Sulfide solid electrolyte, preparation method thereof, battery and electric equipment

Abstract

The invention provides a sulfide solid electrolyte and a preparation method thereof, a battery and electric equipment, and relates to the technical field of solid electrolytes.The preparation method comprises the steps that a hydrophobic material and a sulfide electrolyte raw material are mixed to obtain an electrolyte mixture; tabletting the electrolyte mixture to form a target product; performing vacuum drying treatment on the target product to obtain a dried product; and putting the dried product into an infiltrating solvent for soaking treatment, taking out the dried product, and performing tabletting treatment again to obtain the sulfide solid electrolyte. According to the preparation method provided by the invention, through an innovative process of introducing and removing a hydrophobic material, the stability problem of the sulfide solid electrolyte in a humid environment is effectively solved, the performance of the sulfide solid electrolyte is prevented from being damaged in the transportation and assembly processes, meanwhile, the excellent performance characteristics of the sulfide solid electrolyte are reserved, and the process compatibility is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of solid electrolytes, and in particular to a sulfide solid electrolyte and a preparation method thereof, a battery and electrical equipment. Background Art

[0002] As an emerging battery technology material, solid electrolytes have received widespread attention in recent years. Its core advantage is that it can significantly improve the safety, energy density and cycle life of batteries, thus providing possibilities for the development of next-generation high-performance batteries. There are many types of solid electrolytes, among which sulfide solid electrolytes (SSE) stand out due to their excellent ionic conductivity and good mechanical properties, becoming an important research direction in the field of solid-state batteries. However, despite the many advantages of sulfide solid electrolytes in performance, their practical application still faces many challenges.

[0003] In the existing solid-state battery technology, sulfide solid electrolytes are considered to be one of the most promising materials. Their high ionic conductivity enables rapid lithium ion transmission, thereby improving the battery's charge and discharge performance. In addition, the mechanical properties of sulfide solid electrolytes also give them good processability and stability during battery assembly. These characteristics make sulfide solid electrolytes occupy an important position in the research and development and industrialization of solid-state batteries, attracting the attention of many research institutions and companies.

[0004] However, sulfide solid electrolytes have some significant defects in practical applications. First, sulfide solid electrolytes are extremely sensitive to moisture and easily react chemically with water, resulting in a decrease in electrolyte performance. This sensitivity makes sulfide solid electrolytes difficult to use in conventional lithium-ion battery manufacturing environments, because existing battery manufacturing processes usually cannot completely avoid the presence of moisture. Secondly, sulfide solid electrolytes easily generate harmful gases in the air, such as hydrogen sulfide (HS), which not only pollutes the environment, but may also have a negative impact on the performance and safety of the battery. In addition, sulfide solid electrolytes have poor air stability, which limits their application in large-scale production and storage processes, and increases production costs and process complexity.

[0005] In summary, although sulfide solid electrolytes have excellent performance in ionic conductivity and mechanical properties, their high sensitivity to moisture and the easy generation of harmful gases in the air have seriously restricted their application in the existing lithium-ion battery manufacturing process. These defects not only increase the complexity and cost of battery manufacturing, but also pose challenges to the safety and environmental friendliness of batteries. Therefore, how to solve these key problems of sulfide solid electrolytes has become a bottleneck that needs to be broken through in the development of current solid-state battery technology.

[0006] In view of this, the present invention is proposed. Summary of the Invention

[0007] The object of the present invention is to provide a sulfide solid electrolyte, a preparation method thereof, a battery and an electricity-related device. The preparation method of the sulfide solid electrolyte significantly improves the environmental stability of the sulfide solid electrolyte, reduces the preparation cost, while maintaining its high-performance characteristics, and improves the compatibility and operability of the process through an innovative process of introducing and removing a hydrophobic material.

[0008] In order to achieve the above object of the present invention, the following technical solutions are specifically adopted:

[0009] In a first aspect, the present invention provides a preparation method of a sulfide solid electrolyte, including:

[0010] Mixing a hydrophobic material with a sulfide electrolyte raw material to obtain an electrolyte mixture;

[0011] Tabletting the electrolyte mixture to form a target product;

[0012] Performing vacuum drying on the target product to obtain a dried product;

[0013] Placing the dried product in an infiltration solvent for soaking treatment, and then performing tabletting treatment again after taking it out to obtain a sulfide solid electrolyte; wherein, the infiltration solvent is inert to the sulfide electrolyte raw material, and the infiltration solvent can dissolve and remove the hydrophobic material in the dried product;

[0014] In an optional embodiment, the hydrophobic material includes thiol substances;

[0015] In an optional embodiment, the soaking time of the soaking treatment is not less than 48 hours;

[0016] In an optional embodiment, the content of the hydrophobic material is 0.5 wt% to 50 wt%.

[0017] In an optional embodiment, the molecular formula of the thiol substance is:

[0018] R n -SH;

[0019] wherein, n≥1; R is selected from at least one of a substituted or unsubstituted alkyl group, an alkenyl group, an alkynyl group and a halogen atom.

