Solid electrolyte and solid battery

Abstract

The invention discloses a small-particle-size sulfide solid electrolyte and application thereof in a solid-state battery. The solid electrolyte comprises sulfide particles, the particle size distribution D50 of the sulfide particles is 0.5-1.5 [mu] m, and the surface of the solid electrolyte has hydrophobic groups. The solid electrolyte provided by the invention can be used for preparing a solid-state battery with excellent battery performance.

Description

Technical Field

[0001] The present application relates to the technical field of all-solid-state lithium-ion batteries, and specifically, to solid electrolytes and solid-state batteries. More specifically, it relates to preparation methods and electronic devices. Background Art

[0002] Solid electrolytes are one of the key materials in the field of electrochemistry and are widely used in solid-state batteries, sensors, and electronic devices. Compared with liquid electrolytes, solid electrolytes have higher safety, a wider operating temperature range, and a longer service life. Among many solid electrolyte materials, sulfide solid electrolytes have main advantages including high ionic conductivity, excellent chemical stability, and low interfacial impedance, and are considered to be the most promising solid electrolyte materials.

[0003] The smaller particle size of small-sized sulfide solid electrolytes makes the ion migration path in the electrolyte shorter. At the same time, small-sized sulfide solid electrolytes can better fill the tiny voids in the battery, thereby improving the interfacial contact between the solid electrolyte and the electrode material. Better interfacial contact can reduce the interfacial impedance, improve the power density and charge-discharge efficiency of the battery. In addition, fine particles have good mechanical properties, which can improve the overall strength and stability of the electrolyte, reduce brittleness, and improve the handling and use safety of the solid electrolyte. However, during the preparation of small-sized sulfide solid electrolytes, particle agglomeration is likely to occur, which may lead to uneven interfaces.

[0004] Therefore, there is an urgent need to develop new solid electrolytes to reduce the phenomenon of particle agglomeration and improve the performance of solid-state batteries. Summary of the Invention

[0005] The present application aims to solve at least one of the technical problems existing in the prior art to some extent. Therefore, the present application provides a solid electrolyte.

[0006] A first aspect of the present application proposes a solid electrolyte. According to an embodiment of the present application, the solid electrolyte includes sulfide particles, and the particle size distribution D 50 of the sulfide particles is 0.5 to 1.5 μm, and the surface of the solid electrolyte has a hydrophobic group. According to an embodiment of the present application, a layer of hydrophobic groups is coated on the surface of the solid electrolyte, which can be evenly dispersed in a solvent and prevent agglomeration between particles. The solid electrolyte according to the embodiment of the present application can be used to prepare a solid-state battery with excellent battery performance.

[0007] In some embodiments, the hydrophobic group is selected from at least one of an alkyl group, a fluorinated group, a siloxane group, and an aromatic group.

[0008] In some embodiments, the hydrophobic group is formed by dispersing a nonionic surfactant in a solvent.

[0009] In some embodiments, the nonionic surfactant is selected from at least one of polyoxyethylene surfactants, polyol surfactants, alkylphenol polyoxyethylene ethers, alkanolamide surfactants, and polyether surfactants.

[0010] In some embodiments, the solvent is selected from at least one of n-hexane, n-heptane, n-decane, n-butyl ether, anisole, toluene, xylene, dibromomethane, cyclohexane, butyl butyrate, and isobutyl isobutyrate.

[0011] In some embodiments, the sulfide particles are selected from at least one of Li2SiS3, Li2SnS3, Li3PS4, Li7PS6, Li7P3S 11 , Li6PS5Cl, Li6PS5Br, Li 5.5 PS 4.5 Cl 0.8 Br 0.7 , Li 10 GeP2S 12 and Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 .

[0012] In some embodiments, the mass ratio of the solid electrolyte to the nonionic surfactant is 1:0.001 to 0.05.

[0013] In some embodiments, the ionic conductivity of the solid electrolyte is 0.1 to 15 mS cm -1 .

[0014] In some embodiments, the particle size distribution D 90 of the sulfide particles is 2 to 5 μm, and D 99 is 3 to 10 μm.

