Sulfide solid electrolyte slurry, high-density sulfide solid electrolyte film and preparation method thereof

Abstract

The invention discloses sulfide solid electrolyte slurry, a high-density sulfide solid electrolyte film and a preparation method thereof, and belongs to the technical field of all-solid-state batteries. The preparation method of the sulfide solid electrolyte slurry comprises the following steps: mixing polythiol, a solvent, a binder and a sulfide solid electrolyte, and stirring to obtain the sulfide solid electrolyte slurry; wherein the polythiol refers to thiol containing more than two sulfydryl groups. The core innovation of the invention lies in that the polythiol is introduced into the sulfide solid electrolyte slurry, and the S-S interaction force between the sulfydryl of the polythiol and the sulfide solid electrolyte is utilized to effectively reduce the distance between the sulfide solid electrolyte and the sulfide solid electrolyte; and the gap between the sulfide solid electrolyte and the sulfide solid electrolyte is reduced, so that the sulfide solid electrolyte film with higher density is prepared.

Description

Technical Field

[0001] The present invention relates to the technical field of all-solid-state batteries, and in particular to a sulfide solid electrolyte slurry, a high-density sulfide solid electrolyte film and a preparation method thereof. Background Art

[0002] Sulfide solid electrolyte film is a key component of sulfide-based all-solid-state batteries. It has ionic conductivity comparable to that of liquid electrolytes and is widely considered to be one of the most promising electrolyte materials for achieving high-energy-density lithium-ion batteries.

[0003] The current mainstream process for preparing sulfide solid electrolyte films is wet slurry coating. Compared with dry preparation, this method can produce thinner sulfide solid electrolyte films. However, whether wet or dry-prepared, sulfide solid electrolyte films generally have a high porosity, which can cause lithium dendrites to grow along the pores and even cause internal short circuits in the battery, posing a serious safety hazard. Currently, there is a lack of research specifically targeting the density of sulfide solid electrolyte films in the existing technology.

[0004] Therefore, the existing technology still needs to be improved and developed. Summary of the Invention

[0005] In view of the above-mentioned deficiencies in the prior art, the object of the present invention is to provide a sulfide solid electrolyte slurry, a high-density sulfide solid electrolyte film and a preparation method thereof, aiming to solve the problem of insufficient density of the existing sulfide solid electrolyte film.

[0006] The technical solutions of the present invention are as follows:

[0007] A first aspect of the present invention provides a method for preparing a sulfide solid electrolyte slurry, which comprises the following steps: mixing a polythiol, a solvent, a binder and a sulfide solid electrolyte, and stirring to obtain a sulfide solid electrolyte slurry; wherein the polythiol refers to a thiol containing two or more thiol groups.

[0008] Optionally, the preparation method specifically comprises the following steps:

[0009] Mixing polythiol and a solvent to obtain a mixed solvent; wherein the polythiol refers to a thiol containing two or more thiol groups;

[0010] mixing a binder with the mixed solvent to obtain a binder solution;

[0011] The sulfide solid electrolyte is mixed with the binder solution and stirred to obtain a sulfide solid electrolyte slurry.

[0012] Optionally, the polythiol is one or more of benzenedithiol, decanedithiol, pentanedithiol, propanedithiol, hexanedithiol, ethanedithiol, butanedithiol, nonanedithiol, octanedithiol, butanedithiol, undecanedithiol, tris(2-mercaptoethyl)amine, 1,3,5-triazine-2,4,6-trisulfide, trimethylolpropane tris(3-mercaptopropionate), tetrakis(pentaerythritol 3-mercaptopropionate), 2,2-bis(mercaptomethyl)-1,3-propanedithiol, 2,5-dimercaptomethyl-1,4-dithiane, and bis(2-mercaptoethyl)sulfide.

