prepare a second mixture having a solid content of 25 wt% to 35 wt%; and A step of preparing a third mixture by adding a solvent to the second mixture, The above binder solution comprises water and a first binder, A method for producing a negative electrode slurry for an all-solid-state battery, wherein the above kneading is performed by applying an instantaneous maximum power load of 1.5 W to 3 W per 1 g of the first mixture to a kneader.

2. In the first paragraph, the cathode material includes a metal and a carbon material, and the carbon material has a specific surface area (BET) of 30 m 2 / g to 60 m 2 / g, a method for producing a negative electrode slurry for an all-solid-state battery.

3. A method for producing a negative electrode slurry for an all-solid-state battery, wherein the first binder comprises at least one selected from the group consisting of an acrylate-based binder, a polyvinylidene fluoride-based binder, a polyvinylpyrrolidone-based binder, a polyvinyl alcohol-based binder, and a cellulose-based binder.

4. A method for producing a negative electrode slurry for an all-solid-state battery, wherein the viscosity of the binder solution in the first paragraph is 500 cps to 3000 cps.

5. A method for producing a negative electrode slurry for an all-solid-state battery, wherein in the first paragraph, the kneading is performed by at least one selected from the group consisting of a paddle mixer, a ribbon mixer, a planetary mixer, a dual shaft mixer mixer, a high-speed impeller mixer, a propeller mixer, and a PD mixer (planetary disperser mixer).

6. A method for producing a negative electrode slurry for an all-solid-state battery, wherein the kneading is performed for 30 to 120 minutes in the first paragraph.

7. A method for producing a negative electrode slurry for an all-solid-state battery, wherein the metal in the first paragraph is at least one selected from the group consisting of gold (Au), indium (In), germanium (Ge), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), and zinc (Zn).

8. A method for producing a negative electrode slurry for an all-solid-state battery, wherein the carbon material is at least one selected from the group consisting of carbon black, acetylene black, furnace black, ketjen black, and graphene.

9. A method for producing a negative electrode slurry for an all-solid-state battery, wherein the weight ratio of the metal and the carbon material in the first paragraph is 1:2 to 20.

10. In the first paragraph, the step of preparing the second mixture comprises: A method for producing a negative electrode slurry for an all-solid-state battery, comprising stirring while adding the binder solution to the first mixture.

11. A method for producing a negative electrode slurry for an all-solid-state battery, wherein the solid content in the third mixture in the first paragraph is 15 wt% to 25 wt%.

12. A method for producing a negative electrode slurry for an all-solid-state battery, further comprising the step of adding a second binder to the third mixture in the first paragraph.

13. A method for producing a negative electrode slurry for an all-solid-state battery, wherein the second binder is added in an amount of 0.5 wt% to 2 wt% based on the total weight of the third mixture in the 12th paragraph.

14. A method for producing a negative electrode slurry for an all-solid-state battery, wherein the second binder comprises at least one selected from the group consisting of a rubber-based binder, an imide-based binder, a nitrile-based binder, an acetate-based binder, and a cyano-based binder.

15. A step of mixing a cathode material and a binder solution to prepare a first mixture having a solid content of 30 wt% to 50 wt%; A step of kneading the first mixture; A step of adding the binder solution to the first mixture to prepare a second mixture having a solid content of 25 wt% to 35 wt%; and A step of preparing a third mixture by adding a solvent to the second mixture, The above binder solution comprises a solvent and a first binder, A method for manufacturing a negative electrode for an all-solid-state battery, wherein the above kneading is performed by applying an instantaneous maximum power load of 1.5 W to 3 W per 1 g of the first mixture to a kneader.

16. In the 15th paragraph, the cathode material includes a metal and a carbon material, and the carbon material has a specific surface area (BET) of 30 m 2 / g to 60 m 2 / g, a method for manufacturing a negative electrode for an all-solid-state battery.

17. A method for manufacturing a negative electrode for an all-solid-state battery, wherein the viscosity of the binder solution in the 15th paragraph is 500 cps to 3000 cps.

18. In the 16th paragraph, the metal is at least one selected from the group consisting of gold (Au), indium (In), germanium (Ge), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), tin (Sn), and zinc (Zn). A method for manufacturing an anode for an all-solid-state battery, wherein the carbon material is at least one selected from the group consisting of carbon black, acetylene black, furnace black, ketjen black, and graphene.

19. A method for manufacturing a negative electrode for an all-solid-state battery, wherein the kneading is performed by at least one kneader selected from the group consisting of a paddle mixer, a ribbon mixer, a planetary mixer, a dual shaft mixer mixer, a high-speed impeller mixer, a propeller mixer, and a PD mixer (planetary disperser mixer) in the 15th paragraph.

20. A negative electrode slurry for an all-solid-state battery manufactured by the method according to claim 1.

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