Solid-state battery cell, battery device, electric device, modified sulfide electrolyte and preparation method therefor

Abstract

A solid-state battery cell, a battery device, an electric device, a modified sulfide electrolyte and a preparation method therefor. The solid-state battery cell comprises a positive electrode, an electrolyte layer, and a negative electrode. The electrolyte layer is located between the positive electrode and the negative electrode. At least one of the positive electrode, the electrolyte layer, and the negative electrode comprises a modified sulfide electrolyte. The modified sulfide electrolyte has a volume‑based particle size Dv50 of 0.1-1 μm. The modified sulfide electrolyte comprises a sulfide electrolyte matrix and a thioether compound located on at least part of the surface of the sulfide electrolyte matrix, and the mass fraction of the thioether compound in the modified sulfide electrolyte is greater than 0 and less than or equal to 1000 μg / g. The solid-state battery cell has a high energy density and good cycle performance.

Description

Solid-state battery cells, battery devices, electrical devices, modified sulfide electrolytes and their preparation methods

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese Patent Application No. 202510386269.6, filed on March 28, 2025, entitled "Solid-state battery cell, battery device, power device, modified sulfide electrolyte and preparation method thereof", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to a solid-state battery cell, a battery device, an electrical device, a modified sulfide electrolyte, and a method for preparing the same. Background Technology

[0004] Compared to battery cells using liquid electrolytes, solid-state battery cells are less prone to combustion and explosion, exhibiting high reliability and high energy density. Increasing the proportion of positive electrode active material in the positive electrode film layer of a solid-state battery cell can further improve its energy density. Conversely, reducing the particle size of the solid electrolyte can decrease its volume fraction while increasing the proportion of positive electrode active material, thus improving the energy density of the solid-state battery cell, all while maintaining the positive electrode ion transport pathway. However, solid-state battery cells commonly use sulfide electrolytes, which have low density and soft texture, making them prone to particle agglomeration. Summary of the Invention

[0005] This disclosure provides a solid-state battery cell, a battery device, an electrical device, a modified sulfide electrolyte, and a method for preparing the same. The solid-state battery cell using the modified sulfide electrolyte has high energy density and good cycle performance.

[0006] In a first aspect, this disclosure provides a solid-state battery cell, including a positive electrode, an electrolyte layer, and a negative electrode, wherein the electrolyte layer is located between the positive electrode and the negative electrode, and at least one of the positive electrode, the electrolyte layer, and the negative electrode includes a modified sulfide electrolyte; the volume distribution particle size Dv50 of the modified sulfide electrolyte is 0.1 μm-1 μm, the modified sulfide electrolyte includes a sulfide electrolyte matrix and a sulfide compound located on at least a portion of the surface of the sulfide electrolyte matrix, and the mass percentage of the sulfide compound in the modified sulfide electrolyte is greater than 0 and less than or equal to 1000 μg / g.

[0007] In some embodiments, the mass percentage of thioether compounds in the modified sulfide electrolyte is from 20 μg / g to 500 μg / g.

[0008] Optionally, the mass percentage of thioether compounds in the modified sulfide electrolyte is from 100 μg / g to 320 μg / g.

[0009] In some embodiments, thioether compounds include monothioether compounds and / or dithioether compounds.

[0010] Optionally, the sulfide compounds include one or more of the following: dimethyl sulfide, diethyl sulfide, dipropyl sulfide, dibutyl sulfide, diisobutyl sulfide, dipentyl sulfide, diisopentyl sulfide, dihexyl sulfide, diisohexyl sulfide, diheptyl sulfide, dioctyl sulfide, diisooctyl sulfide, dimethyl disulfide, diethyl disulfide, dipropyl disulfide, dibutyl disulfide, diisobutyl disulfide, dipentyl disulfide, diisopentyl disulfide, dihexyl disulfide, diisohexyl disulfide, diheptyl disulfide, dioctyl disulfide, and diisooctyl disulfide.

[0011] In some embodiments, the modified sulfide electrolyte further includes an organic solvent located on at least a portion of the surface of the sulfide electrolyte matrix. The organic solvent includes an organic solvent containing oxygen atoms, the organic solvent containing oxygen atoms having a boiling point greater than 100°C, and the organic solvent containing oxygen atoms including one or more of ester solvents and ether solvents.

[0012] Optionally, the ester solvent includes one or more of butyl acetate, isobutyl acetate, amyl acetate, isoamyl acetate, hexyl acetate, isohexyl acetate, heptyl acetate, octyl acetate, butyl propionate, isobutyl propionate, amyl propionate, hexyl propionate, heptyl propionate, octyl propionate, ethyl butyrate, propyl butyrate, butyl butyrate, isobutyl isobutyrate, isooctyl butyrate, and octyl butyrate.

[0013] Optionally, the ether solvent includes one or more of n-butyl ether, heptyl ether, n-pentyl ether, isopentyl ether, anisole, and phenethyl ether.

[0014] In some embodiments, the organic solvent also includes an oxygen-free organic solvent with a boiling point greater than 90°C, and the oxygen-free organic solvent includes one or more of alkane solvents and aromatic hydrocarbon solvents.

[0015] Optionally, in the organic solvent, the mass percentage of the organic solvent that does not contain oxygen atoms is greater than or equal to the mass percentage of the organic solvent that contains oxygen atoms.

[0016] Optionally, the organic solvents that do not contain oxygen atoms include one or more of toluene, ethylbenzene, o-xylene, m-xylene, p-xylene, pseudotrimethylbenzene, mesitylene, n-heptane, n-dodecane, and n-tetradecane.

[0017] In some embodiments, the organic solvent has a mass percentage in the modified sulfide electrolyte that is greater than 0 and less than or equal to 10,000 μg / g, and may be selected as 55 μg / g to 1,000 μg / g.

[0018] In some embodiments, the sulfide electrolyte matrix includes a material with the molecular formula Li 6+m+l P 1-m M m S 5-n+l N n Y 1-l , wherein 0≤m<1, 0≤n<1, -1<l<1, M comprises one or more elements selected from the group consisting of Ge, Si, Sn, Al, Zr and Sb, N comprises one or more elements selected from the group consisting of O, Se and Te, and Y comprises one or more elements selected from the group consisting of Cl, Br and I.

[0019] In some embodiments, the positive electrode comprises a positive electrode film layer, the positive electrode film layer comprises a positive electrode active material and a modified sulfide electrolyte, and the positive electrode active material comprises one or more of lithium transition metal oxides and modified materials thereof, lithium-containing phosphates and modified materials thereof, lithium titanate, lithium niobate, sulfur, selenium and tellurium.

[0020] In some embodiments, the electrolyte layer comprises the modified sulfide electrolyte.

[0021] In some embodiments, the negative electrode comprises lithium or a lithium alloy, or the negative electrode comprises a negative electrode active material and the modified sulfide electrolyte, and the negative electrode active material comprises one or more of natural graphite, artificial graphite, mesocarbon microbeads, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate and metal oxides.

[0022] In a second aspect, the present disclosure provides a battery device, which comprises a plurality of the solid-state battery cells according to the first aspect.

[0023] In a third aspect, the present disclosure provides an electricity-consuming device, which comprises the solid-state battery cell according to the first aspect or the battery device according to the second aspect.

[0024] In a fourth aspect, the present disclosure provides a modified sulfide electrolyte, wherein the volume distribution particle size Dv50 of the modified sulfide electrolyte is 0.1 μm-1 μm, the modified sulfide electrolyte comprises a sulfide electrolyte matrix and a thioether compound located on at least part of the surface of the sulfide electrolyte matrix, and the mass proportion of the thioether compound in the modified sulfide electrolyte is greater than 0 and less than or equal to 1000 μg / g.

[0025] The modified sulfide electrolyte provided by the embodiments of the present disclosure has a volume distribution particle size Dv50 of 0.1 μm-1 μm. When the small-sized modified sulfide electrolyte is used in the positive electrode and / or negative electrode of a solid-state battery cell, the volume proportion of the solid electrolyte can be reduced, the proportion of the electrode active material can be increased, and thus the gravimetric energy density of the solid-state battery cell can be improved; when the small-sized modified sulfide electrolyte is used in the electrolyte layer of a solid-state battery cell, the thickness of the electrolyte layer can be reduced, and thus the volumetric energy density of the solid-state battery cell can be improved.

[0026] This disclosure improves the dispersibility of the modified sulfide electrolyte in slurries (such as positive electrode slurries, negative electrode slurries, and electrolyte slurries) by having at least a portion of the surface of the sulfide electrolyte matrix covered with sulfide compounds, and by ensuring that the mass percentage of the sulfide compounds in the modified sulfide electrolyte is greater than 0 and less than or equal to 1000 μg / g. This enhances the uniformity of the positive electrode, electrolyte layer, and / or negative electrode of the solid-state battery cell, thereby facilitating the full utilization of the ion conduction function of the modified sulfide electrolyte and improving the charge-discharge performance and cycle performance of the solid-state battery cell. However, an excessively high mass percentage of sulfide compounds will reduce the ionic conductivity of the modified sulfide electrolyte, affecting the cycle performance of the solid-state battery cell.

[0027] In some embodiments, the mass percentage of thioether compounds in the modified sulfide electrolyte is from 20 μg / g to 500 μg / g.

[0028] Optionally, the mass percentage of thioether compounds in the modified sulfide electrolyte is from 100 μg / g to 320 μg / g.

[0029] Appropriate amounts of sulfide compounds can better improve the dispersion uniformity of modified sulfide electrolytes in slurries (such as positive electrode slurry, negative electrode slurry, and electrolyte slurry), improve the consistency of the positive electrode, electrolyte layer, and / or negative electrode of solid-state battery cells, and thus help improve the charge-discharge performance and cycle performance of solid-state battery cells; it can also make modified sulfide electrolytes have higher ionic conductivity.

[0030] In some embodiments, thioether compounds include monothioether compounds and / or dithioether compounds.

[0031] Optionally, the sulfide compounds include one or more of the following: dimethyl sulfide, diethyl sulfide, dipropyl sulfide, dibutyl sulfide, diisobutyl sulfide, dipentyl sulfide, diisopentyl sulfide, dihexyl sulfide, diisohexyl sulfide, diheptyl sulfide, dioctyl sulfide, diisooctyl sulfide, dimethyl disulfide, diethyl disulfide, dipropyl disulfide, dibutyl disulfide, diisobutyl disulfide, dipentyl disulfide, diisopentyl disulfide, dihexyl disulfide, diisohexyl disulfide, diheptyl disulfide, dioctyl disulfide, and diisooctyl disulfide.

[0032] In some embodiments, the modified sulfide electrolyte further includes an organic solvent located on at least a portion of the surface of the sulfide electrolyte matrix. The organic solvent includes an organic solvent containing oxygen atoms, the organic solvent containing oxygen atoms having a boiling point greater than 100°C, and the organic solvent containing oxygen atoms including one or more of ester solvents and ether solvents.

[0033] Optionally, the ester solvent comprises one or more of butyl acetate, isobutyl acetate, amyl acetate, isoamyl acetate, hexyl acetate, isohexyl acetate, heptyl acetate, octyl acetate, butyl propionate, isobutyl propionate, amyl propionate, hexyl propionate, heptyl propionate, octyl propionate, ethyl butyrate, propyl butyrate, butyl butyrate, isobutyl isobutyrate, isooctyl butyrate and octyl butyrate.

[0034] Optionally, the ether solvent comprises one or more of n-butyl ether, heptyl ether, n-amyl ether, isoamyl ether, anisole and phenetole.

[0035] In some embodiments, the organic solvent further comprises an oxygen-free organic solvent, the boiling point of the oxygen-free organic solvent is higher than 90°C, and the oxygen-free organic solvent comprises one or more of alkane solvents and aromatic hydrocarbon solvents.

[0036] Optionally, in the organic solvent, the mass proportion of the oxygen-free organic solvent is greater than or equal to the mass proportion of the oxygen-containing organic solvent.

[0037] Optionally, the oxygen-free organic solvent comprises one or more of toluene, ethylbenzene, o-xylene, m-xylene, p-xylene, trimethylbenzene, mesitylene, n-heptane, n-dodecane and n-tetradecane.

[0038] In some embodiments, the mass proportion of the organic solvent in the modified sulfide electrolyte is greater than 0 and less than or equal to 10000μg / g, and can be optionally 55μg / g to 1000μg / g.

[0039] In some embodiments, the sulfide electrolyte matrix comprises a material with the molecular formula Li 6+m+l P 1-m M m S 5-n+l N n Y 1-l , wherein 0≤m<1, 0≤n<1, -1<l<1, M comprises one or more of Ge, Si, Sn, Al, Zr and Sb, N comprises one or more of O, Se and Te, and Y comprises one or more of Cl, Br and I.

[0040] Fifthly, this disclosure provides a method for preparing a modified sulfide electrolyte, comprising the following steps: grinding the raw materials used to prepare the sulfide electrolyte matrix and then sintering them at high temperature under a protective gas atmosphere to obtain a coarse powder sulfide electrolyte matrix; adding the coarse powder sulfide electrolyte matrix, grinding media, and organic solvent into a grinding apparatus, grinding the materials, and then separating the solid powder; the organic solvent includes an organic solvent containing oxygen atoms, the boiling point of the organic solvent containing oxygen atoms being greater than 100°C, and the organic solvent containing oxygen atoms including one or more of ester solvents and ether solvents. Furthermore, organic solvents containing oxygen atoms can react with the sulfide electrolyte matrix to form sulfide compounds; the separated solid powder is vacuum dried at 80℃-200℃ for 2h-10h to obtain modified sulfide electrolyte. The volume distribution particle size Dv50 of the modified sulfide electrolyte is 0.1μm-1μm. The modified sulfide electrolyte includes a sulfide electrolyte matrix and sulfide compounds located on at least part of the surface of the sulfide electrolyte matrix, and the mass percentage of sulfide compounds in the modified sulfide electrolyte is greater than 0 and less than or equal to 1000μg / g.

