Solid electrolyte slurry, electrode slurry, solid electrolyte sheet, electrode sheet, solid battery cell, battery device, and electric device

Abstract

The invention provides a solid electrolyte slurry, an electrode slurry, a solid electrolyte sheet, an electrode sheet, a solid battery monomer, a battery device and a power utilization device.The solid electrolyte slurry comprises a sulfide solid electrolyte material, a solvent and a binder dissolved in the solvent, and the solvent is a non-polar solvent, a weak-polar solvent or a mixed solvent of the non-polar solvent and the weak-polar solvent; the binding agent comprises a polyacrylate binding agent and a non-polar polyolefin binding agent. The slurry disclosed by the invention has high dispersity, high suspension property and good cohesiveness, and can enable the solid-state battery monomer to have high initial coulombic efficiency when being used in the solid-state battery monomer.

Description

Technical Field

[0001] This disclosure relates to a solid electrolyte slurry, an electrode slurry, a solid electrolyte sheet, an electrode sheet, a solid battery cell, a battery device, and an electrical device. Background Technology

[0002] Solid-state battery cells use solid electrolyte sheets instead of non-aqueous organic electrolytes. Since solid electrolyte sheets cannot spontaneously permeate into the electrodes, solid electrolyte materials are usually used in combination with electrode active materials to improve the electrode's ion transport characteristics. Sulfide solid electrolyte materials are currently one of the ideal solid electrolyte materials; however, their oxidation and reduction resistance are poor, resulting in a limited range of solvents and binders that can be used. This also leads to poor dispersibility of slurries containing sulfides, making them prone to gelation and sedimentation problems. Summary of the Invention

[0003] This disclosure provides a solid electrolyte slurry, an electrode slurry, a solid electrolyte sheet, an electrode sheet, a solid battery cell, a battery device, and an electrical device. The slurry has high dispersibility, high suspension, and good adhesion. When used in a solid battery cell, it enables the solid battery cell to have a high initial coulombic efficiency.

[0004] In a first aspect, this disclosure provides a solid electrolyte slurry, the solid electrolyte slurry comprising a sulfide solid electrolyte material, a solvent, and a binder dissolved in the solvent, wherein the solvent is a nonpolar solvent, a weakly polar solvent, or a mixture thereof, and the binder comprises a polyacrylate binder and a nonpolar polyolefin binder; the polyacrylate binder comprises a structural unit shown in Formula 1, wherein R1 is selected from C2 to C10 alkyl, and R2, R3, and R4 are each independently selected from H or C1 to C3 alkyl.

[0005]

[0006] By including both polyacrylate binders and non-polar polyolefin binders in the binder, the slurry can exhibit high dispersibility, high suspension, and good adhesion, thus improving sedimentation and gelation issues. Simultaneously, it enhances the adhesion between the solid electrolyte sheet and the electrode. Furthermore, the polyacrylate binders and non-polar polyolefin binders disclosed herein do not react with the sulfide solid electrolyte material, minimizing their impact on the ionic conductivity of the sulfide solid electrolyte material. When used in solid-state battery cells, the solid electrolyte slurry of this disclosure can also enable the solid-state battery cells to achieve high initial coulombic efficiency.

[0007] In some embodiments, the nonpolar polyolefin adhesive includes a homopolymer nonpolar polyolefin adhesive selected from one of the following monomers, and one or more copolymer nonpolar polyolefin adhesives selected from two or more of the following monomers: ethylene, propylene, butene, isobutene, pentene, hexene, heptyl, octene, butadiene, pentene, isoprene, hexadiene, octadiene, 2,3-dimethyl-1,3-butadiene, 3-methyl-1,3-pentadiene, and 4-methyl-1,3-pentadiene.

[0008] In some embodiments, the nonpolar polyolefin adhesive includes one or more of polyethylene, polypropylene, polybutene, polyisobutylene, polybutadiene, polyisoprene, ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-octene copolymer, ethylene-propylene-butene copolymer, ethylene-propylene-octene copolymer, isoprene-butadiene copolymer, ethylene-isoprene copolymer, and ethylene-hexadiene copolymer.

[0009] Non-polar polyolefin binders within the above-mentioned range can dissolve well in solvents and give the slurry good suspension stability.

[0010] In some embodiments, the mass ratio of the polyacrylate adhesive to the nonpolar polyolefin adhesive is 50:50 to 95:5.

[0011] When the mass ratio of polyacrylate binder to non-polar polyolefin binder is within the above range, the slurry can better combine high dispersibility, high suspension and good adhesion, and can also enable solid-state battery cells to have higher initial coulombic efficiency.

[0012] In some embodiments, the weight-average molecular weight of the polyacrylate adhesive is 900,000 to 2,000,000.

[0013] Polyacrylate adhesives with a weight-average molecular weight within the above range can dissolve well in solvents and give the slurry good dispersibility and adhesion.

[0014] In some embodiments, the weight-average molecular weight of the nonpolar polyolefin adhesive is 450,000 to 850,000.

[0015] Non-polar polyolefin binders with a weight-average molecular weight within the above range can dissolve well in solvents and give the slurry good suspension stability.

[0016] In some embodiments, the solvent includes toluene, xylene, trimethylbenzene, 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, and so on. One or more of the following: cyclohexane, tert-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, vinyl dichloride, petroleum ether, trifluoroacetic acid, butyl chloride, trichloroethylene, carbon tetrachloride, propyl ether, diethyl ether, butyl acetate, and ethyl acetate.

[0017] In some embodiments, the solid electrolyte slurry further includes one or more of halide solid electrolyte materials and oxide solid electrolyte materials.

[0018] In a second aspect, this disclosure provides a solid electrolyte sheet obtained by drying the solid electrolyte slurry of the first aspect.

[0019] Thirdly, this disclosure provides an electrode slurry, which is a positive electrode slurry, comprising a positive active material, a positive conductive agent, and a solid electrolyte slurry as described in the first aspect.

[0020] This can improve the sedimentation and gelation problems of the positive electrode slurry, enhance the coating quality of the positive electrode slurry, improve the adhesion of the positive electrode sheet, increase the ionic conductivity of the positive electrode sheet, reduce the impedance of the positive electrode sheet, and enable solid-state battery cells to have high initial coulombic efficiency.

[0021] Fourthly, this disclosure provides an electrode sheet comprising a positive current collector and a positive electrode film layer located on at least one surface of the positive current collector, the positive electrode film layer being obtained by drying an electrode slurry according to the third aspect.

[0022] Fifthly, this disclosure provides an electrode slurry, the electrode slurry being a negative electrode slurry, the negative electrode slurry comprising a negative electrode active material and a solid electrolyte slurry as described in the first aspect.

[0023] This can improve the sedimentation and gelation problems of the negative electrode slurry, enhance the coating quality of the negative electrode slurry, improve the adhesion of the negative electrode sheet, increase the ionic conductivity of the negative electrode sheet, reduce the impedance of the negative electrode sheet, and enable solid-state battery cells to have high initial coulombic efficiency.

[0024] In some embodiments, the electrode slurry further includes a negative electrode conductive agent.

[0025] In a sixth aspect, this disclosure provides an electrode sheet comprising a negative current collector and a negative electrode film layer located on at least one surface of the negative current collector, the negative electrode film layer being obtained by drying the electrode slurry of the fifth aspect.

