Solid electrolyte slurry and preparation method therefor

Abstract

The present invention relates to a solid electrolyte slurry and a preparation method therefor, and, more specifically, the method comprises: preparing a slurry mixture by mixing a solid electrolyte, a binder and a solvent; performing primary kneading on the slurry mixture in which the solid amount has adjusted to 65-80 wt%; injecting a solvent into the slurry mixture in which the primary kneading has been completed; and performing secondary kneading on the slurry mixture in which the solid amount has been adjusted to 55-65 wt%.

Description

Solid electrolyte slurry and method for producing the same

[0001] The present invention relates to a solid electrolyte slurry, a method for producing the same, a solid electrolyte layer produced thereby, and an all-solid-state battery.

[0002]

[0003] 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.

[0004] 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.

[0005]

[0006] The problem to be solved by the present invention is to provide a solid electrolyte slurry having improved dispersion characteristics of a solid electrolyte and a binder.

[0007] Another problem to be solved by the present invention is to provide a method for producing a solid electrolyte slurry having improved dispersion characteristics of a solid electrolyte and a binder.

[0008]

[0009] According to the concept of the present invention, a method for producing a solid electrolyte slurry may include: producing a slurry mixture by mixing a solid electrolyte, a binder, and a solvent; performing a first kneading process on the slurry mixture having a solid content adjusted to 65 wt% to 80 wt%; adding a solvent to the slurry mixture having completed the first kneading process; and performing a second kneading process on the slurry mixture having a solid content adjusted to 55 wt% to 65 wt%.

[0010] According to another concept of the present invention, a method for producing a solid electrolyte slurry may include: producing a slurry mixture by mixing a solid electrolyte, a binder, and a solvent; performing a first kneading process on the slurry mixture having a solid content adjusted to 65 wt% to 80 wt%; introducing a solvent into the slurry mixture having completed the first kneading process to reduce the solid content; and performing a second kneading process on the slurry mixture having reduced the solid content. The first kneading process may be performed at 25°C to 60°C for 10 to 70 minutes. Alternatively, the first kneading process may be performed for 30 to 70 minutes.

[0011] According to another concept of the present invention, a solid electrolyte slurry may include a solid electrolyte, a binder, and a solvent. The solid electrolyte slurry may have a viscosity of 200 mPa·s to 2,000 mPa·s at a shear rate of 10 (1 / s) as measured by shear viscosity measurement.

[0012]

[0013] The present invention can improve the dispersibility and viscosity of a solid electrolyte slurry by performing a primary kneading process at a relatively high solid content and high temperature. The present invention can produce an economical slurry with excellent physical properties by optimizing the primary kneading process without additional processes. The solid electrolyte slurry according to the present invention can have a low viscosity relative to a specific solid content. The solid electrolyte slurry of the present invention can have excellent phase stability. The solid electrolyte slurry of the present invention can have excellent adhesiveness when coated on an electrode.

[0014]

[0015] FIG. 1a is a flowchart showing a method for manufacturing a solid electrolyte slurry according to embodiments of the present invention.

[0016] Figure 1b is a flowchart showing a method for manufacturing a solid electrolyte slurry according to another embodiment of the present invention.

[0017] FIG. 2a and FIG. 2b are schematic diagrams each illustrating a method for forming a solid electrolyte layer using a solid electrolyte slurry according to embodiments of the present invention.

[0018] FIG. 3a is an enlarged cross-sectional view of area M of FIG. 2a for explaining a solid electrolyte slurry according to one embodiment of the present invention.

[0019] Figure 3b is an enlarged view illustrating a solid electrolyte slurry according to a comparative example of the present invention.

[0020] FIG. 4 is a cross-sectional view illustrating an all-solid-state battery according to embodiments of the present invention.

[0021] Figure 5 shows the results of measuring the shear viscosity of the slurry of Example 1 and the slurry of Comparative Example 1.

[0022] Figure 6a shows the results of comparing the shear viscosity of the slurry of Example 1 before and after being left to stand.

[0023] Figure 6b shows the results of comparing the shear viscosity of the slurry of Comparative Example 1 before and after being left to stand.

[0024] Figure 7a is a photograph showing the results of the FOG gauge evaluation of the slurry of Example 1.