[0013] Further optionally, the polythiol is one or more of decanedithiol, pentanedithiol, hexanedithiol, nonanedithiol, octanedithiol, bis(2-mercaptoethyl)sulfide, and 2,5-dimercaptomethyl-1,4-dithiane.

[0014] Optionally, the solvent is one or more of tetrahydrofuran, 2-methyltetrahydrofuran, dimethyl sulfoxide, acetonitrile, dioxane, methyl ethyl ketone, benzene solvents, and compounds containing ester bonds;

[0015] Wherein, the benzene solvent is one or more of toluene, xylene, and anisole;

[0016] The compound containing an ester bond is one or more of butyl acetate, methyl acetate, ethyl acetate, butyl butyrate, and isobutyl isobutyrate.

[0017] Optionally, in the mixed solvent, the mass ratio of polythiol to solvent is (1-30): (70-99);

[0018] The binder is one or more of carboxymethyl cellulose, polymethyl methacrylate, polyisobutylene, nitrile rubber, butadiene rubber, styrene-butadiene rubber, polyacrylonitrile, polytetrafluoroethylene, polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, and polystyrene-butadiene-styrene;

[0019] In the binder solution, the mass ratio of the binder to the mixed solvent is (1-10):(90-99).

[0020] Optionally, the sulfide solid electrolyte is Li3PS4, Li7P3S 11 、Li 10 GeP2S 12 、Li 3.833 Sn 0.867 S4, Li 6-y PS 5-y X 1+y One or more of, wherein X = one or more of Cl, Br, I, F, and the value of y ranges from 0 to 2.0;

[0021] The sulfide solid electrolyte is in granular form, with a particle size of 0.5-15 μm;

[0022] In the sulfide solid electrolyte slurry, the mass ratio of the sulfide solid electrolyte to the binder is (90-99.5): (0.5-10).

[0023] A second aspect of the present invention provides a sulfide solid electrolyte slurry, which is prepared using the preparation method of the sulfide solid electrolyte slurry described in the present invention.

[0024] A third aspect of the present invention provides a method for preparing a high-density sulfide solid electrolyte film, comprising the steps of:

[0025] coating the sulfide solid electrolyte slurry of the present invention on a substrate;

[0026] The coated sulfide solid electrolyte slurry is dried under a vacuum environment to obtain the high-density sulfide solid electrolyte film.

[0027] A fourth aspect of the present invention provides a high-density sulfide solid electrolyte film, which is prepared using the method for preparing a high-density sulfide solid electrolyte film of the present invention.

[0028] Beneficial effect: In the present invention, by introducing a small amount of polythiol (containing two or more thiol groups) into the sulfide solid electrolyte slurry, the SS bond interaction force between its thiol group (-SH) and the sulfide solid electrolyte is utilized, thereby reducing the distance between the sulfide solid electrolytes and the gap between the sulfide solid electrolytes, reducing the solid content of the sulfide solid electrolyte slurry, and ultimately achieving the purpose of improving the density of the sulfide solid electrolyte film. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a state diagram of the sulfide solid electrolyte in the slurry when polythiol is present, where polythiol takes butanedithiol as an example, and the sulfide solid electrolyte takes a sulfide solid electrolyte containing P=S bonds on the surface as an example. DETAILED DESCRIPTION

[0030] The present invention provides a sulfide solid electrolyte slurry, a high-density sulfide solid electrolyte film, and a method for preparing the same. To clarify the objectives, technical solutions, and effects of the present invention, the present invention is described in further detail below. It should be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention.

[0031] Whether the sulfide solid electrolyte film is prepared by a wet method or a dry method, its porosity is usually high, which may cause lithium dendrites to grow along the gaps and even cause internal short circuits in the battery, posing a serious safety hazard. At present, there is a lack of research in the prior art specifically targeting the density of sulfide solid electrolyte films. Based on this, the purpose of the present invention is to improve the density of sulfide solid electrolyte films. The present invention introduces a small amount of polythiol into the sulfide solid electrolyte slurry and utilizes its effect on the sulfide solid electrolyte to reduce the distance between sulfide solid electrolyte particles and increase the solid content of the sulfide solid electrolyte slurry, ultimately achieving the purpose of improving the density of the sulfide solid electrolyte film.

