Dispersant solution and preparation method therefor, solid electrolyte slurry, electrode slurry, solid-state battery cell and electric device

Abstract

Provided in the present disclosure are a dispersant solution and a preparation method therefor, a solid electrolyte slurry, an electrode slurry, a solid-state battery cell and an electric device. The dispersant solution comprises a solvent and a dispersant dissolved in the solvent, wherein the solvent is a non-polar solvent, a weakly polar solvent, or a mixed solvent of the two; and the dispersant comprises an acrylic saturated alkyl ester type polymeric dispersant and a polar non-ionic polymeric dispersant, with the polar non-ionic polymeric dispersant containing at least one of a carboxylic acid group, a carboxylic acid salt, a sulfonic acid group, an amido, a hydroxyl and an ether bond. The dispersant solution can improve the dispersion uniformity of a solid electrolyte slurry and an electrode slurry, and can also improve the coating quality of the slurries, such that the capacity performance characteristics of a solid-state battery cell can be improved.

Description

Dispersant solution and preparation method thereof, solid electrolyte slurry, electrode slurry, solid-state battery cell and electric device

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese Patent Application No. 202411127658.9, filed on August 16, 2024, entitled “Dispersant solution and preparation method thereof, solid electrolyte slurry, electrode slurry, solid-state battery cell and electric device”, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present disclosure relates to a dispersant solution and preparation method thereof, solid electrolyte slurry, electrode slurry, solid-state battery cell and electric device. BACKGROUND

[0004] The solid-state battery cell replaces the non-aqueous organic electrolyte with a solid electrolyte film. Since the solid electrolyte film cannot spontaneously penetrate into the electrode, the solid electrolyte material and the electrode active material are usually used together to improve the ion transport properties of the electrode. Sulfide solid electrolyte material has high ionic conductivity and is one of the ideal solid electrolyte materials at present, but it has poor oxidation resistance and reduction resistance, which leads to a small range of solvents that can be selected, and also leads to poor dispersibility of the slurry containing it, which cannot be coated or has poor coating quality. SUMMARY

[0005] The present disclosure provides a dispersant solution and preparation method thereof, solid electrolyte slurry, electrode slurry, solid-state battery cell and electric device, which can improve the dispersion uniformity of the solid electrolyte slurry and the electrode slurry, and also improve the coating quality of the slurry, thereby improving the capacity performance of the solid-state battery cell.

[0006] In a first aspect, the present disclosure provides a dispersant solution, the dispersant solution comprising a solvent and a dispersant dissolved in the solvent, the solvent being a non-polar solvent, a weakly polar solvent or a mixed solvent of the two, the dispersant comprising a saturated alkyl acrylate polymer dispersant and a polar non-ionic polymer dispersant, the polar non-ionic polymer dispersant containing at least one of a carboxylic acid group, a carboxylic acid salt, a sulfonic acid group, an amine group, a hydroxyl group and an ether bond.

[0007] The polar non-ionic polymer dispersant contains at least one of a carboxylic acid group, a carboxylic acid salt, a sulfonic acid group, an amine group, a hydroxyl group and an ether bond, and has good dispersing effect. The saturated alkyl acrylate polymer dispersant can reconcile the difference in polarity between the polar non-ionic polymer dispersant and the non-polar solvent and / or the weakly polar solvent, so that each component of the dispersant can be dissolved in the non-polar solvent and / or the weakly polar solvent, and the dispersant solution also has good dispersing effect.

[0008] The dispersant solution of the present disclosure can be used in solid electrolyte slurries and electrode slurries, especially solid electrolyte slurries and electrode slurries including sulfide solid electrolyte materials, to improve the dispersion uniformity of the slurries, the coating quality of the slurries, and the capacity performance of the solid-state battery cells.

[0009] In some embodiments, the saturated alkyl acrylate high-molecular dispersant includes a structural unit shown in Formula 1, R1 is selected from C2 to C10 alkyl, and R2, R3, and R4 are each independently selected from H or C1 to C3 alkyl. In this way, the saturated alkyl acrylate high-molecular dispersant can have better dispersibility.

[0010] In some embodiments, the saturated alkyl acrylate high-molecular dispersant has a weight average molecular weight of 700,000 to 1,200,000.

[0011] In some embodiments, the polar non-ionic high-molecular dispersant includes one or more of polyacrylic acid, polyacrylic acid salt, polyvinylpyrrolidone, polyvinyl alcohol, polyethylene glycol, and polyether dispersant. The polar non-ionic high-molecular dispersant can have better dispersibility in the above range, which can further improve the dispersion uniformity of the slurry, the coating quality of the slurry, and the capacity performance of the solid-state battery cells.

[0012] In some embodiments, the mass ratio of the saturated alkyl acrylate high-molecular dispersant to the polar non-ionic high-molecular dispersant is 85:15 to 95:5. The mass ratio of the saturated alkyl acrylate high-molecular dispersant to the polar non-ionic high-molecular dispersant in the above range can make the polar non-ionic high-molecular dispersant better dissolved in non-polar solvents and / or weakly polar solvents, and can make the dispersant solution have better dispersibility, which can further improve the dispersion uniformity of the slurry, the coating quality of the slurry, and the capacity performance of the solid-state battery cells.

[0013] In some embodiments, the solvent includes one or more of toluene, xylene, mesitylene, chlorobenzene, o-dichlorobenzene, anisole, n-hexane, n-pentane, isopentane, n-heptane, n-octane, isooctane, n-decane, trichlorotrifluoroethane, dichloromethane, trichloromethane, 2-methylpentane, 2,2-dimethylpentane, 3-methylpentane, 2,3-dimethylpentane, 2-methylhexane, 2,2-dimethylhexane, 3-methylhexane, 2,3-dimethylhexane, 3-ethylhexane, cyclohexane, cycloheptane, methylcyclohexane, t-butylcyclohexane, tetrahydrofuran, cyclopentene, cyclohexene, 1-methylcyclohexene, 4-methylcyclohexene, 1-ethylcyclohexene, 1,4-dimethylcyclohexene, 2,4-dimethyl-3-pentanone, cyclohexanone, methylformamide, 1-hexene, 2-hexene, 1-heptene, 2-heptene, 1-octene, 2-octene, ethylene dichloride, petroleum ether, trifluoroacetic acid, butyl chloride, trichloroethylene, carbon tetrachloride, propyl ether, diethyl ether, butyl acetate, ethyl acetate.

[0014] In some embodiments, the mass fraction of the dispersant in the dispersant solution is 8%-12%.

[0015] In a second aspect, the present disclosure provides a method for preparing the dispersant solution of the first aspect, including the following steps: dissolving the saturated alkyl acrylate high molecular dispersant into a solvent to obtain an intermediate solution, the solvent being a non-polar solvent, a weakly polar solvent, or a mixed solvent of the two; adding a polar non-ionic high molecular dispersant into the obtained intermediate solution and stirring uniformly to obtain the dispersant solution, the polar non-ionic high molecular dispersant containing at least one of a carboxylic acid group, a carboxylic acid salt, a sulfonic acid group, an amine group, and an ether bond.

