CN-121983647-A - Solid electrolyte, preparation method thereof, battery assembly and power utilization device

Abstract

The application relates to the field of batteries, in particular to a solid electrolyte, a preparation method thereof, a battery assembly and an electric device, wherein the solid electrolyte comprises a solid electrolyte main body; the coating layer is arranged on the surface of the solid electrolyte main body, the coating layer contains a coating agent, the coating agent contains a hydrophobic group and a heteroatom group, and the heteroatom in the heteroatom group comprises at least one of N, P, S and O. The solid electrolyte has excellent air stability.

Inventors

• Song Lingxin
• HAN AIGUO

Assignees

• 比亚迪股份有限公司

Dates

Publication Date

20260505

Application Date

20250709

Claims (20)

1. 1. A solid state electrolyte, comprising: A solid electrolyte body; The coating layer is arranged on the surface of the solid electrolyte main body, the coating layer contains a coating agent, the coating agent contains a hydrophobic group and a heteroatom group, and the heteroatom in the heteroatom group comprises at least one of N, P, S and O.
2. 2. The solid state electrolyte of claim 1 wherein the heteroatom in the heteroatom group comprises S.
3. 3. The solid state electrolyte of claim 1 or 2, wherein the heteroatom group comprises at least one of a thioether group, a thiol group, a thioester group, a thioketone group, a sulfonyl group, a phosphate group, a carboxylate group and an amino group, preferably comprises at least one of a thioether group, a thiol group, a thioester group, a thioketone group, a sulfonyl group.
4. 4. A solid state electrolyte according to any one of claims 1 to 3 wherein the hydrophobic groups comprise at least one of C5-C30 alkyl groups, fluoroalkyl groups, siloxane groups, substituted alkyl groups comprising benzene rings and/or heterocyclic structures.
5. 5. The solid state electrolyte of any one of claims 1-4, wherein the solid state electrolyte body comprises a sulfide solid state electrolyte.
6. 6. The solid state electrolyte of claim 5, wherein the sulfide solid state electrolyte comprises a sulfur silver germanium ore type electrolyte Li n PS m X, wherein n is 5-7, m is 4-6, and X comprises at least one of Cl, br, and I.
7. 7. The solid state electrolyte of any one of claims 1 to 6 wherein the capping agent comprises at least one of undecylthiol, dodecylmercaptan, dodecylsulfide, dodecylmethyl sulfide, didodecyldisulfide, tetradecylthiol, hexadecyl sulfide, dioctadecyl disulfide, docosyl mercaptan, dodecyltrimethoxysilane, octadecyltrimethoxysilane, dodecyl phosphate, bis (2-ethylhexyl) phosphate, C8-C18 perfluoroalkyl phosphate, preferably at least one of undecylthiol, dodecyl mercaptan, dodecyl sulfide, dodecyl methyl sulfide, didodecyl disulfide, tetradecylthiol, hexadecyl sulfide, dioctadecyl disulfide, docosyl mercaptan.
8. 8. The solid electrolyte according to any one of claims 1to 7, wherein the heteroatom group is adsorbed on the surface of the solid electrolyte body, and the molecular chains of the coating agent are arranged along the radial direction of the solid electrolyte body.
9. 9. The solid electrolyte according to any one of claims 1 to 8, wherein a ratio of a mass of the coating layer to a mass of the solid electrolyte body is 0.0001 to 0.1.
10. 10. A method of preparing the solid electrolyte of any one of claims 1 to 9, comprising: And stirring and mixing the solid electrolyte main body and the coating agent, so that the coating agent is adsorbed on the surface of the solid electrolyte main body, and the solid electrolyte is obtained.
11. 11. The method according to claim 10, comprising: Stirring and mixing the solid electrolyte main body, the coating agent and the dispersing agent to obtain a first mixture; Removing the dispersant from the first mixture to obtain the solid electrolyte.
12. 12. The method of claim 11, wherein the agitating and mixing the solid electrolyte body, the capping agent, and the dispersing agent comprises: stirring and mixing the coating agent and the dispersing agent to obtain a second mixture; and mixing the second mixture with the solid electrolyte main body, and stirring at 40-120 ℃ to obtain the first mixture.
13. 13. The method of claim 11 or 12, wherein the solid electrolyte body, the coating agent and the dispersing agent are present in a ratio of 100 g:0.01-10 g:400-600 ml.
14. 14. The method of any one of claims 11-13, wherein the dispersant comprises at least one of toluene, o-xylene, m-xylene, p-xylene, benzene, mesitylene, n-heptane, n-hexane, n-octane, n-nonane, n-decane, cyclohexane, cyclopentane, methylcyclohexane, ethylcyclohexane, dimethyl benzene, dimethylformamide, and dimethyl sulfoxide.
15. 15. The method according to any one of claims 11 to 14, wherein the water content of the dispersant is not more than 100ppm, preferably not more than 20ppm.
16. 16. The method according to any one of claims 11 to 15, wherein the dispersant in the first mixture is removed by a reduced pressure evaporation method.
17. 17. The method according to any one of claims 11 to 16, further comprising drying the dispersant-removed product after removing the dispersant from the first mixture to obtain the solid electrolyte.
18. 18. A battery comprising the solid electrolyte of any one of claims 1 to 9.
19. 19. A battery assembly comprising the solid electrolyte of any one of claims 1 to 9 or the battery of claim 18.
20. 20. An electrical device comprising the solid electrolyte of any one of claims 1 to 9, the battery of claim 18, or the battery assembly of claim 19.