[0020] In an optional embodiment, the treatment environment of the mixing treatment is that the concentrations of oxygen and water are both lower than 0.5 ppm; and / or, the mixing treatment method is stirring and mixing; and / or, the stirring speed of the stirring and mixing is not less than 1500 rpm / min, and the stirring time is not less than 60 min.

[0021] In an alternative embodiment, the sulfide electrolyte raw material includes at least one of a binary sulfide solid electrolyte material, a glass-ceramic electrolyte material, and a crystalline sulfide solid electrolyte material.

[0022] In an alternative embodiment, the binary sulfide solid electrolyte material includes:

[0023] At least one of a Li2S-P2S5 based electrolyte, a Li2S-Sb2S3 based electrolyte, a Li2S-Sb2S3 based electrolyte, a Li2S-SnS2 based electrolyte, and a Li2S-SiS2 based electrolyte;

[0024] In an alternative embodiment, the Li2S-P2S5 based electrolyte is 20Li2S-80P2S5.

[0025] In an alternative embodiment, the glass-ceramic electrolyte material includes Li7P3S 11 .

[0026] In an alternative embodiment, the molecular formula of the crystalline sulfide solid electrolyte material is any one of the following 3:

[0027] Molecular formula 1: Li 3+x M 1-x P x S4; wherein, M represents Ge or Si; x represents the doping ratio;

[0028] Molecular formula 2: Li6PS5X; wherein, X represents a halogen;

[0029] Molecular formula 3: Li 10 MP2S 12 ; wherein, M represents Ge or Si.

[0030] In an alternative embodiment, the crystalline sulfide solid electrolyte material is Li 10 GeP2S 12 .

[0031] Second, the present invention provides a sulfide solid electrolyte prepared by the preparation method of the sulfide solid electrolyte according to any one of the foregoing embodiments.

[0032] Third, the present invention provides a battery including the sulfide solid electrolyte according to the foregoing embodiment.

[0033] Fourth, the present invention provides an electricity-related device including the battery according to the foregoing embodiment.

[0034] The present invention provides a sulfide solid electrolyte, a preparation method thereof, a battery and an electricity-related device. Through innovative process design, stable preparation under conventional conditions is achieved, while significantly improving its environmental adaptability and process compatibility.

[0035] Sulfide solid electrolytes are extremely sensitive to moisture and oxygen, and are prone to absorbing moisture and hydrolyzing in the air, generating harmful gases (such as hydrogen sulfide), resulting in performance degradation. In the present invention, the provided preparation method introduces a hydrophobic material (such as thiol) during the preparation process, providing a protective layer for the sulfide electrolyte. This hydrophobic material can effectively prevent the electrolyte from contacting with moisture during transportation, storage and battery assembly, thus significantly improving its environmental stability. This protection mechanism enables the sulfide electrolyte to be processed and stored in a relatively relaxed environment, reducing the strict requirements for a low-oxygen and low-humidity environment, reducing equipment investment and energy consumption, and thus significantly reducing production costs.

[0036] The preparation method of the sulfide solid electrolyte provided by the present invention realizes remarkable beneficial effects through the innovative process of introducing and removing the hydrophobic material, especially in improving the environmental stability of the electrolyte, preventing performance damage and process compatibility.

[0037] First of all, sulfide solid electrolytes are extremely sensitive to moisture and are prone to absorbing moisture and hydrolyzing during transportation, storage and battery assembly, resulting in performance degradation or even generating harmful gases (such as hydrogen sulfide). In the present invention, a hydrophobic material (such as thiol) is introduced during the preparation process, providing a temporary protective layer for the sulfide electrolyte, effectively preventing the electrolyte from contacting with moisture. This protection mechanism significantly improves the stability of the sulfide electrolyte in a humid environment, avoiding deterioration and performance damage caused by moisture contact during transportation and assembly, thus extending the service life of the electrolyte and improving its reliability in practical applications.

[0038] Secondly, through vacuum drying and immersion treatment with an infiltrating solvent, this method can completely remove the hydrophobic material while ensuring that the crystal structure and ionic conductivity of the sulfide electrolyte are not affected. This completely reversible process design not only solves the problem of the sensitivity of sulfide electrolytes to moisture, but also retains their excellent ionic conductivity and mechanical properties. The finally obtained sulfide solid electrolyte has performance equivalent to that of the unmodified electrolyte, but has stronger environmental adaptability, providing strong support for the application of high-performance batteries.

[0039] In addition, through simple mixing, tabletting, drying, and soaking processes, this preparation method enables the stable preparation of sulfide solid electrolytes. This process is not only simple and easy to control but also compatible with existing battery manufacturing processes. In this way, the preparation of sulfide solid electrolytes no longer relies on complex equipment and harsh environmental conditions, reducing production costs and enhancing their application potential on existing lithium-ion battery production lines, facilitating the industrial development of solid-state batteries.