[0016] The present application dissolves the saturated alkyl acrylate high molecular dispersant into a non-polar solvent and / or a weakly polar solvent to obtain an intermediate solution, and then dissolves a polar non-ionic high molecular dispersant into the intermediate solution, so that the saturated alkyl acrylate high molecular dispersant can mediate the difference in polarity between the polar non-ionic high molecular dispersant and the non-polar solvent and / or the weakly polar solvent, so that each component of the dispersant can be dissolved in the non-polar solvent and / or the weakly polar solvent, and a dispersant solution with good dispersion effect can be obtained. When the dispersant solution is used in a solid electrolyte slurry and an electrode slurry, especially a solid electrolyte slurry and an electrode slurry including a sulfide solid electrolyte material, the dispersion uniformity of the slurry can be improved, the coating quality of the slurry can be improved, and the capacity performance of a solid battery cell can be improved.

[0017] In a third aspect, the present disclosure provides a solid electrolyte slurry including a sulfide solid electrolyte material and the dispersant solution of the first aspect or the dispersant solution prepared by the method of the second aspect.

[0018] In some embodiments, the solid-state electrolyte slurry further comprises one or more of a halide solid-state electrolyte material, an oxide solid-state electrolyte material.

[0019] In a fourth aspect, the present disclosure provides an electrode slurry, comprising a positive electrode active material, a sulfide solid-state electrolyte material, a positive electrode conductive agent, a positive electrode binder, and the dispersant solution of the first aspect or prepared by the method of the second aspect.

[0020] In a fifth aspect, the present disclosure provides an electrode slurry, comprising a negative electrode active material, a sulfide solid-state electrolyte material, a negative electrode binder, and the dispersant solution of the first aspect or prepared by the method of the second aspect.

[0021] In a sixth aspect, the present disclosure provides a solid-state battery cell, comprising a positive electrode sheet, a solid-state electrolyte film, and a negative electrode sheet, the solid-state electrolyte film being located between the positive electrode sheet and the negative electrode sheet, the positive electrode sheet comprising a positive electrode current collector and a positive electrode film layer located on at least one surface of the positive electrode current collector, the positive electrode film layer being obtained by drying the electrode slurry of the fourth aspect; and / or, the solid-state electrolyte film being obtained by drying the solid-state electrolyte slurry of the third aspect.

[0022] In some embodiments, the negative electrode sheet comprises a negative electrode current collector and a lithium-based metal layer located on at least one surface of the negative electrode current collector.

[0023] In some embodiments, the negative electrode sheet comprises a negative electrode current collector and a negative electrode film layer located on at least one surface of the negative electrode current collector, the negative electrode film layer being obtained by drying the electrode slurry of the fifth aspect.

[0024] In a seventh aspect, the present disclosure provides an electric device comprising the solid-state battery cell of the sixth aspect. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following will briefly introduce the drawings needed to be used in the embodiments of the present disclosure. Obviously, the drawings described below are only some embodiments of the present disclosure, and other drawings can also be obtained according to the drawings without paying creative labor for those skilled in the art.

[0026] FIG. 1 shows a schematic diagram of a solid-state battery cell provided by some embodiments of the present disclosure.

[0027] FIG. 2 shows a schematic diagram of an electric device provided by some embodiments of the present disclosure.

[0028] FIG. 3 shows the flowability test results of the positive electrode slurry prepared by Comparative Example 1.

[0029] FIG. 4 shows the flowability test results of the positive electrode slurry prepared by Example 1.

[0030] In the drawings, the drawings are not necessarily drawn to scale. DETAILED DESCRIPTION

[0031] Hereinafter, embodiments of a dispersant solution and a method for producing the same, a solid electrolyte slurry, an electrode slurry, a solid battery cell, and an electric device according to the present disclosure will be described in detail with appropriate reference to the accompanying drawings. However, there will be cases where unnecessary detailed description is omitted. For example, there will be cases where detailed description of matters known well, repeated description of substantially identical structures are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate understanding by those skilled in the art. In addition, the drawings and the following description are provided so that those skilled in the art can fully understand the present disclosure, and are not intended to limit the subject matter recited in the claims.

[0032] The "range" disclosed in the present disclosure is defined in the form of a lower limit and an upper limit, and a given range is defined by selecting one lower limit and one upper limit, and the selected lower limit and upper limit define the boundaries of a particular range. The range defined in this way can be inclusive or exclusive of the end values, and can be arbitrarily combined, i.e., any lower limit can be combined with any upper limit to form a range. For example, if the ranges 60-120 and 80-110 are listed for a particular parameter, it is understood that the ranges 60-110 and 80-120 are also contemplated. In addition, if the minimum range values 1 and 2 are listed, and if the maximum range values 3, 4, and 5 are listed, the following ranges are all contemplated: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In the present disclosure, unless otherwise specified, a numerical range "a-b" represents a shorthand notation for any real combination of integers between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been listed herein, and "0-5" is just a shorthand notation for these numerical combinations. In addition, when a parameter is stated to be ≥2 integers, it is equivalent to disclose that the parameter is, for example, integer 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0033] Unless otherwise specified, all embodiments and optional embodiments of the present disclosure can be combined with each other to form new technical solutions, and such technical solutions should be considered to be included in the disclosure content of the present disclosure.

[0034] Unless otherwise specified, all technical features and optional technical features of the present disclosure can be combined with each other to form new technical solutions, and such technical solutions should be considered to be included in the disclosure content of the present disclosure.

[0035] If not otherwise specified, all steps of the present disclosure can be performed in sequence or randomly, preferably in sequence. For example, the method comprising steps (a) and (b) means that the method can comprise steps (a) and (b) in sequence, or steps (b) and (a) in sequence. For example, the method comprising step (c) means that step (c) can be added to the method in any sequence, for example, the method can comprise steps (a), (b) and (c), or steps (a), (c) and (b), or steps (c), (a) and (b), etc.

[0036] If not otherwise specified, in the present disclosure, the terms "first", "second", etc. are used to distinguish different objects, rather than to describe a specific sequence or primary and secondary relationship.

[0037] In the present disclosure, the terms "a plurality of", "a plurality of" refer to two or more.

[0038] In the description of the embodiments of the present disclosure, if not otherwise specified, the first feature is "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature can be "above", "over" and "on" the second feature, which can be that the first feature is directly above or obliquely above the second feature, or only means that the horizontal height of the first feature is higher than that of the second feature. The first feature can be "below", "under" and "under" the second feature, which can be that the first feature is directly below or obliquely below the second feature, or only means that the horizontal height of the first feature is less than that of the second feature.

[0039] Unless otherwise specified, the test temperature of each parameter mentioned in the present disclosure is 25℃.