[0026] In a seventh aspect, this disclosure provides a solid-state battery cell comprising a positive electrode, a solid electrolyte sheet, and a negative electrode, wherein the solid electrolyte sheet is located between the positive electrode and the negative electrode, the positive electrode comprising a positive current collector and a positive electrode film layer located on at least one surface of the positive current collector, the positive electrode film layer being obtained by drying an electrode slurry according to a third aspect; and / or, the solid electrolyte sheet being obtained by drying a solid electrolyte slurry according to a first aspect.

[0027] In some embodiments, the negative electrode includes a negative current collector and a lithium-based metal layer located on at least one surface of the negative current collector.

[0028] In some embodiments, the negative electrode sheet includes a negative current collector and a negative electrode film layer located on at least one surface of the negative current collector, the negative electrode film layer being obtained by drying an electrode slurry of the fifth aspect.

[0029] Eighthly, this disclosure provides a battery device comprising a plurality of solid-state battery cells as described in the seventh aspect.

[0030] Ninthly, this disclosure provides an electrical device that includes a solid-state battery cell (as described in the seventh aspect) or a battery device (as described in the eighth aspect). Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings used in the embodiments of this disclosure will be briefly described below. Obviously, the drawings described below are merely some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on the drawings without any creative effort.

[0032] Figure 1 A schematic diagram of a solid-state battery cell provided in some embodiments of this disclosure is shown.

[0033] Figure 2 A schematic diagram of an electrical device provided in some embodiments of this disclosure is shown.

[0034] The accompanying drawings are not necessarily drawn to scale. Detailed Implementation

[0035] The following detailed description, with appropriate reference to the accompanying drawings, specifically discloses embodiments of the solid electrolyte slurry, electrode slurry, solid electrolyte sheet, electrode sheet, solid-state battery cell, battery device, and power supply device of this disclosure. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of practically identical structures may be omitted. This is to avoid unnecessarily lengthy descriptions and to facilitate understanding by those skilled in the art. Furthermore, the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand this disclosure and are not intended to limit the subject matter of the claims.

[0036] The "range" disclosed in this disclosure is defined by a lower limit and an upper limit, whereby a given range is defined by selecting a lower limit and an upper limit, which define the boundaries of the particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also expected. Furthermore, if minimum range values ​​1 and 2 are listed, and if maximum range values ​​3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this disclosure, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0037] Unless otherwise specified, all embodiments and optional embodiments of this disclosure may be combined with each other to form new technical solutions, and such technical solutions should be considered as included in the disclosure of this disclosure.

[0038] Unless otherwise specified, all technical features and optional technical features of this disclosure can be combined to form new technical solutions, and such technical solutions should be considered as included in the disclosure of this disclosure.

[0039] Unless otherwise specified, all steps in this disclosure may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order; for example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0040] Unless otherwise specified, in this disclosure, the terms "first," "second," etc., are used to distinguish different objects, rather than to describe a specific order or primary / secondary relationship.

[0041] In this disclosure, the terms "multiple" or "a variety" refer to two or more kinds.

[0042] In the description of the embodiments of this disclosure, unless otherwise specified, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0043] Unless otherwise stated, the test temperature for all parameters mentioned in this disclosure is 25°C.

[0044] The solid-state battery cell mentioned in the embodiments of this disclosure can independently perform charge and discharge functions. After discharge, it can be reactivated by charging to allow for continued use. The solid-state battery cell can be cylindrical, cuboid, or other shapes, and the embodiments of this disclosure are not limited in this regard. Figure 1 This is an example of a rectangular solid-state battery cell 5.

[0045] The battery apparatus mentioned in the embodiments of this disclosure may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly may include multiple solid-state battery cells, which are connected in series, parallel, or mixed connections via busbars.

[0046] In some embodiments, a battery cell assembly is typically formed by arranging multiple solid-state battery cells.

[0047] As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple solid-state battery cells together to form an independent module. As another example, a battery module can be formed by bundling multiple solid-state battery cells together with cable ties.

[0048] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cells housed within the housing.

[0049] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0050] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple solid-state battery cells to the housing.

[0051] As an example, the enclosure may include a first enclosure and a second enclosure. The first enclosure and the second enclosure are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first enclosure may be a top cover or a bottom plate.

[0052] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0053] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0054] The technical solutions described in this disclosure are applicable to various electrical devices that use solid-state battery cells or battery devices, such as, but not limited to, mobile devices (e.g., mobile phones, tablets, laptops, etc.), electric vehicles (e.g., pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc. Solid-state battery cells and battery devices are used to store or provide electrical energy.

[0055] Figure 2 This is a schematic diagram of an example electrical device. The device could be a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc.

[0056] Due to the unique structure of sulfide solid electrolyte materials, their oxidation and reduction resistance are poor, thus requiring the matching solvents and binders to be weakly polar or non-polar. Furthermore, sulfide solid electrolyte materials typically have small particle sizes and large specific surface areas, which can lead to dispersion problems in slurries containing sulfide solid electrolyte materials, such as slurry gelation and sedimentation.

[0057] Currently, traditional binders used in lithium-ion batteries, such as polyvinylidene fluoride (PVDF), styrene-butadiene rubber (SBR), sodium carboxymethyl cellulose (CMC), and polyacrylic acid (PAA), are unsuitable for slurry systems containing sulfide solid electrolyte materials. Solid-state battery cells typically use binders such as nitrile butadiene rubber (NBR), hydrogenated nitrile butadiene rubber (HNBR), and SEBS (a linear triblock copolymer with polystyrene as the end segment and ethylene-butene copolymer obtained by hydrogenating polybutadiene as the middle elastic block). However, these binders cannot simultaneously improve the sedimentation and gelation problems of the slurry, and they also lead to a significant loss of ionic conductivity, resulting in a low initial coulombic efficiency of solid-state battery cells.

[0058] Based on this, the present disclosure provides a solid electrolyte slurry with high dispersibility and high suspension properties, which, when used in solid-state battery cells, enables the solid-state battery cells to have high initial coulombic efficiency.

[0059] The solid electrolyte slurry disclosed herein includes a sulfide solid electrolyte material, a solvent, and a binder dissolved in the solvent. The solvent is a non-polar solvent, a weakly polar solvent, or a mixture of both. The binder includes polyacrylate binders and non-polar polyolefin binders.

[0060] Polyacrylate adhesives include the structural units shown in Formula 1, where R1 is selected from C2 to C10 alkyl groups, and R2, R3, and R4 are each independently selected from H or C1 to C3 alkyl groups.

[0061]

[0062] The R1 group in the molecular structure of polyacrylate binders is selected from C2 to C10 alkyl groups. These are nonpolar groups with lipophilic properties, while the ester groups exhibit weak polarity and hydrophilicity. This allows polyacrylate binders to have a dispersing effect, while the ester groups in their molecular structure provide strong adhesive properties. Therefore, polyacrylate binders possess both dispersibility and high adhesiveness. However, they suffer from poor long-term suspension stability in nonpolar and / or weakly polar solvents, resulting in poor slurry storage performance.

[0063] Non-polar polyolefin binders can be stably and uniformly dispersed in non-polar and / or weakly polar solvents for a long time. Their molecular structure consists entirely of non-polar segments, and their interaction with sulfide solid electrolyte material particles is weak. This reduces the formation of agglomerates with sulfide solid electrolyte material particles, thus reducing sedimentation problems in the slurry and providing good anti-settling effects. However, their molecular structure does not contain strongly adhesive functional groups.