[0040] In summary, the preparation method provided by the present invention effectively solves the stability problem of sulfide solid electrolytes in humid environments through an innovative process of introducing and removing hydrophobic materials, preventing performance degradation during transportation and assembly, while retaining their excellent performance characteristics and improving process compatibility. These beneficial effects lay a solid foundation for the wide application and commercial development of sulfide solid electrolytes. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0042] Figure 1 It is a schematic flow chart of the preparation method of the sulfide solid electrolyte in the embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0043] The following will describe the implementation schemes of the present invention in detail in conjunction with the embodiments. However, those skilled in the art will understand that the following embodiments are only used to illustrate the present invention and should not be regarded as limiting the scope of the present invention. For those conditions not specified in the embodiments, they are carried out according to the conventional conditions or the conditions recommended by the manufacturer. For the reagents or instruments not specified for the manufacturer, they are all conventional products that can be obtained through commercial procurement.

[0044] Reference Figure 1 , in the embodiment of the present application, a preparation method of a sulfide solid electrolyte is provided, including:

[0045] Step S1: Mix a hydrophobic material with a sulfide electrolyte raw material to obtain an electrolyte mixture.

[0046] In this step, the hydrophobic material is mixed with the sulfide electrolyte raw material to form a composite electrolyte mixture.

[0047] Specifically, this step should be carried out in an environment with low oxygen and low humidity (such as in a glove box, where the oxygen and water content is less than 0.5 ppm). The hydrophobic material and the sulfide electrolyte raw material are mixed in a certain proportion. The mixing can be achieved by mechanical stirring, ball milling, etc., so as to obtain an electrolyte mixture containing the hydrophobic material, and this mixture has better moisture resistance.

[0048] The addition of the hydrophobic material can effectively prevent the sulfide electrolyte from contacting with moisture during the mixing process, thus avoiding its hydrolysis and deterioration and improving the stability of the mixture.

[0049] Furthermore, the hydrophobic material can include thiol substances.

[0050] Step S2: Tablet the electrolyte mixture to form the target product.

[0051] In this step, the mixed electrolyte mixture is made into a sheet-shaped target product through a tableting process. The electrolyte mixture is put into a mold and tableted using a tableting machine, so as to obtain an electrolyte sheet with a certain shape and density.

[0052] Tableting can improve the denseness of the electrolyte, enhance its mechanical properties, and facilitate subsequent processing and application.

[0053] Step S3: Vacuum-dry the target product to obtain a dried product.

[0054] The tableted target product is vacuum-dried to remove the excess solvent and moisture therein. Specifically, the tableted target product can be put into a vacuum oven, and appropriate vacuum degree and temperature are set for drying treatment, so as to obtain a dried electrolyte sheet, and the excess solvent and moisture on its surface and inside are removed.

[0055] Vacuum drying can effectively remove moisture and further improve the stability and performance of the electrolyte.

[0056] Step S4: Immerse the dried product in an infiltration solvent for soaking treatment, and then, after taking it out, tablet it again to obtain a sulfide solid electrolyte; wherein, the infiltration solvent is inert to the sulfide electrolyte raw material, and the infiltration solvent can dissolve and remove the hydrophobic material in the dried product.

[0057] The dried electrolyte sheet is put into the infiltration solvent for soaking, and the hydrophobic material therein is dissolved and removed by the solvent. Then, it is taken out and tableted again to obtain the final sulfide solid electrolyte.

[0058] It should be noted that "the infiltration solvent is inert to the sulfide electrolyte raw material" means that there is no chemical reaction between the infiltration solvent and the sulfide electrolyte raw material, that is, the solvent will not have a negative impact on the chemical structure, performance or stability of the sulfide electrolyte. This inertness is the key to ensuring that during the soaking process, the solvent can effectively remove the hydrophobic material while keeping the crystal structure and ionic conductivity of the sulfide electrolyte undisturbed. The infiltration solvent needs to meet the following conditions: being inert to the sulfide electrolyte raw material; being able to dissolve and remove hydrophobic materials (such as thiol substances).

[0059] It should be noted that the infiltration solvent can include, but is not limited to, acetone, acetonitrile, tetrahydrofuran, isopropanol, and the like.

[0060] Specifically, the dried product can be soaked in the infiltration solvent so that the hydrophobic material is completely removed, and the electrolyte sheet is restored to a pure sulfide solid electrolyte, and its crystal structure and ionic conductivity are not affected. By soaking to remove the hydrophobic material, the completely reversible preparation of the electrolyte is realized, which not only solves the stability problem of the sulfide electrolyte in a humid environment, but also retains its excellent performance.

[0061] It should be noted that the sulfide solid electrolyte is extremely sensitive to moisture and oxygen, and is prone to absorb moisture and hydrolyze in the air, generating harmful gases (such as hydrogen sulfide), resulting in performance degradation. In this embodiment, by introducing a hydrophobic material (such as thiol) during the preparation process, a protective layer is provided for the sulfide electrolyte. This hydrophobic material can effectively prevent the electrolyte from contacting with moisture during transportation, storage and battery assembly, thereby significantly improving its environmental stability. This protection mechanism enables the sulfide electrolyte to be processed and stored in a relatively relaxed environment, reduces the strict requirements for a low-oxygen and low-humidity environment, reduces equipment investment and energy consumption, and thus significantly reduces the production cost.