[0032] In one embodiment, a method for preparing a sulfide solid electrolyte slurry is provided, comprising the following steps: mixing a polythiol, a solvent, a binder and a sulfide solid electrolyte, and stirring to obtain a sulfide solid electrolyte slurry; wherein the polythiol refers to a thiol containing two or more thiol groups.

[0033] Combine Figure 1 As shown, the core innovation of the embodiment of the present invention is to introduce a small amount of polythiol ( Figure 1 Taking butanedithiol as an example), the SS bond interaction force between its thiol group (-SH) and the sulfide solid electrolyte is used to effectively reduce the distance between the sulfide solid electrolytes and the gap between the sulfide solid electrolytes, thereby preparing a sulfide solid electrolyte film with higher density.

[0034] In one embodiment, a method for preparing a sulfide solid electrolyte slurry is provided, comprising the following steps:

[0035] Mixing polythiol and a solvent to obtain a mixed solvent; wherein the polythiol refers to a thiol containing two or more thiol groups;

[0036] mixing a binder with the mixed solvent to obtain a binder solution;

[0037] The sulfide solid electrolyte is mixed with the binder solution and stirred to obtain a sulfide solid electrolyte slurry.

[0038] Adding the raw materials in the above order is conducive to obtaining a sulfide solid electrolyte slurry with better effects.

[0039] In this embodiment, polythiol refers to a thiol containing two or more thiol groups. In other words, any thiol containing two or more thiol groups is applicable and can reduce the distance between sulfide solid electrolytes, reduce the gap between sulfide solid electrolytes, increase the solid content of the sulfide solid electrolyte slurry, and ultimately achieve the purpose of increasing the density of the sulfide solid electrolyte film.

[0040] In a preferred embodiment, the polythiol is one or more of benzenedithiol, decanedithiol, pentanedithiol, propanedithiol, hexanedithiol, ethanedithiol, butanedithiol, nonanedithiol, octanedithiol, butanedithiol, undecanedithiol, tris(2-mercaptoethyl)amine, 1,3,5-triazine-2,4,6-trisulfide, trimethylolpropane tris(3-mercaptopropionate), tetrakis(pentaerythritol 3-mercaptopropionate), 2,2-bis(mercaptomethyl)-1,3-propanedithiol, 2,5-dimercaptomethyl-1,4-dithiane, and bis(2-mercaptoethyl)sulfide.

[0041] In a most preferred embodiment, the polythiol is one or more of decanedithiol, pentanedithiol, hexanedithiol, nonanedithiol, octanedithiol, bis(2-mercaptoethyl)sulfide, and 2,5-dimercaptomethyl-1,4-dithiane. The use of the above polythiol can further increase the solid content of the sulfide solid electrolyte slurry and improve the density of the sulfide solid electrolyte film.

[0042] In one embodiment, the solvent may be one or more of tetrahydrofuran, 2-methyltetrahydrofuran, dimethyl sulfoxide, acetonitrile, dioxane, methyl ethyl ketone, benzene solvents, compounds containing ester bonds, or other polar solvents.

[0043] In one embodiment, the benzene solvent is one or more of toluene, xylene, and anisole.

[0044] In one embodiment, the compound containing an ester bond is one or more of butyl acetate, methyl acetate, ethyl acetate, butyl butyrate, and isobutyl isobutyrate.

[0045] In one embodiment, in the mixed solvent, the mass ratio of polythiol to solvent is (1-30): (70-99), such as 1:70, 1:80, 1:90, 1:99, 10:70, 12:75, 14:80, 15:81, 16:82, 17:83, 20:90, 22:92, 25:90, 28:99, 30:70, 30:80, 30:90, 30:99, etc. Other specific point values ​​within the above numerical range can be selected and are not listed one by one here.

