Preparation method of sulfide solid electrolyte slurry, preparation method of positive plate, all-solid-state battery and preparation method of all-solid-state battery

Abstract

The invention discloses a preparation method of sulfide solid electrolyte slurry, a preparation method of a positive plate, an all-solid-state battery and a preparation method of the all-solid-state battery. The method comprises the following steps: preparing modified perfluoropolyether oil by taking perfluoropolyether carboxylic acid as a raw material, and mixing the modified perfluoropolyether oil with lithium salt, a suspension stabilizing additive and sulfide electrolyte to prepare the slurry. The modified perfluoropolyether oil adopts asymmetric end group design, one end is an epoxypropyl ether group, and the other end is a cyano group. The modified perfluoropolyether oil is introduced as a protective medium and an ionic conduction enhancer of the sulfide electrolyte, so that the problems of air stability, space charge layer and high-voltage operation of the sulfide electrolyte are solved, the process is simple, the cost is low, and the method has a good industrial application prospect. According to the all-solid-state battery disclosed by the invention, the gel-state ion conduction layer is formed between the positive plate and the electrolyte layer, and the gel-state ion conduction layer has high viscoelasticity and can keep good solid-solid interface contact under a relatively low external pressure condition.

Description

Technical Field

[0001] This invention relates to the technical field of solid-state batteries, specifically to a method for preparing a sulfide solid electrolyte slurry, a method for preparing a positive electrode sheet, an all-solid-state battery, and a method for preparing the same. Background Technology

[0002] All-solid-state lithium batteries use solid electrolytes instead of traditional liquid electrolytes, offering advantages such as high safety and high energy density, making them a crucial development direction for next-generation energy storage technology. Among various solid electrolyte systems, sulfide solid electrolytes stand out due to their high ionic conductivity (up to 10⁻⁶ Ω·cm). -3 -10 -2 It has attracted much attention due to its S / cm (close to the level of liquid electrolyte) and good machinability.

[0003] However, sulfide solid electrolytes face three major technical challenges in practical applications: First, it has poor air stability. The PS chemical bonds in sulfide electrolytes are weak and in a metastable state, making them more prone to reacting with water or oxygen to form PO bonds, releasing toxic H2S gas in the process. This not only worsens the ionic conductivity of the electrolyte but also poses serious safety hazards, greatly limiting its industrial application.

[0004] Second, the space charge layer effect. Sulfides are single-ionic conductors, and S... 2- For Li + The binding force of lithium is extremely weak. When a sulfide electrolyte forms a solid-solid contact with an oxide cathode or a graphite, silicon, or lithium metal anode, due to the large difference in chemical potential between the different materials, lithium ions at the interface will spontaneously migrate from the electrolyte to the active material interface, forming a space charge layer. The presence of the space charge layer significantly increases the interfacial reaction impedance and deteriorates the electrochemical performance of the battery.

[0005] Third, the requirement for high-voltage operation. Because it is difficult to form a tight solid-solid interface contact between the sulfide electrolyte and the electrode material, traditional sulfide-based all-solid-state batteries require an external pressure of up to about 600 MPa during operation to maintain a good solid-solid contact and achieve high performance. This poses a huge challenge to battery system design and practical applications.

[0006] Currently, a common technique to address these issues is to coat and dope the surface of sulfide electrolytes to form heterostructures, thereby improving stability and mitigating the space charge layer effect. While these methods have achieved some success, introducing other phases can affect the homogenization of the material, add new interfacial impedances, and the processes are complex and costly, making it difficult to meet the needs of large-scale industrialization.

[0007] Therefore, developing a technical solution that can simultaneously address the issues of air stability, space charge layer, and high-voltage operation of sulfide solid electrolytes is of great significance for promoting the industrialization of all-solid-state batteries. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of the above-mentioned background technology and provide a method for preparing sulfide solid electrolyte slurry, a method for preparing positive electrode sheet, an all-solid-state battery and the same method. This invention introduces modified perfluoropolyether oil as a protective medium and ion conduction enhancer for sulfide electrolyte, and solves the problems of air stability, space charge layer and high-voltage operation of sulfide electrolyte. The process is simple, the cost is low and it has good prospects for industrial application.