[0062] The innovation of the method provided in this embodiment lies in its completely reversible process design. During the preparation process, a hydrophobic material (such as thiol) is introduced to enhance the moisture resistance of the electrolyte, and in subsequent steps, through vacuum drying and soaking in the infiltration solvent, the hydrophobic material is completely removed. This process not only removes the hydrophobic material, but also ensures that the crystal structure and ionic conductivity of the sulfide electrolyte are not affected. The finally obtained sulfide solid electrolyte is comparable to the unmodified electrolyte in terms of ionic conductivity, mechanical properties, etc., and at the same time has better environmental adaptability. This completely reversible process design not only solves the problem of the moisture sensitivity of the sulfide electrolyte, but also ensures that its high-performance characteristics are retained.

[0063] In practical applications, sulfide solid electrolytes are prone to deterioration due to environmental humidity during transportation and battery assembly, resulting in impaired performance. In this embodiment, by introducing a hydrophobic material (such as thiol), a temporary protective layer is provided for the electrolyte, effectively preventing the electrolyte from coming into contact with moisture during transportation and assembly. This protection mechanism not only extends the service life of the electrolyte but also improves its reliability and safety in practical applications.

[0064] This method realizes the stable preparation of sulfide solid electrolytes through simple mixing, pressing, drying, and soaking treatments. This process is not only simple and easy to control but also compatible with existing battery manufacturing processes. In this way, the preparation of sulfide solid electrolytes no longer depends on complex equipment and harsh environmental conditions, thereby enhancing its application potential on existing lithium-ion battery production lines and facilitating the industrial development of solid-state batteries.

[0065] In summary, the preparation method of the sulfide solid electrolyte provided in this embodiment significantly improves the environmental stability of the electrolyte and solves the problem of deterioration caused by moisture contact during transportation and assembly through an innovative process of introducing and removing a hydrophobic material (such as thiol). At the same time, this process is completely reversible and can restore the original performance of the electrolyte after removing the hydrophobic material, ensuring that its ionic conductivity and mechanical properties are not affected. In addition, this method is simple to operate and easy to be compatible with existing processes, laying a solid foundation for the wide application and commercial development of sulfide solid electrolytes.

[0066] In some embodiments, the soaking time of the soaking treatment is not less than 48 hours.

[0067] In some embodiments, the content of the hydrophobic material is 0.5 wt% - 50 wt%. The content can be, for example, 0.5 wt%, 1 wt%, 5 wt%, 10 wt%, 20 wt%, 30 wt%, 40 wt%, 50 wt%, and so on.

[0068] In some embodiments, the molecular formula of the thiol substance is:

[0069] R n -SH; where n ≥ 1; R is selected from at least one of substituted or unsubstituted alkyl, alkenyl, alkynyl, and halogen atoms.

[0070] As described above, thiol substances play an important role as hydrophobic materials in the preparation of sulfide solid electrolytes. Among them, the molecular formula indicates that each thiol molecule contains at least one mercapto (-SH) functional group. R represents an organic group connected to the mercapto group, which can be at least one of substituted or unsubstituted alkyl, alkenyl, alkynyl, and halogen atoms. This structural design endows thiol substances with good hydrophobicity, enabling them to effectively protect sulfide electrolytes from moisture erosion during the preparation process.

[0071] Among them, R represents an organic group connected to the mercapto group, and it can be the following types:

[0072] (1) Alkyl (Alkyl, C≥1): Saturated hydrocarbon group, such as methyl (CH-), ethyl (CH-), etc.

[0073] (2) Alkenyl (Alkenyl, C≥2): Hydrocarbon group containing a carbon-carbon double bond, such as vinyl (CH=CH-), etc.

[0074] (3) Alkynyl (Alkynyl, C≥3): Hydrocarbon group containing a carbon-carbon triple bond, such as ethynyl (C≡CH), etc.

[0075] (4) Halogen atom (Halogen): Such as fluorine (F), chlorine (Cl), bromine (Br), iodine (I), etc.

[0076] The hydrophobicity of thiol substances enables them to form a protective layer during the preparation of sulfide electrolytes, preventing the sulfide electrolytes from contacting with moisture, thereby avoiding their hydrolysis and deterioration. This protection mechanism significantly improves the stability of sulfide electrolytes in a humid environment, especially during transportation, storage, and battery assembly. In addition, thiol substances can be completely removed during subsequent soaking treatment to ensure that the ionic conductivity and mechanical properties of the finally obtained sulfide solid electrolyte are not affected.

[0077] In some embodiments, the treatment environment for the mixing treatment is that the concentrations of oxygen and water are both lower than 0.5 ppm.