[0046] In a preferred embodiment, in the mixed solvent, the mass ratio of polythiol to solvent is 17:83.

[0047] In one embodiment, the binder is one or more of carboxymethyl cellulose, polymethyl methacrylate, polyisobutylene, nitrile rubber, butadiene rubber, styrene-butadiene rubber, polyacrylonitrile, polytetrafluoroethylene, polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, polystyrene-butadiene-styrene, etc.

[0048] In one embodiment, in the binder solution, the mass ratio of the binder to the mixed solvent is (1-10): (90-99), such as 1:90, 1:95, 1:99, 3:90, 3:97, 3:99, 5:90, 5:95, 5:99, 10:90, 10:95, 10:99, etc. Other specific point values ​​within the above numerical range can be selected and will not be listed one by one here.

[0049] In a preferred embodiment, in the binder solution, the mass ratio of the binder to the mixed solvent is 3:97. This mass ratio is beneficial to further improve the density of the sulfide solid electrolyte film.

[0050] In one embodiment, the sulfide solid electrolyte is Li3PS4, Li7P3S 11 、Li 10 GeP2S 12 、Li 3.833 Sn 0.867 S4, Li 6-y PS 5-y X 1+y One or more of the following, wherein X = one or more of Cl, Br, I, F, and the value range of y is 0-2.0.

[0051] In one embodiment, the sulfide solid electrolyte is in a granular form with a particle size of 0.5-15 μm.

[0052] In one embodiment, in the sulfide solid electrolyte slurry, the mass ratio of the sulfide solid electrolyte to the binder is (90-99.5): (0.5-10), such as 90:0.5, 90:0.8, 90:10, 95:0.5, 95:0.8, 95:10, 99.5:0.5, 99.5:0.8, 99.5:10, etc. Other specific point values ​​within the above numerical range can be selected, and no further examples are given here.

[0053] In a preferred embodiment, the mass ratio of the sulfide solid electrolyte to the binder in the sulfide solid electrolyte slurry is 96.5:3.5. This mass ratio is conducive to further improving the density of the sulfide solid electrolyte film.

[0054] In one embodiment, a sulfide solid electrolyte slurry is provided, wherein the sulfide solid electrolyte slurry is prepared using the preparation method of the sulfide solid electrolyte slurry described in the embodiment of the present invention.

[0055] In one embodiment, a method for preparing a high-density sulfide solid electrolyte film is provided, comprising the steps of:

[0056] coating the sulfide solid electrolyte slurry described in an embodiment of the present invention on a substrate;

[0057] The coated sulfide solid electrolyte slurry is dried under a vacuum environment to obtain the high-density sulfide solid electrolyte film.

[0058] In the embodiment of the present invention, polythiol is used as an additive to the sulfide solid electrolyte slurry to increase the solid content of the sulfide solid electrolyte slurry, thereby ultimately achieving the purpose of increasing the density of the sulfide solid electrolyte film.

[0059] In one embodiment, the coating thickness of the sulfide solid electrolyte slurry is 30-300 μm, such as 30 μm, 50 μm, 100 μm, 200 μm, 300 μm, etc.

[0060] In one embodiment, the drying temperature is 50-160°C, such as 50°C, 60°C, 80°C, 100°C, 150°C, 160°C, etc.

[0061] In one embodiment, the substrate is one of a positive electrode film, a negative electrode film, a PI film, an ultra-thin aluminum foil, an ultra-thin carbon-coated aluminum foil, an ultra-thin copper foil, an ultra-thin carbon-coated copper foil, a stainless steel foil, and the like.

[0062] In one embodiment, the positive electrode film is an electrode film prepared by dry or wet methods using common positive electrode materials for lithium ion batteries, sodium ion batteries, potassium ion batteries, etc.