[0040] The battery device mentioned in the embodiments of the present disclosure can comprise one or more solid-state battery cell assemblies for providing voltage and capacity. The solid-state battery cell assembly can comprise a plurality of solid-state battery cells connected in series, in parallel or in a mixed manner through a busbar component.

[0041] In some embodiments, the solid-state battery cell assembly is usually formed by arranging a plurality of solid-state battery cells; as an example, the solid-state battery cell assembly can be a battery module formed by arranging and fixing a plurality of solid-state battery cells into an independent module. As an example, the battery module can be formed by bundling a plurality of solid-state battery cells by a cable tie.

[0042] In some embodiments, the battery device can be a battery pack including a case and one or more solid-state battery cell assemblies housed in the case. As an example, the solid-state battery cell assembly can be a battery module, which can be housed in the case by securing the battery module in the case. As another example, the solid-state battery cell assembly can also be housed in the case by securing a plurality of solid-state battery cells directly to the case.

[0043] A solid-state battery cell is the smallest unit that constitutes a battery device and is capable of performing charging and discharging functions by itself. The solid-state battery cell can have a cylindrical shape, a cuboid shape, or other shapes, which are not limited in the embodiments of the present disclosure. FIG. 1 is a solid-state battery cell 5 having a cuboid structure as an example.

[0044] Due to the particularity of the structure of the sulfide solid-state electrolyte material, the oxidation resistance and reduction resistance thereof are poor, and thus the solvent to be matched needs to be weakly polar or non-polar. The current dispersant is mainly a hydrophilic dispersant, which has a large polarity, and thus the dispersant cannot be dissolved in a non-polar solvent or a weakly polar solvent. In addition, the particle size of the sulfide solid-state electrolyte material is usually small, and the specific surface area is large, which further leads to poor dispersibility of the slurry containing the sulfide solid-state electrolyte material, poor coating quality of the slurry, and affects the capacity performance of the solid-state battery cell.

[0045] Based on this, the present disclosure provides a dispersant solution, which can improve the dispersion uniformity of the solid-state electrolyte slurry and the electrode slurry, and also improve the coating quality of the slurry, thereby improving the capacity performance of the solid-state battery cell.

[0046] The dispersant solution provided by the present disclosure includes a solvent and a dispersant dissolved in the solvent, the solvent is a non-polar solvent, a weakly polar solvent, or a mixed solvent of the two, and the dispersant includes a saturated alkyl acrylate high molecular dispersant and a polar non-ionic high molecular dispersant, the polar non-ionic high molecular dispersant contains at least one of a carboxylic acid group, a carboxylic acid salt, a sulfonic acid group, an amine group, a hydroxyl group, and an ether bond.

[0047] The polar non-ionic high molecular dispersant contains at least one of a carboxylic acid group, a carboxylic acid salt, a sulfonic acid group, an amine group, a hydroxyl group, and an ether bond, and has good dispersion effect. The saturated alkyl acrylate high molecular dispersant can adjust the polarity difference between the polar non-ionic high molecular dispersant and the non-polar solvent and / or the weakly polar solvent, so that each component of the dispersant can be dissolved in the non-polar solvent and / or the weakly polar solvent, and the dispersant solution also has good dispersion effect.

[0048] The dispersion solution of the present disclosure can be used in a solid electrolyte slurry and an electrode slurry, in particular, a solid electrolyte slurry and an electrode slurry including a sulfide solid electrolyte material, to improve the dispersion uniformity of the slurry, improve the coating quality of the slurry, and improve the capacity performance of a solid battery cell.

[0049] In some embodiments, the saturated alkyl acrylate-based high molecular dispersant includes a structural unit shown in Formula 1, R1 is selected from C2 to C10 alkyl, and R2, R3, R4 are each independently selected from H or C1 to C3 alkyl. In this way, the saturated alkyl acrylate-based high molecular dispersant can have better dispersibility.

[0050] R1 is selected from C2 to C10 alkyl, and R1 can be a linear alkyl or a branched alkyl, for example, R1 can be ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, pentyl, hexyl, heptyl, octyl, nonyl, or decyl.

[0051] Alternatively, R1 can be selected from C3 to C8 alkyl.

[0052] R2, R3, R4 are each independently selected from H or C1 to C3 alkyl. Alternatively, R2, R3, R4 are each independently selected from H or methyl. More alternatively, R2 is selected from methyl, and R3, R4 are selected from H.

[0053] In some embodiments, the saturated alkyl acrylate-based high molecular dispersant can have a weight average molecular weight of 700,000 to 1,200,000, for example, 700,000, 750,000, 800,000, 850,000, 900,000, 950,000, 1,000,000, 1,050,000, 1,100,000, 1,150,000, 1,200,000, or a range consisting of any of the above values.

[0054] The weight average molecular weight of the high molecular dispersant refers to the weight average molecular weight converted by standard polystyrene using gel permeation chromatography (GPC).

[0055] In some embodiments, the polar nonionic high molecular dispersant can include one or more of polyacrylic acid, polyacrylic acid salt, polyvinylpyrrolidone, polyvinyl alcohol, polyethylene glycol, and polyether dispersant.

[0056] The polar nonionic high molecular dispersant can have better dispersibility within the above range, thereby further improving the dispersion uniformity of the slurry, improving the coating quality of the slurry, and improving the capacity performance of a solid battery cell.

[0057] Alternatively, the polyacrylic acid salt can include sodium polyacrylate.

[0058] Optionally, the polyether dispersant can include one or more of alkylphenol-modified polyoxyethylene ethers, fatty alcohol-modified polyoxyethylene ethers, fatty acid-modified polyoxyethylene ethers.

[0059] In some embodiments, the mass ratio of the saturated alkyl acrylate high-molecular dispersant to the polar nonionic high-molecular dispersant can be 85:15 to 95:5, for example, can be 85:15, 86:14, 87:13, 88:12, 89:11, 90:10, 91:9, 92:8, 93:7, 94:6, 95:5, or a range consisting of any of the above values.

[0060] The mass ratio of the saturated alkyl acrylate high-molecular dispersant to the polar nonionic high-molecular dispersant in the above range can not only make the polar nonionic high-molecular dispersant better dissolved in the nonpolar solvent and / or weakly polar solvent, but also make the dispersant solution have better dispersibility, thereby further improving the dispersion uniformity of the slurry, improving the coating quality of the slurry, and also improving the capacity performance of the solid-state battery cell.