[0015] The second aspect of the present application provides a solid-state battery. According to the embodiments of the present application, the solid-state battery includes: the solid electrolyte, a negative electrode sheet, and a positive electrode sheet described in the first aspect of the present application. The solid-state battery according to the embodiments of the present application has excellent battery performance.

[0016] The third aspect of the present application provides an electronic device. According to the embodiments of the present application, the electronic device includes: the solid-state battery described in the second aspect of the present application.

[0017] A fourth aspect of the present application provides a method for preparing the solid electrolyte described in the first aspect of the present application. According to an embodiment of the present application, the method includes subjecting sulfide particles to a surface treatment with hydrophobic groups; grinding the sulfide particles after the surface treatment with hydrophobic groups to obtain the solid electrolyte; wherein, the particle size distribution D of the sulfide particles 50 is 0.5 - 1.5 μm. According to the method of the embodiment of the present application, the steps are simple and feasible, and a small particle size sulfide solid electrolyte with an increased contact area with the active material can be prepared.

[0018] In some embodiments, the method further includes grinding the sulfide particles after the surface treatment with hydrophobic groups.

[0019] Additional aspects and advantages of the present application will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present application. Description of the Drawings

[0020] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the description of the embodiments in conjunction with the following drawings, wherein:

[0021] Figure 1 is the particle size distribution curve of the small particle size sulfide solid electrolyte material obtained in Example 1 of the present application.

[0022] Figure 2 is the particle size distribution curve of the small particle size sulfide solid electrolyte material obtained in Comparative Example 1 of the present application.

[0023] Figure 3 is the scanning electron microscope image of the small particle size sulfide solid electrolyte material obtained in Example 1 of the present application.

[0024] Figure 4 is the charge-discharge curve (0.1C) of the first cycle of the assembled solid-state battery using the sulfide solid electrolyte materials obtained in Example 1 and Comparative Example 1 of the present application. Detailed Description of the Embodiments

[0025] The embodiments of the present application will be described in detail below. Examples of the embodiments are shown in the drawings, but there may be cases where unnecessary detailed descriptions are omitted. For example, there may be cases where detailed descriptions of well-known matters are omitted and repeated descriptions of actually identical structures are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art. In addition, the drawings and the following description are provided for those skilled in the art to fully understand the present application and are not intended to limit the subject matter recited in the claims.

[0026] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by those skilled in the technical field to which this application belongs; the terms used in this application are only for the purpose of describing specific embodiments and are not intended to limit this application; unless otherwise specified, the numerical values of the various parameters mentioned in this application can be measured by various common measurement methods in the art (for example, they can be tested according to the methods given in the embodiments of this application).

[0027] The terms "comprising" and "having" and any variations thereof in the description and claims of this application are open expressions, that is, they include the content specified in this application, but do not exclude other aspects of the content.

[0028] In the description of this application, it should be understood that the orientation or positional relationship indicated by terms such as "width" and "thickness" is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to this application.

[0029] In the description of this application, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. The "first feature" and "second feature" may include one or more of such features.

[0030] In the description of this application, it should be understood that the orientation or positional relationship indicated by terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to this application.

[0031] In the description of this application, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or simply means that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or simply means that the first feature has a lower horizontal height than the second feature.

[0032] In the description of the present application, the meaning of "a plurality of" is two or more.

[0033] In the description of the present application, "A and / or B" may include the case of A alone, the case of B alone, and any one of the cases of A and B. Here, A and B are only for illustration, and they can be any technical features connected by "and / or" in the present application.

[0034] In the description of the present application, the term "sulfide solid electrolyte" refers to a solid ionic conductor composed of sulfide particles formed by sulfur elements and metals (such as lithium, phosphorus, germanium, etc.). Its core function is to transport lithium ions (Li+) inside the battery, replacing the traditional liquid electrolyte, thereby improving the safety and energy density of the battery.

[0035] If there is no special instruction, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0036] The prior art realizes the low-temperature sintering temperature and the refinement of particles by adopting the method of sintering first and then crushing to prepare small-particle-size sulfide solid electrolytes. However, the particle size of the sulfide solid electrolyte is relatively large and they are all agglomerated together, which will affect the performance of the prepared battery. To overcome this problem, the present application improves the interaction force between sulfide solid electrolytes by using a non-ionic surfactant to prepare small-particle-size non-agglomerated sulfide solid electrolytes, thereby improving the battery performance.