[0063] In one embodiment, the negative electrode film is an electrode film prepared by dry or wet methods using common negative electrode materials for lithium ion batteries, sodium ion batteries, potassium ion batteries, etc.

[0064] In one embodiment, a high-density sulfide solid electrolyte film is provided, wherein the high-density sulfide solid electrolyte film is prepared using the method for preparing the high-density sulfide solid electrolyte film described in an embodiment of the present invention.

[0065] The present invention will be further described below with reference to specific examples.

[0066] Example 1

[0067] A method for preparing a sulfide solid electrolyte slurry and a high-density sulfide solid electrolyte film comprises the following steps:

[0068] 2.5 g of pentanedithiol and 12.6 g of xylene were mixed to obtain a mixed solvent;

[0069] Dissolve 0.4 g of nitrile rubber in the above mixed solvent to obtain a binder solution;

[0070] 12.5 g of Li with a D50 of 2.28 μm was added 5.6 PS 4.6 Cl 1.4 Add it to the above binder solution, stir and mix vigorously to obtain a uniform sulfide solid electrolyte slurry.

[0071] The obtained sulfide solid electrolyte slurry was applied to a thickness of 180 μm.

[0072] The coated sulfide solid electrolyte film was vacuum dried at 120° C. for 12 hours to obtain a dry sulfide solid electrolyte film.

[0073] The film density of the sulfide solid electrolyte film was measured to be 1.7096 g / cm after 500 MPa isostatic pressing. 3 .

[0074] Example 2

[0075] A method for preparing a sulfide solid electrolyte slurry and a high-density sulfide solid electrolyte film comprises the following steps:

[0076] 2.5 g of hexanedithiol and 12.6 g of xylene were mixed to obtain a mixed solvent;

[0077] Dissolve 0.4 g of nitrile rubber in the above mixed solvent to obtain a binder solution;

[0078] 12.5 g of Li with a D50 of 2.28 μm was added 5.6 PS 4.6 Cl 1.4 Add it to the above binder solution, stir and mix vigorously to obtain a uniform sulfide solid electrolyte slurry.

[0079] The obtained sulfide solid electrolyte slurry was applied to a thickness of 180 μm.

[0080] The coated sulfide solid electrolyte film was vacuum dried at 120° C. for 12 hours to obtain a dry sulfide solid electrolyte film.

[0081] The film density of the sulfide solid electrolyte film was measured to be 1.6586 g / cm after 500 MPa isostatic pressing.3 .

[0082] Example 3

[0083] A method for preparing a sulfide solid electrolyte slurry and a high-density sulfide solid electrolyte film comprises the following steps:

[0084] Mix 2.5 g of octanedithiol with 12.6 g of xylene to obtain a mixed solvent;

[0085] Dissolve 0.4 g of nitrile rubber in the above mixed solvent to obtain a binder solution;

[0086] 12.5 g of Li with a D50 of 2.28 μm was added 5.6 PS 4.6 Cl 1.4 Add it to the above binder solution, stir and mix vigorously to obtain a uniform sulfide solid electrolyte slurry.

[0087] The obtained sulfide solid electrolyte slurry was applied to a thickness of 180 μm.

[0088] The coated sulfide solid electrolyte film was vacuum dried at 120° C. for 12 hours to obtain a dry sulfide solid electrolyte film.

[0089] The film density of the sulfide solid electrolyte film was measured to be 1.5966 g / cm after 500 MPa isostatic pressing. 3 .

[0090] Example 4

[0091] A method for preparing a sulfide solid electrolyte slurry and a high-density sulfide solid electrolyte film comprises the following steps:

[0092] 2.5 g of nonanedithiol was mixed with 12.6 g of xylene to obtain a mixed solvent;

[0093] Dissolve 0.4 g of nitrile rubber in the above mixed solvent to obtain a binder solution;

[0094] 12.5 g of Li with a D50 of 2.28 μm was added 5.6 PS 4.6 Cl 1.4 Add it to the above binder solution, stir and mix vigorously to obtain a uniform sulfide solid electrolyte slurry.