[0061] The solvent is a nonpolar solvent, a weakly polar solvent, or a mixed solvent of the two, and in some embodiments, the solvent can include, but is not limited to, one or more of toluene, xylene, mesitylene, chlorobenzene, o-dichlorobenzene, anisole, n-hexane, n-pentane, isopentane, n-heptane, n-octane, isooctane, n-decane, trichlorotrifluoroethane, dichloromethane, trichloromethane, 2-methylpentane, 2,2-dimethylpentane, 3-methylpentane, 2,3-dimethylpentane, 2-methylhexane, 2,2-dimethylhexane, 3-methylhexane, 2,3-dimethylhexane, 3-ethylhexane, cyclohexane, cycloheptane, methylcyclohexane, t-butylcyclohexane, tetrahydrofuran, cyclopentene, cyclohexene, 1-methylcyclohexene, 4-methylcyclohexene, 1-ethylcyclohexene, 1,4-dimethylcyclohexene, 2,4-dimethyl-3-pentanone, cyclohexanone, methylformamide, 1-hexene, 2-hexene, 1-heptene, 2-heptene, 1-octene, 2-octene, dichloroethylene, petroleum ether, trifluoroacetic acid, butyl chloride, trichloroethylene, carbon tetrachloride, propyl ether, diethyl ether, butyl acetate, ethyl acetate.

[0062] In some embodiments, the mass fraction of the dispersant in the dispersant solution can be 8%-12%, for example, can be 8%, 8.2%, 8.4%, 8.6%, 8.8%, 9%, 9.2%, 9.4%, 9.6%, 9.8%, 10%, 10.2%, 10.4%, 10.6%, 10.8%, 11%, 11.2%, 11.4%, 11.6%, 11.8%, 12%, or a range consisting of any of the above values.

[0063] The embodiment of the present disclosure further provides a preparation method of the dispersant solution.

[0064] The preparation method of the dispersant solution comprises the following steps: dissolving the saturated alkyl acrylate polymer dispersant into a solvent to obtain an intermediate solution, the solvent being a non-polar solvent, a weakly polar solvent or a mixed solvent of the two; adding a polar non-ionic polymer dispersant into the obtained intermediate solution and stirring uniformly to obtain the dispersant solution, the polar non-ionic polymer dispersant containing at least one of a carboxylic acid group, a carboxylic acid salt, a sulfonic acid group, an amine group and an ether bond.

[0065] The polar non-ionic polymer dispersant containing at least one of the carboxylic acid group, the carboxylic acid salt, the sulfonic acid group, the amine group and the ether bond has both lipophilic alkyl groups and hydrophilic polar groups, so that the molecular structure makes the polar non-ionic polymer dispersant soluble in water, alcohol, alkane, carboxylic acid, amine and other polar organic solvents, and has good dispersion effect. However, the polar non-ionic polymer dispersant has strong polarity and cannot be fully dissolved in non-polar solvents and / or weakly polar solvents.

[0066] The saturated alkyl acrylate polymer dispersant can be dissolved in non-polar solvents and / or weakly polar solvents, but has poor dispersion effect.

[0067] The present application dissolves the saturated alkyl acrylate polymer dispersant into non-polar solvents and / or weakly polar solvents to obtain an intermediate solution, and then dissolves the polar non-ionic polymer dispersant into the intermediate solution, so that the saturated alkyl acrylate polymer dispersant adjusts the polarity difference between the polar non-ionic polymer dispersant and the non-polar solvents and / or weakly polar solvents, so that each dispersant component can be dissolved in the non-polar solvents and / or weakly polar solvents, and a dispersant solution with good dispersion effect can be obtained. The dispersant solution is used in solid electrolyte slurry and electrode slurry, especially solid electrolyte slurry and electrode slurry containing sulfide solid electrolyte materials, so that the dispersion uniformity of the slurry can be improved, the coating quality of the slurry can be improved, and the capacity performance of the solid-state battery cell can be improved.

[0068] The embodiment of the present disclosure further provides a solid electrolyte slurry.

[0069] The solid electrolyte slurry of the present disclosure comprises a sulfide solid electrolyte material and the dispersant solution provided by the present disclosure or prepared by the method of the present disclosure. Therefore, the solid electrolyte slurry provided by the present disclosure has good dispersion uniformity.

[0070] In some embodiments, the sulfide solid-state electrolyte material can include one or more of Li6PS5X, LGPS-like sulfide solid-state electrolyte material, multi-element sulfide solid-state electrolyte material, X including one or more elements of F, Cl, Br, and I.

[0071] Optionally, the LGPS-like sulfide solid-state electrolyte material can include Li 10±δ5 Ge 1-g G g P 2-q Q q S 12-w W w , 0≤δ5<1, 0≤g≤1, 0≤q≤2, 0≤w<1, G including one or both of Si and Sn, Q including Sb, W including one or more elements of O, Se, Te, Cl, Br, I, and F.

[0072] Optionally, the multi-element sulfide solid-state electrolyte material can include one or more of Li2S-P2S5, Li2S-SiS2, (100-u-v)Li2S·uP2S5·vM m N n , 0<u<100, 0<v<100, 0<u+v<100, 0≤m<4, 0≤n<6, M including one or more elements of Li, B, Ge, Si, Sn, and Sb, N including one or more elements of S, Se, Te, O, Cl, Br, I, and F.

[0073] In some embodiments, as an example, the sulfide solid-state electrolyte material can include one or more of Li6PS5Cl, Li6PS5Br, Li 10 GeP2S 12 , Li3PS4, Li7P3S 11 .

[0074] In some embodiments, the average particle size of the sulfide solid-state electrolyte material can be 50 nm-5 μm, for example, can be 1 nm, 10 nm, 20 nm, 50 nm, 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, or a range consisting of any of the foregoing.

[0075] In some embodiments, the solid-state electrolyte slurry can further include one or more of halide solid-state electrolyte material, oxide solid-state electrolyte material.

[0076] In some embodiments, the halide solid-state electrolyte material can include one or more of Li3YCl6, Li3YBr6, Li3ErCl6, Li3InCl6, Li3InBr6.

[0077] In some embodiments, the oxide solid-state electrolyte material can include one or more of perovskite-structured oxide solid-state electrolyte material, garnet-structured oxide solid-state electrolyte material, oxide solid-state electrolyte material having NASICON structure, oxide solid-state electrolyte material having LISICON structure.

[0078] In some embodiments, the solid-state electrolyte slurry can further include a binder, which can include one or more of methylvinyl silicone rubber, nitrile butadiene rubber (NBR), hydrogenated nitrile butadiene rubber (HNBR), styrene butadiene rubber (SBR), thermoplastic styrene butadiene rubber (SBS), isoprene rubber, butadiene rubber (BR), ethyl cellulose, fluoroelastomer, acrylate rubber.

[0079] The present disclosure further provides an electrode slurry. The electrode slurry can be a positive electrode slurry or a negative electrode slurry.

[0080] In some embodiments, the electrode slurry is a positive electrode slurry, which can include a positive active material, a sulfide solid-state electrolyte material, a positive electrode conductive agent, a positive electrode binder, and the dispersant solution provided by the present disclosure or prepared by the method of the present disclosure. Thus, the positive electrode slurry provided by the present disclosure has good dispersion uniformity.