[0025] Figure 7b is a photograph showing the FOG gauge evaluation results of the slurry of Comparative Example 1.

[0026] Figure 8a shows the TOF-SIMS analysis results for the slurry of Example 1.

[0027] Figure 8b shows the TOF-SIMS analysis results for the slurry of Comparative Example 1.

[0028] Figure 9 shows the results of evaluating the adhesive strength of the slurry of Example 1 and the slurry of Comparative Example 1.

[0029]

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] The present invention relates to a method for producing an anode slurry for an all-solid-state battery having an effect of improving dispersibility and stability, a cathode slurry produced thereby, and an electrode for an all-solid-state battery produced by applying the anode slurry.

[0035]

[0036] Method for preparing solid electrolyte slurry

[0037] FIG. 1A is a flowchart illustrating a method for preparing a solid electrolyte slurry according to embodiments of the present invention. Referring to FIG. 1A, a method for preparing a solid electrolyte slurry according to an embodiment of the present invention may include a step (S10) of preparing a slurry mixture by mixing a solid electrolyte, a binder, and a solvent, a step (S22) of performing a first kneading process on the slurry mixture, a step (S23) of performing a second kneading process on the slurry mixture, and a step (S30) of performing a defoaming process on the slurry mixture.

[0038] A slurry mixture can be prepared by placing a solid electrolyte, a binder, and a solvent into a container and mixing them (S10). The solid electrolyte may be a powder-type solid electrolyte. According to one embodiment, the solid electrolyte may include a sulfide-based solid electrolyte with excellent lithium ion conductivity characteristics.

[0039] A sulfide-based solid electrolyte can be manufactured by treating starting materials such as Li2S and P2S5 by a melting rapid cooling method or a mechanical milling method, for example. In addition, a heat treatment can be performed after the treatment. The solid electrolyte can be amorphous, crystalline, or a mixture thereof. In addition, the solid electrolyte can be, for example, a material containing sulfur (S), phosphorus (P), and lithium (Li) as constituent elements among the above-described sulfide-based solid electrolyte materials. For example, the solid electrolyte can be a material containing Li2S-P2S5. When using a sulfide-based solid electrolyte material containing Li2S-P2S5 to form a solid electrolyte, the mixing molar ratio of Li2S and P2S5 is, for example, in the range of Li2S:P2S5=50:50 to 90:10.

[0040] Sulfide-based solid electrolytes include, for example, 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 xIt may include at least one selected from (0≤x≤2).

[0041] 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 (0≤x≤2) may be an argyrodite-type compound including at least one selected from Li6PS5Cl, Li6PS5Br, and Li6PS5I. In particular, the sulfide-based solid electrolyte may be an argyrodite-type compound including at least one selected from Li6PS5Cl, Li6PS5Br, and Li6PS5I. Alternatively, the sulfide-based solid electrolyte may be Li 7-a M a PS 6-c X c It may be an argyrodite-type compound containing (0≤a≤2, (0≤c≤2)), where 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.

[0042] The binder may include at least one selected from the group consisting of a cellulose polymer, a rubber binder, an acrylate binder, an imide binder, a polyvinylidene fluoride binder, a polyvinylpyrrolidone binder, a nitrile binder, an acetate binder, and a cyano binder.

[0043] The cellulose-based polymer may include at least one selected from the group consisting of, for example, 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.

[0044] The above acrylate compound may be, for example, polyacrylic acid (PAA), polymethylmethacrylate, polyisobutylmethacrylate, polyethylacrylate, polybutyl acrylate, or polyethylhexyl acrylate (poly(2-ethylhexyl acrylate)).

[0045] The above imide compound may be, for example, polyimide or polyamide imide.

[0046] The polyvinylidene fluoride compound may be, for example, polyvinylidene fluoride-co-hexafluoropropylene, polyvinylidene fluoride-co-trichloroethylene, polyvinylidene fluoride-co-tetrafluoroethylene, polyvinylidene fluoride-co-trifluoroethylene, polyvinylidene fluoride-co-trifluorochloroethylene, polyvinylidene fluoride-co-hexafluoropropylene (PVdF) or polyvinylidene fluoride-co-trichloroethylene.

[0047] The above polyvinylpyrrolidone compound may be, for example, polyvinylpyrrolidone.