[0041] The surface of coarse sulfide electrolyte matrix particles typically contains unbonded or weakly bonded sulfur ions. This disclosure introduces an oxygen-containing organic solvent with a boiling point greater than 100°C, including one or more ester and ether solvents, during the micronization process of the coarse sulfide electrolyte matrix through grinding. These oxygen-containing organic solvent molecules adhere to the surface of the sulfide electrolyte matrix particles and react with the sulfur ions to form sulfide ether compounds. This reduces the agglomeration of small particles after micronization during grinding, thereby preparing a modified sulfide electrolyte with a volume distribution particle size (Dv50) of 0.1 μm-1 μm. Using this small-sized modified sulfide electrolyte as the positive and / or negative electrode of a solid-state battery cell can reduce the volume fraction of the solid-state electrolyte and increase the proportion of electrode active material, thus improving the mass energy density of the solid-state battery cell. Using this small-sized modified sulfide electrolyte as the electrolyte layer of a solid-state battery cell can reduce the thickness of the electrolyte layer, thereby improving the volumetric energy density of the solid-state battery cell. In addition, the presence of sulfide compounds can improve the dispersibility of modified sulfide electrolytes in slurries (such as positive electrode slurry, negative electrode slurry, and electrolyte slurry), improve the consistency of the positive electrode, electrolyte layer, and / or negative electrode of solid-state battery cells, thereby helping to fully utilize the ion conduction effect of modified sulfide electrolytes, improve the charge and discharge performance of solid-state battery cells, and improve the cycle performance of solid-state battery cells.

[0042] Organic solvents containing oxygen atoms have boiling points greater than 100°C. These organic solvents include one or more of ester solvents and ether solvents. These organic solvents containing oxygen atoms have low reactivity with the sulfide electrolyte matrix, which can also avoid excessively reducing the ionic conductivity of the modified sulfide electrolyte.

[0043] The present invention discloses a method of vacuum drying the solid powder separated after grinding at 80℃-200℃ for 2h-10h. This method allows some organic solvent to remain on the surface of the sulfide electrolyte matrix particles, which facilitates the homogenization of solid-state battery cells, improves the dispersibility of modified sulfide electrolyte in slurries (such as positive electrode slurry, negative electrode slurry, and electrolyte slurry), and also helps to reduce the agglomeration problem of modified sulfide electrolyte particles.

[0044] In some embodiments, the grinding speed is 300 rpm to 2300 rpm.

[0045] In some embodiments, the grinding process takes 30 minutes to 10 hours.

[0046] In some embodiments, the grinding media are zirconia balls with a diameter of 0.4 mm to 3 mm.

[0047] In some embodiments, the mass ratio of the grinding media to the coarse powder sulfide electrolyte matrix is ​​5:1 to 10:1.

[0048] In some embodiments, the mass ratio of organic solvent to coarse sulfide electrolyte matrix is ​​2:1 to 18:1.

[0049] In some embodiments, the ester solvent includes one or more of butyl acetate, isobutyl acetate, amyl acetate, isoamyl acetate, hexyl acetate, isohexyl acetate, heptyl acetate, octyl acetate, butyl propionate, isobutyl propionate, amyl propionate, hexyl propionate, heptyl propionate, octyl propionate, ethyl butyrate, propyl butyrate, butyl butyrate, isobutyl isobutyrate, isooctyl butyrate, and octyl butyrate. These ester solvents exhibit low reactivity with the sulfide electrolyte matrix, thereby avoiding excessive reduction in the ionic conductivity of the modified sulfide electrolyte.

[0050] In some embodiments, the ether solvent includes one or more of n-butyl ether, heptyl ether, n-pentyl ether, isopentyl ether, anisole, and phenethyl ether. These ether solvents have low reactivity with the sulfide electrolyte matrix, thereby avoiding excessive reduction of the ionic conductivity of the modified sulfide electrolyte.

[0051] In some embodiments, the organic solvent also includes an oxygen-free organic solvent with a boiling point greater than 90°C, and the oxygen-free organic solvent includes one or more of alkane solvents and aromatic hydrocarbon solvents.

[0052] Organic solvents containing oxygen atoms can react with sulfide electrolyte matrices to form thioether compounds, while organic solvents without oxygen atoms, such as alkanes and aromatics, do not react with the sulfide electrolyte matrix. Therefore, by including both oxygen-containing and oxygen-free organic solvents, thioether compounds can be formed, thereby improving the dispersibility of modified sulfide electrolytes in slurries (such as positive electrode slurries, negative electrode slurries, and electrolyte slurries), enhancing the consistency of the positive electrode, electrolyte layer, and / or negative electrode in solid-state battery cells, and thus facilitating the full utilization of the ion conduction function of the modified sulfide electrolyte. It can also reduce the agglomeration of small particles after micronization of the sulfide electrolyte matrix during the grinding process; and it can give the prepared modified sulfide electrolyte higher ionic conductivity, enabling solid-state battery cells to possess both high energy density and good cycle performance.

[0053] In some embodiments, the oxygen-free organic solvent includes one or more of toluene, ethylbenzene, o-xylene, m-xylene, p-xylene, pseudotrimethylbenzene, mesitylene, n-heptane, n-dodecane, and n-tetradecane.

[0054] In some embodiments, the mass ratio of the organic solvent containing oxygen atoms to the organic solvent without oxygen atoms is 1:39 to 1:1. Attached Figure Description

[0055] 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.

[0056] Figure 1 shows a schematic diagram of a solid-state battery cell provided in some embodiments of this disclosure.

[0057] Figure 2 shows a schematic diagram of an electrical device provided in some embodiments of this disclosure.

[0058] Figure 3 is a scanning electron microscope (SEM) image of the modified sulfide electrolyte prepared in Example 1.

[0059] Figure 4 is a scanning electron microscope (SEM) image of the modified sulfide electrolyte prepared in Comparative Example 1.

[0060] The accompanying drawings are not necessarily drawn to scale. Detailed Implementation

[0061] The following detailed description, with appropriate reference to the accompanying drawings, provides specific embodiments of the solid-state battery cell, battery device, power-consuming device, modified sulfide electrolyte, and methods for preparing the present 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 the present disclosure and are not intended to limit the subject matter of the claims.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] In this disclosure, the terms "multiple" or "a variety" refer to two or more kinds.

[0068] 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.

[0069] Unless otherwise stated, the test temperature for all parameters mentioned in this disclosure is 25°C.

[0070] The solid-state battery cells mentioned in the embodiments of this disclosure can independently perform charging and discharging functions. Solid-state battery cells can be cylindrical, cuboid, or other shapes, and the embodiments of this disclosure are not limited in this respect. Figure 1 shows a cuboid solid-state battery cell 5 as an example.

[0071] 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.

[0072] In some embodiments, a battery cell assembly is typically formed by arranging multiple solid-state battery cells.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple solid-state battery cells to the housing.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] Figure 2 is a schematic diagram of an example electrical device. This electrical device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc.

[0082] The solid-state battery cells disclosed herein may include coin cells, hard-case cells, pouch cells, etc.

[0083] In view of the problems mentioned in the background art, the present disclosure provides a modified sulfide electrolyte and a method for preparing the same, as well as a solid-state battery cell, a battery device and an electrical device containing the same. The solid-state battery cell using the modified sulfide electrolyte has high energy density and good cycle performance.

[0084] The modified sulfide electrolyte provided in this embodiment has a volume distribution particle size Dv50 of 0.1 μm-1 μm. The modified sulfide electrolyte includes a sulfide electrolyte matrix and sulfide compounds located on at least a portion of the surface of the sulfide electrolyte matrix. The mass percentage of sulfide compounds in the modified sulfide electrolyte is greater than 0 and less than or equal to 1000 μg / g.

[0085] The modified sulfide electrolyte provided in this embodiment has a volume distribution particle size Dv50 of 0.1 μm-1 μm. The small-sized modified sulfide electrolyte can be used as the positive and / or negative electrode of a solid-state battery cell, which can reduce the volume ratio of the solid electrolyte and increase the ratio of electrode active materials, thereby improving the mass energy density of the solid-state battery cell. The small-sized modified sulfide electrolyte can also be used as the electrolyte layer of a solid-state battery cell, which can reduce the thickness of the electrolyte layer, thereby improving the volumetric energy density of the solid-state battery cell.

[0086] This disclosure improves the dispersibility of the modified sulfide electrolyte in slurries (such as positive electrode slurries, negative electrode slurries, and electrolyte slurries) by having at least a portion of the surface of the sulfide electrolyte matrix covered with sulfide compounds, and by ensuring that the mass percentage of the sulfide compounds in the modified sulfide electrolyte is greater than 0 and less than or equal to 1000 μg / g. This enhances the uniformity of the positive electrode, electrolyte layer, and / or negative electrode of the solid-state battery cell, thereby facilitating the full utilization of the ion conduction function of the modified sulfide electrolyte and improving the charge-discharge performance and cycle performance of the solid-state battery cell. However, an excessively high mass percentage of sulfide compounds will reduce the ionic conductivity of the modified sulfide electrolyte, affecting the cycle performance of the solid-state battery cell.

[0087] The volume distribution particle size Dv50 of the modified sulfide electrolyte is 0.1μm-1μm, for example, it can be 0.1μm, 0.2μm, 0.3μm, 0.4μm, 0.5μm, 0.6μm, 0.7μm, 0.8μm, 0.9μm, 1μm, or any combination of the above values.

[0088] Dv50 represents the particle size corresponding to a cumulative volumetric distribution percentage of 50% for the material. It can be measured using a laser particle size analyzer, referring to GB / T 19077-2016. During testing, add 1g of the sample to a clean small beaker and 20ml of deionized water. Sonicate at 53kHz / 120W for 5 minutes to ensure complete dispersion. Turn on the laser particle size analyzer, clean the optical path system, and automatically test the background. Stir the sonicated solution to ensure uniform dispersion, place it in the sample cell as required, and begin measuring the particle size. A MasterSizer 3000 laser particle size analyzer can be used as the testing instrument.

[0089] Optionally, the volume distribution particle size Dv50 of the modified sulfide electrolyte is 0.1μm-0.8μm, 0.1μm-0.7μm, 0.1μm-0.6μm, 0.2μm-0.8μm, 0.2μm-0.7μm, 0.2μm-0.6μm, 0.3μm-0.8μm, 0.3μm-0.7μm, or 0.3μm-0.6μm.

[0090] The mass percentage of thioether compounds in the modified sulfide electrolyte is greater than 0 and less than or equal to 1000 μg / g, for example, it can be 100 μg / g, 120 μg / g, 140 μg / g, 160 μg / g, 180 μg / g, 200 μg / g, 220 μg / g, 240 μg / g, 260 μg / g, 280 μg / g, 300 μg / g, 320 μg / g, 340 μg / g, 360 μg / g, 380 μg / g, 400 μg / g, 420 μg / g, 440 μg / g, 460 μg / g, 480 μg / g, 500 μg / g, 5 20μg / g, 540μg / g, 560μg / g, 580μg / g, 600μg / g, 620μg / g, 640μg / g, 660μg / g, 680μg / g, 700μg / g, 720μg / g, 740μg / g, 760μg / g, 780 μg / g, 800 μg / g, 820 μg / g, 840 μg / g, 860 μg / g, 880 μg / g, 900 μg / g, 920 μg / g, 940 μg / g, 960 μg / g, 980 μg / g, 1000 μg / g, or a range consisting of any of the above values.

[0091] Optionally, the mass percentage of sulfide compounds in the modified sulfide electrolyte can be 20 μg / g to 1000 μg / g, 20 μg / g to 800 μg / g, 20 μg / g to 700 μg / g, 20 μg / g to 600 μg / g, 20 μg / g to 500 μg / g, 20 μg / g to 400 μg / g, 20 μg / g to 320 μg / g, 50 μg / g to 1000 μg / g, 50 μg / g to 800 μg / g, 50 μg / g to 700 μg / g, 50 μg / g to 600 μg / g, 50 μg / g to 500 μg / g, 50 μg / g to 400 μg / g, 50 μg / g to 320 μg / g, 50 μg / g to 1000 μg / g, 50 μg / g to 800 μg / g, 50 μg / g to 700 μg / g, 50 μg / g to 600 μg / g, 50 μg / g to 500 μg / g, 50 μg / g to 400 μg / g, 50 μg / g to 320 μg / g. 20μg / g, 100μg / g to 1000μg / g, 100μg / g to 800μg / g, 100μg / g to 700μg / g, 10 0μg / g to 600μg / g, 100μg / g to 500μg / g, 100μg / g to 400μg / g, 100μg / g to 320μ g / g, 120μg / g to 1000μg / g, 120μg / g to 800μg / g, 120μg / g to 700μg / g, 120μg / g to 600μg / g, 120μg / g to 500μg / g, 120μg / g to 400μg / g, 120μg / g to 320μg / g.

[0092] Appropriate amounts of sulfide compounds can better improve the dispersion uniformity of modified sulfide electrolytes in slurries (such as positive electrode slurry, negative electrode slurry, and electrolyte slurry), improve the consistency of the positive electrode, electrolyte layer, and / or negative electrode of solid-state battery cells, and thus help improve the charge-discharge performance and cycle performance of solid-state battery cells; it can also make modified sulfide electrolytes have higher ionic conductivity.

[0093] In some embodiments, thioether compounds may include monothioether compounds and / or dithioether compounds.

[0094] Optionally, the sulfide compound may include one or more of the following: dimethyl sulfide, diethyl sulfide, dipropyl sulfide, dibutyl sulfide, diisobutyl sulfide, dipentyl sulfide, diisopentyl sulfide, dihexyl sulfide, diisohexyl sulfide, diheptyl sulfide, dioctyl sulfide, diisooctyl sulfide, dimethyl disulfide, diethyl disulfide, dipropyl disulfide, dibutyl disulfide, diisobutyl disulfide, dipentyl disulfide, diisopentyl disulfide, dihexyl disulfide, diisohexyl disulfide, diheptyl disulfide, dioctyl disulfide, and diisooctyl disulfide.