[0081] The types of sulfide solid-state electrolyte materials are described above and will not be repeated here.

[0082] In some embodiments, the positive active material can include one or more of lithium transition metal oxide and modified materials thereof, lithium-containing phosphates and modified materials thereof, lithium titanate, sulfur, selenium, tellurium.

[0083] Optionally, examples of lithium transition metal oxides can include, but are not limited to, one or more of lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide.

[0084] Optionally, examples of lithium-containing phosphates can include, but are not limited to, one or more of lithium iron phosphate, a composite of lithium iron phosphate and carbon, lithium manganese phosphate, a composite of lithium manganese phosphate and carbon, lithium manganese iron phosphate, a composite of lithium manganese iron phosphate and carbon.

[0085] In some embodiments, in order to further improve the energy density of the solid-state battery monomer, the positive active material can include a general formula of Li a Nib Co c M d O e A f LiCoO2, LiNiO2, LiMnO2, LiMn2O4, LiNi

[0086] As an example, the positive active material can include, but is not limited to, LiCoO2, LiNiO2, LiMnO2, LiMn2O4, LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2(abbreviated as NCM333), LiNi 0.5 Co 0.2 Mn 0.3 O2(abbreviated as NCM523), LiNi 0.5 Co 0.25 Mn 0.25 O2(abbreviated as NCM211), LiNi 0.6 Co 0.2 Mn 0.2 O2(abbreviated as NCM622), LiNi 0.8 Co 0.1 Mn 0.1 O2(abbreviated as NCM811), LiNi 0.96 Co 0.02 Mn 0.02 O2(abbreviated as Ni96), LiNi 0.80 Co 0.15 Al 0.05 O2, LiFePO4, LiMnPO4, and their respective modified compounds.

[0087] The solid-state battery cell will be accompanied by Li deintercalation and consumption during charging and discharging, and the molar content of Li is different when the solid-state battery cell is discharged to different states. In the enumeration of the positive active material in the present disclosure, the molar content of Li is the initial state of the material, i.e., the state before feeding, and the positive active material is applied to the solid-state battery cell. After charging and discharging cycles, the molar content of Li will change. In the enumeration of the positive active material in the present disclosure, the molar content of O is only the theoretical state value, and the release of oxygen from the lattice will cause the molar content of O to change, and the actual molar content of O will also appear to float.

[0088] The modified compounds of the above positive active materials can be doping modification and / or surface coating modification of the positive active materials.

[0089] In some embodiments, the positive electrode binder can include, but is not limited to, one or more of methyl vinyl silicone rubber, nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), styrene butadiene rubber (SBR), thermoplastic styrene butadiene rubber (SBS), isoprene rubber, butadiene rubber (BR), ethyl cellulose, fluoroelastomer, acrylate rubber.

[0090] In some embodiments, the positive electrode conductive agent can include, but is not limited to, one or more of super P, acetylene black, carbon black, ketjen black, carbon dots, carbon nanotubes, graphene, vapor grown carbon fiber (VGCF).

[0091] In some embodiments, the electrode slurry is a negative electrode slurry, which can include a negative electrode active material, a sulfide solid-state electrolyte material, a negative electrode binder, and the dispersant solution provided by the present disclosure or prepared by the method of the present disclosure.

[0092] The types of sulfide solid-state electrolyte materials are described above and will not be repeated here.

[0093] In some embodiments, the negative electrode active material can include, but is not limited to, one or more of natural graphite, artificial graphite, mesocarbon microbeads, soft carbon, hard carbon, silicon-based material, tin-based material, lithium titanate, metal oxide.

[0094] Optionally, the silicon-based material can include, but is not limited to, one or more of elemental silicon, silicon oxide, silicon-carbon composite, silicon-nitrogen composite, and silicon alloy material.

[0095] Optionally, the tin-based material can include, but is not limited to, one or more of elemental tin, tin oxide, and tin alloy material.

[0096] Optionally, the metal oxide includes one or more of TiO2, MoO2, In2O3, Al2O3, Cu2O, VO2, Ga2O3, Sb2O5, Bi2O5.

[0097] In some embodiments, the negative electrode binder can include, but is not limited to, one or more of methyl vinyl silicone rubber, nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), styrene butadiene rubber (SBR), thermoplastic styrene butadiene rubber (SBS), isoprene rubber, butadiene rubber (BR), ethyl cellulose, fluoroelastomer, acrylate rubber.

[0098] In some embodiments, the negative electrode slurry can further include a negative electrode conductive agent.

[0099] In some embodiments, the negative conductive agent can include, but is not limited to, one or more of super-P, conductive graphite, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and vapor grown carbon fiber (VGCF).

[0100] The present disclosure also provides a solid-state battery cell, which includes a positive electrode sheet, a solid-state electrolyte film, and a negative electrode sheet, the solid-state electrolyte film being located between the positive electrode sheet and the negative electrode sheet.

[0101] In some embodiments, the positive electrode sheet can include a positive electrode current collector and a positive electrode film layer located on at least one surface of the positive electrode current collector. The positive electrode current collector has two opposite surfaces in the thickness direction of itself, and the positive electrode film layer is disposed on either one or both of the two opposite surfaces of the positive electrode current collector.

[0102] In some embodiments, the positive electrode film layer can be obtained by drying the positive electrode slurry provided by the present disclosure.

[0103] In some embodiments, the mass content of the sulfide solid-state electrolyte material in the positive electrode film layer can be 1-25%, for example, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, or a range consisting of any of the above values, based on the total mass of the positive electrode film layer being 100%.

[0104] Optionally, the mass content of the sulfide solid-state electrolyte material in the positive electrode film layer can be 5-25%.

[0105] In some embodiments, the mass content of the dispersant in the positive electrode film layer can be 0.3-1.5%, based on the total mass of the positive electrode film layer being 100%. The mass content of the dispersant is the sum of the mass contents of the saturated alkyl acrylate polymer dispersant and the polar non-ionic polymer dispersant.

[0106] In some embodiments, the positive electrode current collector can be a metal foil or a composite current collector. As an example of the metal foil, an aluminum foil can be used. The composite current collector can include a polymer material base layer and a metal material layer formed on at least one surface of the polymer material base layer. As an example, the metal material can include, but is not limited to, one or more of aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy. As an example, the polymer material base layer can include, but is not limited to, one or more of polypropylene, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene.

[0107] In some embodiments, the negative electrode sheet can include a negative electrode current collector and a lithium-based metal layer located on at least one surface of the negative electrode current collector. The negative electrode current collector has two opposite surfaces in the thickness direction of the negative electrode current collector, and the lithium-based metal layer is disposed on any one or both of the two opposite surfaces of the negative electrode current collector.

[0108] In some embodiments, the lithium-based metal layer can be metallic lithium or a lithium alloy, and the mass fraction of lithium in the lithium alloy is greater than 90%.