[0048] The nitrile compound may be, for example, polyacrylonitrile or an acrylonitrile-styrene-butadiene copolymer.

[0049] The acetate compound may be, for example, polyvinylacetate, polyethylene-co-vinyl acetate, cellulose acetate, cellulose acetate butyrate, or cellulose acetate propionate.

[0050] The above cyano compound may be, for example, cyanoethyl sucrose.

[0051] In one embodiment of the present invention, the binder may include at least one of carboxymethyl cellulose (CMC), styrene butadiene rubber (SBR), and nitrile butadiene rubber (NBR).

[0052] The binder may be added so that the binder content in the slurry mixture is 1 wt% to 10 wt%. If the binder content is below the above range, the binder dispersion effect may be reduced in the kneading process described below. If the binder content exceeds the above range, the slurry phase stability may be reduced due to binder agglomeration.

[0053] For example, the solvent may include at least one selected from the group consisting of water, methanol, ethanol, ethylene glycol, diethylene glycol, glycerol, isobutyryl isobutyrate, xylene, toluene, benzene, and hexane. The solvent may include an aqueous solvent. The type of the aqueous solvent may not be limited. In one embodiment, the solvent may be water.

[0054] The solids content of the slurry mixture can be controlled by using a solvent. The solids content of the slurry mixture according to the present embodiment can be controlled to be between 65 wt% and 80 wt%. The slurry mixture according to the present embodiment can be prepared to have a relatively high solids content.

[0055] A mixing process can be performed on the slurry mixture (S20). The mixing process can be performed using a mixer or a kneader. In one embodiment of the present invention, the mixing process can be performed using a PD mixer (Planetary Disperser mixer), a planetary mixer, a paddle mixer, a ribbon mixer, a dual shaft mixer mixer, a high-speed impeller mixer, or a propeller mixer.

[0056] The mixing process (S20) may include a first kneading process (S22) and a second kneading process (S23). The first kneading process (S22) and the second kneading process (S23) may be performed sequentially within a single mixer.

[0057] The first kneading process (S22) according to the present invention can be performed on a slurry mixture having a relatively high solids content. As a result, the slurry mixture can be transformed into a matte slurry through the first kneading process (S22).

[0058] The solids content of the slurry mixture in the first kneading process (S22) may be 65 wt% to 80 wt%. The first kneading process (S22) may be performed at 25°C to 60°C for 10 to 70 minutes.

[0059] By adding a solvent to the slurry mixture after the primary kneading process (S22) has been completed, the solids content of the slurry mixture can be reduced. In one embodiment of the present invention, an additive may be further added to the slurry mixture. For example, the additive may include at least one selected from the group consisting of a filler, a coating agent, a dispersant, and an ion-conducting aid.

[0060] A secondary kneading process using a mixer may be performed on the slurry mixture to which a solvent has been added (S23). The solids content of the slurry mixture in the secondary kneading process (S23) may be 55 wt% to 65 wt%. The secondary kneading process (S23) may be performed at 10°C to 25°C for 20 minutes to 50 minutes. In one embodiment, the process temperature of the secondary kneading process (S23) may be lower than the process temperature of the primary kneading process (S22). The secondary kneading process (S23) may be performed for a shorter time than the primary kneading process (S22).

[0061] The secondary kneading process (S23) according to the present invention can be performed on a slurry having a lower solid content than the primary kneading process (S22). This allows a solid electrolyte slurry having a desired viscosity to be produced.

[0062] A defoaming process can be performed on the solid electrolyte slurry after the mixing process (S20) has been completed (S30). The defoaming process can remove air bubbles remaining within the solid electrolyte slurry.

[0063]

[0064] FIG. 1B is a flowchart illustrating a method for manufacturing a solid electrolyte slurry according to another embodiment of the present invention. Referring to FIG. 1B, the mixing process (S20) may further include a wetting process (S21). The wetting process (S21) may be performed before the primary kneading process (S22). In one embodiment, the solid content of the slurry mixture in the wetting process (S21) may be 65 wt% to 80 wt%. The wetting process (S21) may be performed at 10°C to 25°C for 5 minutes to 30 minutes. In one embodiment, the wetting process (S21) may be performed multiple times (e.g., twice).