Description

Solid electrolyte, preparation method thereof, battery assembly and power utilization device Technical Field The application relates to the technical field of batteries, in particular to a solid electrolyte, a preparation method thereof, a battery assembly and an electric device. Background All-solid-state batteries, which have higher safety, energy density and cycle life, are considered as important developments in the next-generation battery technology. However, solid electrolytes for all-solid batteries are susceptible to moisture absorption reactions when exposed to moisture in the air, resulting in reduced electrochemical performance and even failure. Therefore, how to effectively isolate the solid electrolyte from the contact of moisture in the air becomes a key problem for research in this field. Currently, the main approach to this problem is to isolate the moisture by physical encapsulation or the introduction of a moisture absorbent. However, these methods have limitations such as complicated encapsulation process, introduction of a moisture absorbent, and the like, which may affect electrochemical performance. Accordingly, there is a need for improvement in the related art for improving the air stability of solid electrolytes. Content of the application The present application aims to solve at least one of the technical problems in the related art to some extent. To this end, the present application proposes a solid electrolyte having excellent air stability, a method of manufacturing the same, a battery pack, and an electric device. In a first aspect of the application, a solid state electrolyte is provided. According to the embodiment of the application, the solid electrolyte comprises a solid electrolyte body and a coating layer, wherein the coating layer is arranged on the surface of the solid electrolyte body, the coating layer contains a coating agent, the coating agent contains a hydrophobic group and a heteroatom group, and the heteroatom in the heteroatom group comprises at least one of N, P, S and O. In the solid electrolyte, the heteroatom group in the coating agent can be attached to the surface of the solid electrolyte main body through coordination, intermolecular acting force and the like of the heteroatom and metal cations in the solid electrolyte main body, and the hydrophobic group in the coating agent can effectively resist the erosion of moisture in air to the solid electrolyte main body, so that the solid electrolyte has excellent air stability. According to an embodiment of the application, the heteroatom in the heteroatom group comprises S. According to an embodiment of the present application, the heteroatom group includes at least one of a thioether group, a thiol group, a thioester group, a thioketone group, a sulfonyl group, a phosphate group, a carboxylate group, and an amino group, and specifically includes at least one of a thioether group, a thiol group, a thioester group, a thioketone group, and a sulfonyl group. According to an embodiment of the present application, the hydrophobic group comprises at least one of a C5-C30 alkyl group, a fluoroalkyl group, a siloxane group, a substituted alkyl group comprising a benzene ring and/or a heterocyclic structure. According to an embodiment of the application, the solid electrolyte body comprises a sulfide solid electrolyte. According to the embodiment of the application, the sulfide solid electrolyte comprises a sulfur silver germanium ore type electrolyte Li nPSm X, wherein n is 5-7, m is 4-6, and X comprises at least one of Cl, br and I. According to an embodiment of the present application, the coating agent includes at least one of undecylthiol, dodecylthiol, dodecylsulfide, dodecylmethyl sulfide, didodecyldisulfide, tetradecylthiol, hexadecylthioether, dioctadecyldisulfide, docosyl mercaptan, dodecyltrimethoxysilane, octadecyltrimethoxysilane, dodecylphosphate, bis (2-ethylhexyl) phosphate, C8-C18 perfluoroalkyl phosphate, and may include at least one of undecylthiol, dodecylthiol, dodecylsulfide, dodecylmethyl sulfide, didodecyldisulfide, tetradecylthiol, hexadecylthioether, dioctadecyldisulfide, and docosyl mercaptan. According to an embodiment of the present application, the hetero atom group is adsorbed on the surface of the solid electrolyte body, and the molecular chains of the coating agent are arranged along the radial direction of the solid electrolyte body. According to the embodiment of the application, the ratio of the mass of the coating layer to the mass of the solid electrolyte body is 0.0001-0.1. In a second aspect of the application, there is provided a method of preparing a solid electrolyte as hereinbefore described. According to an embodiment of the application, the method comprises the steps of stirring and mixing a solid electrolyte body and a coating agent, so that the coating agent is adsorbed on the surface of the solid electrolyte body, and the solid electrolyte is obtained. The method is s