[0109] Optionally, the other elements in the lithium alloy can include one or more of In, Mg, Al, Zn, Sn, Ag, Au, Ga, Pt, and Fe.

[0110] Optionally, the lithium alloy can include a Li-In alloy, a Li-Mg alloy, a Li-Al alloy, a Li-Zn alloy, a Li-Fe alloy, or the like.

[0111] In other embodiments, the negative electrode sheet can include a negative electrode current collector and a negative electrode film layer located on at least one surface of the negative electrode current collector, and the negative electrode film layer includes a negative electrode active material and a negative electrode binder.

[0112] The types of the negative electrode active material and the negative electrode binder are described above and will not be repeated here.

[0113] Optionally, the negative electrode film layer can further include a sulfide solid electrolyte material. The types of the sulfide solid electrolyte material are described above and will not be repeated here.

[0114] Optionally, the mass content of the sulfide solid electrolyte material in the negative electrode film layer can be 1%-25% based on the total mass of the negative electrode film layer, for example, can be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, or a range consisting of any of the above values. More optionally, the mass content of the sulfide solid electrolyte material in the negative electrode film layer can be 5%-25%.

[0115] Optionally, the negative electrode film layer can further include a negative electrode conductive agent. The types of the negative electrode conductive agent are described above and will not be repeated here.

[0116] In yet other embodiments, the negative electrode sheet can include a negative electrode current collector and a negative electrode film layer located on at least one surface of the negative electrode current collector, and the negative electrode film layer can be obtained by drying a negative electrode slurry provided by the present disclosure.

[0117] Optionally, the content of the sulfide solid electrolyte material in the negative electrode film layer can be 1% to 25%, for example, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, or a range formed by any of the above values, based on 100% of the total mass of the negative electrode film layer. More optionally, the content of the sulfide solid electrolyte material in the negative electrode film layer can be 5% to 25%.

[0118] Optionally, the content of the dispersant in the negative electrode film layer can be 0.3% to 1%, based on 100% of the total mass of the negative electrode film layer. The content of the dispersant is the sum of the content of the saturated alkyl acrylate high molecular dispersant and the content of the polar non-ionic high molecular dispersant.

[0119] In some embodiments, the negative current collector can employ a metal foil or a composite current collector. As an example of the metal foil, a copper foil can be employed. The composite current collector can include a polymer material base layer and a metal material layer formed on at least one surface of the polymer material base layer. As an example, the metal material can include, but is not limited to, one or more of copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy. As an example, the polymer material base layer can include, but is not limited to, one or more of polypropylene, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene, and polyethylene.

[0120] In some embodiments, the solid electrolyte film can include a solid electrolyte material.

[0121] Optionally, the solid electrolyte material can include one or more of a sulfide solid electrolyte material, a halide solid electrolyte material, and an oxide solid electrolyte material.

[0122] The types of the sulfide solid electrolyte material, the halide solid electrolyte material, and the oxide solid electrolyte material are described above and will not be repeated here.

[0123] In some embodiments, the solid electrolyte film can be obtained by drying the solid electrolyte slurry provided by the present disclosure.

[0124] Optionally, the content of the dispersant in the solid electrolyte film can be 0.3% to 1.5%, based on 100% of the total mass of the solid electrolyte film. The content of the dispersant is the sum of the content of the saturated alkyl acrylate high molecular dispersant and the content of the polar non-ionic high molecular dispersant.

[0125] In some embodiments, the solid-state electrolyte film can have a thickness of 10-50 μm, for example, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, or a range consisting of any of the above values.

[0126] Methods for preparing solid-state battery cells are known. In some embodiments, a positive electrode sheet, a solid-state electrolyte film, and a negative electrode sheet can be assembled to obtain an electrode assembly, and the electrode assembly can be placed in an outer package to obtain a solid-state battery cell.

[0127] The embodiments of the present disclosure also provide a power-using device, which comprises the battery device provided by the embodiments of the present disclosure. The battery device can be used as a power source of the power-using device, or can be used as an energy storage unit of the power-using device. The power-using device can be, but is not limited to, a mobile device (for example, a mobile phone, a tablet computer, a notebook computer, etc.), an electric vehicle (for example, a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, an electric bicycle, an electric scooter, an electric golf cart, an electric truck, etc.), an electric train, a ship and a satellite, an energy storage system, etc.

[0128] The power-using device can select the type of the battery device (for example, a solid-state battery cell, a battery module, or a battery pack) according to the use requirement of the power-using device.

[0129] FIG. 2 is a schematic diagram of a power-using device as an example. The power-using device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc. In order to meet the requirement of high power and high energy density of the power-using device, a battery pack or a battery module can be used.

[0130] The power-using device as another example can be a mobile phone, a tablet computer, a notebook computer, etc. The power-using device usually requires thin and light, and a solid-state battery cell can be used as a power source.

[0131] Embodiments

[0132] The following examples are intended to more specifically describe the present disclosure, and are merely illustrative in nature as various modifications and variations will be apparent to those skilled in the art. Unless otherwise stated, all parts, percentages, and ratios reported in the following examples are based on mass, and all reagents used in the examples are commercially available or synthesized according to conventional methods and used directly without further purification, and the instruments used in the examples are commercially available.

[0133] Comparative Example 1

[0134] The positive active material LiNi 0.8 Co 0.1 Mn 0.1O2, sulfide solid electrolyte material Li6PS5Cl, positive electrode conductive agent vapor grown carbon fiber (VGCF), and positive electrode binder nitrile rubber were weighed and mixed in a solid mass ratio of 80:17:2:1, and then added to a weakly polar solvent dimethylbenzene to prepare a positive electrode slurry. The positive electrode slurry was then coated on both sides of an aluminum foil, dried, and cut to obtain a positive electrode sheet.

[0135] A negative electrode active material silicon-carbon composite material and a negative electrode binder styrene-butadiene rubber were weighed and mixed in a solid mass ratio of 90:10, and then added to a solvent N-methylpyrrolidone to prepare a negative electrode slurry. The negative electrode slurry was then coated on both sides of a copper foil, dried, and cut to obtain a negative electrode sheet. A sulfide solid electrolyte material Li6PS5Cl and a binder nitrile rubber were weighed and mixed in a solid mass ratio of 90:10, and then added to a weakly polar solvent dimethylbenzene to prepare a solid electrolyte slurry. The solid electrolyte slurry was then coated on the surface of the negative electrode film layer prepared above, with a coating thickness of 40 μm, dried, and cut to obtain a negative electrode sheet having a solid electrolyte film layer.

[0136] The negative electrode sheet, the positive electrode sheet, and the negative electrode sheet were sequentially placed in the order of negative electrode sheet-positive electrode sheet-negative electrode sheet to obtain a laminated electrode assembly. The laminated electrode assembly was placed in an outer package to obtain a solid-state battery cell.