[0095] Alternatively, the sulfide compound may include one or more of dimethyl sulfide, diethyl sulfide, dipropyl sulfide, dibutyl sulfide, diisobutyl sulfide, dimethyl disulfide, diethyl disulfide, dipropyl disulfide, dibutyl disulfide, and diisobutyl disulfide.

[0096] In some embodiments, the modified sulfide electrolyte may further include an organic solvent located on at least a portion of the surface of the sulfide electrolyte matrix, the organic solvent including an organic solvent containing oxygen atoms, the organic solvent containing oxygen atoms having a boiling point greater than 100°C.

[0097] Organic solvents containing oxygen atoms include one or more of ester solvents and ether solvents.

[0098] Optionally, the ester solvent may include one or more of the following: butyl acetate, isobutyl acetate, amyl acetate, isoamyl acetate, hexyl acetate, isohexyl acetate, heptyl acetate, octyl acetate, butyl propionate, isobutyl propionate, amyl propionate, hexyl propionate, heptyl propionate, octyl propionate, ethyl butyrate, propyl butyrate, butyl butyrate, isobutyl isobutyrate, isooctyl butyrate, and octyl butyrate.

[0099] Alternatively, the ester solvent may include one or more of butyl acetate, isobutyl acetate, butyl propionate, isobutyl propionate, ethyl butyrate, propyl butyrate, butyl butyrate, and isobutyl isobutyrate.

[0100] Optionally, the ether solvent may include one or more of n-butyl ether, heptyl ether, n-pentyl ether, isopentyl ether, anisole, and phenethyl ether.

[0101] Alternatively, the ether solvent may include one or more of n-butyl ether, anisole, and phenethyl ether.

[0102] In some embodiments, the organic solvent may further include an oxygen-free organic solvent having a boiling point greater than 90°C.

[0103] Optionally, in the organic solvent, the mass percentage of the organic solvent that does not contain oxygen atoms is greater than or equal to the mass percentage of the organic solvent that contains oxygen atoms.

[0104] Optionally, organic solvents that do not contain oxygen atoms may include one or more of alkane solvents and aromatic hydrocarbon solvents.

[0105] Alternatively, the oxygen-free organic solvent may include one or more of toluene, ethylbenzene, o-xylene, m-xylene, p-xylene, pseudotrimethylbenzene, mesitylene, n-heptane, n-dodecane, and n-tetradecane.

[0106] In some embodiments, the organic solvent includes an organic solvent containing oxygen atoms, and the mass percentage of the organic solvent in the modified sulfide electrolyte is greater than 0 and less than or equal to 10000 μg / g, for example, it can be 55 μg / g, 60 μg / g, 70 μg / g, 80 μg / g, 90 μg / g, 100 μg / g, 110 μg / g, 120 μg / g, 130 μg / g, 140 μg / g, 150 μg / g, etc. g / g, 160μg / g, 170μg / g, 180μg / g, 190μg / g, 200μg / g, 300μg / g, 400μg / g, 500μg / g, 600μg / g, 700μg / g, 800μg / g, 900μg / g, 1000μg / g, 1100μg / g, 1200μg / g, 1300μg / g, 1400μg / g, 1 500μg / g, 1600μg / g, 1700μg / g, 1800μg / g, 1900μg / g, 2000μg / g, 2200μg / g, 2400μg / g, 26 00μg / g, 2800μg / g, 3000μg / g, 3200μg / g, 3400μg / g, 3600μg / g, 3800μg / g, 4000μg / g, 420 0 μg / g, 4400 μg / g, 4600 μg / g, 4800 μg / g, 5000 μg / g, 5500 μg / g, 6000 μg / g, 6500 μg / g, 7000 μg / g, 7500 μg / g, 8000 μg / g, 8500 μg / g, 9000 μg / g, 9500 μg / g, 10000 μg / g, or any range of the above values.

[0107] Optionally, the organic solvent includes an organic solvent containing oxygen atoms, and the mass percentage of the organic solvent in the modified sulfide electrolyte can be from 55 μg / g to 2000 μg / g, 55 μg / g to 1500 μg / g, 55 μg / g to 1000 μg / g, 55 μg / g to 800 μg / g, 55 μg / g to 500 μg / g, 55 μg / g to 400 μg / g, 55 μg / g to 300 μg / g, or 55 μg / g to 200 μg / g.

[0108] In some embodiments, the organic solvent includes organic solvents containing oxygen atoms and organic solvents without oxygen atoms. The mass percentage of the organic solvent in the modified sulfide electrolyte is greater than 0 and less than or equal to 10,000 μg / g, for example, it can be 55 μg / g, 60 μg / g, 70 μg / g, 80 μg / g, 90 μg / g, 100 μg / g, 110 μg / g, 120 μg / g, 130 μg / g, 140 μg / g, etc. μg / g, 150μg / g, 160μg / g, 170μg / g, 180μg / g, 190μg / g, 200μg / g, 300μg / g, 400μg / g, 500μg / g, 600μg / g, 700μg / g, 800μg / g, 900μg / g, 1000μg / g, 1100μg / g, 1200μg / g, 1300μg / g, 1400 μg / g, 1500μg / g, 1600μg / g, 1700μg / g, 1800μg / g, 1900μg / g, 2000μg / g, 2200μg / g, 2400μg / g, 2600μg / g, 2800μg / g, 3000μg / g, 3200μg / g, 3400μg / g, 3600μg / g, 3800μg / g, 4000μg / g, 4200μg / g, 4400μg / g, 4600μg / g, 4800μg / g, 5000μg / g, 5500μg / g, 6000μg / g, 6500μg / g, 7000μg / g, 7500μg / g, 8000μg / g, 8500μg / g, 9000μg / g, 9500μg / g, 10000μg / g, or any range of the above values.

[0109] Optionally, the organic solvent includes organic solvents containing oxygen atoms and organic solvents without oxygen atoms, and the mass percentage of the organic solvent in the modified sulfide electrolyte can be from 55 μg / g to 2000 μg / g, 55 μg / g to 1500 μg / g, 55 μg / g to 1000 μg / g, 55 μg / g to 800 μg / g, 55 μg / g to 500 μg / g, 55 μg / g to 400 μg / g, 55 μg / g to 300 μg / g, or 55 μg / g to 200 μg / g.

[0110] The mass percentages of thioether compounds and organic solvents in the modified sulfide electrolyte can be determined by headspace gas chromatography-mass spectrometry.

[0111] In some embodiments, the sulfide electrolyte matrix may be a sulfide-germanium ore type electrolyte.

[0112] Optionally, the sulfide electrolyte matrix includes Li 6+m+l P 1-m Mm S 5-n+l N n Y 1-l material, 0≤m<1, 0≤n<1, -1<l<1, M comprises one or more elements selected from Ge, Si, Sn, Al, Zr and Sb, N comprises one or more elements selected from O, Se and Te, and Y comprises one or more elements selected from Cl, Br and I.

[0113] Optionally, m=0 and n=0, that is, Li 6+m+l P 1-m M m S 5-n+l N n Y 1-l is Li 6+l PS 5+l Y 1-l .

[0114] By way of example, the sulfide electrolyte matrix may comprise Li6PS5Cl, Li6PS5Br, Li6PS5I, Li6PS5Cl 0.5 Br 0.5 , Li 5.5 PS 4.5 Cl 1.5 , Li 5.5 PS 4.5 Br 1.5 one or more of.

[0115] Embodiments of the present disclosure further provide a preparation method of a modified sulfide electrolyte.

[0116] The preparation method of the modified sulfide electrolyte comprises the following steps: grinding each raw material for preparing a sulfide electrolyte matrix, and then performing high-temperature sintering under a protective gas atmosphere to obtain a coarse powder sulfide electrolyte matrix; adding the coarse powder sulfide electrolyte matrix, a grinding medium and an organic solvent into a grinding device, after grinding treatment, separating out solid powder, wherein the organic solvent comprises an oxygen atom-containing organic solvent, the boiling point of the oxygen atom-containing organic solvent is higher than 100°C, the oxygen atom-containing organic solvent comprises one or more of ester solvents and ether solvents, and the oxygen atom-containing organic solvent can react with the sulfide electrolyte matrix to form a thioether compound; drying the separated solid powder in vacuum at 80°C-200°C for 2h-10h to obtain the modified sulfide electrolyte, wherein the volume distribution particle size Dv50 of the modified sulfide electrolyte is 0.1μm-1μm, the modified sulfide electrolyte comprises the sulfide electrolyte matrix and the thioether compound located on at least part of the surface of the sulfide electrolyte matrix, and the mass proportion of the thioether compound in the modified sulfide electrolyte is greater than 0 and less than or equal to 1000μg / g.

[0117] The surface of coarse sulfide electrolyte matrix particles typically contains unbonded or weakly bonded sulfur ions. This disclosure introduces an oxygen-containing organic solvent with a boiling point greater than 100°C, including one or more ester and ether solvents, during the micronization process of the coarse sulfide electrolyte matrix through grinding. These oxygen-containing organic solvent molecules adhere to the surface of the sulfide electrolyte matrix particles and react with the sulfur ions to form sulfide ether compounds. This reduces the agglomeration of small particles after micronization during grinding, thereby preparing a modified sulfide electrolyte with a volume distribution particle size (Dv50) of 0.1 μm-1 μm. Using this small-sized modified sulfide electrolyte as the positive and / or negative electrode of a solid-state battery cell can reduce the volume fraction of the solid-state electrolyte and increase the proportion of electrode active material, thus improving the mass energy density of the solid-state battery cell. Using this small-sized modified sulfide electrolyte as the electrolyte layer of a solid-state battery cell can reduce the thickness of the electrolyte layer, thereby improving the volumetric energy density of the solid-state battery cell. In addition, the presence of sulfide compounds can improve the dispersibility of modified sulfide electrolytes in slurries (such as positive electrode slurry, negative electrode slurry, and electrolyte slurry), improve the consistency of the positive electrode, electrolyte layer, and / or negative electrode of solid-state battery cells, thereby helping to fully utilize the ion conduction effect of modified sulfide electrolytes, improve the charge and discharge performance of solid-state battery cells, and improve the cycle performance of solid-state battery cells.

[0118] Organic solvents containing oxygen atoms have boiling points greater than 100°C. These organic solvents include one or more of ester solvents and ether solvents. These organic solvents containing oxygen atoms have low reactivity with the sulfide electrolyte matrix, which can also avoid excessively reducing the ionic conductivity of the modified sulfide electrolyte.

[0119] The present invention discloses a method of vacuum drying the solid powder separated after grinding at 80℃-200℃ for 2h-10h. This method allows some organic solvent to remain on the surface of the sulfide electrolyte matrix particles, which facilitates the homogenization of solid-state battery cells, improves the dispersibility of modified sulfide electrolyte in slurries (such as positive electrode slurry, negative electrode slurry, and electrolyte slurry), and also helps to reduce the agglomeration problem of modified sulfide electrolyte particles.

[0120] Adjusting vacuum drying parameters, such as temperature and time, can regulate the mass percentage of residual organic solvent in the modified sulfide electrolyte.

[0121] The temperature for vacuum drying is 80℃-200℃, for example, it can be 80℃, 90℃, 100℃, 110℃, 120℃, 130℃, 140℃, 150℃, 160℃, 170℃, 180℃, 190℃, 200℃, or any combination of the above values.

[0122] Optionally, the vacuum drying temperature can be 80℃-180℃, 80℃-170℃, 80℃-160℃, 80℃-150℃, 80℃-140℃, 80℃-130℃, 80℃-120℃, 90℃-180℃, 90℃-170℃, 90℃-160℃, 90℃-150℃, 90℃-140℃, 90℃-130℃, 90℃-120℃, 100℃-180℃, 100℃-170℃, 100℃-160℃, 100℃-150℃, 100℃-140℃, 100℃-130℃, or 100℃-120℃.

[0123] The vacuum drying time is 2h-10h, for example, it can be 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, 6h, 6.5h, 7h, 7.5h, 8h, 8.5h, 9h, 9.5h, 10h, or any combination of the above values.

[0124] Optionally, the vacuum drying time is 2h-9h, 2h-8h, 2h-7h, 2h-6h, 2.5h-9h, 2.5h-8h, 2.5h-7h, or 2.5h-6h.

[0125] Adjusting the grinding process parameters, such as rotation speed, time, amount of grinding media, and the composition and amount of organic solvent, can regulate the volume distribution particle size Dv50 of the modified sulfide electrolyte.

[0126] In some embodiments, the grinding speed can be 300rpm-2300rpm, for example, it can be any range of the following values: 300rpm, 400rpm, 500rpm, 600rpm, 700rpm, 800rpm, 900rpm, 1000rpm, 1100rpm, 1200rpm, 1300rpm, 1400rpm, 1500rpm, 1600rpm, 1700rpm, 1800rpm, 1900rpm, 2000rpm, 2100rpm, 2200rpm, 2300rpm.

[0127] In some embodiments, the grinding time can be 30 min to 10 h, for example, it can be 30 min, 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h, 10 h, or any range of the above values.

[0128] In some embodiments, the grinding media can be zirconia balls with a diameter of 0.4 mm to 3 mm.

[0129] In some embodiments, the mass ratio of the grinding media to the coarse powder sulfide electrolyte matrix can be from 5:1 to 10:1, for example, it can be 5:1, 5.5:1, 6:1, 6.5:1, 7:1, 7.5:1, 8:1, 8.5:1, 9:1, 9.5:1, 10:1, or any range of the above values.

[0130] Organic solvents containing oxygen atoms include one or more of ester solvents and ether solvents.