[0009] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a method for preparing a sulfide solid electrolyte slurry, comprising the following steps: S1. Preparation of modified perfluoropolyether oil: Using perfluoropolyether carboxylic acid as raw material, modified perfluoropolyether oil is prepared by acyl chloride reaction, cyano end group introduction, epoxy end group introduction and hydrogenation reduction treatment; wherein, the modified perfluoropolyether oil has a perfluoropolyether oil as the backbone structure and adopts an asymmetric end group design, with one end being an epoxy propylene ether group and the other end being a cyano group; S2. Lithium salt dissolution: In a planetary mixer under vacuum or inert gas protection, the modified perfluoropolyether oil and lithium salt are mixed and stirred at a speed of 150-250 rpm for 150-210 min to completely dissolve the lithium salt. S3. Add suspension stabilizer: Add suspension stabilizer to the mixture obtained in step S2 and continue stirring for 10-20 minutes to disperse it evenly. S4. Add sulfide electrolyte in batches: Add the sulfide electrolyte powder to the mixture obtained in step S3 in batches, with an interval of 3-7 minutes between each batch; S5. High-speed mixing: After all the sulfide electrolyte powder has been added, increase the stirring speed to 400-600 rpm and continue stirring for 3-5 hours to obtain a uniform and stable sulfide solid electrolyte slurry. The sulfide solid electrolyte slurry comprises the following components by mass percentage: 70%-80% sulfide electrolyte, 15%-30% modified perfluoropolyether oil, 1%-2% lithium salt, and 0.05%-0.15% suspension stabilizer additive; the sulfide electrolyte is selected from one or a combination of two of Li6PS5Cl or Li3PS4, and the particle size D50 is 0.5-2μm.

[0010] Furthermore, the preparation method of the modified perfluoropolyether oil in step S1 specifically includes the following steps: S101, Acyl chloride reaction: Perfluoropolyether carboxylic acid with a number average molecular weight of 1500-2500 is reacted with thionyl chloride at 50-70℃ for 3-5h, and excess thionyl chloride is removed by vacuum distillation to obtain perfluoropolyether acyl chloride. S102, Introduction of cyano end groups: Under an inert atmosphere, 4-aminobenzyl cyanide and triethylamine catalyst are added to the perfluoropolyether acyl chloride, and the reaction is carried out at 70-90℃ for 5-7h. A cyano end group is introduced at one end of the perfluoropolyether molecular chain through an amidation reaction, wherein the molar ratio of 4-aminobenzyl cyanide to perfluoropolyether acyl chloride is 1.0-1.2:1. S103, Introduction of epoxy end groups: Epichlorohydrin is added to the product obtained in step S102, and the reaction is carried out at 50-70℃ for 5-7h under potassium hydroxide catalysis. Epichlorohydrin ether groups are introduced at the other end of the perfluoropolyether molecular chain through etherification reaction, wherein the molar ratio of epichlorohydrin to perfluoropolyether acyl chloride is 1.0-1.5:1. S104, Hydrogenation Reduction: Using a Pd / C catalyst, hydrogenation reduction is carried out under a hydrogen pressure of 0.3-0.7 MPa to control the functionality and obtain a modified perfluoropolyether oil, wherein the molar ratio of epoxy groups to cyano groups is 1.0-1.5:1; the volatilization temperature of the modified perfluoropolyether oil is above 250℃, and the structural formula of the epoxy propylene ether group is -O-CH2-CH(-O-)-CH2.

[0011] Further, the lithium salt is one or more of lithium bis(trifluoromethanesulfonyl)imide, lithium bis(fluorosulfonyl)imide, lithium tetrafluoroborate, and lithium difluorooxalate borate; the suspension stabilizing additive is one or more of trimethylsilylthiol, perfluorooctylthiol, dodecylthiol, and mercaptopropyltrimethoxysilane; the thiol group forms hydrogen bonds with the sulfide electrolyte surface to prevent particle sedimentation and enhance dispersion stability; Furthermore, the preparation method of the sulfide solid electrolyte slurry also includes step S6: heating the slurry obtained in step S5 to 90-110℃ and maintaining it for 2-4 hours to allow the modified perfluoropolyether oil to polymerize in situ and form a gel-like particle structure; after the slurry after heating and polymerization is exposed to air at 35℃ for 4-6 hours, the H2S release is less than 0.5 ppm, the H2S inhibition rate is greater than 99.9%, and the ionic conductivity is 9.0 × 10⁻⁶. -4 Up to 1.0×10 -3 S / cm.