[0065] The solids content of the slurry mixture can be increased by additionally adding a raw material solution to the slurry mixture after the wetting process (S21) has been completed. The raw material solution may include a solid electrolyte, a binder, and a solvent. The solid electrolyte, binder, and solvent may be the same as or similar to those described above. In another embodiment of the present invention, the raw material solution may not be additionally added.

[0066] A first kneading process using a mixer can be performed on a slurry mixture to which a raw material solution has been added (S22). The solids content of the slurry mixture in the first kneading process (S22) can be 65 wt% to 80 wt%. The first kneading process (S22) can be performed at 25°C to 60°C for 10 to 70 minutes.

[0067]

[0068] FIG. 2a and FIG. 2b are schematic diagrams each illustrating a method for forming a solid electrolyte layer using a solid electrolyte slurry according to embodiments of the present invention.

[0069] Referring to FIG. 2a, a solid electrolyte slurry (SES) manufactured using the manufacturing method of FIG. 1a or FIG. 1b may be applied onto an electrode layer (ELL). The electrode layer (ELL) may include a positive electrode layer or a negative electrode layer of an all-solid-state battery. A more specific description of the positive electrode layer or negative electrode layer of an all-solid-state battery will be described below with reference to FIG. 4.

[0070] A solid electrolyte slurry (SES) can be applied onto an electrode layer (ELL) using a coating apparatus (COT). For example, the solid electrolyte slurry (SES) can be applied using a doctor blade, spraying, bar coating, slot die coating, or other methods.

[0071] Referring to FIG. 2b, a porous substrate (PSU) may be provided on a substrate (SUB). For example, the porous substrate (PSU) may include a non-woven fabric. A solid electrolyte slurry (SES) manufactured using the manufacturing method of FIG. 1a or FIG. 1b may be applied onto the porous substrate (PSU). The solid electrolyte slurry (SES) may be applied onto the porous substrate (PSU) via a coating device (COT).

[0072] The solid electrolyte slurry (SES) can penetrate into the porous substrate (PSU) and form a solid electrolyte layer together with the porous substrate (PSU). The solid electrolyte layer manufactured according to the present embodiment can have a free-standing film form.

[0073]

[0074] solid electrolyte slurry

[0075] FIG. 3a is an enlarged cross-sectional view of area M of FIG. 2a for explaining a solid electrolyte slurry according to one embodiment of the present invention.

[0076] Referring to FIG. 3a, a solid electrolyte slurry according to the present invention may include solid electrolyte particles (SEL), a first binder (BID1), and a second binder (BID2). The first binder (BID1) and the second binder (BID2) may include the same material. The first binder (BID1) may cover the surface of the solid electrolyte particles (SEL). The second binder (BID2) may have an aggregated form between the solid electrolyte particles (SEL).

[0077] The solid electrolyte slurry according to the present invention can have a first binder (BID1) that covers the entire surface of the solid electrolyte particles (SEL). The first binder (BID1) can uniformly coat the surface of the solid electrolyte particles (SEL). The second binder (BID2) is almost absent, and the size of the second binder (BID2) can be relatively small. For example, the average size of the second binder (BID2) can be smaller than the average particle diameter (D50) of the solid electrolyte particles (SEL).

[0078] The solid electrolyte slurry according to the present invention may have a relatively low viscosity compared to other slurries having the same solid content. According to the results of measuring the shear viscosity of the solid electrolyte slurry of the present invention, the viscosity may be 100 mPa·s to 4,000 mPa·s, more specifically, 200 mPa·s to 2,000 mPa·s, at a shear rate of 10 (1 / s).

[0079] The solid electrolyte slurry according to the present invention can have relatively excellent dispensability compared to other slurries having the same solid content. According to the results of measuring the shear viscosity of the solid electrolyte slurry of the present invention, the ratio of the viscosity at a shear rate of 10 (1 / s) to the viscosity at 1000 (1 / s), i.e., the Thixotropic Index (TI), can be 0.2 or more. More specifically, the TI can be 0.2 to 0.5.

[0080] In one embodiment, the solid electrolyte slurry coated on the electrode may have an adhesive strength of 0.4 gf / mm to 0.8 gf / mm. The adhesive strength may refer to an adhesive strength between the electrode and the solid electrolyte layer formed from the slurry. The adhesive strength may be measured using a tensile strength tester. The adhesive strength may refer to an adhesive strength before the electrode and the solid electrolyte layer are rolled. In other words, the adhesive strength may change after the electrode and the solid electrolyte layer are rolled.