[0037] Based on this, in the first aspect of the present application, the present application proposes a solid electrolyte. According to an embodiment of the present application, the solid electrolyte includes sulfide particles, and the particle size distribution D of the sulfide particles 50 is 0.5 - 1.5 μm, for example, it can be 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, 1.1 μm, 1.2 μm, 1.3 μm, 1.4 μm, 1.5 μm, and the range values between them, such as 0.6 - 1.5 μm, 0.7 - 1.5 μm. According to an embodiment of the present application, the surface of the solid electrolyte is coated with a hydrophobic group, which can be evenly dispersed in the solvent and prevent agglomeration between particles. The solid electrolyte according to the embodiment of the present application can be used to prepare a solid battery with excellent battery performance.

[0038] According to an embodiment of the present application, the hydrophobic group is selected from at least one of an alkyl group, a fluorinated group, a siloxane group, and an aromatic group.

[0039] According to an embodiment of the present application, the alkyl group includes but is not limited to methyl (-CH3), ethyl (-C2H5), or a long-chain alkyl group (such as -C 12 H 25)。

[0040] According to an embodiment of the present application, the fluorinated group includes but is not limited to trifluoromethyl (-CF3), perfluoroalkyl (-C n F 2n+1 , such as -C8F 17 ) or fluoroaryl (such as -C6F5).

[0041] According to an embodiment of the present application, the siloxane group forms a siloxane network on the surface of the sulfide through a silane coupling agent (such as methyltrimethoxysilane, phenyltriethoxysilane).

[0042] According to an embodiment of the present application, the aromatic group includes but is not limited to phenyl (-C6H5), naphthyl (-C 10 H7) or substituted aryl (such as -C6H4-OCH3).

[0043] According to an embodiment of the present application, the hydrophobic group is formed by dispersing a nonionic surfactant in a solvent.

[0044] According to an embodiment of the present application, the nonionic surfactant is selected from at least one of polyoxyethylene surfactants, polyol surfactants, alkylphenol polyoxyethylene ethers, alkanolamide surfactants, and polyether surfactants.

[0045] According to an embodiment of the present application, the polyoxyethylene surfactant dispersed in a solvent is suitable for forming hydrophobic groups of long-chain alkyl (C 12 ~C 18 )(such as oleic acid group, stearic acid group), aryl (such as benzene ring, benzyl) on the surface of sulfide particles of the solid electrolyte. Among them, the hydrophobic group interacts with the solvent, while the hydrophilic group extends in the solution. When sulfide particles are present, the surfactant molecules will adsorb on the surface of the sulfide particles, thereby forming hydrophobic groups (tiny micelle or emulsion structures) on the surface of the solid electrolyte.

[0046] According to an embodiment of the present application, the polyol surfactant is suitable for forming long-chain fatty acid alkyl ((C 12 ~C 18 )(such as oleic acid group, palmitic acid group)) on the surface of sulfide particles of the solid electrolyte.

[0047] According to an embodiment of the present application, the alkylphenol polyoxyethylene ether (APEO type) is suitable for forming alkylphenyl (such as nonylphenyl, octylphenyl) on the surface of sulfide particles of the solid electrolyte.

[0048] According to an embodiment of the present application, the alkanolamide surfactant is suitable for forming medium-length alkyl chains (C8~C14 )(such as coconut oil-based, lauric acid-based).

[0049] According to an embodiment of the present application, the polyether surfactant is suitable for forming a methyl side chain (-CH3) of polyoxypropylene chains (PPO) on the surface of sulfide particles of the solid electrolyte.

[0050] According to an embodiment of the present application, the polyoxyethylene surfactant includes but is not limited to at least one of fatty alcohol polyoxyethylene ether and alkylphenol polyoxyethylene ether.

[0051] According to an embodiment of the present application, the polyol surfactant includes but is not limited to at least one of sorbitan fatty acid ester and polyoxyethylene sorbitan fatty acid ester.

[0052] According to an embodiment of the present application, the alkanolamide surfactant includes but is not limited to at least one of coconut monoethanolamide and coconut diethanolamide.