[0012] Secondly, the present invention provides a method for preparing a positive electrode sheet, which employs a dry process and includes the following steps: S1. Adhesive fiberization: Polytetrafluoroethylene adhesive is fiberized to form a fibrous structure; S2. Mixed ball milling: The positive electrode active material, conductive agent, and fiberized binder are mixed with the sulfide solid electrolyte slurry prepared by the method described in the first aspect above and ball milled to obtain a mixture. The modified perfluoropolyether oil in the slurry acts as a lubricant in this stage. S3. Roll forming: The mixture is laid on the current collector and repeatedly rolled using a hot roller press at a temperature of 80-90℃ to reduce the mixture to the target thickness and form an electrode sheet. S4. Thermal curing: The rolled electrode sheet is placed in a vacuum environment and dried at 100-120℃ for 2-4 hours to allow the modified perfluoropolyether oil in the slurry to undergo thermal polymerization and curing, forming a cross-linked gel-like ion conduction network between the positive electrode active material and the sulfide electrolyte, thus obtaining a dry-process positive electrode sheet.

[0013] Furthermore, the positive electrode active material is one or more of nickel-cobalt-manganese ternary positive electrode material (NCM811), lithium iron phosphate (LFP), and nickel-cobalt-aluminum ternary positive electrode material (NCA); the conductive agent is one or more of conductive carbon black (SP), carbon nanotubes (CNT), graphene, and Ketjen black (KB); and the current collector is one or more of carbon-coated aluminum foil, graphite-coated aluminum foil, graphene-coated aluminum foil, and carbon nanotube-coated aluminum foil. By weight, the positive electrode active material comprises 200-220 parts, the polytetrafluoroethylene binder comprises 2-4 parts, the conductive agent comprises 2-3 parts, and the sulfide solid electrolyte slurry comprises 40-60 parts; in step S3, the hot rolling temperature is 80-90℃, and the thickness of the electrode sheet after rolling is 80-120μm, wherein the compaction density of the nickel-cobalt-manganese ternary positive electrode material or the nickel-cobalt-aluminum ternary positive electrode material is 3.0-3.5g / cm³. 3 The compacted density of lithium iron phosphate is 2.3-2.6 g / cm³. 3 .

[0014] Thirdly, the present invention provides a method for preparing a positive electrode sheet, which employs a wet process and includes the following steps: S1. Preparation of positive electrode slurry: Polyvinylidene fluoride adhesive is dissolved in N-methylpyrrolidone solvent to form a gel, and then positive electrode active material, conductive agent and sulfide solid electrolyte slurry prepared by the method described in the first aspect above after heating and polymerization are added, and the mixture is stirred and dispersed evenly to obtain positive electrode slurry. S2. Coating: The positive electrode slurry is coated onto the current collector to form a wet film; S3. Drying and Rolling: The coated current collector is placed in a vacuum environment and dried at 100-120℃ for 6-8 hours to fully remove the N-methylpyrrolidone solvent. Then, it is rolled to the target thickness to obtain a wet cathode sheet.

[0015] Furthermore, the positive electrode active material is one or more of nickel-cobalt-manganese ternary positive electrode material (NCM811), lithium iron phosphate (LFP), and nickel-cobalt-aluminum ternary positive electrode material (NCA); the current collector is one or more of carbon-coated aluminum foil, graphite-coated aluminum foil, graphene-coated aluminum foil, and carbon nanotube-coated aluminum foil. By weight, the positive electrode active material comprises 200-220 parts, the polyvinylidene fluoride binder comprises 2-4 parts, the conductive agent comprises 2-3 parts, the sulfide solid electrolyte slurry comprises 40-60 parts, and the N-methylpyrrolidone solvent comprises 120-160 parts; the thickness of the rolled electrode sheet is 80-120 μm, wherein the compaction density of the nickel-cobalt-manganese ternary positive electrode material or the nickel-cobalt-aluminum ternary positive electrode material is 3.0-3.5 g / cm³. 3 The compacted density of lithium iron phosphate is 2.3-2.6 g / cm³. 3 .