[0081] The solid electrolyte slurry according to the present invention can have low viscosity and excellent dispersibility relative to its solid content. Therefore, as shown in Fig. 3a, a solid electrolyte layer manufactured using the solid electrolyte slurry can uniformly coat the surface of solid electrolyte particles (SEL) with the binder mostly in the form of the first binder (BID1). As a result, a solid electrolyte layer manufactured using the slurry of the present invention can have improved electrical properties.

[0082]

[0083] All-solid-state batteries

[0084] 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).

[0085] 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.

[0086] 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.

[0087] 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).

[0088] 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.

[0089] Lithium transition metal oxides include, for example, Li a A 1-b B b D2(0.90≤a≤1, 0≤b≤0.5), Li aHAVE BEEN 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 Mr 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 Mr 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 b HAVE BEEN c G d O2(0.90≤a≤1, 0≤b≤0.9, 0≤c≤0.5, 0.001≤d≤0.1), Li a Ni b Co c Mr 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 bO2(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-f It may be a compound represented by any one of Fe2(PO4)3(0≤f≤2), LiFePO4. In these compounds, a capital letter “” is Ni, Co, Mn, or a combination thereof, a capital letter “” is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element, or a combination thereof, a capital letter “” is O, F, S, P, or a combination thereof, a capital letter “” is Co, Mn, or a combination thereof, a capital letter “” is F, S, P, or a combination thereof, a capital letter “” is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof, a capital letter “” is Ti, Mo, Mn, or a combination thereof, a capital letter “” is Cr, V, Fe, Sc, Y, or a combination thereof, and a capital letter “” is V, Cr, Mn, Co, Ni, Cu, or a combination thereof.

[0090] 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 Mn z 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.

[0091] 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.

[0092] 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, thereby reducing metal dissolution of the positive electrode active material in a charged state. 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.

[0093] 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.

[0094] 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).

[0095] 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(0≤x≤2) may be an argyrodite-type compound including at least one selected from. In particular, the sulfide-based solid electrolyte may be an argyrodite-type compound including at least one selected from Li6PS5Cl, Li6PS5Br, and Li6PS5I. 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.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] 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.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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).

[0104] 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.

[0105] 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.

[0106] 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.

[0107] 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. In one embodiment, the cathode coating layer (220) may include a mixture of carbon black and silver (Ag).

[0108] 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.

[0109] 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).

[0110] 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).

[0111] The solid electrolyte layer (300) of the all-solid-state battery according to the present embodiment can be manufactured using the solid electrolyte slurry described above. In one embodiment, the solid electrolyte layer (300) can be formed by directly coating on the positive electrode layer (100) and / or the negative electrode layer (200), as shown in FIG. 2a. In another embodiment, the solid electrolyte layer (300) can be manufactured in the form of a self-supporting film, as shown in FIG. 2b, and interposed between the positive electrode layer (100) and the negative electrode layer (200).

[0112]

[0113] Hereinafter, embodiments of the present invention will be described in more detail. However, the following embodiments are provided merely to aid understanding of the present invention, and the scope of the present invention is not limited thereby.

[0114]

[0115] Example 1

[0116] A slurry mixture was prepared by adding Li6PS5Cl, an acrylic binder (SX-A334, Zeon), and isobutyryl isobutyrate (IBIB) solvent to a container. The solid content of the mixture was adjusted to 70.4%. The composition of the slurry mixture was such that the weight ratio of sulfide-based solid electrolyte: acrylate rubber was 98:2.

[0117] The slurry mixture was placed in a PD (Planetary Despa) mixer and subjected to primary kneading. The primary kneading was performed for 50 minutes with the planetary speed set at 75 rpm.

[0118] Additives and water were added to the slurry mixture after the first kneading process, adjusting the solids content to 60.3%. Secondary kneading was performed using a PD mixer. Secondary kneading was performed for 35 minutes at 75 rpm on the Planetary and 1000 / 2500 rpm on the Despa.

[0119] The slurry after the second kneading process was defoamed for 30 minutes.