[0095] The obtained sulfide solid electrolyte slurry was applied to a thickness of 180 μm.

[0096] The coated sulfide solid electrolyte film was vacuum dried at 120° C. for 12 hours to obtain a dry sulfide solid electrolyte film.

[0097] The film density of the sulfide solid electrolyte film was measured to be 1.5967 g / cm after 500 MPa isostatic pressing. 3 .

[0098] Example 5

[0099] A method for preparing a sulfide solid electrolyte slurry and a high-density sulfide solid electrolyte film comprises the following steps:

[0100] 2.5 g of decanedithiol and 12.6 g of xylene were mixed to obtain a mixed solvent;

[0101] Dissolve 0.4 g of nitrile rubber in the above mixed solvent to obtain a binder solution;

[0102] 12.5 g of Li with a D50 of 2.28 μm was added 5.6 PS 4.6 Cl 1.4 Add it to the above binder solution, stir and mix vigorously to obtain a uniform sulfide solid electrolyte slurry.

[0103] The obtained sulfide solid electrolyte slurry was applied to a thickness of 180 μm.

[0104] The coated sulfide solid electrolyte film was vacuum dried at 120° C. for 12 hours to obtain a dry sulfide solid electrolyte film.

[0105] The film density of the sulfide solid electrolyte film was measured to be 1.5694 g / cm after 500 MPa isostatic pressing. 3 .

[0106] Example 6

[0107] A method for preparing a sulfide solid electrolyte slurry and a high-density sulfide solid electrolyte film comprises the following steps:

[0108] 0.7 g of bis(2-mercaptoethyl)sulfide was mixed with 10.26 g of butyl acetate to obtain a mixed solvent;

[0109] Dissolve 0.35 g of polyisobutylene in the above mixed solvent to obtain a binder solution;

[0110] 9.7 g of Li with a D50 of 0.853 μm was added 5.8 PS 4.8 Cl 0.5 Br 0.7 Add it to the above binder solution, stir and mix vigorously to obtain a uniform sulfide solid electrolyte slurry.

[0111] The obtained sulfide solid electrolyte slurry was applied to a thickness of 120 μm.

[0112] The coated sulfide solid electrolyte film was vacuum dried at 85° C. for 16 h to obtain a dry sulfide solid electrolyte film.

[0113] The film density of the sulfide solid electrolyte film was measured to be 1.5521 g / cm after 500 MPa isostatic pressing. 3 .

[0114] Example 7

[0115] A method for preparing a sulfide solid electrolyte slurry and a high-density sulfide solid electrolyte film comprises the following steps:

[0116] 0.7 g of 2,5-dimercaptomethyl-1,4-dithiane was mixed with 10.26 g of butyl acetate to obtain a mixed solvent;

[0117] Dissolve 0.35 g of polyisobutylene in the above mixed solvent to obtain a binder solution;

[0118] 9.7 g of Li with a D50 of 0.853 μm was added 5.8 PS 4.8 Cl 0.5 Br 0.7 Add it to the above binder solution, stir and mix vigorously to obtain a uniform sulfide solid electrolyte slurry.

[0119] The obtained sulfide solid electrolyte slurry was applied to a thickness of 120 μm.

[0120] The coated sulfide solid electrolyte film was vacuum dried at 85° C. for 16 h to obtain a dry sulfide solid electrolyte film.

[0121] The film density of the sulfide solid electrolyte film was measured to be 1.5967 g / cm after 500 MPa isostatic pressing. 3 .