[0064] By including both polyacrylate binders and non-polar polyolefin binders in the binder, the slurry can exhibit high dispersibility, high suspension, and good adhesion, thus improving sedimentation and gelation issues. Simultaneously, it enhances the adhesion between the solid electrolyte sheet and the electrode. Furthermore, the polyacrylate binders and non-polar polyolefin binders disclosed herein do not react with the sulfide solid electrolyte material, minimizing their impact on the ionic conductivity of the sulfide solid electrolyte material. When used in solid-state battery cells, the solid electrolyte slurry of this disclosure can also enable the solid-state battery cells to achieve high initial coulombic efficiency.

[0065] R1 is selected from C2 to C10 alkyl groups. R1 can be a straight-chain alkyl group or a branched-chain alkyl group. For example, R1 can be ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, pentyl, hexyl, heptyl, octyl, nonyl, or decyl.

[0066] Alternatively, R1 may be selected from C3 to C8 alkyl groups.

[0067] Within the above range, R1 can both ensure that the polyacrylate binder is well dissolved in the solvent and that the slurry containing the polyacrylate binder has good dispersibility and adhesion.

[0068] R2, R3, and R4 are each independently selected from H or C1 to C3 alkyl groups. Optionally, R2, R3, and R4 are each independently selected from H or methyl groups. More preferably, R2 is selected from methyl groups, and R3 and R4 are selected from H groups.

[0069] R2, R3, and R4, within the aforementioned range, can both ensure that the polyacrylate binder dissolves well in the solvent and that the slurry containing the polyacrylate binder has good dispersibility and adhesion.

[0070] In some embodiments, the weight-average molecular weight of the polyacrylate adhesive can be 900,000 to 2,000,000, for example, 900,000, 1,000,000, 1,100,000, 1,200,000, 1,300,000, 1,400,000, 1,500,000, 1,600,000, 1,700,000, 1,800,000, 1,900,000, 2,000,000, or any range of the above values.

[0071] Polyacrylate adhesives with a weight-average molecular weight within the above range can dissolve well in solvents and give the slurry good dispersibility and adhesion.

[0072] In some embodiments, the nonpolar polyolefin adhesive may include a homopolymer nonpolar polyolefin adhesive selected from one of the following monomers, or one or more copolymer nonpolar polyolefin adhesives selected from two or more of the following monomers: ethylene, propylene, butene, isobutene, pentene, hexene, heptyl, octene, butadiene, pentene, isoprene, hexadiene, octadiene, 2,3-dimethyl-1,3-butadiene, 3-methyl-1,3-pentadiene, and 4-methyl-1,3-pentadiene.

[0073] In some embodiments, nonpolar polyolefin adhesives may include one or more of polyethylene, polypropylene, polybutene, polyisobutylene, polybutadiene, polyisoprene, ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-octene copolymer, ethylene-propylene-butene copolymer, ethylene-propylene-octene copolymer, isoprene-butadiene copolymer, ethylene-isoprene copolymer, and ethylene-hexadiene copolymer.

[0074] Non-polar polyolefin binders within the above-mentioned range can dissolve well in solvents and give the slurry good suspension stability.

[0075] In some embodiments, the weight-average molecular weight of the nonpolar polyolefin adhesive can be 450,000 to 850,000, for example, it can be 450,000, 480,000, 500,000, 520,000, 540,000, 560,000, 580,000, 600,000, 620,000, 640,000, 660,000, 680,000, 700,000, 720,000, 740,000, 760,000, 780,000, 800,000, 820,000, 850,000, or any combination of the above values.

[0076] Non-polar polyolefin binders with a weight-average molecular weight within the above range can dissolve well in solvents and give the slurry good suspension stability.

[0077] The weight-average molecular weight of polyacrylate adhesives and non-polar polyolefin adhesives refers to the weight-average molecular weight calculated using gel permeation chromatography (GPC) and converted to standard polystyrene.

[0078] In some embodiments, the mass ratio of polyacrylate adhesive to nonpolar polyolefin adhesive can be from 50:50 to 95:5, for example, 50:50, 51:49, 52:48, 53:47, 54:46, 55:45, 56:44, 57:43, 58:42, 59:41, 60:40, 61:39, 62:38, 63:37, 64:36, 65:35, 66:34, 67:33, 68:32, 69 :31, 70:30, 71:29, 72:28, 73:27, 74:26, 75:25, 76:24, 77:23, 78:22, 79:21, 80:20, 81:19, 82:18, 83:17, 84:16, 85:15, 86:14, 87:13, 88:12, 89:11, 90:10, 91:9, 92:8, 93:7, 94:6, 95:5, or any range of the above values.

[0079] When the mass ratio of polyacrylate binder to non-polar polyolefin binder is within the above range, the slurry can better combine high dispersibility, high suspension and good adhesion, and can also enable solid-state battery cells to have higher initial coulombic efficiency.

[0080] Optionally, the mass ratio of polyacrylate adhesive to non-polar polyolefin adhesive can be 50:50 to 90:10, 50:50 to 85:15, 50:50 to 80:20, 55:45 to 90:10, 55:45 to 85:15, 55:45 to 80:20, 60:40 to 90:10, 60:40 to 85:15, or 60:40 to 80:20.

[0081] The solvent is a nonpolar solvent, a weakly polar solvent, or a mixture of both. In some embodiments, the solvent may include, but is not limited to, toluene, xylene, trimethylbenzene, 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- The following are one or more of the following: ethylhexane, cyclohexane, cycloheptane, methylcyclohexane, tert-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, vinyl dichloride, petroleum ether, trifluoroacetic acid, butyl chloride, trichloroethylene, carbon tetrachloride, propyl ether, diethyl ether, butyl acetate, and ethyl acetate.

[0082] In some embodiments, the sulfide solid electrolyte material may include one or more of Li6PS5X, LGPS-based sulfide solid electrolyte materials, and poly-sulfide solid electrolyte materials, where X includes one or more elements selected from F, Cl, Br, and I.

[0083] Optionally, the LGPS-based sulfide solid electrolyte material may include Li

[0086] ,

[0087] , 11 ,

[0089] , 10 ,

[0088] , , , , 12 , 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 includes one or two elements selected from Si and Sn, Q includes Sb, and W includes one or more elements selected from O, Se, Te, Cl, Br, I, and F.

[0084] Optionally, the poly-sulfide solid electrolyte material may include one or more of Li2S-P2S5, Li2S-SiS2, Li2S-GeS2, (100 - u - v)Li2S·uP2S5·vM m N n where 0 < u < 100, 0 < v < 100, 0 < u + v < 100, 0 ≤ m < 4, 0 ≤ n < 6, M includes one or more elements selected from Li, B, Ge, Si, Sn, and Sb, and N includes one or more elements selected from S, Se, Te, O, Cl, Br, I, and F.

[0085] In some embodiments, by way of example, the sulfide solid electrolyte material may include one or more of Li6PS5Cl, Li6PS5Br, Li 10 GeP2S 12 、Li3PS4、Li7P3S 11 among others.

[0086] In some embodiments, the average particle size of the sulfide solid electrolyte material may be 50 nm - 5 μm.

[0087] In some embodiments, the solid electrolyte slurry may further include one or more of halide solid electrolyte materials and oxide solid electrolyte materials.