[0078] It should be noted that sulfide electrolytes (such as Li2S, P2S5, etc.) will undergo hydrolysis reactions when contacting with moisture, generating toxic hydrogen sulfide (H2S) gas. For example, phosphorus pentasulfide (P2S5) will hydrolyze to form phosphoric acid and hydrogen sulfide when encountering water. This reaction not only causes the deterioration and performance decline of the electrolyte material, but also poses hazards to the environment and operators. Therefore, the moisture content must be strictly controlled during the preparation process to avoid the occurrence of hydrolysis reactions.

[0079] Moreover, sulfide electrolytes are prone to oxidation reactions with oxygen in air, leading to changes in the material structure and a decrease in ionic conductivity. For example, lithium sulfide (Li2S) is highly hygroscopic in air and reacts with oxygen. To maintain the chemical stability and electrochemical performance of the electrolyte material, mixing treatment needs to be carried out in a low-oxygen environment.

[0080] Carrying out the mixing treatment in a low-oxygen and low-humidity environment can ensure highly consistent conditions during the preparation process, thereby guaranteeing the stability and repeatability of the quality and performance of the electrolyte material. This environmental control is particularly important for large-scale production and industrial applications because it can reduce fluctuations in material properties caused by environmental factors.

[0081] By preparing the sulfide electrolyte in a low-oxygen and low-humidity environment, it can be ensured that the electrolyte material has better stability and safety during subsequent battery assembly and use. This not only helps to improve the cycle life and energy density of the battery but also reduces the risk of short circuit or leakage during battery use.

[0082] Specifically, in the above-mentioned low-oxygen and low-humidity environment, operations can be carried out in a glove box to maintain the oxygen content and humidity in the environment and provide a stable processing environment for the preparation process.

[0083] The mixing treatment method is stirring and mixing.

[0084] The stirring speed of the stirring and mixing is not less than 1500 rpm / min, and the stirring time is not less than 60 min.

[0085] During the preparation process of the sulfide solid electrolyte, the mixing treatment is a key step to uniformly disperse the hydrophobic material (such as thiol substances) and the sulfide electrolyte raw materials. The stirring and mixing method and its specific parameters (stirring speed not less than 1500 rpm / min, stirring time not less than 60 minutes) mentioned in the examples are to ensure the uniformity and consistency of the mixture, thereby improving the performance and stability of the electrolyte.

[0086] Usually, a planetary mixer or a high-speed ball mill is used to achieve this stirring speed. The planetary mixer can provide uniform shear force while rotating at high speed, ensuring the uniformity of the mixture.

[0087] In actual operation, the stirring time can be adjusted according to the specific type of mixing equipment (such as planetary mixer, ball mill, etc.). For example, if a planetary mixer is used, the stirring time can be set to 60 minutes; if a ball mill is used, the time may need to be adjusted appropriately according to the rotation speed of the ball mill and the type of grinding medium.

[0088] In some embodiments, the sulfide electrolyte raw materials include at least one of binary sulfide solid electrolyte materials, glass-ceramic electrolyte materials, and crystalline sulfide solid electrolyte materials.

[0089] In some embodiments, the binary sulfide solid electrolyte materials include:

[0090] At least one of Li2S-P2S5-based electrolytes, Li2S-Sb2S3-based electrolytes, Li2S-Sb2S3-based electrolytes, Li2S-SnS2-based electrolytes, and Li2S-SiS2-based electrolytes.

[0091] In some embodiments, the Li2S-P2S5-based electrolyte is 20Li2S-80P2S5.

[0092] In some embodiments, the glass-ceramic electrolyte materials include Li7P3S 11 .

[0093] In some embodiments, the molecular formula of the crystalline sulfide solid electrolyte material is any one of the 3 molecular formulas in Table 1:

[0094] Table 1. Molecular Formulas of Crystalline Sulfide Solid Electrolyte Materials

[0095] NO. Molecular formula Symbol meaning Example Molecular formula 1 <![CDATA[Li 3+x M 1-x P x S4]]> M represents Ge or Si; x represents the doping ratio <![CDATA[Li 3.25 Ge 0.25 P 0.75 S4 <!-- 6 -->]]> Molecular formula 2 <![CDATA[Li6PS5X]]> The halogen may include but is not limited to Cl, Br, I <![CDATA[Li6PS5Cl(LPSCl)]]> Molecular formula 3 <![CDATA[Li 10 MP2S 12 > M represents Ge or Si <![CDATA[Li 10 GeP2S 12 (LGPS)]]>

[0096] In some embodiments, the crystalline sulfide solid electrolyte material is Li 10 GeP2S 12 .

[0097] By selecting different types of sulfide electrolyte raw materials, the performance of the electrolyte can be optimized according to the requirements of specific application scenarios. For example, binary sulfide electrolytes are suitable for scenarios with high requirements for ionic conductivity, while glass-ceramic and crystalline electrolytes are more suitable for scenarios that require high stability and mechanical properties.

[0098] Different types of sulfide electrolyte raw materials have different performance characteristics. By selecting appropriate raw materials, the performance of the electrolyte can be optimized during the preparation process, such as increasing ionic conductivity, improving mechanical properties, or enhancing environmental stability.