[0053] According to an embodiment of the present application, the polyether surfactant includes but is not limited to at least one of polypropylene glycol-polyoxyethylene block copolymer and polyethylene glycol-polypropylene glycol-polyethylene glycol.

[0054] According to an embodiment of the present application, the solvent is selected from at least one of n-hexane, n-heptane, n-decane, n-butyl ether, anisole, toluene, xylene, dibromomethane, cyclohexane, butyl butyrate, and isobutyl isobutyrate.

[0055] According to an embodiment of the present application, the material of the solid electrolyte is selected from Li2SiS3, Li2SnS3, Li3PS4, Li7PS6, Li7P3S 11 , Li6PS5Cl, Li6PS5Br, Li 5.5 PS 4.5 Cl 0.8 Br 0.7 , Li 10 GeP2S 12 and Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 and at least one of the following.

[0056] According to an embodiment of the present application, the mass ratio of the solid electrolyte to the non-ionic surfactant is 1:0.001 to 0.05. For example, the mass ratio of the solid electrolyte to the non-ionic surfactant is 1:0.001, 1:0.005, 1:0.01, 1:0.02, 1:0.03, 1:0.04, and 1:0.05, as well as the range values therebetween, such as 1:0.005 to 0.05 and 1:0.01 to 0.05.

[0057] According to an embodiment of the present application, the ionic conductivity of the solid electrolyte is 0.1 to 15 mS cm -1 . For example, the ionic conductivity of the solid electrolyte is 0.1 mS cm -1 , 0.5 mS cm -1 , 1 mS cm -1 , 2 mS cm -1 , 3 mS cm -1 , 4 mS cm -1 , 5 mS cm -1 , 6 mS cm -1 , 7 mS cm -1 , 8 mS cm -1 , 9 mS cm -1 , 10 mS cm -1 , 11 mS cm -1 , 12 mS cm -1 , 13 mS cm -1 , 14 mS cm -1 , and 15 mS cm -1 , as well as the range values therebetween, such as 0.5 to 15 mS cm -1 , 1 to 15 mS cm -1 .

[0058] According to an embodiment of the present application, the particle size distribution D 90 of the sulfide particles is 2 to 5 μm. For example, it can be 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm, and 5 μm, as well as the range values therebetween, such as 2.5 to 5 μm and 3 to 5 μm; D 99 is 3 to 10 μm. For example, it can be 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, and 10 μm, as well as the range values therebetween, such as 4 to 10 μm and 5 to 10 μm.

[0059] A second aspect of the present application provides a solid-state battery. According to an embodiment of the present application, the solid-state battery includes: a solid electrolyte layer, a negative electrode sheet, and a positive electrode sheet as described in the first aspect of the present application. The solid-state battery according to the embodiment of the present application has excellent battery performance. According to an embodiment of the present application, it should be noted that the "solid-state battery" includes all-solid-state batteries and batteries containing a certain proportion of liquid electrolyte, such as semi-solid-state batteries and quasi-solid-state batteries. Specifically, an all-solid-state battery does not contain any liquid electrolyte, and all electrolytes are solid. This type of battery usually has higher safety because the solid electrolyte is not flammable and can inhibit the growth of lithium dendrites, thereby reducing the risk of short circuit. In addition, the all-solid-state battery usually has a higher energy density because metallic lithium can be used as the negative electrode material to achieve a higher energy density. The all-solid-state battery has a long cycle life, a wide temperature adaptation range, and better mechanical strength and stability. A semi-solid-state battery contains a small amount of liquid electrolyte, usually with a mass percentage of the liquid electrolyte of about 5-10%. While maintaining a high ion transport rate of a certain liquid battery, the semi-solid-state battery improves safety and is a transitional technology between traditional liquid lithium batteries and all-solid-state batteries. A quasi-solid-state battery refers to a battery with a mass percentage of liquid electrolyte less than 5%. This type of battery has a higher content of solid electrolyte and less liquid electrolyte, and its safety is better than that of semi-solid-state batteries but still not as good as that of all-solid-state batteries. The solid-state battery according to the embodiment of the present application has improved battery performance.

[0060] A third aspect of the present application provides an electronic device. According to an embodiment of the present application, the electronic device includes: the solid-state battery as described in the second aspect of the present application.