[0122] Comparative Example 1

[0123] A method for preparing a sulfide solid electrolyte slurry and a sulfide solid electrolyte film comprises the following steps:

[0124] Dissolve 0.4 g of nitrile rubber in 15.1 g of xylene solvent to obtain a binder solution;

[0125] 12.5 g of Li with a D50 of 2.28 μm was added 5.6 PS 4.6 Cl 1.4Add it to the above binder solution, stir and mix vigorously to obtain a uniform sulfide solid electrolyte slurry.

[0126] The obtained sulfide solid electrolyte slurry was applied to a thickness of 180 μm.

[0127] The coated sulfide solid electrolyte film was vacuum dried at 120° C. for 12 hours to obtain a dry sulfide solid electrolyte film.

[0128] The film density of the sulfide solid electrolyte film was measured to be 1.5442 g / cm after 500 MPa isostatic pressing. 3 .

[0129] Comparative Example 2

[0130] A method for preparing a sulfide solid electrolyte slurry and a sulfide solid electrolyte film comprises the following steps:

[0131] 0.35 g of polyisobutylene was dissolved in 11.0 g of butyl acetate solvent to obtain a binder solution;

[0132] 9.7 g of Li with a D50 of 0.853 μm was added 5.8 PS 4.8 Cl 0.5 Br 0.7 Add it to the above binder solution, stir and mix vigorously to obtain a uniform sulfide solid electrolyte slurry.

[0133] The obtained sulfide solid electrolyte slurry was applied to a thickness of 120 μm.

[0134] The coated sulfide solid electrolyte film was vacuum dried at 85° C. for 16 h to obtain a dry sulfide solid electrolyte film.

[0135] The film density of the sulfide solid electrolyte film was measured to be 1.5216 g / cm after 500 MPa isostatic pressing. 3 .

[0136] Table 1 compares the film densities of the sulfide solid electrolyte slurries prepared in Examples 1-7 and Comparative Examples 1-2 after coating, drying, and isostatic pressing. As shown in Table 1, the sulfide solid electrolyte films prepared from the sulfide solid electrolyte slurries containing polythiol exhibit higher densities. Furthermore, shorter polythiol chain lengths lead to higher densities in the resulting sulfide solid electrolyte films.

[0137] Table 1

[0138] project <![CDATA[Volume / cm 3 > Mass / g <![CDATA[Density / (g / cm 3 )]]> Example 1 0.120495 0.206 1.7096 Example 2 0.129021 0.214 1.6586 Example 3 0.129021 0.206 1.5966 Example 4 0.113361 0.181 1.5967 Example 5 0.120169 0.174 1.5694 Comparative Example 1 0.132110 0.204 1.5442 Example 6 0.045667 0.119 1.5521 Example 7 0.043433 0.113 1.5967 Comparative Example 2 0.046583 0.122 1.5216

[0139] In summary, the present invention provides a sulfide solid electrolyte slurry, a high-density sulfide solid electrolyte film and a preparation method thereof. The preparation method of the sulfide solid electrolyte slurry comprises the steps of: mixing a polythiol and a solvent to obtain a mixed solvent; wherein the polythiol refers to a thiol containing two or more thiol groups; mixing a binder with the mixed solvent to obtain a binder solution; mixing a sulfide solid electrolyte with the binder solution and stirring to obtain a sulfide solid electrolyte slurry. The core innovation of the present invention is that a small amount of polythiol is introduced into the sulfide solid electrolyte slurry, and the SS interaction force between its thiol group (-SH) and the sulfide solid electrolyte is utilized to effectively reduce the distance between the sulfide solid electrolyte and the sulfide solid electrolyte, and reduce the gap between the sulfide solid electrolyte and the sulfide solid electrolyte, thereby preparing a sulfide solid electrolyte film with higher density.

[0140] It should be understood that the application of the present invention is not limited to the above examples. For those skilled in the art, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A method for preparing a sulfide solid electrolyte slurry, characterized in that: The following steps are involved: Polythiol, a solvent, a binder and a sulfide solid electrolyte are mixed and stirred to obtain a sulfide solid electrolyte slurry; wherein the polythiol refers to a thiol containing two or more thiol groups.