[0099] Certain raw materials (such as binary sulfide electrolytes) have lower costs and are suitable for large-scale production; while certain high-performance raw materials (such as crystalline sulfide electrolytes) have higher costs but can significantly improve the overall performance of the battery and are suitable for the application of high-performance batteries.

[0100] In this embodiment, by clarifying the types of sulfide electrolyte raw materials, diverse options are provided for the preparation of sulfide solid electrolytes. By selecting binary sulfide, glass-ceramic or crystalline sulfide electrolyte materials, the performance of the electrolyte can be optimized according to specific requirements, achieving high ionic conductivity, good mechanical properties and environmental stability. This diverse raw material selection provides important technical support for the wide application of sulfide solid electrolytes.

[0101] In an embodiment of the present application, a sulfide solid electrolyte is provided, which is prepared by the preparation method of the sulfide solid electrolyte according to any one of the foregoing embodiments.

[0102] In an embodiment of the present application, a battery is provided, including the sulfide solid electrolyte according to the foregoing embodiment.

[0103] In this embodiment, a battery is provided, which uses the sulfide solid electrolyte prepared by the foregoing method. This means that the electrolyte part of the battery adopts specific sulfide solid electrolyte materials, which have excellent properties including high ionic conductivity, good mechanical properties and environmental stability through unique preparation processes (such as introducing and removing hydrophobic materials).

[0104] Specifically, a complete battery may further include other key components, for example, but not limited to:

[0105] (1) Cathode material: It can be a lithium transition metal oxide (such as LiCoO2, LiFePO4, etc.), which is used to store and release lithium ions.

[0106] (2) Anode material: It can be lithium metal or a lithium alloy, which is used to store lithium ions.

[0107] (3) Current collector: It is used to collect and conduct current, usually an aluminum foil (for the cathode) and a copper foil (for the anode).

[0108] (4) Battery housing and encapsulation: It protects the internal structure of the battery and prevents the influence of the external environment on the battery.

[0109] In an embodiment of the present application, an electricity-related device is provided, including the battery according to the foregoing embodiment.

[0110] An electricity-related device refers to a device that involves power transmission, conversion, storage or use during operation. These devices are widely used in various fields, including energy, transportation, industry, medical treatment, etc. Its core function is to utilize electricity to achieve specific mechanical, chemical or electronic functions.

[0111] The electrified devices described in this embodiment can cover multiple fields and application scenarios, including transportation tools such as electric vehicles, hybrid vehicles, electric motorcycles, and electric bicycles. These devices utilize batteries with high energy density and fast charge-discharge capabilities to achieve efficient power output and long battery life. In addition, it also includes consumer electronic devices such as smartphones, laptops, tablets, and smartwatches, which rely on high-performance batteries to achieve long battery life and high safety. In the medical field, implantable devices such as pacemakers and defibrillators, as well as portable medical devices such as blood glucose meters and portable electrocardiographs, rely on batteries with high reliability and long life to ensure patient safety. Industrial devices such as power tools, industrial robots, and uninterruptible power supplies (UPS) utilize high-performance batteries to achieve efficient operation and high safety. In addition, aerospace devices such as drones, satellites, and electric aircraft also benefit from the high energy density and lightweight characteristics of high-performance batteries. These electrified devices significantly improve the overall performance, safety, and service life by using the above-mentioned batteries and are widely used in multiple fields such as energy, transportation, industry, medical, and consumer electronics.

[0112] The present invention will be further described below through specific embodiments. However, it should be understood that these embodiments are only for more detailed description and should not be construed as limiting the present invention in any form.

[0113] Table 2. Main process parameters in the examples and comparative examples

[0114] Item Example 1 Example 2 Example 3 Comparative example 1 Comparative example 2 Hydrophobic material 1-Dodecanethiol 1-Dodecanethiol 1-Decanethiol × Ethylene oxide Hydrophobic material content wt% 0.4％ 1％ 5％ × 5％ Sulfide electrolyte raw material <![CDATA[Li 10 GeP2S 12 > <![CDATA[Li 10 GeP2S 12 > <![CDATA[Li7P3S 11 > <![CDATA[Li 10 GeP2S 12 > <![CDATA[Li 10 GeP2S 12 >

[0115] Example 1

[0116] In this embodiment, a sulfide solid electrolyte is prepared according to the following method. The process parameters can be referred to Table 2.

[0117] Preparation method:

[0118] (1) Add the hydrophobic material and the sulfide electrolyte raw materials into a stirring tank. This step is carried out in a glove box with the oxygen and water content below 0.5 ppm. After the feeding is completed, seal the tank and take it out, then put it into a stirring kettle for stirring to obtain an electrolyte mixture. Then dry the mixture in a vacuum oven with the oven conditions of -95 Kpa, drying temperature of 35 °C, and drying time of 120 min.

[0119] (2) Press the dried electrolyte mixture to form multiple parallel target products. For the multiple target products prepared, a part of them is used for the detection experiments with different humidity and different times in the comparative test experiments respectively, and the other part is used for the preparation process of the following step (3).