[0131] Adjusting the composition and amount of organic solvent can regulate the types of sulfide compounds formed and their mass percentage in the modified sulfide electrolyte.

[0132] In some embodiments, the ester solvent may include one or more of the following: butyl acetate, isobutyl acetate, amyl acetate, isoamyl acetate, hexyl acetate, isohexyl acetate, heptyl acetate, octyl acetate, butyl propionate, isobutyl propionate, amyl propionate, hexyl propionate, heptyl propionate, octyl propionate, ethyl butyrate, propyl butyrate, butyl butyrate, isobutyl isobutyrate, isooctyl butyrate, and octyl butyrate.

[0133] These ester solvents have low reactivity with the sulfide electrolyte matrix, which also avoids excessively reducing the ionic conductivity of the modified sulfide electrolyte.

[0134] Optionally, the ester solvent may include one or more of butyl acetate, isobutyl acetate, butyl propionate, isobutyl propionate, ethyl butyrate, propyl butyrate, butyl butyrate, and isobutyl isobutyrate.

[0135] Alternatively, the ester solvent may include one or more of butyl acetate, isobutyl acetate, butyl propionate, isobutyl propionate, butyl butyrate, and isobutyl isobutyrate.

[0136] In some embodiments, the ether solvent may include one or more of n-butyl ether, heptyl ether, n-pentyl ether, isopentyl ether, anisole, and phenethyl ether.

[0137] These ether solvents have low reactivity with the sulfide electrolyte matrix, which can avoid excessively reducing the ionic conductivity of the modified sulfide electrolyte.

[0138] Optionally, the ether solvent may include one or more of n-butyl ether, anisole, and phenethyl ether.

[0139] In some embodiments, the organic solvent may further include an oxygen-free organic solvent having a boiling point greater than 90°C.

[0140] Optionally, organic solvents that do not contain oxygen atoms may include one or more of alkane solvents and aromatic hydrocarbon solvents.

[0141] Alternatively, the oxygen-free organic solvent may include one or more of toluene, ethylbenzene, o-xylene, m-xylene, p-xylene, pseudotrimethylbenzene, mesitylene, n-heptane, n-dodecane, and n-tetradecane.

[0142] Organic solvents containing oxygen atoms can react with sulfide electrolyte matrices to form thioether compounds, while organic solvents without oxygen atoms, such as alkanes and aromatics, do not react with the sulfide electrolyte matrix. Therefore, by including both oxygen-containing and oxygen-free organic solvents, thioether compounds can be formed, thereby improving the dispersibility of modified sulfide electrolytes in slurries (such as positive electrode slurries, negative electrode slurries, and electrolyte slurries), enhancing the consistency of the positive electrode, electrolyte layer, and / or negative electrode in solid-state battery cells, and thus facilitating the full utilization of the ion conduction function of the modified sulfide electrolyte. It can also reduce the agglomeration of small particles after micronization of the sulfide electrolyte matrix during the grinding process; and it can give the prepared modified sulfide electrolyte higher ionic conductivity, enabling solid-state battery cells to possess both high energy density and good cycle performance.

[0143] In some embodiments, the mass ratio of the organic solvent containing oxygen atoms to the organic solvent without oxygen atoms can be from 1:39 to 1:1, for example, it can be 1:39, 1:35, 1:30, 1:25, 1:20, 1:15, 1:10, 1:9, 1:8, 1:7, 1:6, 1:5, 1:4, 1:3, 1:2, 1:1, or any range of the above values.

[0144] When the mass ratio of organic solvent containing oxygen atoms to organic solvent without oxygen atoms is within the above range, the prepared modified sulfide electrolyte can have an appropriate amount of thioether compounds, and the prepared modified sulfide electrolyte can also have a high ionic conductivity.

[0145] Optionally, the mass ratio of the organic solvent containing oxygen atoms to the organic solvent without oxygen atoms can be 1:10 to 1:1, 1:5 to 1:1, or 1:3 to 1:1.

[0146] When the mass ratio of organic solvent containing oxygen atoms to organic solvent without oxygen atoms is within the above range, the prepared modified sulfide electrolyte can have a high ionic conductivity and can further improve the dispersibility of the modified sulfide electrolyte in slurries (such as positive electrode slurry, negative electrode slurry, and electrolyte slurry).

[0147] In some embodiments, the mass ratio of the organic solvent to the coarse powder sulfide electrolyte matrix can be from 2:1 to 18:1, for example, it can be 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, or any range of the above values.

[0148] In some embodiments, the process of separating solid powder after grinding can employ centrifugation or filtration.

[0149] In some embodiments, the coarse powder sulfide electrolyte matrix is ​​obtained by grinding the raw materials and then sintering them at high temperature under a protective gas atmosphere.

[0150] Optionally, the protective gas may include one or more of nitrogen, argon, and helium.

[0151] Optionally, the high-temperature sintering temperature can be 350℃-600℃, for example, it can be 350℃, 360℃, 370℃, 380℃, 390℃, 400℃, 410℃, 420℃, 430℃, 440℃, 450℃, 460℃, 470℃, 480℃, 490℃, 500℃, 510℃, 520℃, 530℃, 540℃, 550℃, 560℃, 570℃, 580℃, 590℃, 600℃, or any combination of the above values.

[0152] Alternatively, the high-temperature sintering temperature can be 450℃-550℃.

[0153] Optionally, the high-temperature sintering time can be 4h-15h, for example, it can be 4h, 5h, 6h, 7h, 8h, 9h, 10h, 11h, 12h, 13h, 14h, 15h, or any range of the above values.

[0154] In some embodiments, the volume distribution particle size Dv50 of the coarse sulfide electrolyte matrix can be 3μm-20μm, for example, it can be 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, 16μm, 17μm, 18μm, 19μm, 20μm, or any range of the above values.

[0155] The solid-state battery cell provided in this disclosure includes a positive electrode, an electrolyte layer, and a negative electrode, with the electrolyte layer located between the positive and negative electrodes. At least one of the positive electrode, electrolyte layer, and negative electrode includes the modified sulfide electrolyte provided in this disclosure or a modified sulfide electrolyte prepared by the preparation method of this disclosure.

[0156] [positive electrode]

[0157] The positive electrode includes a positive electrode film, which in turn includes the positive electrode active material and a solid electrolyte.

[0158] In some embodiments, the positive electrode further includes a positive current collector, and the positive electrode film layer is located on at least one surface of the positive current collector. The positive 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 current collector.

[0159] In some embodiments, the positive current collector may be a metal foil or a composite current collector. The metal foil may be a pure metal, an alloy, or a surface-treated metal, such as, but not limited to, stainless steel foil, carbon-coated aluminum foil, or aluminum foil. The composite current collector may include a polymer substrate and a metal layer formed on at least one surface of the polymer substrate. As an example, the metal layer may include, but is not limited to, one or more of aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys. As an example, the polymer substrate may include, but is not limited to, one or more of polypropylene, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene.

[0160] 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, lithium niobate, sulfur, selenium, and tellurium.

[0161] Optionally, examples of lithium transition metal oxides may include, but are not limited to, one or more of lithium cobalt oxides, lithium nickel oxides, lithium manganese oxides, lithium nickel cobalt oxides, lithium manganese cobalt oxides, lithium nickel manganese oxides, lithium nickel cobalt manganese oxides, lithium nickel cobalt aluminum oxides, and lithium-rich manganese-based materials.

[0162] 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.

[0163] 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 fone or more of lithium transition metal oxides and modified materials thereof. 0.8 ≤ a ≤ 1.2, 0.5 ≤ b < 1, 0 < c < 1, 0 < d < 1, 1 ≤ e ≤ 2, 0 ≤ f ≤ 1, M may comprise one or more of Mn, Al, Zr, Zn, Cu, Cr, Mg, Fe, V, Ti and B, and A may comprise one or more of N, F, S and Cl. Optionally, 0.6 ≤ b < 1, 0.8 ≤ b < 1.

[0164] By way of example, the positive electrode active material may 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 one or more of respective modified materials thereof.

[0165] The modified material of each of the foregoing positive electrode active materials may be doping modification and / or surface coating modification performed on the positive electrode active material.

[0166] During charging and discharging of a solid-state battery cell, it is accompanied by deintercalation and consumption of Li, and the molar content of Li in the solid-state battery cell is different when discharged to different states. In the enumeration of positive electrode active materials in the present disclosure, the molar content of Li refers to the initial state of the material, that is, the state before feeding; after the positive electrode active material is applied to a solid-state battery cell and undergoes charge-discharge cycles, the molar content of Li will change. In the enumeration of positive electrode active materials in the present disclosure, the molar content of O is only a theoretical state value; lattice oxygen release will lead to changes in the molar content of O, and the actual molar content of O will also fluctuate.

[0167] In some embodiments, the positive electrode film layer may further comprise a positive electrode conductive agent.

[0168] Optionally, the positive electrode conductive agent may be one or more of the following, including but not limited to superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes (CNTs), graphene, carbon nanofibers, and vapor-grown carbon fibers (VGCF).

[0169] In some embodiments, the positive electrode film layer may further include a positive electrode binder.

[0170] Optionally, the positive electrode binder may include, but is not limited to, one or more of the following: polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), ethylene-tetrafluoroethylene-propylene terpolymer, ethylene-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, cis-butadiene rubber (BR), ethyl cellulose, fluororubber, and acrylate rubber.

[0171] In some embodiments, the mass percentage of the solid electrolyte in the positive electrode film layer can be 5%-30%, 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%, 26%, 27%, 28%, 29%, 30%, or any range of the above values.

[0172] In some embodiments, the solid electrolyte in the positive electrode film may include one or more of the commonly used sulfide electrolytes, halide electrolytes, and oxide electrolytes in the art.

[0173] Optionally, the sulfide electrolyte may include Li 6+m+l P 1-m M m S 5-n+l N n Y 1-l The material, with the molecular formula Li 10±δ Ge 1-g G g P 2-q Q q S 12-w W w Materials, Li 4-v Ge 1-v P vone or more of S4, Li₂S-P₂S₅-based materials, Li₂S-SiS₂-based materials, Li₂S-MeS-P₂S₅-based materials, and LiGeGaS-based materials, 0≤m<1, 0≤n<1, -1<l<1, M includes one or more elements selected from Ge, Si, Sn, Al, Zr and Sb, N includes one or more elements selected from O, Se and Te, Y includes one or more elements selected from Cl, Br and I, 0≤δ<1, 0≤g≤1, 0≤q≤2, 0≤w<1, G includes one or two elements selected from Si and Sn, Q includes Sb, W includes one or more elements selected from O, Se, Te, Cl, Br and I, 0<v<1, Me includes one or more elements selected from Si, Ge, Sn and Al. By way of example, the sulfide electrolyte may include Li₆PS₅Cl, Li₆PS₅Br, Li₆PS₅I, Li₆PS₅Cl 0.5 Br 0.5 , Li 5.5 PS 4.5 Cl 1.5 , Li 5.5 PS 4.5 Br 1.5 , Li 10 GeP₂S 12 , Li₃PS₄, Li₇P₃S 11 , Li 3.25 Ge 0.25 P 0.75 S₄, Li₆GaGe₂S 10 one or more of the foregoing.

[0174] Optionally, the halide electrolyte may include, but is not limited to, one or more of Li₃YCl₆, Li₃YBr₆, Li₃ErCl₆, Li₃InCl₆, and Li₃InBr₆.

[0175] Optionally, the oxide electrolyte may include one or more of NASICON-type solid electrolytes, LISICON-type solid electrolytes, perovskite-type solid electrolytes, and garnet-type solid electrolytes. By way of example, the oxide electrolyte may include, but is not limited to, Li₅La₃Ti₂O 12 , Li₇La₃Zr₂O 12 , Li₄Ti₅O 12 , Li 14 Zn(GeO₄)₄, LiTi₂(PO₄)₃, Li 1+x Al x Ti 2-x (PO₄)₃, Li 1+y Al y Ge 2-yOne or more of (PO4)3, 0 <x<2,0<y<2。

[0176] In other embodiments, the solid electrolyte in the positive electrode film may include the modified sulfide electrolyte provided in the embodiments of this disclosure.

[0177] Alternatively, the positive electrode film layer is prepared by a wet process.

[0178] Optionally, the modified sulfide electrolyte provided in this embodiment of the present disclosure can be dispersed in a solvent with positive electrode active material, positive electrode binder, positive electrode conductive agent and other components and stirred evenly to prepare a positive electrode slurry. The positive electrode slurry is then coated on a positive electrode current collector and dried to obtain a positive electrode.

[0179] The modified sulfide electrolyte provided in this disclosure includes a sulfide electrolyte matrix and sulfide compounds located on at least a portion of the surface of the sulfide electrolyte matrix, wherein the mass percentage of the sulfide compounds in the modified sulfide electrolyte is greater than 0 and less than or equal to 1000 μg / g. The presence of sulfide compounds can improve the dispersibility of the cathode slurry and enhance the consistency of the cathode, thereby facilitating the full utilization of the ion conduction function of the modified sulfide electrolyte, improving the charge-discharge performance of solid-state battery cells, and enhancing the cycle performance of solid-state battery cells.

[0180] In some other embodiments, the solid electrolyte in the positive electrode film may include the modified sulfide electrolyte provided in the embodiments of this disclosure and other solid electrolytes, which may include one or more of the sulfide electrolytes, halide electrolytes and oxide electrolytes commonly used in the art.

[0181] Alternatively, the positive electrode film layer is prepared by a wet process.

[0182] Optionally, the modified sulfide electrolyte and other solid electrolytes provided in the embodiments of this disclosure can be dispersed in a solvent with positive electrode active material, positive electrode binder, positive electrode conductive agent and other components and stirred evenly to prepare a positive electrode slurry. The positive electrode slurry is then coated on a positive electrode current collector and dried to obtain a positive electrode.