[0120]

[0121] Comparative Example 1

[0122] A slurry mixture was prepared by adding Li6PS5Cl, an acrylic binder (SX-A334, Zeon), and isobutyryl isobutyrate (IBIB) solvent to a container. The solids content of the mixture was adjusted to 60.8%.

[0123] The slurry mixture was placed in a PD mixer and subjected to primary kneading. The primary kneading was performed for 32 minutes at a planetary speed of 75 rpm.

[0124] Additives and water were added to the slurry mixture after the first kneading process to adjust the solids content to 60.3%. The second kneading was performed using a PD mixer. The second kneading was performed for 45 minutes at 75 rpm on the Planetary and 1000 / 2500 rpm on the Despa.

[0125] The slurry after the second kneading process was defoamed for 30 minutes.

[0126]

[0127] Evaluation Example 1: Cathode Slurry Surface Image Analysis

[0128] The surface images of the slurries according to Example 1 and Comparative Example 1 are schematically illustrated in FIGS. 3a and 3b, respectively.

[0129] Referring to FIG. 3a, as described above, the slurry of Example 1 has the first binder (BID1) uniformly coating the entire surface of the solid electrolyte particles (SEL). In addition, the second binder (BID2) is distributed in a relatively small size and small amount.

[0130] Referring to FIG. 3b, the slurry of Comparative Example 1 may have the first binder (BID1) cover only a portion of the surface of the solid electrolyte particles (SEL). The first binder (BID1) may not uniformly cover the surface of the solid electrolyte particles (SEL). A large amount of the second binder (BID2) may be located between the solid electrolyte particles (SEL). For example, the average size of the second binder (BID2) may be larger than the average particle diameter (D50) of the solid electrolyte particles (SEL).

[0131] Comparing FIGS. 3a and 3b, it can be confirmed that the binder of the slurry of Example 1 is uniformly adsorbed on the surface of the solid electrolyte particles compared to the slurry of Comparative Example 1. In other words, the slurry of Example 1 can have superior dispersibility and phase stability compared to the slurry of Comparative Example 1.

[0132]

[0133] Evaluation Example 2: Measurement of shear viscosity

[0134] The shear viscosity of the slurry of Example 1 and the slurry of Comparative Example 1 was measured using an Anton Paar Rheometer. 10 ml of the slurry was added to the equipment, and the shear viscosity was measured. The results are shown in Fig. 5.

[0135] Referring to Fig. 5, the slurry of Comparative Example 1 was measured to have a ratio of viscosity at a shear rate of 10 (1 / s) to viscosity at 1000 (1 / s), i.e., a TI (Thixotropic Index) of less than 0.2. On the other hand, the slurry of Example 1 was measured to have a TI (Thixotropic Index) of greater than 0.2.

[0136] It was confirmed that the slurry of Comparative Example 1 had a viscosity greater than 1,000 mPa·s at a shear rate of 10 (1 / s). On the other hand, it was confirmed that the slurry of Example 1 had a viscosity less than 1,000 mPa·s at a shear rate of 10 (1 / s).

[0137] Looking at the N region of Fig. 5, it was confirmed that shear thickening occurred in the slurry of Comparative Example 1. On the other hand, shear thickening did not occur in the slurry of Example 1.

[0138] Although the slurry of Example 1 and the slurry of Comparative Example 1 have the same solid content, it can be confirmed that the slurry of Example 1 has improved dispersibility and viscosity compared to the slurry of Comparative Example 1.

[0139]

[0140] Evaluation Example 3: Slurry Phase Stability Evaluation

[0141] The slurry of Example 1 was left for one day without stirring. Thereafter, the shear viscosity was measured as in Evaluation Example 2, and the results are shown in Fig. 6a. The slurry of Comparative Example 1 was left for one day without stirring. Thereafter, the shear viscosity was measured as in Evaluation Example 2, and the results are shown in Fig. 6b.

[0142] Referring to Fig. 6a, it can be confirmed that the viscosity of the slurry of Example 1 increased by 59% after being left for one day compared to the viscosity on the day it was manufactured. Referring to Fig. 6b, it can be confirmed that the viscosity of the slurry of Comparative Example 1 increased by 100% after being left for one day compared to the viscosity on the day it was manufactured.