[0061] A fourth aspect of the present application provides a method for preparing the solid electrolyte as described in the first aspect of the present application. According to an embodiment of the present application, the method includes subjecting sulfide particles to a surface treatment with a hydrophobic group to obtain the solid electrolyte; wherein, the particle size distribution D 50 of the sulfide particles is 0.5 to 1.5 μm. The method according to the embodiment of the present application is simple and easy to implement, and can prepare small-particle-size sulfide solid electrolytes with an increased contact area with the active material.

[0062] According to an embodiment of the present application, the method further includes grinding the sulfide particles after the surface treatment with a hydrophobic group.

[0063] The solution of this application will be explained below in conjunction with embodiments. Those skilled in the art will understand that the following embodiments are only used to illustrate this application and should not be regarded as limiting the scope of this application. For those without specific techniques or conditions noted in the embodiments, the techniques or conditions described in the literature in this field or according to the product specifications are followed. For reagents or instruments without the manufacturer noted, they are all conventional products that can be obtained through commercial purchases.

[0064] Example 1

[0065] This example provides a preparation of a small-particle-size sulfide solid electrolyte. Among them, the solid electrolyte contains Li6PS5Cl sulfide particles, and the hydrophobic group comes from Tween 80. The specific preparation process includes the following steps:

[0066] (1) Uniformly disperse the non-ionic surfactant Tween 80 in the n-heptane solvent to obtain a Tween 80 - n-heptane solvent complex;

[0067] (2) Uniformly mix the solid electrolyte containing Li6PS5Cl sulfide particles with the Tween 80 - n-heptane solvent complex obtained in step (1), where the mass ratio of Li6PS5Cl to Tween 80 is 1:0.02;

[0068] (3) After grinding the uniformly mixed material for 2 h, perform drying and cooling to finally obtain a small-particle-size sulfide solid electrolyte.

[0069] (4) Use a laser particle size distribution analyzer to experiment on the sulfide solid electrolyte obtained in step (3) to obtain a particle size distribution curve, specifically refer to Figure 1 , and use a scanning electron microscope to experiment to obtain a scanning electron microscope image, specifically refer to Figure 2 .

[0070] Example 2

[0071] This example has the same steps as Example 1, the difference is that the mass ratio of Li6PS5Cl to Tween 80 is 1:0.001, and other processes are basically the same as those in Example 1.

[0072] Example 3

[0073] This example has the same steps as Example 1, the difference is that the mass ratio of Li6PS5Cl to Tween 80 is 1:0.05, and other processes are basically the same as those in Example 1.

[0074] Example 4

[0075] This example has the same steps as Example 1, except that the hydrophobic group is from Triton X-100 (the non-ionic surfactant is Triton X-100), and the other processes are basically the same as those in Example 1.

[0076] Example 5

[0077] This example has the same steps as Example 1, except that the hydrophobic group is from AEO-9 (the non-ionic surfactant is AEO-9), and the other processes are basically the same as those in Example 1.

[0078] Example 6

[0079] This example has the same steps as Example 1, except that the sulfide solid electrolyte material is Li6PS5Br, and the other processes are basically the same as those in Example 1.

[0080] Example 7

[0081] This example has the same steps as Example 1, except that the sulfide solid electrolyte material is Li 5.5 PS 4.5 Cl 0.8 Br 0.7 , and the other processes are basically the same as those in Example 1.

[0082] Example 8

[0083] This example has the same steps as Example 1, except that the solvent is xylene, and the other processes are basically the same as those in Example 1.

[0084] Example 9

[0085] This example has the same steps as Example 1, except that the solvent is ethylene glycol dimethyl ether, and the other processes are basically the same as those in Example 1.

[0086] Example 10

[0087] This example has the same steps as Example 1, except that the mass ratio of Li6PS5Cl to Tween 80 is 1:0.0009, and the other processes are basically the same as those in Example 1.

[0088] Example 11

[0089] This example has the same steps as Example 1, except that the mass ratio of Li6PS5Cl to Tween 80 is 1:0.06, and the other processes are basically the same as those in Example 1.

[0090] Example 12

[0091] This example has the same steps as Example 1, except that the hydrophobic group is derived from detergent 6501 (the non-ionic surfactant is detergent 6501), and the other processes are basically the same as those in Example 1.