[0183] The modified sulfide electrolyte provided in this disclosure includes a sulfide electrolyte matrix and sulfide compounds located on at least a portion of the surface of the sulfide electrolyte matrix, wherein the mass percentage of the sulfide compounds in the modified sulfide electrolyte is greater than 0 and less than or equal to 1000 μg / g. The presence of sulfide compounds can improve the dispersibility of the cathode slurry and enhance the consistency of the cathode, thereby facilitating the full utilization of the ion conduction function of the modified sulfide electrolyte, improving the charge-discharge performance of solid-state battery cells, and enhancing the cycle performance of solid-state battery cells.

[0184] [Electrolyte layer]

[0185] The electrolyte layer includes a solid electrolyte.

[0186] In some embodiments, the solid electrolyte in the electrolyte layer may comprise one or more of sulfide electrolytes, halide electrolytes, and oxide electrolytes commonly used in the art.

[0187] Optionally, the sulfide electrolyte may comprise a material with the molecular formula Li 6+m+l P 1-m M m S 5-n+l N n Y 1-l , a material with the molecular formula Li 10±δ Ge 1-g G g P 2-q Q q S 12-w W w , Li 4-v Ge 1-v P v S4, one or more of Li2S-P2S5-based materials, Li2S-SiS2-based materials, Li2S-MeS-P2S5-based materials, and LiGeGaS-based materials, wherein 0≤m<1, 0≤n<1, -1<l<1, M comprises one or more elements selected from the group consisting of Ge, Si, Sn, Al, Zr and Sb, N comprises one or more elements selected from the group consisting of O, Se and Te, Y comprises one or more elements selected from the group consisting of Cl, Br and I, 0≤δ<1, 0≤g≤1, 0≤q≤2, 0≤w<1, G comprises one or two elements selected from the group consisting of Si and Sn, Q comprises Sb, W comprises one or more elements selected from the group consisting of O, Se, Te, Cl, Br and I, 0<v<1, and Me comprises one or more elements selected from the group consisting of Si, Ge, Sn and Al. By way of example, the sulfide electrolyte may comprise one or more of Li6PS5Cl, Li6PS5Br, Li6PS5I, Li6PS5Cl 0.5 Br 0.5 , Li 5.5 PS 4.5 Cl 1.5 , Li 5.5 PS 4.5 Br 1.5 , Li 10 GeP2S 12 , Li3PS4, Li7P3S 11 , Li 3.25 Ge 0.25 P 0.75 S4, Li6GaGe2S 10

[0188] ​Optionally, the halide electrolyte may be one or more of Li3YCl6, Li3YBr6, Li3ErCl6, Li3InCl6, and Li3InBr6, including but not limited to.

[0189] Optionally, the oxide electrolyte may include one or more of the following: NASICON-type solid-state electrolyte, LISICON-type solid-state electrolyte, perovskite-type solid-state electrolyte, and garnet-type solid-state electrolyte. As an example, the oxide electrolyte may include, but is not limited to, Li5La3Ti2O 12 Li7La3Zr2O 12 Li4Ti5O 12 Li 14 Zn(GeO4)4, LiTi2(PO4)3, Li 1+x Al x Ti 2-x (PO4)3, Li 1+y Al y Ge 2-y One or more of (PO4)3, 0 <x<2,0<y<2。

[0190] In other embodiments, the solid electrolyte in the electrolyte layer may include the modified sulfide electrolyte provided in the embodiments of this disclosure.

[0191] In some other embodiments, the solid electrolyte in the electrolyte layer may include the modified sulfide electrolyte provided in the embodiments of this disclosure and other solid electrolytes, which may include one or more of the sulfide electrolytes, halide electrolytes and oxide electrolytes commonly used in the art.

[0192] In some embodiments, the electrolyte layer may further include an adhesive. Optionally, the adhesive may include, but is not limited to, one or more of the following: polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-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, cis-butadiene rubber (BR), ethyl cellulose, fluororubber, and acrylate rubber.

[0193] [negative electrode]

[0194] In some embodiments, the negative electrode may include lithium or a lithium alloy.

[0195] For example, the negative electrode can be a metal sheet, such as a lithium sheet or a lithium alloy sheet. Alternatively, the negative electrode 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 lithium-based metal layer can be metallic lithium or a lithium alloy. The negative electrode 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 electrode current collector.

[0196] Optionally, other elements in the lithium alloy may include, but are not limited to, one or more of In, Mg, Al, Zn, Sn, Ag, Au, Ga, Pt, and Fe.

[0197] Alternatively, the lithium alloy may include, but is not limited to, InLi alloy, Li-Mg alloy, Li-Al alloy, Li-Zn alloy, Li-Fe alloy, etc.

[0198] In other embodiments, the negative electrode 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 comprising a negative electrode active material. 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.

[0199] Optionally, the negative electrode active material may include one or more of the following: natural graphite, artificial graphite, mesophase micro carbon spheres, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, and metal oxides.

[0200] Optionally, the silicon-based material may include, but is not limited to, one or more of elemental silicon, silicon oxide, 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 oxide, and tin alloys. Optionally, the metal oxide may include, but is not limited to, one or more of TiO2, MoO2, In2O3, Al2O3, Cu2O, VO2, Ga2O3, Sb2O5, and Bi2O5.

[0201] In some embodiments, the negative electrode film layer may further include a negative electrode binder.

[0202] Optionally, the negative electrode binder may include, but is not limited to, one or more of the following: polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), ethylene-tetrafluoroethylene-propylene terpolymer, ethylene-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, styrene-butadiene rubber (SBR), water-soluble unsaturated resin SR-1B, polyacrylic acid, polymethacrylic acid, sodium polyacrylate, polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), carboxymethyl chitosan (CMCS), 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.

[0203] In some embodiments, the negative electrode film layer may or may not include a negative electrode conductive agent.

[0204] Optionally, the negative electrode conductive agent may be one or more of the following, including but not limited to superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes (CNTs), graphene, carbon nanofibers, and vapor-grown carbon fibers (VGCF).

[0205] In some embodiments, the negative electrode film layer may or may not include a solid electrolyte.

[0206] Optionally, the mass percentage of the solid electrolyte in the negative electrode film can be less than 30%.

[0207] In some embodiments, the negative electrode film layer includes a solid electrolyte, which may include one or more of the commonly used sulfide electrolytes, halide electrolytes, and oxide electrolytes in the art.

[0208] Optionally, the sulfide electrolyte may include Li 6+m+l P 1-m M m S 5-n+l N n Y 1-l The material, with the molecular formula Li 10±δ Ge 1-g G g P 2-q Q q S 12-w W w Materials, Li 4-v Ge 1-v P vS4, one or more of Li₂S-P₂S₅-based materials, Li₂S-SiS₂-based materials, Li₂S-MeS-P₂S₅-based materials, and LiGeGaS-based materials, 0≤m<1, 0≤n<1, -1<l<1, M comprises one or more of elements selected from Ge, Si, Sn, Al, Zr and Sb, N comprises one or more of elements selected from O, Se and Te, Y comprises one or more of elements selected from Cl, Br and I, 0≤δ<1, 0≤g≤1, 0≤q≤2, 0≤w<1, G comprises one or two of elements selected from Si and Sn, Q comprises Sb, W comprises one or more of elements selected from O, Se, Te, Cl, Br and I, 0<v<1, Me comprises one or more of elements selected from Si, Ge, Sn and Al. By way of example, the sulfide electrolyte may comprise Li₆PS₅Cl, Li₆PS₅Br, Li₆PS₅I, Li₆PS₅Cl 0.5 Br 0.5 , Li 5.5 PS 4.5 Cl 1.5 , Li 5.5 PS 4.5 Br 1.5 , Li 10 GeP₂S 12 , Li₃PS₄, Li₇P₃S 11 , Li 3.25 Ge 0.25 P 0.75 S₄, Li₆GaGe₂S 10 one or more of the above.

[0209] Optionally, the halide electrolyte may include, but is not limited to, one or more of Li₃YCl₆, Li₃YBr₆, Li₃ErCl₆, Li₃InCl₆, and Li₃InBr₆.

[0210] Optionally, the oxide electrolyte may include one or more of NASICON-type solid electrolytes, LISICON-type solid electrolytes, perovskite-type solid electrolytes, and garnet-type solid electrolytes. By way of example, the oxide electrolyte may include, but is not limited to, Li₅La₃Ti₂O 12 , Li₇La₃Zr₂O 12 , Li₄Ti₅O 12 , Li 14 Zn(GeO₄)₄, LiTi₂(PO₄)₃, Li 1+x Al x Ti 2-x (PO₄)₃, Li 1+y Al y Ge 2-yOne or more of (PO4)3, 0 <x<2,0<y<2。

[0211] In other embodiments, the negative electrode film layer includes a solid electrolyte, which may include the modified sulfide electrolyte provided in the embodiments of this disclosure.

[0212] Alternatively, the negative electrode film layer is prepared by a wet process.

[0213] Optionally, the modified sulfide electrolyte provided in this embodiment of the present disclosure can be dispersed in a solvent and stirred evenly to prepare a negative electrode slurry. The negative electrode slurry is then coated on a negative electrode current collector and dried to obtain a negative electrode.

[0214] The modified sulfide electrolyte provided in this disclosure includes a sulfide electrolyte matrix and sulfide compounds located on at least a portion of the surface of the sulfide electrolyte matrix, wherein the mass percentage of the sulfide compounds in the modified sulfide electrolyte is greater than 0 and less than or equal to 1000 μg / g. The presence of sulfide compounds can improve the dispersibility of the negative electrode slurry and enhance the consistency of the negative electrode, thereby facilitating the full utilization of the ion conduction function of the modified sulfide electrolyte, improving the charge-discharge performance of solid-state battery cells, and enhancing the cycle performance of solid-state battery cells.

[0215] In some other embodiments, the negative electrode film layer includes a solid electrolyte, which may include the modified sulfide electrolyte provided in the embodiments of this disclosure and other solid electrolytes. Other solid electrolytes may include one or more of the commonly used sulfide electrolytes, halide electrolytes, and oxide electrolytes in the art.

[0216] Alternatively, the negative electrode film layer is prepared by a wet process.

[0217] Optionally, the modified sulfide electrolyte and other solid electrolytes provided in the embodiments of this disclosure can be dispersed in a solvent with components such as negative electrode active material and negative electrode binder and stirred evenly to prepare a negative electrode slurry. The negative electrode slurry is then coated on a negative electrode current collector and dried to obtain a negative electrode.

[0218] The modified sulfide electrolyte provided in this disclosure includes a sulfide electrolyte matrix and sulfide compounds located on at least a portion of the surface of the sulfide electrolyte matrix, wherein the mass percentage of the sulfide compounds in the modified sulfide electrolyte is greater than 0 and less than or equal to 1000 μg / g. The presence of sulfide compounds can improve the dispersibility of the negative electrode slurry and enhance the consistency of the negative electrode, thereby facilitating the full utilization of the ion conduction function of the modified sulfide electrolyte, improving the charge-discharge performance of solid-state battery cells, and enhancing the cycle performance of solid-state battery cells.

[0219] In some embodiments, the negative electrode current collector may be a metal foil or a composite current collector. The metal foil may be a pure metal, an alloy, or a surface-treated metal, such as, but not limited to, stainless steel foil, copper foil, and nickel foil. The composite current collector may include a polymer substrate and a metal layer formed on at least one surface of the polymer substrate. As an example, the metal layer may include, but is not limited to, one or more of copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys. As an example, the polymer substrate may include, but is not limited to, one or more of polypropylene, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene, and polyethylene.

[0220] In some embodiments, the solid-state battery cell may further include an outer packaging for accommodating the electrode assembly formed by assembling the negative electrode, electrolyte layer, and positive 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).

[0221] [Preparation Method]

[0222] The methods for preparing solid-state battery cells are well known. For example, the assembly methods of solid-state battery cells include, but are not limited to, coin cells, hard-case cells, and pouch cells.

[0223] Example

[0224] 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.

[0225] Example 1

[0226] Preparation of modified sulfide electrolytes

[0227] Li2S, P2S5, and LiCl were mixed uniformly according to the stoichiometric ratio and sintered at 550℃ for 12h under an argon atmosphere to obtain a coarse sulfide electrolyte matrix Li6PS5Cl. The volume distribution particle size Dv50 of the coarse sulfide electrolyte matrix Li6PS5Cl was 15μm.

[0228] The coarse sulfide electrolyte matrix Li6PS5Cl, zirconia balls, and organic solvent were added to a grinding jar and ground at 300 rpm for 5 hours, followed by centrifugation. The mass ratio of zirconia balls to coarse sulfide electrolyte matrix Li6PS5Cl was 10:1; the organic solvent was butyl acetate, and the mass ratio of organic solvent to coarse sulfide electrolyte matrix Li6PS5Cl was 4:1. Some butyl acetate reacted with the sulfide electrolyte matrix to form sulfide compounds.

[0229] The centrifuged powder was dried in a vacuum oven at 80°C for 5 hours to obtain the modified sulfide electrolyte. The volume distribution particle size (Dv50) of the modified sulfide electrolyte was 0.5 μm, and the modified sulfide electrolyte comprised a sulfide electrolyte matrix Li6PS5Cl and butyl acetate and thioether compounds located on at least a portion of the surface of the Li6PS5Cl matrix. The thioether compounds included dibutyl sulfide and dibutyl disulfide. The mass percentage of butyl acetate in the modified sulfide electrolyte was 120 μg / g, and the mass percentage of the thioether compounds was 260 μg / g.

[0230] Preparation of solid-state battery cells

[0231] In an argon atmosphere, the positive electrode active material LiNi 0.8 Co 0.1 Mn 0.1 O2, the modified sulfide electrolyte, the positive electrode binder polyvinylidene fluoride (PVDF), and the positive electrode conductive agent vapor-grown carbon fiber (VGCF) are dispersed in p-xylene at a mass ratio of 85:13:1:1 and stirred evenly to prepare a positive electrode slurry with a solid content of 60%; the positive electrode slurry is coated on the positive electrode current collector aluminum foil and dried to obtain the positive electrode.