[0143] It was confirmed that the slurry of Example 1 had better phase stability than the slurry of Comparative Example 1.

[0144]

[0145] Evaluation Example 4: FOG Gauge Evaluation

[0146] The fineness of the slurries of Example 1 and Comparative Example 1 was measured using the Fineness (FOG) test method (ELCOMETER Grind Gauge (2020M002)). Fineness is the reading obtained from a particle sizer under specific conditions. Fineness refers to the size of the largest particles in the final dispersion, not the average particle size or particle density.

[0147] To conduct the FOG test, a small amount of slurry sample was placed at the end of the gauge, and a scraper was attached perpendicularly to the gauge. The scraper was pulled along the gauge at a constant speed to scrape it. The FOG gauge evaluation results for the slurry of Example 1 are shown in Figure 7a, and the FOG gauge evaluation results for the slurry of Comparative Example 1 are shown in Figure 7b.

[0148] Referring to Fig. 7a, it can be confirmed that the slurry of Example 1 has a fineness of about 6 μm. Referring to Fig. 7b, it can be confirmed that the slurry of Comparative Example 1 has a fineness of about 6 μm. Consequently, it can be confirmed that the slurry of Example 1 has better dispersibility than the slurry of Comparative Example 1.

[0149]

[0150] Evaluation Example 5: TOF-SIMS Analysis of Slurry

[0151] TOF-SIMS analysis was performed on the slurry of Example 1. ION-TOF's TOF.SIMS-5 was used for TOF-SIMS analysis. The TOF-SIMS analysis results are shown in Fig. 8a. TOF-SIMS analysis was performed on the slurry of Comparative Example 1, and the results are shown in Fig. 8b.

[0152] Referring to FIGS. 8a and 8b, the Cl mapping results show that the distribution of Example 1 is superior to that of Comparative Example 1. In other words, it can be confirmed that the distribution of the solid electrolyte in the slurry of Example 1 is superior to that of Comparative Example 1.

[0153] Looking at the CN mapping results, it can be confirmed that the distribution of Example 1 is superior to that of Comparative Example 1. In other words, it can be confirmed that the distribution of the binder in the slurry of Example 1 is superior to that of Comparative Example 1.

[0154]

[0155] Evaluation Example 6: Evaluation of Adhesion of Solid Electrolyte Layer

[0156] A solid electrolyte layer was prepared by directly coating the slurry of Example 1 onto the cathode. The surface of the solid electrolyte layer was attached to a slide glass with double-sided tape. The remaining unattached portion of the slide glass was fastened to a tensile strength tester (Shimadzu). The slide glass was lifted by the tensile strength tester within a stroke range of 0 mm to 35 mm. The average value of the data in the range of 10 mm to 30 mm was calculated. The calculated average value (gf) was divided by the width of the slide glass (26 mm) to convert it to gf / mm. The adhesive strength was measured for three samples.

[0157] The slurry of Comparative Example 1 was also evaluated for adhesive strength using the same method as described above. The results of Example 1 and Comparative Example 1 are shown in Fig. 9.

[0158] Referring to Fig. 9, in the case of Example 1, the average value of the three samples was 0.643 gf / mm. In the case of Comparative Example 1, the average value of the three samples was 0.094 gf / mm. That is, it can be confirmed that the solid electrolyte layer manufactured with the slurry of Example 1 has better adhesive strength than the solid electrolyte layer manufactured with the slurry of Comparative Example 1.

[0159]

[0160] 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.

Claims

1. Preparing a slurry mixture by mixing a solid electrolyte, a binder, and a solvent; Performing a first kneading process on the slurry mixture having a solid content adjusted to 65 wt% to 80 wt%; Adding a solvent to the slurry mixture after completing the first kneading process; and A method for producing a solid electrolyte slurry, comprising performing a second kneading process on the slurry mixture having a solid content adjusted to 55 wt% to 65 wt%.

2. In paragraph 1, A method for producing a solid electrolyte slurry, wherein the above first kneading process is performed at 25°C to 60°C for 10 to 70 minutes.

3. In paragraph 1, A method for producing a solid electrolyte slurry, wherein the above secondary kneading process is performed at 10°C to 25°C for 20 to 50 minutes.

4. In paragraph 1, A method for producing a solid electrolyte slurry, further comprising performing a defoaming process on the slurry mixture after completing the secondary kneading process.