[0092] Example 13

[0093] This example has the same steps as Example 1, except that the sulfide particles are Li 3.2 Ge 0.2 P 0.8 S4, and the other processes are basically the same as those in Example 1.

[0094] Comparative Example 1

[0095] This comparative example has the same steps as Example 1, except that

[0096] in step (1) of this comparative example, Tween 80 is not added, and the other processes are basically the same as those in Example 1.

[0097] For the obtained sulfide solid electrolyte, a particle size distribution curve graph is obtained by using a laser particle size analyzer. For details, see Figure 3 .

[0098] Comparative Example 2

[0099] This comparative example has the same steps as Example 6, except that

[0100] in step (1) of this comparative example, Tween 80 is not added, and the other processes are basically the same as those in Example 6.

[0101] Comparative Example 3

[0102] The difference from Example 7 is that:

[0103] in step (1) of this comparative example, Tween 80 is not added, and the others are the same as those in Example 7.

[0104] Test Example

[0105] Ionic conductivity test: Weigh 150 mg of the sulfide solid electrolyte material, place it in a mold with an inner diameter of 10 mm, press it with stainless steel current collector rods on the upper and lower sides, apply a pressure of 370 MPa for 5 min, and conduct an AC impedance test at 25 °C using an electrochemical workstation. The amplitude of the alternating current is 15 mV, and the frequency range is 0.01 HZ to 1 MHz.

[0106] Assembly of solid-state lithium battery: Among them, the solid-state lithium battery is composed of a high-nickel cathode material, a lithium-indium alloy anode, and the sulfide solid electrolyte material prepared in Example 1 13 or Comparative Example 1 3 above. The specific assembly process is as follows: First, 100 mg of the sulfide solid electrolyte is loaded into a Φ10 mm mold and pressed into an intermediate layer sheet under a pressure of 200 MPa; then, 10 mg of the composite cathode material (composed of 9 mg of the high-nickel cathode material and 1 mg of the sulfide solid electrolyte) is added to one end of the intermediate layer sheet and pressed into shape under a pressure of 200 MPa; finally, a certain amount of the lithium-indium alloy anode is added to the other end of the intermediate layer sheet and assembled into a all-solid-state lithium battery under a pressure of 240 MPa.

[0107] Testing of all-solid-state lithium battery: The test temperature is 25 °C, and the voltage range is 2.6 - 4.4 V vs. Li + / Li. The first-cycle charge-discharge capacity of the full cell is carried out at a current density of 0.1C (1C = 200 mA g -1 ). The first-cycle charge-discharge curves of the assembled solid-state batteries of the sulfide solid electrolyte materials obtained in Example 1 and Comparative Example 1 are shown in Figure 4 .

[0108] Table 1: Particle size distribution, ionic conductivity, and solid-state battery data of the sulfide solid electrolytes in Examples 1 - 13 and Comparative Examples 1 - 3.

[0109]

[0110]

[0111] Comparing Comparative Example 1 with Example 1, it can be obtained that the solid-state battery prepared without adding the non-ionic surfactant Tween 80 to the solid electrolyte has a higher capacitance, indicating that adding the non-ionic surfactant Tween 80 to the solid electrolyte is beneficial for preparing a solid electrolyte that can improve the performance of the solid-state battery.

[0112] Comparing Comparative Example 2 with Example 6, it can be obtained that the solid-state battery prepared without adding the non-ionic surfactant Tween 80 to the solid electrolyte has a higher capacitance, indicating that adding the non-ionic surfactant Tween 80 to the solid electrolyte is beneficial for preparing a solid electrolyte that can improve the performance of the solid-state battery.

[0113] Comparing Comparative Example 3 with Example 7, it can be obtained that the solid-state battery prepared without adding the non-ionic surfactant Tween 80 to the solid electrolyte has a higher capacitance, indicating that adding the non-ionic surfactant Tween 80 to the solid electrolyte is beneficial for preparing a solid electrolyte that can improve the performance of the solid-state battery.

[0114] Comparing Example 1, Example 8 and Example 9, it can be seen that the solid-state battery prepared with n-heptane or xylene as the solvent has a higher capacitance than that prepared with ethylene glycol dimethyl ether as the solvent. This shows that using n-heptane or xylene as the solvent is more conducive to preparing a solid electrolyte that can improve the performance of the solid-state battery.