2. The method for preparing the sulfide solid electrolyte slurry according to claim 1, wherein: The preparation method specifically comprises the following steps: Mixing polythiol and a solvent to obtain a mixed solvent; wherein the polythiol refers to a thiol containing two or more thiol groups; mixing a binder with the mixed solvent to obtain a binder solution; The sulfide solid electrolyte is mixed with the binder solution and stirred to obtain a sulfide solid electrolyte slurry.

3. The method for preparing a sulfide solid electrolyte slurry according to claim 1 or 2, characterized in that: The polythiol is one of benzenedithiol, decanedithiol, pentanedithiol, propanedithiol, hexanedithiol, ethanedithiol, butanedithiol, nonanedithiol, octanedithiol, butanedithiol, undecanedithiol, tris(2-mercaptoethyl)amine, 1,3,5-triazine-2,4,6-trisulfide, trimethylolpropane tris(3-mercaptopropionate), tetrakis(pentaerythritol 3-mercaptopropionate), 2,2-bis(mercaptomethyl)-1,3-propanedithiol, 2,5-dimercaptomethyl-1,4-dithiane, and bis(2-mercaptoethyl)sulfide.

4. The method for preparing the sulfide solid electrolyte slurry according to claim 3, characterized in that: The polythiol is one or more of decanedithiol, pentanedithiol, hexanedithiol, nonanedithiol, octanedithiol, bis(2-mercaptoethyl)sulfide, and 2,5-dimercaptomethyl-1,4-dithiane.

5. The method for preparing the sulfide solid electrolyte slurry according to claim 2, characterized in that: The solvent is one or more of tetrahydrofuran, 2-methyltetrahydrofuran, dimethyl sulfoxide, acetonitrile, dioxane, methyl ethyl ketone, benzene solvents, and compounds containing ester bonds; Wherein, the benzene solvent is one or more of toluene, xylene, and anisole; The compound containing an ester bond is one or more of butyl acetate, methyl acetate, ethyl acetate, butyl butyrate, and isobutyl isobutyrate; In the mixed solvent, the mass ratio of polythiol to solvent is (1-30):(70-99).

6. The method for preparing the sulfide solid electrolyte slurry according to claim 2, characterized in that: The binder is one or more of carboxymethyl cellulose, polymethyl methacrylate, polyisobutylene, nitrile rubber, butadiene rubber, styrene-butadiene rubber, polyacrylonitrile, polytetrafluoroethylene, polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, and polystyrene-butadiene-styrene; In the binder solution, the mass ratio of the binder to the mixed solvent is (1-10):(90-99).

7. The method for preparing a sulfide solid electrolyte slurry according to claim 1 or 2, characterized in that: The sulfide solid electrolyte is Li3PS4, Li7P3S 11 、Li 10 GeP2S 12 、Li 3.833 Sn 0.867 S4, Li 6-y PS 5-y X 1+y One or more of, wherein X = one or more of Cl, Br, I, F, and the value of y ranges from 0 to 2.0; The sulfide solid electrolyte is in granular form, with a particle size of 0.5-15 μm; In the sulfide solid electrolyte slurry, the mass ratio of the sulfide solid electrolyte to the binder is (90-99.5): (0.5-10).

8. A sulfide solid electrolyte slurry, characterized in that: The sulfide solid electrolyte slurry is prepared by the preparation method of any one of claims 1 to 7.

9. A method for preparing a high-density sulfide solid electrolyte film, characterized in that: Including steps: coating the sulfide solid electrolyte slurry according to claim 8 on a substrate; The coated sulfide solid electrolyte slurry is dried under a vacuum environment to obtain the high-density sulfide solid electrolyte film.

10. A high-density sulfide solid electrolyte film, characterized in that: The high-density sulfide solid electrolyte film is prepared by the preparation method of claim 9.

Images