[0088] In some embodiments, the halide solid electrolyte material may include one or more of Li3YCl6, Li3YBr6, Li3ErCl6, Li3InCl6, and Li3InBr6.

[0089] In some embodiments, the oxide solid electrolyte material may include one or more of the following: perovskite structure oxide solid electrolyte material, garnet structure oxide solid electrolyte material, NASICON structure oxide solid electrolyte material, and LISICON structure oxide solid electrolyte material.

[0090] This disclosure also provides a method for preparing a solid electrolyte slurry, which can prepare the solid electrolyte slurry provided in this disclosure.

[0091] The preparation method of solid electrolyte slurry includes the following steps: stirring sulfide solid electrolyte material, polyacrylate binder and non-polar polyolefin binder in a solvent to obtain solid electrolyte slurry. The solvent is a non-polar solvent, a weakly polar solvent or a mixture of the two.

[0092] This disclosure also provides a solid electrolyte sheet, which is obtained by drying the solid electrolyte slurry provided in this disclosure.

[0093] In some embodiments, the total mass content of polyacrylate binders and non-polar polyolefin binders in the solid electrolyte sheet, based on 100% of the total mass of the solid electrolyte sheet, can be 0.5%-10%, for example, it can be 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, or any range of the above values.

[0094] In some embodiments, the thickness of the solid electrolyte sheet can be 10 μm-50 μm.

[0095] This disclosure also provides an electrode paste. The electrode paste can be a positive electrode paste or a negative electrode paste.

[0096] In some embodiments, the electrode slurry is a positive electrode slurry, which may include a positive electrode active material, a positive electrode conductive agent, and a solid electrolyte slurry provided in this disclosure.

[0097] This can improve the sedimentation and gelation problems of the positive electrode slurry, enhance the coating quality of the positive electrode slurry, improve the adhesion of the positive electrode sheet, increase the ionic conductivity of the positive electrode sheet, reduce the impedance of the positive electrode sheet, and enable solid-state battery cells to have high initial coulombic efficiency.

[0098] In some embodiments, the positive electrode active material may include one or more of lithium transition metal oxides and their modified forms, lithium phosphates and their modified forms, lithium titanate, sulfur, selenium, and tellurium.

[0099] Optionally, examples of lithium transition metal oxides may 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, and lithium nickel cobalt aluminum oxide.

[0100] Optionally, examples of lithium phosphates may include, but are not limited to, one or more of lithium iron phosphate, lithium iron phosphate and carbon composites, lithium manganese phosphate, lithium manganese phosphate and carbon composites, lithium manganese iron phosphate, and lithium manganese iron phosphate and carbon composites.

[0101] In some embodiments, to further improve the energy density of a solid-state battery cell, the positive electrode active material may include materials of the general formula Li. a Ni b Co c M d O e A f One or more of lithium transition metal oxides and their modified materials. 0.8≤a≤1.2, 0.5≤b<1, 0<c<1, 0<d<1, 1≤e≤2, 0≤f≤1, M may include one or more of Mn, Al, Zr, Zn, Cu, Cr, Mg, Fe, V, Ti and B, and A may include one or more of N, F, S and Cl.

[0102] As an example, the positive electrode active material may include, but is not limited to, LiCoO2, LiNiO2, LiMnO2, LiMn2O4, and 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 One or more of O2, LiFePO4, LiMnPO4 and their respective modified materials.

[0103] During the charging and discharging process, solid-state battery cells undergo Li insertion / extraction and consumption, resulting in varying Li molar content at different discharge states. In this disclosure, the Li molar content listed for positive electrode active materials represents the initial state of the material, i.e., the state before material addition. As the positive electrode active material is applied to a solid-state battery cell, the Li molar content changes after charge-discharge cycles. Similarly, the O molar content listed for positive electrode active materials in this disclosure is only a theoretical value; lattice oxygen release causes changes in the O molar content, leading to fluctuations in the actual O molar content.

[0104] The modified materials for the above-mentioned positive electrode active materials can be the positive electrode active materials through doping modification and / or surface coating modification.

[0105] In some embodiments, the positive electrode conductive agent may be one or more of the following: superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, carbon nanofibers, and vapor-grown carbon fibers (VGCF).

[0106] This disclosure also provides a method for preparing a positive electrode slurry, which can prepare the positive electrode slurry of this disclosure.

[0107] In some embodiments, the preparation method of the positive electrode slurry includes the following steps: stirring the sulfide solid electrolyte material, polyacrylate binder, and non-polar polyolefin binder in a solvent to obtain a solid electrolyte slurry, wherein the solvent is a non-polar solvent, a weakly polar solvent, or a mixture of the two; adding the positive electrode active material and the positive electrode conductive agent to the solid electrolyte slurry and stirring to obtain a positive electrode slurry.

[0108] In some other embodiments, the preparation method of the positive electrode slurry includes the following steps: stirring the positive electrode active material, positive electrode conductive agent, sulfide solid electrolyte material, polyacrylate binder, and non-polar polyolefin binder in a solvent to obtain the positive electrode slurry, wherein the solvent is a non-polar solvent, a weakly polar solvent, or a mixture of the two.

[0109] This disclosure also provides a positive electrode sheet, which is obtained by drying the positive electrode slurry provided in this disclosure.

[0110] In some embodiments, the electrode slurry is a negative electrode slurry, which may include a negative electrode active material and the solid electrolyte slurry provided in this disclosure.

[0111] This can improve the sedimentation and gelation problems of the negative electrode slurry, enhance the coating quality of the negative electrode slurry, improve the adhesion of the negative electrode sheet, increase the ionic conductivity of the negative electrode sheet, reduce the impedance of the negative electrode sheet, and enable solid-state battery cells to have high initial coulombic efficiency.

[0112] In some embodiments, the negative electrode active material may include, but is not limited to, one or more of natural graphite, artificial graphite, mesophase microcarbon spheres, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, and metal oxides. Optionally, the silicon-based material may include, but is not limited to, one or more of elemental silicon, silicon oxides, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Optionally, the tin-based material may include, but is not limited to, one or more of elemental tin, tin oxides, and tin alloys. Optionally, the metal oxide includes one or more of TiO2, MoO2, In2O3, Al2O3, Cu2O, VO2, Ga2O3, Sb2O5, and Bi2O5.

[0113] In some embodiments, the negative electrode slurry may further include a negative electrode conductive agent. Optionally, the negative electrode conductive agent may be one or more of the following: superconducting carbon, conductive graphite, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, carbon nanofibers, and vapor-grown carbon fibers (VGCF).

[0114] This disclosure also provides a method for preparing a negative electrode slurry, which can prepare the negative electrode slurry of this disclosure.

[0115] In some embodiments, the method for preparing the negative electrode slurry includes the following steps: stirring a sulfide solid electrolyte material, a polyacrylate binder, and a non-polar polyolefin binder in a solvent to obtain a solid electrolyte slurry, wherein the solvent is a non-polar solvent, a weakly polar solvent, or a mixture of both; adding a negative electrode active material and an optional negative electrode conductive agent to the solid electrolyte slurry and stirring to obtain a negative electrode slurry.

[0116] In some other embodiments, the method for preparing the negative electrode slurry includes the following steps: stirring the negative electrode active material, optional negative electrode conductive agent, sulfide solid electrolyte material, polyacrylate binder, and non-polar polyolefin binder in a solvent to obtain the negative electrode slurry, wherein the solvent is a non-polar solvent, a weakly polar solvent, or a mixture of both.