[0115] Comparing Example 1 - 3 and Example 10 - 11, it can be seen that the solid-state battery prepared with a solid electrolyte having a mass ratio of Li6PS5Cl to Tween 80 of 1:0.001 - 0.05 has a higher capacitance. This shows that within the range of the mass ratio of Li6PS5Cl to Tween 80 of 1:0.001 - 0.05, it is conducive to preparing a solid electrolyte that can improve the performance of the solid-state battery.

[0116] Comparing Example 1, Example 4, Example 5 and Example 12, it can be seen that the solid-state battery prepared with non-ionic surfactants such as Tween80, Triton X-100, and AEO-9 has a higher capacitance than that prepared with the non-ionic surfactant Nanjing 6501. This shows that Tween 80, Triton X-100, and AEO-9 are more conducive to preparing a solid electrolyte that can improve the performance of the solid-state battery than Nanjing 6501.

[0117] Comparing Example 1, Example 7 and Example 13, it can be seen that the solid-state battery prepared with sulfide solid electrolyte materials such as Li6PS5Cl, Li 5.5 PS 4.5 Cl 0.8 Br 0.7 has a higher capacitance than that prepared with the sulfide solid electrolyte material Li 3.2 Ge 0.2 P 0.8 S4. This shows that Li6PS5Cl, Li 5.5 PS 4.5 Cl 0.8 Br 0.7 is more conducive to preparing a solid electrolyte that can improve the performance of the solid-state battery than Li 3.2 Ge 0.2 P 0.8 S4.

[0118] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc., mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of this application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0119] Although the embodiments of this application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting this application. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of this application.

Claims

1. A solid electrolyte, characterized in that, Comprising sulfide particles, the particle size distribution D 50 of which is 0.5 to 1.5 μm, and the surface of the solid electrolyte has a hydrophobic group.

2. The solid electrolyte according to claim 1, characterized in that, The hydrophobic group is selected from at least one of an alkyl group, a fluorinated group, a siloxane group, and an aromatic group; Optionally, the hydrophobic group is formed by dispersing a nonionic surfactant in a solvent.

3. The solid electrolyte according to claim 2, wherein, The nonionic surfactant is selected from at least one of a polyoxyethylene type surfactant, a polyol type surfactant, an alkylphenol polyoxyethylene ether, an alkanolamide type surfactant, and a polyether type surfactant.

4. The solid electrolyte according to claim 2, characterized in that, The solvent is selected from at least one of n-hexane, n-heptane, n-decane, n-butyl ether, anisole, toluene, xylene, dibromomethane, cyclohexane, butyl butyrate, and isobutyl isobutyrate.

5. The solid electrolyte according to claim 1, characterized in that, The sulfide particles are selected from at least one of Li2SiS3, Li2SnS3, Li3PS4, Li7PS6, Li7P3S 11 , Li6PS5Cl, Li6PS5Br, Li 5.5 PS 4.5 Cl 0.8 Br 0.7 , Li 10 GeP2S 12 and Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 among others.

6. The solid electrolyte according to claim 2, wherein The mass ratio of the solid electrolyte to the nonionic surfactant is 1:0.001 to 0.

05.

7. The solid electrolyte according to claim 1, characterized in that, The ionic conductivity of the solid electrolyte is 0.1 to 15 mS cm -1 .

8. The solid electrolyte according to claim 1, wherein The particle size distribution D of the sulfide particles 90 is 2 to 5 μm, and D 99 is 3 to 10 μm.

9. A solid-state battery, characterized in that, Comprising: The solid electrolyte, the negative electrode sheet, and the positive electrode sheet according to any one of claims 1 to 8.

10. An electronic device, characterized in that, Comprising: The solid-state battery according to claim 9.

11. A method for preparing the solid electrolyte according to any one of 1 to 8, characterized in that, Comprising: Subjecting sulfide particles to surface treatment with a hydrophobic group to obtain the solid electrolyte; Among them, the particle size distribution D of the sulfide particles 50 is 0.5 to 1.5 μm.

12. The method according to claim 11, wherein Further comprising: Grinding the sulfide particles treated with the hydrophobic group.

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