[0016] Fourthly, the present invention provides a method for preparing an all-solid-state battery, comprising the following steps: S1. Electrolyte layer coating: The sulfide solid electrolyte slurry prepared by the above method is coated onto the surface of the dry positive electrode or the wet positive electrode using the casting method. The coating method is adopted by scraping, and the scraper height is controlled to be 40-60μm. S2. In-situ polymerization: The coated positive electrode sheet is placed in a vacuum environment and heated at 90-110℃ for 2-4 hours to allow the modified perfluoropolyether oil in the slurry to undergo in-situ thermal polymerization, forming an integrated structure of positive electrode-electrolyte layer. S3. Roll forming: Roll forming is performed on the integrated positive electrode-electrolyte layer structure obtained in step S2, and the total thickness is controlled to be 120-150μm. S4. Stacked assembly: The integrated positive electrode and negative electrode are stacked according to the designed number of layers, and then the tabs are welded and packaged to obtain a soft pack battery. The negative electrode is a lithium copper composite strip, which includes a copper foil substrate with a thickness of 6-10μm and a metallic lithium layer with a thickness of 8-12μm composite on one side of the copper foil substrate. S5. Isostatic Pressure Treatment: The pouch cell is placed in a temperature isostatic pressure apparatus and subjected to isostatic pressure treatment at a temperature of 40-60℃ and a pressure of 40-60MPa. The pressurization time is 3-7 minutes, the pressurization gradient is 8-12MPa / min, the holding time is 3-7 minutes, and the depressurization gradient is 8-12MPa / min, to obtain an all-solid-state battery.

[0017] Preferably, in step S1, the scraper height is 50 μm; in step S3, the total thickness of the integrated positive electrode-electrolyte layer structure after rolling is 135 μm; in step S4, the thickness of the copper foil substrate is 8 μm, and the thickness of the lithium metal layer is 10 μm; in step S5, the isostatic pressing temperature is 50 °C, the isostatic pressure is 50 MPa, the pressurization time is 5 min, the pressurization gradient is 10 MPa / min, the holding time is 5 min, and the depressurization gradient is 10 MPa / min.

[0018] Fifthly, the present invention provides an all-solid-state battery, which is prepared by the above-described preparation method; the all-solid-state battery includes a positive electrode, an electrolyte layer and a negative electrode, wherein a gel-state ion-conducting layer is formed between the positive electrode and the electrolyte layer, and the gel-state ion-conducting layer is composed of a cross-linked network structure formed by thermal polymerization of modified perfluoropolyether oil and a lithium salt, wherein the cross-linked network structure includes a polyether network formed by ring-opening polymerization of epoxy propylene ether groups and a triazine ring structure formed by cyano trimerization; Under a clamping force of 50 kg, the all-solid-state battery has an initial coulombic efficiency of ≥88%, a 0.2C discharge capacity of ≥0.95 Ah, a 2C discharge capacity of ≥0.89 Ah, and a cycle test under 0.5C charging / 1C discharging conditions, with a cycle count of ≥220 when the capacity decays to 70%.

[0019] Compared with the prior art, the present invention has the following advantages: Firstly, the sulfide electrolyte slurry of this invention exhibits excellent air stability. The addition of modified perfluoropolyether oil provides hydrophobic and oxygen-repellent properties, effectively isolating moisture and oxygen from contact with the sulfide electrolyte and preventing PS bond hydrolysis. After exposure to air at 35°C for 4 hours, the slurry prepared by this invention shows an H2S release of less than 3 ppm (less than 0.5 ppm after heating and polymerization) and an H2S inhibition rate greater than 99%, significantly superior to pure sulfide electrolytes (H2S release > 1000 ppm, inhibition rate < 30%), providing favorable conditions for the industrial-scale continuous production of sulfide solid-state batteries.

[0020] Secondly, the sulfide electrolyte slurry of this invention, through modification of the cyano groups in the perfluoropolyether oil, can coordinate with lithium ions on the surface of the sulfide electrolyte to form a nanoscale thin film, and through a trimerization reaction, form a triazine ring structure. The nitrogen atoms on the ring complex with lithium salts to form lithium-cyanide complexes, enhancing ion conductivity. Simultaneously, the polyether network formed by the ring-opening polymerization of the epoxypropylene ether group also possesses lithium-ion conductivity. The ionic conductivity of the slurry of this invention is 9.0 × 10⁻⁶. -4 Up to 1.0×10 -3 It has a conductivity of S / cm and remains essentially unchanged before and after air exposure, exhibiting high ionic conductivity.

[0021] Thirdly, the sulfide electrolyte slurry of the present invention, through the gel-like ion-conducting layer formed by the thermal polymerization of modified perfluoropolyether oil, can effectively alleviate the space charge layer effect caused by the difference in lithium ion chemical potential between the positive electrode active material and the sulfide electrolyte, reduce interfacial impedance, and improve the electrochemical performance of the battery.