[0117] This disclosure also provides a negative electrode sheet, which is obtained by drying the negative electrode slurry provided in this disclosure.

[0118] This disclosure also provides a solid-state battery cell, which includes a positive electrode, a solid electrolyte sheet, and a negative electrode, with the solid electrolyte sheet located between the positive electrode and the negative electrode.

[0119] [Positive electrode tablets]

[0120] In some embodiments, the positive electrode sheet may include a positive current collector and a positive electrode film layer located on at least one surface of the positive current collector. The positive electrode film layer includes a positive active material, a positive conductive agent, a sulfide solid electrolyte material, a polyacrylate binder, and a non-polar polyolefin binder. The types of positive active material, positive conductive agent, sulfide solid electrolyte material, polyacrylate binder, and non-polar polyolefin binder can be referred to above and will not be repeated here. Alternatively, the positive electrode film layer may be obtained by drying the positive electrode slurry provided in this disclosure.

[0121] The positive electrode current collector has two surfaces opposite each other in its thickness direction, and the positive electrode film layer is disposed on either or both of the two opposite surfaces of the positive electrode current collector.

[0122] In some embodiments, the mass content of sulfide solid electrolyte material in the positive electrode film layer can be 5%-25% based on the total mass of the positive electrode film layer as 100%, for example, it can be 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, or any range of the above values.

[0123] In some embodiments, the total mass content of polyacrylate binders and non-polar polyolefin binders in the positive electrode film layer, based on 100% of the total mass of the positive electrode film layer, can be 0.5%-10%, for example, it can be 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, or any range of the above values.

[0124] In some embodiments, the positive current collector may be a metal foil or a composite current collector. Examples of metal foils include aluminum foil, carbon-coated aluminum foil, and stainless steel foil. The composite current collector may include a polymer substrate and a metal layer formed on at least one surface of the polymer substrate. Examples of metal materials include, but are not limited to, one or more of aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys. Examples of polymer substrates include, but are not limited to, one or more of polypropylene, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene.

[0125] [Negative electrode plate]

[0126] In some embodiments, the negative electrode sheet may include a negative current collector and a lithium-based metal layer located on at least one surface of the negative current collector. The negative current collector has two surfaces opposite each other in its thickness direction, and the lithium-based metal layer is disposed on either or both of the two opposite surfaces of the negative current collector.

[0127] In some embodiments, the lithium-based metal layer may include lithium or a lithium alloy, wherein the lithium alloy contains more than 90% lithium by mass.

[0128] Alternatively, other elements in the lithium alloy may include one or more of In, Mg, Al, Zn, Sn, Ag, Au, Ga, Pt, and Fe.

[0129] Alternatively, lithium alloys may include Li-In alloys, Li-Mg alloys, Li-Al alloys, Li-Zn alloys, Li-Fe alloys, etc.

[0130] In other embodiments, the negative electrode sheet may include 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 including a negative electrode active material and a negative electrode binder. The negative electrode current collector has two surfaces opposite each other in its thickness direction, and the negative electrode film layer is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0131] In some embodiments, the negative electrode active material may include, but is not limited to, one or more of natural graphite, artificial graphite, mesophase microcarbon spheres, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, and metal oxides. Optionally, the silicon-based material may include, but is not limited to, one or more of elemental silicon, silicon oxides, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Optionally, the tin-based material may include, but is not limited to, one or more of elemental tin, tin oxides, and tin alloys. Optionally, the metal oxide includes one or more of TiO2, MoO2, In2O3, Al2O3, Cu2O, VO2, Ga2O3, Sb2O5, and Bi2O5.

[0132] Optionally, the negative electrode binder may include one or more of the following: methyl vinyl silicone rubber, nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), styrene-butadiene rubber (SBR), thermoplastic styrene-butadiene rubber (SBS), isoprene rubber, cis-butadiene rubber (BR), ethyl cellulose, fluororubber, and acrylate rubber.

[0133] Optionally, the negative electrode film layer may also include a negative electrode conductive agent. The negative electrode conductive agent may include, but is not limited to, one or more of superconducting carbon, conductive graphite, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, carbon nanofibers, and vapor-grown carbon fibers (VGCF).

[0134] In some other embodiments, the negative electrode sheet may include 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 includes a negative electrode active material, a sulfide solid electrolyte material, a polyacrylate binder, and a non-polar polyolefin binder. The types of negative electrode active material, sulfide solid electrolyte material, polyacrylate binder, and non-polar polyolefin binder can be referred to above and will not be repeated here. Alternatively, the negative electrode film layer may be obtained by drying the negative electrode slurry provided in this disclosure.

[0135] Optionally, based on the total mass of the negative electrode film layer as 100%, the mass content of the sulfide solid electrolyte material in the negative electrode film layer can be 5%-25%, for example, it can be 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, or any combination of the above values.

[0136] Optionally, based on the total mass of the negative electrode film layer as 100%, the total mass content of polyacrylate binders and non-polar polyolefin binders in the negative electrode film layer can be 0.5%-10%, for example, it can be 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, or any combination of the above values.

[0137] Optionally, the negative electrode film layer may also include a negative electrode conductive agent. The negative electrode conductive agent may include, but is not limited to, one or more of superconducting carbon, conductive graphite, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, carbon nanofibers, and vapor-grown carbon fibers (VGCF).

[0138] In some embodiments, the negative electrode current collector may be a metal foil or a composite current collector. Examples of metal foils include copper foil, nickel foil, copper alloy foil, and nickel alloy foil. The composite current collector may include a polymer substrate and a metal layer formed on at least one surface of the polymer substrate. Examples of metal materials include, but are not limited to, one or more of copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys. Examples of polymer substrates include, but are not limited to, one or more of polypropylene, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene, and polyethylene.

[0139] [Solid Electrolyte Sheets]

[0140] In some embodiments, the solid electrolyte sheet includes a solid electrolyte material. Optionally, the solid electrolyte material may include one or more of sulfide solid electrolyte materials, halide solid electrolyte materials, and oxide solid electrolyte materials. The types of sulfide solid electrolyte materials, halide solid electrolyte materials, and oxide solid electrolyte materials can be found above and will not be repeated here.

[0141] Optionally, the solid electrolyte sheet may also include a binder. The binder may include, but is not limited to, one or more of the following: polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), PVDF-tetrafluoroethylene-propylene terpolymer, PVDF-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, styrene-butadiene rubber (SBR), water-soluble unsaturated resin SR-1B, methyl vinyl silicone rubber, nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), thermoplastic styrene-butadiene rubber (SBS), isoprene rubber, butadiene rubber (BR), ethyl cellulose, fluororubber, and acrylate rubber.

[0142] In other embodiments, the solid electrolyte sheet may include a sulfide solid electrolyte material, a polyacrylate binder, and a non-polar polyolefin binder. The types of sulfide solid electrolyte material, polyacrylate binder, and non-polar polyolefin binder can be referred to above and will not be repeated here; or, the solid electrolyte sheet may be obtained by drying the solid electrolyte slurry provided in this disclosure.

[0143] In some embodiments, the total mass content of polyacrylate binders and non-polar polyolefin binders in the solid electrolyte sheet, based on 100% of the total mass of the solid electrolyte sheet, can be 0.5%-10%, for example, it can be 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, or any range of the above values.