[0120] (3) Press the target product into tablets and dry them in a vacuum oven; among them, the oven conditions are -95 Kpa, drying temperature 80 °C, and drying time 180 min. One part is used for the ionic conductivity detection experiment in the comparative test experiment respectively, and the other part is used for the treatment of the following step (4).

[0121] (4) Take some of the baked tablets and soak them in acetone solution (wetting solvent) for 48 h. The soaking process needs to be carried out in a closed environment filled with polytetrafluoroethylene. Take the acetone solution after soaking and conduct GC-MS testing to measure the content of mercaptan.

[0122] It should be noted that the wetting solvent used in the embodiment is acetone solution. In addition, acetonitrile, tetrahydrofuran, isopropanol, etc. can also be selected.

[0123] Example 2

[0124] In this example, a sulfide solid electrolyte is prepared according to the following method.

[0125] Preparation method:

[0126] Basically the same as Example 1, the differences are shown in Table 2.

[0127] Example 3

[0128] In this example, a sulfide solid electrolyte is prepared according to the following method.

[0129] Preparation method:

[0130] Basically the same as Example 1, the differences are shown in Table 2.

[0131] Comparative Example 1

[0132] In this example, a sulfide solid electrolyte is prepared according to the following method.

[0133] Preparation method:

[0134] Basically the same as Example 1, the difference is that step (1) is not carried out, and the electrolyte mixture is directly pressed into tablets. Specifically refer to Table 2.

[0135] Comparative Example 2

[0136] In this example, a sulfide solid electrolyte is prepared according to the following method.

[0137] Preparation method:

[0138] Basically the same as Example 1, the difference is that step (1) is not carried out, and the electrolyte mixture is directly pressed into tablets. Specifically refer to Table 2.

[0139] Comparative Test Experiment 1:

[0140] Test method:

[0141] Take the target products prepared in step (2) of the examples and comparative examples, and detect the ionic conductivity and H2S generation amount under different humidity levels (0.05% RH, 2% RH, 6% RH, 15% RH, and 20%) and different exposure times in a closed space at room temperature (25°C ± 2°C); among them, the exposure times are 5 hours, 1 day, 2 days, and 3 days respectively.

[0142] Test results:

[0143] Table 3. Performance parameters in the examples and comparative examples (humidity 0.05% RH)

[0144]

[0145] Table 4. Performance parameters in the examples and comparative examples (humidity 2% RH)

[0146]

[0147] Table 5. Performance parameters in the examples and comparative examples (humidity 6% RH)

[0148]

[0149] Table 6. Performance parameters in the examples and comparative examples (humidity 15% RH)

[0150]

[0151] Table 7. Performance parameters in the examples and comparative examples (humidity 20% RH)

[0152]

[0153] Analysis:

[0154] The results of Comparative Test Experiment 1 show that the introduction and removal of the hydrophobic material have a significant positive impact on the performance of the sulfide solid electrolyte. It can be seen from the experimental data that the ionic conductivity of Examples 1, 2, and 3 under different humidity conditions shows good stability. Even in a high-humidity environment (such as 20% RH), after 72 hours of exposure, its ionic conductivity can still remain at a high level, with almost no obvious decrease compared to the initial value. This indicates that the removal process of the hydrophobic material is reversible and will not have a negative impact on the conductivity of the electrolyte. In contrast, since Comparative Examples 1 and 2 did not use the hydrophobic material, the ionic conductivity decreased rapidly under high-humidity conditions, and the performance was significantly impaired, which further proves the importance of the hydrophobic material in improving the environmental stability of the electrolyte.

[0155] Meanwhile, the experimental results also show that hydrophobic materials can effectively inhibit the reaction between sulfide electrolytes and moisture to generate the harmful gas H2S. Under high humidity conditions, the H2S production amounts in Examples 1, 2, and 3 are much lower than those in the comparative examples, indicating that the hydrophobic materials provide an effective protective layer for the electrolyte, preventing the hydrolysis reaction of the electrolyte in a humid environment. This protection mechanism enables the sulfide electrolyte to be processed and stored in a relatively relaxed environment, reducing the strict requirements for a low-oxygen and low-humidity environment, decreasing equipment investment and energy consumption, and thus significantly reducing production costs.

[0156] In the actual battery production process, the introduction and removal process of this hydrophobic material has important application value. It can not only remove the hydrophobic material after the battery is dried without affecting the conductivity of the electrolyte, but also provide protection when the electrolyte is exposed to a humid environment to avoid performance degradation. This shows that this process can improve the productivity of solid electrolytes in the battery production process, making the dew point requirement for the workshop environment less stringent, and at the same time solving the concern about performance degradation caused by the introduction of other substances. By adjusting the type and content of the hydrophobic material, the performance of the electrolyte can be further optimized to maintain good stability under different humidity conditions. Therefore, this method provides a feasible and effective solution for the industrial development of sulfide solid electrolytes.