[0232] In an argon atmosphere, silicon powder (the negative electrode active material), the modified sulfide electrolyte prepared above, and polyvinylidene fluoride (PVDF) (the negative electrode binder) are dispersed in p-xylene at a mass ratio of 80:17:3 and stirred evenly to prepare a negative electrode slurry with a solid content of 50%. The negative electrode slurry is coated on copper foil (the negative electrode current collector) and dried to obtain the negative electrode.

[0233] In an argon atmosphere, commercially available sulfide electrolyte Li6PS5Cl and binder nitrile rubber (NBR) are dispersed in p-xylene at a mass ratio of 99:1 and stirred evenly to prepare a slurry with a solid content of 50%. The slurry is coated on a PET film, dried, and then the PET film is removed to obtain the electrolyte layer.

[0234] An electrolyte layer is coated onto the surface of the positive electrode film, and the electrolyte layer is transferred to the positive electrode by cold pressing at 10 MPa. Then, the negative electrode is attached to the other side of the electrolyte layer to obtain a solid-state battery cell.

[0235] Example 2

[0236] Except for the following differences, the preparation of solid-state battery cells is the same as in Example 1.

[0237] Preparation of modified sulfide electrolytes

[0238] Li2S, P2S5, and LiCl were mixed uniformly according to the stoichiometric ratio and sintered at 550℃ for 12h under an argon atmosphere to obtain a coarse sulfide electrolyte matrix Li6PS5Cl. The volume distribution particle size Dv50 of the coarse sulfide electrolyte matrix Li6PS5Cl was 15μm.

[0239] The coarse sulfide electrolyte matrix Li6PS5Cl, zirconia balls, and organic solvent were added to a grinding jar and ground at 300 rpm for 5 hours, followed by centrifugation. The mass ratio of zirconia balls to coarse sulfide electrolyte matrix Li6PS5Cl was 10:1; the organic solvent was n-butyl ether, and the mass ratio of the organic solvent to the coarse sulfide electrolyte matrix Li6PS5Cl was 4:1. Some of the n-butyl ether reacted with the sulfide electrolyte matrix to form sulfide compounds.

[0240] The centrifuged powder was dried in a vacuum oven at 100°C for 4 hours to obtain the modified sulfide electrolyte. The volume distribution particle size (Dv50) of the modified sulfide electrolyte was 0.5 μm. The modified sulfide electrolyte consisted of a sulfide electrolyte matrix Li6PS5Cl and n-butyl ether and thioether compounds located on at least a portion of the surface of the sulfide electrolyte matrix Li6PS5Cl. The thioether compounds included dibutyl sulfide and dibutyl disulfide. The mass percentage of n-butyl ether in the modified sulfide electrolyte was 170 μg / g, and the mass percentage of thioether compounds in the modified sulfide electrolyte was 320 μg / g.

[0241] Example 3

[0242] Except for the following differences, the preparation of solid-state battery cells is the same as in Example 1.

[0243] Preparation of modified sulfide electrolytes

[0244] Li2S, P2S5, and LiCl were mixed uniformly according to the stoichiometric ratio and sintered at 550℃ for 12h under an argon atmosphere to obtain a coarse sulfide electrolyte matrix Li6PS5Cl. The volume distribution particle size Dv50 of the coarse sulfide electrolyte matrix Li6PS5Cl was 15μm.

[0245] The coarse sulfide electrolyte matrix Li6PS5Cl, zirconia balls, and organic solvent were added to a grinding jar and ground at 300 rpm for 5 hours, followed by centrifugation. The mass ratio of zirconia balls to coarse sulfide electrolyte matrix Li6PS5Cl was 10:1; the organic solvent was a mixture of n-heptane and butyl acetate, with a mass ratio of 1:1, and the mass ratio of organic solvent to coarse sulfide electrolyte matrix Li6PS5Cl was 4:1. Some butyl acetate reacted with the sulfide electrolyte matrix to form sulfide compounds.

[0246] The centrifuged powder was dried in a vacuum oven at 80°C for 5 hours to obtain the modified sulfide electrolyte. The volume distribution particle size (Dv50) of the modified sulfide electrolyte was 0.6 μm. The modified sulfide electrolyte consisted of a sulfide electrolyte matrix Li6PS5Cl and n-heptane, butyl acetate, and thioether compounds located on at least a portion of the surface of the sulfide electrolyte matrix Li6PS5Cl. The thioether compounds included dibutyl sulfide and dibutyl disulfide. The total mass percentage of n-heptane and butyl acetate in the modified sulfide electrolyte was 55 μg / g, and the mass percentage of thioether compounds in the modified sulfide electrolyte was 110 μg / g.

[0247] Example 4

[0248] Except for the following differences, the preparation of solid-state battery cells is the same as in Example 1.

[0249] Preparation of modified sulfide electrolytes

[0250] Li2S, P2S5, and LiCl were mixed uniformly according to the stoichiometric ratio and sintered at 550℃ for 12h under an argon atmosphere to obtain a coarse sulfide electrolyte matrix Li6PS5Cl. The volume distribution particle size Dv50 of the coarse sulfide electrolyte matrix Li6PS5Cl was 15μm.

[0251] The coarse sulfide electrolyte matrix Li6PS5Cl, zirconia balls, and organic solvent were added to a grinding jar and ground at 300 rpm for 5 hours, followed by centrifugation. The mass ratio of zirconia balls to coarse sulfide electrolyte matrix Li6PS5Cl was 10:1; the organic solvent was a mixture of n-heptane and n-butyl ether, with a mass ratio of 1:1, and the mass ratio of organic solvent to coarse sulfide electrolyte matrix Li6PS5Cl was 4:1. Some of the n-butyl ether reacted with the sulfide electrolyte matrix to form sulfide compounds.

[0252] The centrifuged powder was dried in a vacuum oven at 100°C for 5 hours to obtain the modified sulfide electrolyte. The volume distribution particle size (Dv50) of the modified sulfide electrolyte was 0.4 μm. The modified sulfide electrolyte consisted of a sulfide electrolyte matrix Li6PS5Cl and n-heptane, n-butyl ether, and thioether compounds located on at least a portion of the surface of the sulfide electrolyte matrix Li6PS5Cl. The thioether compounds included dibutyl sulfide and dibutyl disulfide. The total mass percentage of n-heptane and n-butyl ether in the modified sulfide electrolyte was 70 μg / g, and the mass percentage of thioether compounds in the modified sulfide electrolyte was 240 μg / g.

[0253] Example 5

[0254] Except for the following differences, the preparation of solid-state battery cells is the same as in Example 1.

[0255] Preparation of modified sulfide electrolytes

[0256] Li2S, P2S5, and LiCl were mixed uniformly according to the stoichiometric ratio and sintered at 550℃ for 12h under an argon atmosphere to obtain a coarse sulfide electrolyte matrix Li6PS5Cl. The volume distribution particle size Dv50 of the coarse sulfide electrolyte matrix Li6PS5Cl was 15μm.

[0257] The coarse sulfide electrolyte matrix Li6PS5Cl, zirconia balls, and organic solvent were added to a grinding jar and ground at 300 rpm for 5 hours, followed by centrifugation. The mass ratio of zirconia balls to coarse sulfide electrolyte matrix Li6PS5Cl was 10:1; the organic solvent was a mixture of toluene and n-butyl ether, with a mass ratio of 1:1, and the mass ratio of organic solvent to coarse sulfide electrolyte matrix Li6PS5Cl was 4:1. Some of the n-butyl ether reacted with the sulfide electrolyte matrix to form sulfide compounds.

[0258] The centrifuged powder was dried in a vacuum oven at 100°C for 6 hours to obtain the modified sulfide electrolyte. The volume distribution particle size (Dv50) of the modified sulfide electrolyte was 0.4 μm. The modified sulfide electrolyte consisted of a sulfide electrolyte matrix Li6PS5Cl and toluene, n-butyl ether, and thioether compounds located on at least a portion of the surface of the sulfide electrolyte matrix Li6PS5Cl. The thioether compounds included dibutyl sulfide and dibutyl disulfide. The total mass percentage of toluene and n-butyl ether in the modified sulfide electrolyte was 150 μg / g, and the mass percentage of thioether compounds in the modified sulfide electrolyte was 200 μg / g.

[0259] Example 6

[0260] Except for the following differences, the preparation of solid-state battery cells is the same as in Example 1.

[0261] Preparation of modified sulfide electrolytes

[0262] Li2S, P2S5, and LiCl were mixed uniformly according to the stoichiometric ratio and sintered at 550℃ for 12h under an argon atmosphere to obtain a coarse sulfide electrolyte matrix Li6PS5Cl. The volume distribution particle size Dv50 of the coarse sulfide electrolyte matrix Li6PS5Cl was 15μm.

[0263] The coarse sulfide electrolyte matrix Li6PS5Cl, zirconia balls, and organic solvent were added to a grinding jar and ground at 300 rpm for 5 hours, followed by centrifugation. The mass ratio of zirconia balls to coarse sulfide electrolyte matrix Li6PS5Cl was 10:1; the organic solvent was a mixture of toluene and butyl acetate with a mass ratio of 1:1, and the mass ratio of organic solvent to coarse sulfide electrolyte matrix Li6PS5Cl was 4:1. Some butyl acetate reacted with the sulfide electrolyte matrix to form sulfide compounds.

[0264] The centrifuged powder was dried in a vacuum oven at 100°C for 6 hours to obtain the modified sulfide electrolyte. The volume distribution particle size (Dv50) of the modified sulfide electrolyte was 0.6 μm. The modified sulfide electrolyte consisted of a sulfide electrolyte matrix Li6PS5Cl and toluene, butyl acetate, and thioether compounds located on at least a portion of the surface of the sulfide electrolyte matrix Li6PS5Cl. The thioether compounds included dibutyl sulfide and dibutyl disulfide. The total mass percentage of toluene and butyl acetate in the modified sulfide electrolyte was 90 μg / g, and the mass percentage of thioether compounds in the modified sulfide electrolyte was 120 μg / g.

[0265] Example 7

[0266] Except for the following differences, the preparation of solid-state battery cells is the same as in Example 1.

[0267] Preparation of modified sulfide electrolytes

[0268] Li2S, P2S5, and LiCl were mixed uniformly according to the stoichiometric ratio and sintered at 550℃ for 12h under an argon atmosphere to obtain a coarse sulfide electrolyte matrix Li6PS5Cl. The volume distribution particle size Dv50 of the coarse sulfide electrolyte matrix Li6PS5Cl was 15μm.

[0269] The coarse sulfide electrolyte matrix Li6PS5Cl, zirconia balls, and organic solvent were added to a grinding jar and ground at 300 rpm for 5 hours, followed by centrifugation. The mass ratio of zirconia balls to coarse sulfide electrolyte matrix Li6PS5Cl was 10:1; the organic solvent was a mixture of toluene and butyl acetate with a mass ratio of 2:1, and the mass ratio of organic solvent to coarse sulfide electrolyte matrix Li6PS5Cl was 4:1. Some butyl acetate reacted with the sulfide electrolyte matrix to form sulfide compounds.

[0270] The centrifuged powder was dried in a vacuum oven at 100°C for 3 hours to obtain the modified sulfide electrolyte. The volume distribution particle size (Dv50) of the modified sulfide electrolyte was 0.5 μm. The modified sulfide electrolyte consisted of a sulfide electrolyte matrix Li6PS5Cl and toluene, butyl acetate, and thioether compounds located on at least a portion of the surface of the sulfide electrolyte matrix Li6PS5Cl. The thioether compounds included dibutyl sulfide and dibutyl disulfide. The total mass percentage of toluene and butyl acetate in the modified sulfide electrolyte was 180 μg / g, and the mass percentage of thioether compounds in the modified sulfide electrolyte was also 180 μg / g.

[0271] Example 8

[0272] Except for the following differences, the preparation of solid-state battery cells is the same as in Example 1.

[0273] Preparation of modified sulfide electrolytes

[0274] Li2S, P2S5, and LiCl were mixed uniformly according to the stoichiometric ratio and sintered at 550℃ for 12h under an argon atmosphere to obtain a coarse sulfide electrolyte matrix Li6PS5Cl. The volume distribution particle size Dv50 of the coarse sulfide electrolyte matrix Li6PS5Cl was 15μm.

[0275] The coarse sulfide electrolyte matrix Li6PS5Cl, zirconia balls, and organic solvent were added to a grinding jar and ground at 300 rpm for 5 hours, followed by centrifugation. The mass ratio of zirconia balls to coarse sulfide electrolyte matrix Li6PS5Cl was 10:1; the organic solvent was a mixture of toluene and butyl acetate with a mass ratio of 3:1, and the mass ratio of organic solvent to coarse sulfide electrolyte matrix Li6PS5Cl was 4:1. Some butyl acetate reacted with the sulfide electrolyte matrix to form sulfide compounds.

[0276] The centrifuged powder was dried in a vacuum oven at 100°C for 2 hours to obtain the modified sulfide electrolyte. The volume distribution particle size (Dv50) of the modified sulfide electrolyte was 0.4 μm. The modified sulfide electrolyte consisted of a sulfide electrolyte matrix Li6PS5Cl and toluene, butyl acetate, and thioether compounds located on at least a portion of the surface of the sulfide electrolyte matrix Li6PS5Cl. The thioether compounds included dibutyl sulfide and dibutyl disulfide. The total mass percentage of toluene and butyl acetate in the modified sulfide electrolyte was 150 μg / g, and the mass percentage of thioether compounds in the modified sulfide electrolyte was 230 μg / g.

[0277] Example 9

[0278] Except for the following differences, the preparation of solid-state battery cells is the same as in Example 1.