[0022] Fourth, a gel-like ion-conducting layer is formed between the positive electrode and the electrolyte layer in the all-solid-state battery of this invention. This gel-like ion-conducting layer has high viscoelasticity and can maintain good solid-solid interface contact under relatively low external pressure. The all-solid-state battery prepared by this invention can exhibit excellent electrochemical performance under a clamping force of 50 kg, overcoming the problem that traditional sulfide solid-state batteries require high-pressure (approximately 600 MPa) operation.

[0023] Fifth, the all-solid-state battery of the present invention has excellent performance. Taking a soft-pack battery with a theoretical capacity of 1Ah as an example, under a clamping force of 50kg, the initial coulombic efficiency of the all-solid-state battery of the present invention is ≥88%, the 0.2C discharge capacity is ≥0.95Ah, the 2C discharge capacity is ≥0.89Ah, and the cycle test under the condition of 0.5C charging / 1C discharging is ≥220 cycles when the capacity decays to 70%, showing excellent capacity utilization, rate performance and cycle life. Attached Figure Description

[0024] Figure 1 This is a schematic flowchart of the method for preparing sulfide solid electrolyte slurry according to the present invention. Detailed Implementation

[0025] The following details the preparation method of the sulfide solid electrolyte slurry, the preparation method of the positive electrode sheet, and the implementation method of the all-solid-state battery of the present invention. This description is provided to enable those skilled in the art to fully understand the present invention and is not intended to limit the subject matter described in the claims.

[0026] The "scope" disclosed in this invention is defined in the form of a lower limit and an upper limit. A given scope is defined by selecting a lower limit and an upper limit, which define the boundaries of the specific scope. The scope defined in this way can include or exclude end values, and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a scope.

[0027] Unless otherwise specified, all embodiments and optional embodiments of the present invention can be combined to form new technical solutions. All technical features and optional technical features of the present invention can be combined to form new technical solutions. All steps of the present invention can be performed sequentially or randomly.

[0028] I. Preparation of Modified Perfluoropolyether Oil Example 1-1 This embodiment provides a method for preparing modified perfluoropolyether oil, the specific steps of which are as follows: Raw material preparation: 100g of perfluoropolyether carboxylic acid (PFPE-COOH, number average molecular weight Mn=2000); 8.5g of epichlorohydrin; 5.2g of 4-aminobenzyl cyanide; 0.15g of potassium hydroxide (KOH); 0.1g of triethylamine; 200mL of anhydrous acetonitrile.

[0029] Synthesis steps: S1. Acyl chloride reaction: 100g of perfluoropolyether carboxylic acid was placed in a three-necked flask, and excess thionyl chloride (SOCl2) was added. The reaction was carried out at 60℃ for 4 hours. After the reaction was completed, excess thionyl chloride was removed by vacuum distillation to obtain perfluoropolyether acyl chloride.

[0030] S2. Introduction of cyano end groups: Under the protection of argon atmosphere, 5.2g of 4-aminobenzyl cyanide (molar ratio of 4-aminobenzyl cyanide to perfluoropolyether acyl chloride is 1.1:1) and 0.1g of triethylamine are added to the obtained perfluoropolyether acyl chloride as catalysts, and the reaction is carried out at 80℃ for 6h. A cyano end group is introduced at one end of the perfluoropolyether molecular chain through amidation reaction.

[0031] S3. Introduction of epoxy end groups: Add 8.5g of epichlorohydrin (molar ratio of 1.2:1 to perfluoropolyether acyl chloride) to the product obtained in step S2, add 0.15g of potassium hydroxide as an alkaline catalyst, and react at 60℃ for 6h. Through etherification reaction, epoxy propylene ether groups are introduced to the other end of the perfluoropolyether molecular chain.

[0032] S4, Hydrogenation Reduction: Using a Pd / C catalyst, the product obtained in step S3 was subjected to hydrogenation reduction treatment for 4 hours under hydrogen pressure of 0.5 MPa and temperature of 50 °C. The functionality was controlled to obtain a light yellow oily modified perfluoropolyether oil (EC-PFPE) with a molar ratio of epoxy groups to cyano groups of 1.2:1.

[0033] Product characterization: The obtained modified perfluoropolyether oil is a pale yellow, transparent, oily liquid with a number-average molecular weight of approximately 2200, an evaporation temperature >250℃, a viscosity of approximately 85 mPa·s at room temperature, and a density of approximately 1.85 g / cm³. 3 .