[0144] In some embodiments, the thickness of the solid electrolyte sheet can be 10 μm-50 μm.

[0145] In some embodiments, the solid-state battery cell may further include an outer packaging for housing the positive electrode, solid electrolyte sheet, and negative electrode. The outer packaging may be a rigid shell, such as a hard plastic shell, aluminum shell, or steel shell. The outer packaging may also be a flexible package, such as a pouch. The material of the flexible package may be plastic, such as one or more of aluminum-plastic film, polypropylene, polybutylene terephthalate (PBT), and polybutylene succinate (PBS).

[0146] The preparation method of solid-state battery cells is well known. In some embodiments, a positive electrode, a solid electrolyte sheet, and a negative electrode 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.

[0147] Example

[0148] The following embodiments describe the disclosure of this disclosure in more detail. These embodiments are merely illustrative, as various modifications and variations will be apparent to those skilled in the art within the scope of this disclosure. Unless otherwise stated, all parts, percentages, and ratios reported in the following embodiments are based on mass, and all reagents used in the embodiments are commercially available or synthesized by conventional methods and can be used directly without further processing, and the instruments used in the embodiments are commercially available.

[0149] Positive electrode paste D1#

[0150] LiNi, the positive electrode active material 0.8 Co 0.1 Mn 0.1 O2, sulfide solid electrolyte material Li6PS5Cl, positive electrode conductive agent vapor-grown carbon fiber (VGCF), and positive electrode binder nitrile rubber are weighed and mixed in a solid mass ratio of 80:16:2:2, and then added to xylene, a weakly polar solvent, and stirred evenly to prepare positive electrode slurry D1#.

[0151] Positive electrode paste D2#

[0152] LiNi, the positive electrode active material 0.8 Co 0.1 Mn 0.1 O2, sulfide solid electrolyte material Li6PS5Cl, positive electrode conductive agent vapor-grown carbon fiber (VGCF), and positive electrode binder polypropylene methacrylate are weighed and mixed in a solid mass ratio of 80:16:2:2, and then added to xylene, a weakly polar solvent, and stirred evenly to prepare positive electrode slurry D2#. The weight-average molecular weight of the positive electrode binder polypropylene methacrylate is between 1 million and 1.01 million.

[0153] Positive electrode paste D3#

[0154] LiNi, the positive electrode active material 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 polypropylene are weighed and mixed in a solid mass ratio of 80:16:2:2, and then added to xylene, a weakly polar solvent, and stirred evenly to prepare positive electrode slurry D3#. The weight-average molecular weight of the positive electrode binder polypropylene is between 500,000 and 510,000.

[0155] Positive electrode paste #1

[0156] LiNi, the positive electrode active material 0.8 Co 0.1 Mn 0.1 O2, sulfide solid electrolyte material Li6PS5Cl, positive electrode conductive agent vapor-grown carbon fiber (VGCF), positive electrode binder polypropylene methacrylate, and positive electrode binder polypropylene are weighed and mixed in a solid mass ratio of 80:16:2:1.6:0.4, and then added to xylene, a weakly polar solvent, and stirred evenly to prepare positive electrode slurry #1. The weight-average molecular weight of the positive electrode binder polypropylene methacrylate is between 1 million and 1.01 million, and the weight-average molecular weight of the positive electrode binder polypropylene is between 500,000 and 510,000.

[0157] Positive electrode paste #2

[0158] LiNi, the positive electrode active material 0.8 Co 0.1 Mn 0.1 O2, sulfide solid electrolyte material Li6PS5Cl, positive electrode conductive agent vapor-grown carbon fiber (VGCF), positive electrode binder polypropylene methacrylate, and positive electrode binder polypropylene are weighed and mixed in a solid mass ratio of 80:16:2:1.2:0.8, and then added to xylene, a weakly polar solvent, and stirred evenly to prepare positive electrode slurry #2. The weight-average molecular weight of the positive electrode binder polypropylene methacrylate is between 1 million and 1.01 million, and the weight-average molecular weight of the positive electrode binder polypropylene is between 500,000 and 510,000.

[0159] Positive electrode paste #3

[0160] LiNi, the positive electrode active material 0.8 Co 0.1 Mn 0.1 O2, sulfide solid electrolyte material Li6PS5Cl, positive electrode conductive agent vapor-grown carbon fiber (VGCF), positive electrode binder polypropylene methacrylate, and positive electrode binder polypropylene are weighed and mixed in a solid mass ratio of 80:16:2:1:1, and then added to xylene, a weakly polar solvent, and stirred evenly to prepare positive electrode slurry #3. The weight-average molecular weight of the positive electrode binder polypropylene methacrylate is between 1 million and 1.01 million, and the weight-average molecular weight of the positive electrode binder polypropylene is between 500,000 and 510,000.

[0161] Positive electrode paste #4

[0162] LiNi, the positive electrode active material 0.8 Co 0.1 Mn 0.1 O2, sulfide solid electrolyte material Li6PS5Cl, positive electrode conductive agent vapor-grown carbon fiber (VGCF), positive electrode binder polypropylene methacrylate, and positive electrode binder polypropylene are weighed and mixed in a solid mass ratio of 80:16:2:1.8:0.2, and then added to xylene, a weakly polar solvent, and stirred evenly to prepare positive electrode slurry #4. The weight-average molecular weight of the positive electrode binder polypropylene methacrylate is between 1 million and 1.01 million, and the weight-average molecular weight of the positive electrode binder polypropylene is between 500,000 and 510,000.

[0163] Positive electrode slurry performance testing

[0164] Place the positive electrode slurry in a beaker and let it stand at 25°C for 24 hours. Pour it out of the beaker and observe whether the slurry can flow continuously. If it cannot flow continuously, it is considered that the slurry has gelled.

[0165] Place the positive electrode slurry in a beaker and let it stand at 25°C for 24 hours. After that, scrape the slurry with a scraper and then scrape it vertically to allow the slurry on top to flow naturally. If there are clumps of slurry remaining on the scraper, the slurry has settled; otherwise, it is considered that the slurry has not settled.

[0166] Table 1

[0167] Serial Number gel problem Settlement problem Positive electrode paste D1# 24h gel-free Settlement occurred within 12 hours. Positive electrode paste D2# 24h gel-free Settlement occurred within 24 hours Positive electrode paste D3# Gel available 24 hours ago No settlement for 24 hours Positive electrode paste #1 24h gel-free No settlement for 24 hours Positive electrode paste #2 24h gel-free No settlement for 24 hours Positive electrode paste #3 24h gel-free No settlement for 24 hours Positive electrode paste #4 24h gel-free No settlement for 24 hours

[0168] The test results above show that the positive electrode slurry disclosed herein does not settle or gel after 24 hours, which can meet the coating requirements of industrial production lines.

[0169] Solid-state battery cell D1#

[0170] The positive electrode paste D1# is coated on both sides of the aluminum foil, dried, and cut to obtain the positive electrode sheet D1#.

[0171] A negative electrode slurry was prepared by mixing silicon-carbon composite material (anode active material) and styrene-butadiene rubber (nenode binder) at a solid mass ratio of 90:10 and adding them to the solvent N-methylpyrrolidone. The negative electrode slurry was then coated on both sides of a copper foil and dried to obtain a negative electrode sheet. A solid electrolyte slurry was prepared by mixing sulfide solid electrolyte material Li6PS5Cl and styrene-butadiene rubber at a solid mass ratio of 90:10 and adding them to the weakly polar solvent xylene. The solid electrolyte slurry was then coated onto the surface of the negative electrode film layer prepared above, dried, and cut to obtain a negative electrode sheet with a solid electrolyte sheet.