[0279] Preparation of modified sulfide electrolytes

[0280] Li2S, P2S5, and LiCl were mixed uniformly according to the stoichiometric ratio and sintered at 550℃ for 12h under an argon atmosphere to obtain a coarse sulfide electrolyte matrix Li6PS5Cl. The volume distribution particle size Dv50 of the coarse sulfide electrolyte matrix Li6PS5Cl was 15μm.

[0281] The coarse sulfide electrolyte matrix Li6PS5Cl, zirconia balls, and organic solvent were added to a grinding jar and ground at 300 rpm for 5 hours, followed by centrifugation. The mass ratio of zirconia balls to coarse sulfide electrolyte matrix Li6PS5Cl was 10:1; the organic solvent was a mixture of toluene and butyl acetate, with a mass ratio of 10:1, and the mass ratio of organic solvent to coarse sulfide electrolyte matrix Li6PS5Cl was 4:1. Some butyl acetate reacted with the sulfide electrolyte matrix to form sulfide compounds.

[0282] The centrifuged powder was dried in a vacuum oven at 100°C for 2 hours to obtain the modified sulfide electrolyte. The volume distribution particle size (Dv50) of the modified sulfide electrolyte was 0.8 μm. The modified sulfide electrolyte consisted of a sulfide electrolyte matrix Li6PS5Cl and toluene, butyl acetate, and thioether compounds located on at least a portion of the surface of the sulfide electrolyte matrix Li6PS5Cl. The thioether compounds included dibutyl sulfide and dibutyl disulfide. The total mass percentage of toluene and butyl acetate in the modified sulfide electrolyte was 100 μg / g, and the mass percentage of thioether compounds in the modified sulfide electrolyte was also 100 μg / g.

[0283] Example 10

[0284] Except for the following differences, the preparation of solid-state battery cells is the same as in Example 1.

[0285] Preparation of modified sulfide electrolytes

[0286] Li2S, P2S5, and LiCl were mixed uniformly according to the stoichiometric ratio and sintered at 550℃ for 12h under an argon atmosphere to obtain a coarse sulfide electrolyte matrix Li6PS5Cl. The volume distribution particle size Dv50 of the coarse sulfide electrolyte matrix Li6PS5Cl was 15μm.

[0287] The coarse sulfide electrolyte matrix Li6PS5Cl, zirconia balls, and organic solvent were added to a grinding jar and ground at 300 rpm for 5 hours, followed by centrifugation. The mass ratio of zirconia balls to coarse sulfide electrolyte matrix Li6PS5Cl was 10:1; the organic solvent was a mixture of toluene and butyl acetate with a mass ratio of 39:1, and the mass ratio of organic solvent to coarse sulfide electrolyte matrix Li6PS5Cl was 4:1. Some butyl acetate reacted with the sulfide electrolyte matrix to form sulfide compounds.

[0288] The centrifuged powder was dried in a vacuum oven at 100°C for 2 hours to obtain the modified sulfide electrolyte. The volume distribution particle size (Dv50) of the modified sulfide electrolyte was 1 μm, and the modified sulfide electrolyte consisted of a sulfide electrolyte matrix Li6PS5Cl and toluene, butyl acetate, and thioether compounds located on at least a portion of the surface of the sulfide electrolyte matrix Li6PS5Cl. The thioether compounds included dibutyl sulfide and dibutyl disulfide. The total mass percentage of toluene and butyl acetate in the modified sulfide electrolyte was 80 μg / g, and the mass percentage of thioether compounds in the modified sulfide electrolyte was 20 μg / g.

[0289] Example 11

[0290] Except for the following differences, the preparation of solid-state battery cells is the same as in Example 1.

[0291] Preparation of modified sulfide electrolytes

[0292] Li2S, P2S5, and LiCl were mixed uniformly according to the stoichiometric ratio and sintered at 550℃ for 12h under an argon atmosphere to obtain a coarse sulfide electrolyte matrix Li6PS5Cl. The volume distribution particle size Dv50 of the coarse sulfide electrolyte matrix Li6PS5Cl was 15μm.

[0293] The coarse sulfide electrolyte matrix Li6PS5Cl, zirconia balls, and organic solvent were added to a grinding jar and ground at 300 rpm for 3 hours, followed by centrifugation. The mass ratio of zirconia balls to coarse sulfide electrolyte matrix Li6PS5Cl was 10:1; the organic solvent was anisole, and the mass ratio of organic solvent to coarse sulfide electrolyte matrix Li6PS5Cl was 4:1. Some butyl acetate reacted with the sulfide electrolyte matrix to form sulfide compounds.

[0294] The centrifuged powder was dried in a vacuum oven at 120°C for 5 hours to obtain the modified sulfide electrolyte. The volume distribution particle size (Dv50) of the modified sulfide electrolyte was 0.5 μm. The modified sulfide electrolyte consisted of a sulfide electrolyte matrix Li6PS5Cl and anisole and thioether compounds located on at least a portion of the surface of the sulfide electrolyte matrix Li6PS5Cl. The thioether compounds included dimethyl sulfide and dimethyl disulfide. The total mass percentage of anisole in the modified sulfide electrolyte was 160 μg / g, and the mass percentage of thioether compounds in the modified sulfide electrolyte was 130 μg / g.

[0295] Example 12

[0296] Except for the following differences, the preparation of solid-state battery cells is the same as in Example 1.

[0297] Preparation of modified sulfide electrolytes

[0298] Li2S, P2S5, and LiCl were mixed uniformly according to the stoichiometric ratio and sintered at 550℃ for 12h under an argon atmosphere to obtain a coarse sulfide electrolyte matrix Li6PS5Cl. The volume distribution particle size Dv50 of the coarse sulfide electrolyte matrix Li6PS5Cl was 15μm.

[0299] The coarse sulfide electrolyte matrix Li6PS5Cl, zirconia balls, and organic solvent were added to a grinding jar and ground at 300 rpm for 3 hours, followed by centrifugation. The mass ratio of zirconia balls to coarse sulfide electrolyte matrix Li6PS5Cl was 10:1; the organic solvent was a mixture of toluene and anisole, with a mass ratio of 1:1, and the mass ratio of organic solvent to coarse sulfide electrolyte matrix Li6PS5Cl was 4:1. Some anisole reacted with the sulfide electrolyte matrix to form sulfide compounds.

[0300] The centrifuged powder was dried in a vacuum oven at 120°C for 4 hours to obtain the modified sulfide electrolyte. The volume distribution particle size (Dv50) of the modified sulfide electrolyte was 0.6 μm. The modified sulfide electrolyte consisted of a sulfide electrolyte matrix Li6PS5Cl and toluene, anisole, and thioether compounds located on at least a portion of the surface of the Li6PS5Cl matrix. The thioether compounds included dimethyl sulfide and dimethyl disulfide. The total mass percentage of toluene and anisole in the modified sulfide electrolyte was 150 μg / g, and the mass percentage of thioether compounds in the modified sulfide electrolyte was 110 μg / g.

[0301] Example 13

[0302] Except for the following differences, the preparation of solid-state battery cells is the same as in Example 1.

[0303] Preparation of modified sulfide electrolytes

[0304] Li2S, P2S5, and LiCl were mixed uniformly according to the stoichiometric ratio and sintered at 550℃ for 12h under an argon atmosphere to obtain a coarse sulfide electrolyte matrix Li6PS5Cl. The volume distribution particle size Dv50 of the coarse sulfide electrolyte matrix Li6PS5Cl was 15μm.

[0305] The coarse sulfide electrolyte matrix Li6PS5Cl, zirconia balls, and organic solvent were added to a grinding jar and ground at 300 rpm for 3 hours, followed by centrifugation. The mass ratio of zirconia balls to coarse sulfide electrolyte matrix Li6PS5Cl was 10:1; the organic solvent was a mixture of n-heptane and anisole, with a mass ratio of 1:1, and the mass ratio of organic solvent to coarse sulfide electrolyte matrix Li6PS5Cl was 4:1. Some anisole reacted with the sulfide electrolyte matrix to form sulfide compounds.

[0306] The centrifuged powder was dried in a vacuum oven at 80°C for 6 hours to obtain the modified sulfide electrolyte. The volume distribution particle size (Dv50) of the modified sulfide electrolyte was 0.5 μm. The modified sulfide electrolyte consisted of a sulfide electrolyte matrix Li6PS5Cl and n-heptane, anisole, and thioether compounds located on at least a portion of the surface of the Li6PS5Cl matrix. The thioether compounds included dimethyl sulfide and dimethyl disulfide. The total mass percentage of n-heptane and anisole in the modified sulfide electrolyte was 80 μg / g, and the mass percentage of thioether compounds in the modified sulfide electrolyte was 120 μg / g.

[0307] Comparative Example 1

[0308] Except for the following differences, the preparation of solid-state battery cells is the same as in Example 1.

[0309] Preparation of modified sulfide electrolytes

[0310] Li2S, P2S5, and LiCl were mixed uniformly according to the stoichiometric ratio and sintered at 550℃ for 12h under an argon atmosphere to obtain a coarse sulfide electrolyte matrix Li6PS5Cl. The volume distribution particle size Dv50 of the coarse sulfide electrolyte matrix Li6PS5Cl was 15μm.

[0311] The coarse sulfide electrolyte matrix Li6PS5Cl, zirconia balls, and organic solvent were added to a grinding jar and ground at 300 rpm for 5 hours, followed by centrifugation. The mass ratio of zirconia balls to coarse sulfide electrolyte matrix Li6PS5Cl was 10:1; the organic solvent was n-heptane, and the mass ratio of organic solvent to coarse sulfide electrolyte matrix Li6PS5Cl was 4:1.

[0312] The centrifuged powder was dried in a vacuum oven at 80°C for 5 hours to obtain the modified sulfide electrolyte. The volume distribution particle size (Dv50) of the modified sulfide electrolyte was 2.3 μm, and the modified sulfide electrolyte consisted of a sulfide electrolyte matrix Li6PS5Cl and n-heptane located on at least a portion of the surface of the sulfide electrolyte matrix Li6PS5Cl, with the mass percentage of n-heptane in the modified sulfide electrolyte being 30 μg / g.

[0313] Comparative Example 2

[0314] Except for the following differences, the preparation of solid-state battery cells is the same as in Example 1.

[0315] Preparation of modified sulfide electrolytes

[0316] Li2S, P2S5, and LiCl were mixed uniformly according to the stoichiometric ratio and sintered at 550℃ for 12h under an argon atmosphere to obtain a coarse sulfide electrolyte matrix Li6PS5Cl. The volume distribution particle size Dv50 of the coarse sulfide electrolyte matrix Li6PS5Cl was 15μm.

[0317] The coarse sulfide electrolyte matrix Li6PS5Cl, zirconia balls, and organic solvent were added to a grinding jar and ground at 300 rpm for 5 hours, followed by centrifugation. The mass ratio of zirconia balls to coarse sulfide electrolyte matrix Li6PS5Cl was 10:1; the organic solvent was toluene, and the mass ratio of organic solvent to coarse sulfide electrolyte matrix Li6PS5Cl was 4:1.

[0318] The centrifuged powder was dried in a vacuum oven at 100°C for 5 hours to obtain the modified sulfide electrolyte. The volume distribution particle size (Dv50) of the modified sulfide electrolyte was 2.8 μm, and the modified sulfide electrolyte consisted of a sulfide electrolyte matrix Li6PS5Cl and toluene located on at least a portion of the surface of the sulfide electrolyte matrix Li6PS5Cl, with the mass percentage of toluene in the modified sulfide electrolyte being 50 μg / g.

[0319] Performance testing

[0320] (1) Ionic conductivity test of modified sulfide electrolyte

[0321] 150 mg of modified sulfide electrolyte powder was pressed into a 10 mm diameter mold under a pressure of 4 tons to prepare an electrolyte disc with a diameter of 10 mm. The electrolyte disc was then coated with a conductive agent, VGCF, as an ion-blocking electrode, and further pressed under a pressure of 1 ton. The ion-blocking electrode was connected to an electrochemical impedance spectroscopy (EIS) workstation for testing. The testing conditions were 25 °C, 150 MPa, a bias voltage of 10 mV, and a frequency range of 1 MHz to 10 Hz. The resistance value R was obtained by reading the intersection of the impedance spectrum curve with the horizontal axis. The ionic conductivity of the modified sulfide electrolyte was calculated using the formula σ = D / (R × S), where σ is the ionic conductivity, D is the thickness of the electrolyte disc, and S is the contact area between the ion-blocking electrode and the electrolyte disc.

[0322] (2) Mass percentage of sulfide compounds and organic solvents in modified sulfide electrolytes

[0323] The results were obtained by headspace gas chromatography-mass spectrometry.

[0324] (3) Slurry performance testing

[0325] The prepared electrode slurry was placed in a beaker and allowed to stand at 25°C for 24 hours. After that, the slurry was poured out of the beaker and the flow was observed. If the flow was not continuous, the slurry was considered to have gelled.

[0326] The prepared electrode slurry was placed in a beaker and allowed to stand at 25°C for 24 hours. If the slurry separated into layers, it was considered to have settled; otherwise, it was considered to have settled.

[0327] (4) Initial discharge capacity test

[0328] At 25°C, solid-state battery cells were charged to 4.3V (vs. Li) at a current density of 0.1C. + / Li), let stand for 10 minutes, then discharge at a current density of 0.1C to 2.6V (vs. Li). + / Li), to obtain the initial discharge capacity.

[0329] (5) Cyclic performance test

[0330] At 65°C, solid-state battery cells were charged to 4.3V (vs. Li) at a current density of 0.1C. + / Li), let stand for 10 minutes, then discharge at a current density of 0.1C to 2.6V (vs. Li). + / Li); then the solid-state battery cells are charged to 4.3V (vs. Li) at a current density of 0.5C. + / Li), let stand for 10 minutes, then discharge at a current density of 0.5C to 2.6V (vs. Li). + / Li), the discharge capacity at this time is denoted as C1; the solid-state battery cell is cycled at a current density of 0.5C according to the above charge and discharge process. The capacity retention rate of the solid-state battery cell after 300 cycles at 0.5C = discharge capacity after 300 cycles at 0.5C / C1 × 100%. The larger this value is, the better the cycle performance of the solid-state battery cell.