[0034] Examples 1-2 This embodiment provides a method for preparing a modified perfluoropolyether oil, which differs from Example 1-1 in that: Raw materials: 100g of perfluoropolyether carboxylic acid (Mn=1500); 4-aminobenzyl cyanide (molar ratio 1.0:1); epichlorohydrin (molar ratio 1.0:1).

[0035] S1, Acyl chloride reaction: react with SOCl2 at 50℃ for 3 hours.

[0036] S2. Introduction of cyano end groups: Reaction at 70℃ for 5 hours. S3. Introduction of epoxy end groups: Reaction at 50℃ for 5 hours. S4. Hydrogenation reduction: Hydrogen pressure 0.3 MPa, to obtain modified perfluoropolyether oil, with a molar ratio of epoxy groups to cyano groups of 1.0:1.

[0037] Product characterization: Number average molecular weight is approximately 1700, evaporation temperature is >250℃, and viscosity at room temperature is approximately 65 mPa·s.

[0038] Examples 1-3 This embodiment provides a method for preparing a modified perfluoropolyether oil, which differs from Example 1-1 in that: Raw materials: 100g of perfluoropolyether carboxylic acid (Mn=2500); 4-aminobenzyl cyanide (molar ratio 1.2:1); epichlorohydrin (molar ratio 1.5:1).

[0039] S1, Acyl chloride reaction: react with SOCl2 at 70℃ for 5 h.

[0040] S2. Introduction of cyano end groups: Reaction at 90℃ for 7 hours. S3. Introduction of epoxy end groups: Reaction at 70℃ for 7 hours. S4. Hydrogenation reduction: Hydrogen pressure 0.7 MPa, to obtain modified perfluoropolyether oil with a molar ratio of epoxy groups to cyano groups of 1.5:1.

[0041] Product characterization: Number average molecular weight approximately 2800, volatile temperature > 255℃, viscosity at room temperature approximately 110 mPa·s.

[0042] Examples 1-4 In this example: raw materials are perfluoropolyether carboxylic acid (Mn=1800); 4-aminobenzyl cyanide (molar ratio 1.05:1); epichlorohydrin (molar ratio 1.1:1).

[0043] S1. Acyl chloride reaction: 55℃ for 3.5 h. S2. Cyano end-group introduction: 75℃ for 5.5 h. S3. Epoxy end-group introduction: 55℃ for 5.5 h. S4. Hydrogenation reduction: Hydrogen pressure 0.4 MPa.

[0044] Product characterization: Epoxy / cyano molar ratio 1.1:1, number average molecular weight approximately 2000, viscosity approximately 75 mPa·s.

[0045] Examples 1-5 This embodiment uses the following raw materials: perfluoropolyether carboxylic acid (Mn=2200); 4-aminobenzyl cyanide (molar ratio 1.15:1); epichlorohydrin (molar ratio 1.3:1).

[0046] S1. Acyl chloride reaction: 65℃ for 4.5 h. S2. Cyano end-group introduction: 85℃ for 6.5 h. S3. Epoxy end-group introduction: 65℃ for 6.5 h. S4. Hydrogenation reduction: Hydrogen pressure 0.6 MPa.

[0047] Product characterization: Epoxy / cyano molar ratio 1.3:1, number average molecular weight approximately 2400, viscosity approximately 95 mPa·s.

[0048] Characterization methods for the modified perfluoropolyether oils of Examples 1-1 to 1-5: 1. Number-average molecular weight (Mn) test: Gel permeation chromatography (GPC) was used with tetrahydrofuran as the mobile phase, a flow rate of 1.0 mL / min, and a column temperature of 35℃. Polystyrene standard was used for calibration to determine the number-average molecular weight of the raw material perfluoropolyether carboxylic acid and the product modified perfluoropolyether oil.

[0049] 2. Determination of the epoxy / cyano molar ratio: using proton nuclear magnetic resonance spectroscopy (NMR spectroscopy). 1 Combined analysis of H-NMR and Fourier transform infrared spectroscopy (FT-IR). 1 H-NMR analysis was performed using CDCl3 as solvent and a 400MHz NMR spectrometer. The molar ratio was calculated by integrating the characteristic peaks of the epoxy group (δ 2.6–2.8 ppm and δ 3.1–3.2 ppm) with those of the benzyl cyano group (δ 7.2–7.4 ppm). FT-IR analysis was performed using the characteristic absorption peak of the epoxy group (915 cm⁻¹). -1 and 840 cm -1 ) and the characteristic absorption peak of cyano (2230 cm⁻¹) -1 The strength ratio was verified.