[0172] The negative electrode sheet, positive electrode sheet, and negative electrode sheet are stacked in sequence, and after hot pressing, they are placed in an outer aluminum-plastic film for encapsulation to obtain solid-state battery cell D1#.

[0173] Solid-state battery cell D2#

[0174] The positive electrode paste D2# is coated on both sides of the aluminum foil, dried, and cut to obtain the positive electrode sheet D2#.

[0175] A negative electrode slurry was prepared by mixing silicon-carbon composite material (anode active material) and styrene-butadiene rubber (nenode binder) at a solid mass ratio of 90:10 and adding them to the solvent N-methylpyrrolidone. The negative electrode slurry was then coated on both sides of a copper foil and dried to obtain a negative electrode sheet. A solid electrolyte slurry was prepared by mixing sulfide solid electrolyte material Li6PS5Cl and styrene-butadiene rubber at a solid mass ratio of 90:10 and adding them to the weakly polar solvent xylene. The solid electrolyte slurry was then coated onto the surface of the negative electrode film layer prepared above, dried, and cut to obtain a negative electrode sheet with a solid electrolyte sheet.

[0176] The negative electrode sheet, positive electrode sheet, and negative electrode sheet are stacked in sequence, and after hot pressing, they are placed in an outer aluminum-plastic film for encapsulation to obtain a solid-state battery cell D2#.

[0177] Solid-state battery cell D3#

[0178] The positive electrode paste D3# is coated on both sides of the aluminum foil, dried, and cut to obtain the positive electrode sheet D3#.

[0179] A negative electrode slurry was prepared by mixing silicon-carbon composite material (anode active material) and styrene-butadiene rubber (nenode binder) at a solid mass ratio of 90:10 and adding them to the solvent N-methylpyrrolidone. The negative electrode slurry was then coated on both sides of a copper foil and dried to obtain a negative electrode sheet. A solid electrolyte slurry was prepared by mixing sulfide solid electrolyte material Li6PS5Cl and styrene-butadiene rubber at a solid mass ratio of 90:10 and adding them to the weakly polar solvent xylene. The solid electrolyte slurry was then coated onto the surface of the negative electrode film layer prepared above, dried, and cut to obtain a negative electrode sheet with a solid electrolyte sheet.

[0180] The negative electrode sheet, positive electrode sheet, and negative electrode sheet are stacked in sequence, and after hot pressing, they are placed in an outer aluminum-plastic film for encapsulation to obtain a solid-state battery cell D3#.

[0181] Solid-state battery cell #1

[0182] The positive electrode paste 1# is coated on both sides of the aluminum foil, dried, and cut to obtain the positive electrode sheet 1#.

[0183] A negative electrode slurry was prepared by mixing silicon-carbon composite material (anode active material) and styrene-butadiene rubber (nenode binder) at a solid mass ratio of 90:10 and adding them to the solvent N-methylpyrrolidone. The negative electrode slurry was then coated on both sides of a copper foil and dried to obtain a negative electrode sheet. A solid electrolyte slurry was prepared by mixing sulfide solid electrolyte material Li6PS5Cl and styrene-butadiene rubber at a solid mass ratio of 90:10 and adding them to the weakly polar solvent xylene. The solid electrolyte slurry was then coated onto the surface of the negative electrode film layer prepared above, dried, and cut to obtain a negative electrode sheet with a solid electrolyte sheet.

[0184] The negative electrode sheet, positive electrode sheet, and negative electrode sheet are stacked in sequence, and after hot pressing, they are placed in an outer aluminum-plastic film for encapsulation to obtain solid-state battery cell #1.

[0185] Solid-state battery cell #2

[0186] The positive electrode paste #2 is coated on both sides of the aluminum foil, dried, and cut to obtain the positive electrode sheet #2.

[0187] A negative electrode slurry was prepared by mixing silicon-carbon composite material (anode active material) and styrene-butadiene rubber (nenode binder) at a solid mass ratio of 90:10 and adding them to the solvent N-methylpyrrolidone. The negative electrode slurry was then coated on both sides of a copper foil and dried to obtain a negative electrode sheet. A solid electrolyte slurry was prepared by mixing sulfide solid electrolyte material Li6PS5Cl and styrene-butadiene rubber at a solid mass ratio of 90:10 and adding them to the weakly polar solvent xylene. The solid electrolyte slurry was then coated onto the surface of the negative electrode film layer prepared above, dried, and cut to obtain a negative electrode sheet with a solid electrolyte sheet.

[0188] The negative electrode sheet, positive electrode sheet, and negative electrode sheet are stacked in sequence, and after hot pressing, they are placed in an outer aluminum-plastic film for encapsulation to obtain solid-state battery cell #2.

[0189] Solid-state battery cell #3

[0190] The positive electrode paste #3 is coated on both sides of the aluminum foil, dried, and cut to obtain the positive electrode sheet #3.

[0191] A negative electrode slurry was prepared by mixing silicon-carbon composite material (anode active material) and styrene-butadiene rubber (nenode binder) at a solid mass ratio of 90:10 and adding them to the solvent N-methylpyrrolidone. The negative electrode slurry was then coated on both sides of a copper foil and dried to obtain a negative electrode sheet. A solid electrolyte slurry was prepared by mixing sulfide solid electrolyte material Li6PS5Cl and styrene-butadiene rubber at a solid mass ratio of 90:10 and adding them to the weakly polar solvent xylene. The solid electrolyte slurry was then coated onto the surface of the negative electrode film layer prepared above, dried, and cut to obtain a negative electrode sheet with a solid electrolyte sheet.

[0192] The negative electrode sheet, positive electrode sheet, and negative electrode sheet are stacked in sequence, and after hot pressing, they are placed in an outer aluminum-plastic film for encapsulation to obtain solid-state battery cell #3.

[0193] Solid-state battery cell #4

[0194] The positive electrode paste #4 is coated on both sides of the aluminum foil, dried, and cut to obtain the positive electrode sheet #4.

[0195] A negative electrode slurry was prepared by mixing silicon-carbon composite material (anode active material) and styrene-butadiene rubber (nenode binder) at a solid mass ratio of 90:10 and adding them to the solvent N-methylpyrrolidone. The negative electrode slurry was then coated on both sides of a copper foil and dried to obtain a negative electrode sheet. A solid electrolyte slurry was prepared by mixing sulfide solid electrolyte material Li6PS5Cl and styrene-butadiene rubber at a solid mass ratio of 90:10 and adding them to the weakly polar solvent xylene. The solid electrolyte slurry was then coated onto the surface of the negative electrode film layer prepared above, dried, and cut to obtain a negative electrode sheet with a solid electrolyte sheet.

[0196] The negative electrode sheet, positive electrode sheet, and negative electrode sheet are stacked in sequence, and after hot pressing, they are placed in an outer aluminum-plastic film for encapsulation to obtain solid-state battery cell #4.