[0331] Table 1

[0332] Table 2

[0333] Figure 3 is a scanning electron microscope (SEM) image of the modified sulfide electrolyte prepared in Example 1. Figure 4 is a scanning electron microscope (SEM) image of the modified sulfide electrolyte prepared in Comparative Example 1. As can be seen from Figures 3 and 4, the modified sulfide electrolyte with a volume distribution particle size Dv50 of 0.1 μm to 1 μm can be prepared by the preparation method disclosed herein.

[0334] The test results in Tables 1 and 2 also show that the surface of the small-particle-size modified sulfide electrolyte of this disclosure has an appropriate amount of thioether compounds, which can not only enable the modified sulfide electrolyte to retain high ionic conductivity, but also improve the dispersibility of the electrode slurry, improve the consistency of the electrode, and improve the specific capacity and cycle performance of the solid-state battery cell.

[0335] 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 essential structure and achieving the same effect as the technical concept within the scope of this disclosure are included in 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 in the scope of this disclosure without departing from the spirit of this disclosure.

Claims

1. A solid-state battery cell, comprising a positive electrode, an electrolyte layer, and a negative electrode, wherein the electrolyte layer is located between the positive electrode and the negative electrode, wherein, At least one of the positive electrode, the electrolyte layer, and the negative electrode comprises a modified sulfide electrolyte; The modified sulfide electrolyte has a volume distribution particle size Dv50 of 0.1 μm-1 μm. The modified sulfide electrolyte includes a sulfide electrolyte matrix and thioether compounds located on at least a portion of the surface of the sulfide electrolyte matrix. The mass percentage of the thioether compounds in the modified sulfide electrolyte is greater than 0 and less than or equal to 1000 μg / g.

2. The solid-state battery cell according to claim 1, wherein, The thioether compound constitutes a mass percentage of 20 μg / g to 500 μg / g in the modified sulfide electrolyte; and / or, The thioether compounds include monothioether compounds and / or dithioether compounds.

3. The solid-state battery cell according to claim 2, wherein, The thioether compound constitutes a mass percentage of 100 μg / g to 320 μg / g in the modified sulfide electrolyte; and / or, The thioether compounds include one or more of the following: dimethyl sulfide, diethyl sulfide, dipropyl sulfide, dibutyl sulfide, diisobutyl sulfide, dipentyl sulfide, diisopentyl sulfide, dihexyl sulfide, diisohexyl sulfide, diheptyl sulfide, dioctyl sulfide, diisooctyl sulfide, dimethyl disulfide, diethyl disulfide, dipropyl disulfide, dibutyl disulfide, diisobutyl disulfide, dipentyl disulfide, diisopentyl disulfide, dihexyl disulfide, diisohexyl disulfide, diheptyl disulfide, dioctyl disulfide, and diisooctyl disulfide.

4. The solid-state battery cell according to any one of claims 1-3, wherein, The modified sulfide electrolyte further includes an organic solvent located on at least a portion of the surface of the sulfide electrolyte matrix. The organic solvent includes an organic solvent containing oxygen atoms, and the organic solvent containing oxygen atoms has a boiling point greater than 100°C. The organic solvent containing oxygen atoms includes one or more of ester solvents and ether solvents.

5. The solid-state battery cell according to claim 4, wherein, The ester solvents include one or more of the following: butyl acetate, isobutyl acetate, amyl acetate, isoamyl acetate, hexyl acetate, isohexyl acetate, heptyl acetate, octyl acetate, butyl propionate, isobutyl propionate, amyl propionate, hexyl propionate, heptyl propionate, octyl propionate, ethyl butyrate, propyl butyrate, butyl butyrate, isobutyl isobutyrate, isooctyl butyrate, and octyl butyrate; and / or, The ether solvents include one or more of n-butyl ether, heptyl ether, n-pentyl ether, isopentyl ether, anisole, and phenethyl ether.

6. The solid-state battery cell according to claim 4 or 5, wherein, The organic solvent also includes an organic solvent that does not contain oxygen atoms, wherein the organic solvent that does not contain oxygen atoms has a boiling point greater than 90°C, and the organic solvent that does not contain oxygen atoms includes one or more of alkane solvents and aromatic hydrocarbon solvents.

7. The solid-state battery cell according to claim 6, wherein, In the organic solvent, the mass percentage of the organic solvent that does not contain oxygen atoms is greater than or equal to the mass percentage of the organic solvent that contains oxygen atoms; and / or, The oxygen-free organic solvents include one or more of toluene, ethylbenzene, o-xylene, m-xylene, p-xylene, pseudotrimethylbenzene, mesitylene, n-heptane, n-dodecane, and n-tetradecane.

8. The solid-state battery cell according to any one of claims 4-7, wherein, The organic solvent has a mass percentage in the modified sulfide electrolyte that is greater than 0 and less than or equal to 10,000 μg / g, and can be selected from 50 μg / g to 1,000 μg / g.

9. The solid-state battery cell according to any one of claims 1-8, wherein, The sulfide electrolyte matrix includes a material with the molecular formula Li 6+m+l P 1-m M m S 5-n+l N n Y 1-l , wherein 0≤m<1, 0≤n<1, -1<l<1, M comprises one or more elements selected from the group consisting of Ge, Si, Sn, Al, Zr and Sb, N comprises one or more elements selected from the group consisting of O, Se and Te, and Y comprises one or more elements selected from the group consisting of Cl, Br and I.

10. The solid-state battery cell according to any one of claims 1-9, wherein, The positive electrode includes a positive electrode film layer, the positive electrode film layer includes a positive electrode active material and the modified sulfide electrolyte according to any one of claims 1-9, the positive electrode active material including one or more of lithium transition metal oxides and their modified materials, lithium phosphates and their modified materials, lithium titanate, lithium niobate, sulfur, selenium, and tellurium; and / or, The electrolyte layer comprises the modified sulfide electrolyte according to any one of claims 1-9; and / or, The negative electrode comprises lithium or a lithium alloy, or the negative electrode comprises a negative electrode active material and the modified sulfide electrolyte according to any one of claims 1-9, wherein the negative electrode active material comprises one or more of natural graphite, artificial graphite, mesophase micro carbon spheres, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, and metal oxides.

11. A battery device comprising a plurality of solid-state battery cells as described in any one of claims 1-10.

12. An electrical device comprising a solid-state battery cell as described in any one of claims 1-10 or a battery device as described in claim 11.

13. A modified sulfide electrolyte, wherein, The modified sulfide electrolyte has a volume distribution particle size Dv50 of 0.1 μm-1 μm. The modified sulfide electrolyte includes a sulfide electrolyte matrix and thioether compounds located on at least a portion of the surface of the sulfide electrolyte matrix. The mass percentage of the thioether compounds in the modified sulfide electrolyte is greater than 0 and less than or equal to 1000 μg / g.

14. The modified sulfide electrolyte according to claim 13, wherein, The thioether compound constitutes a mass percentage of 20 μg / g to 500 μg / g in the modified sulfide electrolyte; and / or, The thioether compounds include monothioether compounds and / or dithioether compounds.

15. The modified sulfide electrolyte according to claim 14, wherein, The thioether compound constitutes a mass percentage of 100 μg / g to 320 μg / g in the modified sulfide electrolyte; and / or, The thioether compounds include one or more of the following: dimethyl sulfide, diethyl sulfide, dipropyl sulfide, dibutyl sulfide, diisobutyl sulfide, dipentyl sulfide, diisopentyl sulfide, dihexyl sulfide, diisohexyl sulfide, diheptyl sulfide, dioctyl sulfide, diisooctyl sulfide, dimethyl disulfide, diethyl disulfide, dipropyl disulfide, dibutyl disulfide, diisobutyl disulfide, dipentyl disulfide, diisopentyl disulfide, dihexyl disulfide, diisohexyl disulfide, diheptyl disulfide, dioctyl disulfide, and diisooctyl disulfide.

16. The modified sulfide electrolyte according to any one of claims 13-15, wherein, The modified sulfide electrolyte further includes an organic solvent located on at least a portion of the surface of the sulfide electrolyte matrix. The organic solvent includes an organic solvent containing oxygen atoms, and the organic solvent containing oxygen atoms has a boiling point greater than 100°C. The organic solvent containing oxygen atoms includes one or more of ester solvents and ether solvents.

17. The modified sulfide electrolyte according to claim 16, wherein, The ester solvents include one or more of the following: butyl acetate, isobutyl acetate, amyl acetate, isoamyl acetate, hexyl acetate, isohexyl acetate, heptyl acetate, octyl acetate, butyl propionate, isobutyl propionate, amyl propionate, hexyl propionate, heptyl propionate, octyl propionate, ethyl butyrate, propyl butyrate, butyl butyrate, isobutyl isobutyrate, isooctyl butyrate, and octyl butyrate; and / or, The ether solvents include one or more of n-butyl ether, heptyl ether, n-pentyl ether, isopentyl ether, anisole, and phenethyl ether.

18. The modified sulfide electrolyte according to claim 16 or 17, wherein, The organic solvent also includes an organic solvent that does not contain oxygen atoms, wherein the organic solvent that does not contain oxygen atoms has a boiling point greater than 90°C, and the organic solvent that does not contain oxygen atoms includes one or more of alkane solvents and aromatic hydrocarbon solvents.

19. The modified sulfide electrolyte according to claim 18, wherein, In the organic solvent, the mass percentage of the organic solvent that does not contain oxygen atoms is greater than or equal to the mass percentage of the organic solvent that contains oxygen atoms; and / or, The oxygen-free organic solvents include one or more of toluene, ethylbenzene, o-xylene, m-xylene, p-xylene, pseudotrimethylbenzene, mesitylene, n-heptane, n-dodecane, and n-tetradecane.

20. The modified sulfide electrolyte according to any one of claims 16-19, wherein, The organic solvent has a mass percentage in the modified sulfide electrolyte that is greater than 0 and less than or equal to 10,000 μg / g, and can be selected from 55 μg / g to 1,000 μg / g.

21. The modified sulfide electrolyte according to any one of claims 13-20, wherein, The sulfide electrolyte matrix comprises a material having a formula Li 6+m+l P 1-m M m S 5-n+l N n Y 1-l , wherein 0≤m<1, 0≤n<1, -1<l<1, M comprises one or more elements selected from the group consisting of Ge, Si, Sn, Al, Zr and Sb, N comprises one or more elements selected from the group consisting of O, Se and Te, and Y comprises one or more elements selected from the group consisting of Cl, Br and I.

22. A method for preparing a modified sulfide electrolyte, comprising the following steps: The raw materials used to prepare the sulfide electrolyte matrix are ground and then sintered at high temperature under a protective gas atmosphere to obtain a coarse powder sulfide electrolyte matrix. A coarse sulfide electrolyte matrix, grinding media, and organic solvent are added to a grinding device. After grinding, the solid powder is separated. The organic solvent includes an organic solvent containing oxygen atoms, and the boiling point of the organic solvent containing oxygen atoms is greater than 100°C. The organic solvent containing oxygen atoms includes one or more of ester solvents and ether solvents, and the organic solvent containing oxygen atoms can react with the sulfide electrolyte matrix to form sulfide compounds. The separated solid powder is vacuum dried at 80℃-200℃ for 2h-10h to obtain a modified sulfide electrolyte. The volume distribution particle size Dv50 of the modified sulfide electrolyte is 0.1μm-1μm. The modified sulfide electrolyte includes a sulfide electrolyte matrix and sulfide compounds located on at least part of the surface of the sulfide electrolyte matrix. The mass percentage of the sulfide compounds in the modified sulfide electrolyte is greater than 0 and less than or equal to 1000μg / g.

23. The preparation method according to claim 22, wherein, The grinding process satisfies at least one of the following conditions (1) to (5): (1) The grinding speed is 300rpm-2300rpm; (2) The grinding process takes 30 min to 10 h. (3) The grinding media is zirconia balls with a diameter of 0.4 mm to 3 mm; (4) The mass ratio of the grinding media to the coarse powder sulfide electrolyte matrix is ​​5:1 to 10:1; (5) The mass ratio of the organic solvent to the crude sulfide electrolyte matrix is ​​2:1 to 18:

1.

24. The preparation method according to claim 22 or 23, wherein, The ester solvents include one or more of the following: butyl acetate, isobutyl acetate, amyl acetate, isoamyl acetate, hexyl acetate, isohexyl acetate, heptyl acetate, octyl acetate, butyl propionate, isobutyl propionate, amyl propionate, hexyl propionate, heptyl propionate, octyl propionate, ethyl butyrate, propyl butyrate, butyl butyrate, isobutyl isobutyrate, isooctyl butyrate, and octyl butyrate; and / or, The ether solvents include one or more of n-butyl ether, heptyl ether, n-pentyl ether, isopentyl ether, anisole, and phenethyl ether.

25. The preparation method according to any one of claims 22-24, wherein, The organic solvent also includes an organic solvent that does not contain oxygen atoms, wherein the organic solvent that does not contain oxygen atoms has a boiling point greater than 90°C, and the organic solvent that does not contain oxygen atoms includes one or more of alkane solvents and aromatic hydrocarbon solvents.

26. The preparation method according to claim 25, wherein, The oxygen-free organic solvents include one or more of toluene, ethylbenzene, o-xylene, m-xylene, p-xylene, pseudotrimethylbenzene, mesitylene, n-heptane, n-dodecane, and n-tetradecane.

27. The preparation method according to claim 25 or 26, wherein, The mass ratio of the organic solvent containing oxygen atoms to the organic solvent without oxygen atoms is 1:39 to 1:1.

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