5. In paragraph 1, A method for producing a solid electrolyte slurry, wherein the solid electrolyte slurry has a viscosity of 200 mPa·s to 2,000 mPa·s at a shear rate of 10 (1 / s) as measured by shear viscosity measurement.

6. In paragraph 1, A method for producing a solid electrolyte slurry, wherein the solid electrolyte slurry has a ratio of viscosity at a shear rate of 10 (1 / s) to viscosity at 1000 (1 / s) of 0.2 to 0.5 as measured by shear viscosity measurement.

7. In paragraph 1, A method for producing a solid electrolyte slurry, wherein the first kneading process and the second kneading process are performed using a PD mixer (Planetary Disperser mixer), a planetary mixer, a paddle mixer, a ribbon mixer, a dual shaft mixer mixer, a high-speed impeller mixer, or a propeller mixer.

8. In paragraph 1, The above solid electrolyte is 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 A method for producing a solid electrolyte slurry comprising an azirodite-type compound selected from (0≤x≤2).

9. In paragraph 1, A method for producing a solid electrolyte slurry, wherein the binder comprises at least one selected from the group consisting of a cellulose-based polymer, a rubber-based binder, an acrylate-based binder, an imide-based binder, a polyvinylidene fluoride-based binder, a polyvinylpyrrolidone-based binder, a nitrile-based binder, an acetate-based binder, and a cyano-based binder.

10. In paragraph 1, A method for producing a solid electrolyte slurry, wherein the solvent comprises at least one selected from the group consisting of water, methanol, ethanol, ethylene glycol, diethylene glycol, glycerol, isobutyryl isobutyrate, xylene, toluene, benzene, and hexane.

11. Preparing a slurry mixture by mixing a solid electrolyte, a binder, and a solvent; Performing a first kneading process on the slurry mixture having a solid content adjusted to 65 wt% to 80 wt%; Adding a solvent to the slurry mixture after completing the first kneading process to reduce the solid content; and Including performing a second kneading process on the slurry mixture having a reduced solids content, A method for producing a solid electrolyte slurry, wherein the above first kneading process is performed at 25°C to 60°C for 10 to 70 minutes.

12. In paragraph 11, A method for producing a solid electrolyte slurry, wherein the above secondary kneading process is performed at 10°C to 25°C for 20 to 50 minutes.

13. In paragraph 11, A method for producing a solid electrolyte slurry, further comprising performing a defoaming process on the slurry mixture after completing the secondary kneading process.

14. In paragraph 11, A method for producing a solid electrolyte slurry, wherein the solid electrolyte slurry has a viscosity of 200 mPa·s to 2,000 mPa·s at a shear rate of 10 (1 / s) as measured by shear viscosity measurement.

15. In paragraph 11, A method for producing a solid electrolyte slurry, wherein the solid electrolyte slurry has a ratio of viscosity at a shear rate of 10 (1 / s) to viscosity at 1000 (1 / s) of 0.2 to 0.5 as measured by shear viscosity measurement.

16. Solid electrolyte slurry comprising solid electrolyte, binder and solvent: The above solid electrolyte slurry has a viscosity of 200 mPa·s to 2,000 mPa·s at a shear rate of 10 (1 / s) as measured by shear viscosity measurement.

17. In paragraph 16, The above solid electrolyte slurry is a solid electrolyte slurry, wherein the ratio of the viscosity at a shear rate of 10 (1 / s) to the viscosity at 1000 (1 / s) is 0.2 to 0.5 as measured by shear viscosity measurement.

18. In paragraph 16, The above solid electrolyte is 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 A solid electrolyte slurry comprising an argyrodite-type compound selected from (0≤x≤2).

19. In Article 16, A solid electrolyte slurry, wherein the binder comprises at least one selected from the group consisting of a cellulose-based polymer, a rubber-based binder, an acrylate-based binder, an imide-based binder, a polyvinylidene fluoride-based binder, a polyvinylpyrrolidone-based binder, a nitrile-based binder, an acetate-based binder, and a cyano-based binder.

20. In paragraph 16, The solid electrolyte slurry coated on the electrode is a solid electrolyte slurry having an adhesive strength of 0.4 gf / mm to 0.8 gf / mm.

Images