[0157] Comparative test experiment 2:

[0158] Experimental method:

[0159] (1) Perform the process treatment in step (3) on both the examples and the comparative examples, and detect the ionic conductivity of the examples and the comparative examples;

[0160] (2) Extract some of the solid electrolyte tablets after the process treatment in step (3) of the examples and the comparative examples for the treatment in step (4), and test the thiol content test and the content test of ethylene oxide.

[0161] Among them, the test conditions for ionic conductivity: the same as in Comparative Test Experiment 1.

[0162] Test results:

[0163] Table 8. Ionic Conductivity of Sulfide Solid Electrolytes in Examples and Comparative Examples

[0164]

[0165] Table 9. Thiol Content and Ethylene Oxide Content in Examples and Comparative Examples

[0166]

[0167] In Table 8, the ionic conductivity data of the target product listed below are the ionic conductivities of the corresponding target product at 0 hours under the condition of 0.05% RH humidity in Comparative Test Experiment 1.

[0168] Method for calculating the absolute difference: Absolute difference = |σ 硫化物固态电解质 -σ 目标产物 |.

[0169] Analysis:

[0170] The data in Table 8 show that in Examples 1 and 2, due to the use of thiol-based hydrophobic materials, even after removing the hydrophobic materials, their ionic conductivities can still maintain a level comparable to the initial value, indicating that the introduction and removal processes of the hydrophobic materials have no negative impact on the electrolyte performance. Although Example 3 uses different sulfide electrolyte raw materials, its ionic conductivity also remains stable, showing good performance.

[0171] In contrast, in Comparative Example 1, no hydrophobic material was used, and its ionic conductivity could still maintain a relatively high level under low humidity conditions. However, in Comparative Example 2, ethylene oxide was used as the hydrophobic material, and its effect was not as good as that of thiol-based substances, resulting in a slightly lower ionic conductivity. This further proves the superiority of thiol-based hydrophobic materials in improving the environmental stability and conductivity of sulfide solid electrolytes.

[0172] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a sulfide solid electrolyte, characterized in that, Including: Mixing a hydrophobic material with a sulfide electrolyte raw material to obtain an electrolyte mixture; Tabletting the electrolyte mixture to form a target product; Performing vacuum drying on the target product to obtain a dried product; Soaking the dried product in an infiltration solvent, and then performing tabletting again after taking it out to obtain a sulfide solid electrolyte; wherein, the infiltration solvent is inert to the sulfide electrolyte raw material, and the infiltration solvent can dissolve and remove the hydrophobic material in the dried product; Preferably, the hydrophobic material includes thiol substances; Preferably, the soaking time for the soaking treatment is not less than 48 hours; Preferably, the content of the hydrophobic material is 0.5 wt% to 50 wt%.

2. The preparation method of the sulfide solid electrolyte according to claim 1, wherein, The molecular formula of the thiol substance is: R n -SH; Wherein, n≥1; R is selected from at least one of substituted or unsubstituted alkyl, alkenyl, alkynyl and halogen atoms.

3. The preparation method of the sulfide solid electrolyte according to claim 1, characterized in that, The treatment environment for the mixing treatment is that the concentrations of oxygen and water are both lower than 0.5 ppm; and / or, The mixing treatment method is stirring and mixing; and / or, The stirring speed for the stirring and mixing is not less than 1500 rpm / min, and the stirring time is not less than 60 min.

4. The preparation method of the sulfide solid electrolyte according to claim 1, wherein, The sulfide electrolyte raw material includes at least one of a binary sulfide solid electrolyte material, a glass-ceramic electrolyte material and a crystalline sulfide solid electrolyte material.

5. The preparation method of the sulfide solid electrolyte according to claim 4, characterized in that, The binary sulfide solid electrolyte material includes: At least one of Li2S-P2S5-based electrolyte, Li2S-Sb2S3-based electrolyte, Li2S-Sb2S3-based electrolyte, Li2S-SnS2-based electrolyte, Li2S-SiS2-based electrolyte; Preferably, the Li2S-P2S5-based electrolyte is 20Li2S-80P2S5.

6. The preparation method of the sulfide solid electrolyte according to claim 4, wherein The glass-ceramic solid electrolyte material includes Li7P3S 11 .

7. The method for preparing a sulfide solid electrolyte according to claim 4, wherein The molecular formula of the crystalline sulfide solid electrolyte material is any one of the following 3: Molecular formula 1: Li 3+x M 1-x P x S4; wherein, M represents Ge or Si; x represents the doping ratio; Molecular formula 2: Li6PS5X; wherein, X represents a halogen; Molecular formula 3: Li 10 MP2S 12 ; wherein, M represents Ge or Si; Preferably, the crystalline sulfide solid electrolyte material is Li 10 GeP2S 12 .

8. A sulfide solid electrolyte, characterized in that, Prepared by the method for preparing a sulfide solid electrolyte according to any one of claims 1-7.

9. A battery, characterized in that, Including the sulfide solid electrolyte according to claim 8.

10. An electricity-related device, characterized in that, Including the battery according to claim 9.

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