[0197] Performance testing

[0198] (1) Impedance and ionic conductivity test of the positive electrode

[0199] 100 mg of positive electrode powder was scraped from the surface of the prepared positive electrode sheet and placed into a sleeve. A pressure of 4000 kg was applied to press it into a positive electrode film, and its thickness was measured and recorded as L. 60 mg of sulfide solid electrolyte material Li6PS5Cl was placed on each side of the sleeve, and a pressure of 2000 kg was applied to each side to press it into a sheet. Then, 60 mg of indium powder was placed on each side of the sleeve, and a pressure of 2000 kg was applied to each side to press it into a sheet. Finally, lithium-plated copper sheets were placed on each side of the sleeve to assemble a symmetrical battery. A pressure of 4000 kg was applied to the symmetrical battery and held for 5 min. The AC impedance value R of the positive electrode sheet was obtained using electrochemical impedance spectroscopy (EIS) on an electrochemical workstation at a test temperature of 25 °C and a test frequency range of 10 Hz. 5 -10 -2 Hz, bias voltage is 10mV.

[0200] The ionic conductivity of the positive electrode is calculated using the following formula: σ = L / (R*S). L is the thickness of the positive electrode film, R is the AC impedance value in the AC impedance spectrum, and S is the area of ​​the positive electrode film.

[0201] (2) First coulombic efficiency test of solid-state battery cell

[0202] The test temperature was 25℃, and the solid-state battery cells were tested under a pressure of 15MPa.

[0203] The solid-state battery cells were charged at a constant current rate of 0.1C to a voltage of 4.3V (vs. Li). + / Li), the charging specific capacity at this time is recorded as the first charging specific capacity; then let it stand for 5 minutes, and then discharge at a constant current rate of 0.1C until the voltage is 2V (vs. Li). + / Li), the discharge specific capacity of this time is recorded as the first-cycle discharge specific capacity.

[0204] The initial coulombic efficiency (%) of a solid-state battery cell = first discharge specific capacity / first charge specific capacity × 100%.

[0205] Table 2

[0206]

[0207] As can be seen from the above test results, the positive electrode paste disclosed herein has good coating quality, and the positive electrode sheet prepared from the positive electrode paste has low impedance and high ionic conductivity.

[0208] The test results above show that the positive electrode sheet prepared from the positive electrode slurry of this disclosure can enable solid-state battery cells to have high initial coulombic efficiency.

[0209] It should be noted that this disclosure is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this disclosure are included within the technical scope of this disclosure. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, are also included within the scope of this disclosure without departing from the spirit of this disclosure.

Claims

1. A solid electrolyte slurry, characterized in that, The solid electrolyte slurry includes a sulfide solid electrolyte material, a solvent, and a binder dissolved in the solvent. The solvent is a non-polar solvent, a weakly polar solvent, or a mixture of both. The binder includes polyacrylate binders and non-polar polyolefin binders. The polyacrylate adhesive comprises the structural unit shown in Formula 1. R1 is selected from C2 to C10 alkyl groups, and R2, R3, and R4 are each independently selected from H or C1 to C3 alkyl groups.

2. The solid electrolyte slurry according to claim 1, characterized in that, The nonpolar polyolefin adhesive includes homopolymer nonpolar polyolefin adhesives selected from one of the following monomers, and copolymer nonpolar polyolefin adhesives selected from two or more of the following monomers: ethylene, propylene, butene, isobutene, pentene, hexene, heptyl, octene, butadiene, pentene, isoprene, hexadiene, octadiene, 2,3-dimethyl-1,3-butadiene, 3-methyl-1,3-pentadiene, and 4-methyl-1,3-pentadiene.

3. The solid electrolyte slurry according to claim 2, characterized in that, The nonpolar polyolefin adhesives include one or more of polyethylene, polypropylene, polybutene, polyisobutylene, polybutadiene, polyisoprene, ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-octene copolymer, ethylene-propylene-butene copolymer, ethylene-propylene-octene copolymer, isoprene-butadiene copolymer, ethylene-isoprene copolymer, and ethylene-hexadiene copolymer.

4. The solid electrolyte slurry according to any one of claims 1-3, characterized in that, The mass ratio of the polyacrylate adhesive to the non-polar polyolefin adhesive is from 50:50 to 95:

5.

5. The solid electrolyte slurry according to any one of claims 1-4, characterized in that, The polyacrylate adhesive has a weight-average molecular weight of 900,000 to 2,000,000; and / or, The weight-average molecular weight of the non-polar polyolefin adhesive is 450,000 to 850,000.

6. The solid electrolyte slurry according to any one of claims 1-5, characterized in that, The solvents include toluene, xylene, trimethylbenzene, chlorobenzene, o-dichlorobenzene, anisole, n-hexane, n-pentane, isopentane, n-heptane, n-octane, isooctane, n-decane, trichlorotrifluoroethane, dichloromethane, chloroform, 2-methylpentane, 2,2-dimethylpentane, 3-methylpentane, 2,3-dimethylpentane, 2-methylhexane, 2,2-dimethylhexane, 3-methylhexane, 2,3-dimethylhexane, 3-ethylhexane, cyclohexane, cycloheptane, and methylcyclohexane. One or more of the following: tert-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, vinyl dichloride, petroleum ether, trifluoroacetic acid, butyl chloride, trichloroethylene, carbon tetrachloride, propyl ether, diethyl ether, butyl acetate, and ethyl acetate.

7. The solid electrolyte slurry according to any one of claims 1-6, characterized in that, The solid electrolyte slurry also includes one or more of halide solid electrolyte materials and oxide solid electrolyte materials.

8. A solid electrolyte sheet, characterized in that, The solid electrolyte sheet is obtained by drying the solid electrolyte slurry according to any one of claims 1-7.

9. An electrode paste, characterized in that, The electrode slurry is a positive electrode slurry, which includes a positive active material, a positive conductive agent, and a solid electrolyte slurry according to any one of claims 1-7.

10. An electrode sheet, characterized in that, The electrode sheet includes a positive current collector and a positive electrode film layer located on at least one surface of the positive current collector, the positive electrode film layer being obtained by drying the electrode slurry according to claim 9.

11. An electrode paste, characterized in that, The electrode slurry is a negative electrode slurry, which includes a negative electrode active material and the solid electrolyte slurry according to any one of claims 1-7.

12. The electrode paste according to claim 11, characterized in that, The electrode slurry also includes a negative electrode conductive agent.

13. An electrode sheet, characterized in that, The electrode sheet includes a negative current collector and a negative electrode film layer located on at least one surface of the negative current collector, the negative electrode film layer being obtained by drying the electrode slurry according to any one of claims 11-12.

14. A solid-state battery cell, comprising a positive electrode, a solid electrolyte sheet, and a negative electrode, wherein the solid electrolyte sheet is located between the positive electrode and the negative electrode, characterized in that, The positive electrode sheet includes a positive current collector and a positive electrode film layer located on at least one surface of the positive current collector, the positive electrode film layer being obtained by drying the electrode slurry according to claim 9; and / or, the solid electrolyte sheet is obtained by drying the solid electrolyte slurry according to any one of claims 1-7.

15. The solid-state battery cell according to claim 14, characterized in that, The negative electrode includes a negative current collector and a lithium-based metal layer located on at least one surface of the negative current collector.

16. The solid-state battery cell according to claim 14, characterized in that, The negative electrode sheet includes 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 according to any one of claims 11-12.

17. A battery device, characterized in that, Includes the solid-state battery cell as described in any one of claims 14-16.

18. An electrical appliance, characterized in that, Includes the solid-state battery cell according to any one of claims 14-16 or the battery device according to claim 17.

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