[0137] Example 1

[0138] Preparation of dispersant solution

[0139] Polypropyl methacrylate having a weight average molecular weight of 1 million was dissolved in dimethylbenzene at a solid content of 8%, and then polyvinylpyrrolidone was added. The polyvinylpyrrolidone was dissolved by sufficient stirring to obtain a dispersant solution. The solid content mass ratio of the polypropyl methacrylate to the polyvinylpyrrolidone was 90:10.

[0140] Preparation of solid-state battery cell

[0141] A positive electrode active material LiNi 0.8 Co 0.1 Mn 0.1 O2, a sulfide solid electrolyte material Li6PS5Cl, a positive electrode conductive agent vapor grown carbon fiber (VGCF), and a positive electrode binder nitrile rubber were weighed and mixed in a solid mass ratio of 80:17:2:1, and then added to a weakly polar solvent dimethylbenzene to prepare a positive electrode slurry. The positive electrode slurry was then coated on both sides of an aluminum foil, dried, and cut to obtain a positive electrode sheet. In the positive electrode film layer, the positive electrode active material LiNi 0.8 Co 0.1 Mn 0.1 O2, a sulfide solid electrolyte material Li6PS5Cl, a positive electrode conductive agent vapor grown carbon fiber (VGCF), a positive electrode binder nitrile rubber, and a dispersant were weighed and mixed in a solid mass ratio of 80:17:2:1.

[0142] The negative electrode active material silicon-carbon composite material and the negative electrode binder styrene-butadiene rubber are weighed and mixed in a solid mass ratio of 90:10 and added to a solvent N-methyl pyrrolidone to prepare a negative electrode slurry. The negative electrode slurry is then coated on both sides of a copper foil, dried, and a negative electrode sheet is obtained. The sulfide solid electrolyte material Li6PS5Cl and the binder nitrile rubber are weighed and mixed in a solid mass ratio of 90:10 and added to a weakly polar solvent dimethylbenzene to prepare a solid electrolyte slurry. The solid electrolyte slurry is then coated on the surface of the negative electrode film layer prepared above, dried, cut, and a negative electrode sheet with a solid electrolyte film layer is obtained.

[0143] The negative electrode sheet-solid electrolyte film layer-positive electrode sheet-negative electrode sheet are sequentially placed in the order of negative electrode sheet-positive electrode sheet-negative electrode sheet to obtain a laminated electrode assembly. The laminated electrode assembly is placed in an outer package to obtain a solid-state battery monomer.

[0144] Example 2

[0145] The preparation method of the solid-state battery monomer is the same as that of Example 1, except for the following differences.

[0146] Preparation of dispersant solution

[0147] The polypropyl methacrylate with a weight average molecular weight of 1 million is dissolved in dimethylbenzene at a solid content of 8%, and then polyvinylpyrrolidone is added. The polyvinylpyrrolidone is dissolved by stirring to obtain a dispersant solution. The solid content mass ratio of polypropyl methacrylate to polyvinylpyrrolidone is 85:15.

[0148] Example 3

[0149] The preparation method of the solid-state battery monomer is the same as that of Example 1, except for the following differences.

[0150] Preparation of dispersant solution

[0151] The polypropyl methacrylate with a weight average molecular weight of 1 million is dissolved in dimethylbenzene at a solid content of 8%, and then polyvinylpyrrolidone is added. The polyvinylpyrrolidone is dissolved by stirring to obtain a dispersant solution. The solid content mass ratio of polypropyl methacrylate to polyvinylpyrrolidone is 95:5.

[0152] Example 4

[0153] The preparation method of the solid-state battery monomer is the same as that of Example 1, except for the following differences.

[0154] Preparation of dispersant solution

[0155] Poly-n-butyl methacrylate with a weight average molecular weight of 1 million was dissolved in xylene at a solid content of 8%, and then polyvinylpyrrolidone was added. The polyvinylpyrrolidone was dissolved by stirring, to obtain a dispersant solution. The solid content mass ratio of the poly-n-butyl methacrylate to the polyvinylpyrrolidone was 90:10.

[0156] Performance test

[0157] The test temperature was 25°C.

[0158] The solid-state battery monomer was charged at a 0.1C rate to a voltage of 4.25V, and the specific capacity at this time was recorded as the first cycle specific charge capacity. Then, the solid-state battery monomer was rested for 5 minutes, and then discharged at a 0.1C rate to a voltage of 2V, and the specific capacity at this time was recorded as the first cycle specific discharge capacity.

[0159] The first coulombic efficiency (%) = first cycle specific discharge capacity / first cycle specific charge capacity x 100%.

[0160] During the test, two parallel samples were prepared for each example and the comparative example, and the test results are shown in Table 1.

[0161] Table 1

[0162] Figures 3 and 4 show the flowability test results of the positive electrode slurries prepared by the comparative example 1 and the example 1, respectively. As shown in Figure 3, the positive electrode slurry prepared by the comparative example 1 has poor flowability, and the coating quality is poor, and there are obvious particles after the slurry is dried.

[0163] From the above test results, it can be seen that the positive electrode slurry using the dispersant solution of the present disclosure has good coating quality, and can make the solid-state battery monomer have high discharge capacity and high first coulombic efficiency.

[0164] It should be noted that the present disclosure is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and embodiments having the same technical idea and playing the same role within the scope of the technical solutions of the present disclosure are all included in the technical scope of the present disclosure. In addition, within the scope of the main idea of the present disclosure, various modifications that can be thought of by those skilled in the art, and other modes constructed by combining part of the components of the embodiments are also included in the scope of the present disclosure.

Claims

1. A dispersant solution, wherein, The dispersant solution comprises a solvent and a dispersant dissolved in the solvent, the solvent is a non-polar solvent, a weakly polar solvent or a mixed solvent of the two, the dispersant comprises a saturated alkyl acrylate high molecular dispersant and a polar non-ionic high molecular dispersant, the polar non-ionic high molecular dispersant contains at least one of a carboxylic acid group, a carboxylic acid salt, a sulfonic acid group, an amine group, a hydroxyl group and an ether bond.

2. The dispersant solution of claim 1, wherein, The saturated alkyl acrylate-based high-molecular dispersant includes a structural unit represented by Formula 1, R1 is selected from C2 to C10 alkyl, R2, R3, R4 are independently selected from H or C1 to C3 alkyl.

3. The dispersant solution of any of claims 1-2, wherein, The weight average molecular weight of the saturated alkyl acrylate high molecular dispersant is 700,000 to 1,200,000.

4. The dispersant solution of any of claims 1-3, wherein, The polar non-ionic high molecular dispersant comprises one or more of polyacrylic acid, polyacrylic acid salt, polyvinylpyrrolidone, polyvinyl alcohol, polyethylene glycol and polyether dispersant.

5. The dispersant solution of any of claims 1-4, wherein, The mass ratio of the saturated alkyl acrylate high molecular dispersant to the polar non-ionic high molecular dispersant is 85:15 to 95:

5.

6. The dispersant solution of any of claims 1-5, wherein, The solvent comprises one or more of toluene, xylene, mesitylene, chlorobenzene, o-dichlorobenzene, anisole, n-hexane, n-pentane, isopentane, n-heptane, n-octane, isooctane, n-decane, trichlorotrifluoroethane, dichloromethane, trichloromethane, 2-methylpentane, 2,2-dimethylpentane, 3-methylpentane, 2,3-dimethylpentane, 2-methylhexane, 2,2-dimethylhexane, 3-methylhexane, 2,3-dimethylhexane, 3-ethylhexane, cyclohexane, cycloheptane, methylcyclohexane, t-butylcyclohexane, tetrahydrofuran, cyclopentene, cyclohexene, 1-methylcyclohexene, 4-methylcyclohexene, 1-ethylcyclohexene, 1,4-dimethylcyclohexene, 2,4-dimethyl-3-pentanone, cyclohexanone, methylformamide, 1-hexene, 2-hexene, 1-heptene, 2-heptene, 1-octene, 2-octene, dichloroethylene, petroleum ether, trifluoroacetic acid, butyl chloride, trichloroethylene, carbon tetrachloride, propyl ether, diethyl ether, butyl acetate, ethyl acetate.

7. The dispersant solution of any of claims 1-6, wherein, The mass fraction of the dispersant in the dispersant solution is 8% to 12%.

8. A method for preparing the dispersant solution of any one of claims 1 to 7, comprising the following steps: dissolving a saturated alkyl acrylate high molecular dispersant into a solvent to obtain an intermediate solution, the solvent being a non-polar solvent, a weakly polar solvent or a mixed solvent of the two; adding a polar non-ionic high molecular dispersant into the obtained intermediate solution and stirring uniformly to obtain a dispersant solution, the polar non-ionic high molecular dispersant containing at least one of a carboxylic acid group, a carboxylic acid salt, a sulfonic acid group, an amine group and an ether bond.

9. A solid electrolyte slurry comprising a sulfide solid electrolyte material and the dispersant solution of any one of claims 1 to 7 or prepared by the method of claim 8.

10. The solid-state electrolyte slurry of claim 9, wherein, The solid electrolyte slurry further comprises one or more of a halide solid electrolyte material and an oxide solid electrolyte material. The dispersant solution comprises a solvent and a dispersant dissolved in the solvent, the solvent is a non-polar solvent, a weakly polar solvent or a mixed solvent of the two, the dispersant comprises a saturated alkyl acrylate high molecular dispersant and a polar non-ionic high molecular dispersant, the polar non-ionic high molecular dispersant contains at least one of a carboxylic acid group, a carboxylic acid salt, a sulfonic acid group, an amine group, a hydroxyl group and an ether bond. R1 is selected from C2 to C10 alkyl, R2, R3, R4 are independently selected from H or C1 to C3 alkyl. The weight average molecular weight of the saturated alkyl acrylate high molecular dispersant is 700,000 to 1,200,000. The polar non-ionic high molecular dispersant comprises one or more of polyacrylic acid, polyacrylic acid salt, polyvinylpyrrolidone, polyvinyl alcohol, polyethylene glycol and polyether dispersant. The mass ratio of the saturated alkyl acrylate high molecular dispersant to the polar non-ionic high molecular dispersant is 85:15 to 95:

5. The solvent comprises one or more of toluene, xylene, mesitylene, chlorobenzene, o-dichlorobenzene, anisole, n-hexane, n-pentane, isopentane, n-heptane, n-octane, isooctane, n-decane, trichlorotrifluoroethane, dichloromethane, trichloromethane, 2-methylpentane, 2,2-dimethylpentane, 3-methylpentane, 2,3-dimethylpentane, 2-methylhexane, 2,2-dimethylhexane, 3-methylhexane, 2,3-dimethylhexane, 3-ethylhexane, cyclohexane, cycloheptane, methylcyclohexane, t-butylcyclohexane, tetrahydrofuran, cyclopentene, cyclohexene, 1-methylcyclohexene, 4-methylcyclohexene, 1-ethylcyclohexene, 1,4-dimethylcyclohexene, 2,4-dimethyl-3-pentanone, cyclohexanone, methylformamide, 1-hexene, 2-hexene, 1-heptene, 2-heptene, 1-octene, 2-octene, dichloroethylene, petroleum ether, trifluoroacetic acid, butyl chloride, trichloroethylene, carbon tetrachloride, propyl ether, diethyl ether, butyl acetate, ethyl acetate. The mass fraction of the dispersant in the dispersant solution is 8% to 12%.

8. A method for preparing the dispersant solution of any one of claims 1 to 7, comprising the following steps: dissolving a saturated alkyl acrylate high molecular dispersant into a solvent to obtain an intermediate solution, the solvent being a non-polar solvent, a weakly polar solvent or a mixed solvent of the two; adding a polar non-ionic high molecular dispersant into the obtained intermediate solution and stirring uniformly to obtain a dispersant solution, the polar non-ionic high molecular dispersant containing at least one of a carboxylic acid group, a carboxylic acid salt, a sulfonic acid group, an amine group and an ether bond.

9. A solid electrolyte slurry comprising a sulfide solid electrolyte material and the dispersant solution of any one of claims 1 to 7 or prepared by the method of claim 8. The solid electrolyte slurry further comprises one or more of a halide solid electrolyte material and an oxide solid electrolyte material.

11. An electrode slurry comprising a positive active material, a sulfide solid-state electrolyte material, a positive conductive agent, a positive binder, and the dispersant solution of any one of claims 1-7 or prepared by the method of claim 8.

12. An electrode slurry comprising a negative active material, a sulfide solid-state electrolyte material, a negative binder, and the dispersant solution of any one of claims 1-7 or prepared by the method of claim 8.

13. A solid state battery cell, wherein, the solid-state battery cell comprises a positive electrode sheet, a solid-state electrolyte film, and a negative electrode sheet, the solid-state electrolyte film is located between the positive electrode sheet and the negative electrode sheet, the positive electrode sheet comprises a positive electrode current collector and a positive electrode film layer located on at least one surface of the positive electrode current collector, the positive electrode film layer is obtained by drying the electrode slurry of claim 11; and / or, the solid-state electrolyte film is obtained by drying the solid-state electrolyte slurry of any one of claims 9-10.

14. The solid state battery cell of claim 13, wherein, the negative electrode sheet comprises a negative electrode current collector and a lithium-based metal layer located on at least one surface of the negative electrode current collector.

15. The solid state battery cell of claim 13, wherein, the negative electrode sheet comprises a negative electrode current collector and a negative electrode film layer located on at least one surface of the negative electrode current collector, the negative electrode film layer is obtained by drying the electrode slurry of claim 12.

16. An electric device comprising the solid-state battery cell of any one of claims 13-15.

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