[0050] 3. Volatilization temperature test: A thermogravimetric analyzer (TGA) was used under a nitrogen atmosphere at a heating rate of 10℃ / min, from room temperature to 400℃. The temperature at which 5% mass loss was recorded was taken as the volatilization temperature.

[0051] 4. Viscosity test: The viscosity was tested using a rotational viscometer (NDJ-8S) under a constant temperature water bath at 25℃. The rotor was model 2# and the rotation speed was 30 rpm. The viscosity value was recorded after the reading stabilized.

[0052] 5. Appearance inspection: Visually observe the color, transparency, and flowability of the sample under natural light.

[0053] Table 1 Characterization data of modified perfluoropolyether oil Test Result Analysis: As shown in Table 1, the modified perfluoropolyether oils prepared in Examples 1-1 to 1-5 have the following characteristics: (1) Molecular weight variation: The number-average molecular weight of the product increases by 200-300 compared to the raw material. This is due to the introduction of cyano end groups (through 4-aminobenzyl cyanide) and epichlorohydrin groups (through epichlorohydrin) at both ends of the perfluoropolyether molecular chain. When the raw material Mn increases from 1500 to 2500, the product Mn increases from 1700 to 2800 accordingly, indicating that the conversion rate of the end group introduction reaction is stable.

[0054] (2) Control of epoxy / cyano molar ratio: By adjusting the feed ratio of epichlorohydrin to 4-aminobenzyl cyanide (1.0-1.5:1 and 1.0-1.2:1), the precise control of the epoxy / cyano molar ratio in the product within the range of 1.0:1 to 1.5:1 was successfully achieved. This ratio directly affects the structure and properties of the crosslinked network during subsequent thermal polymerization.

[0055] (3) Excellent thermal stability: The volatilization temperature of all embodiments is greater than 250℃, and the highest can reach more than 255℃ (Examples 1-3), indicating that the modified perfluoropolyether oil has excellent thermal stability, which can meet the requirements of the 90-120℃ heat treatment process in the preparation of solid-state batteries, and will not affect the performance due to volatilization during battery use.

[0056] (4) Viscosity is positively correlated with molecular weight: Viscosity increases with the increase of raw material molecular weight, from 65 mPa·s (Mn=1500) to 110 mPa·s (Mn=2500). Higher viscosity is beneficial to the suspension stability of the slurry, but too high a viscosity will affect the coating processing performance. Therefore, it is necessary to select an appropriate molecular weight range according to the actual process requirements. Example 1-1 (Mn=2000, viscosity 85 mPa·s) is the preferred solution, which has both good processing performance and suspension stability.

[0057] (5) Appearance consistency: All products of the examples were pale yellow oily liquids, transparent and uniform, without any suspended matter or sediment, indicating that the synthesis process was stable and the product purity was high.

[0058] II. Preparation of Sulfide Solid Electrolyte Slurry Example 2-1 This embodiment provides a method for preparing a sulfide solid electrolyte slurry, the specific steps of which are as follows: Raw material preparation: Modified perfluoropolyether oil (product of Example 1-1): 20g; Li6PS5Cl electrolyte (D50=1μm): 70g; Lithium bis(trifluoromethanesulfonyl)imide (LiTFSI): 1.5g; Trimethylsilylthiol (TMS-SH) suspending agent: 0.1g.

[0059] By weight percentage: modified perfluoropolyether oil 21.8%, sulfide electrolyte 76.4%, LiTFSI 1.6%, TMS-SH 0.1%.

[0060] Slurry preparation process: S1. Lithium salt dissolution: In an argon-protected planetary mixer, add modified perfluoropolyether oil and LiTFSI, and stir at 200 rpm for 180 min until LiTFSI is completely dissolved and the solution is uniform and transparent.

[0061] S2. Add suspension stabilizer: Add TMS-SH and continue stirring for 15 minutes to disperse it evenly.

[0062] S3. Add sulfide electrolyte in batches: Add Li6PS5Cl powder in batches of 5g each, with a 5min interval between batches, for a total of 14 batches.

[0063] S4. High-speed mixing: After all the ingredients are added, increase the speed to 500 rpm and continue stirring for 4 hours to obtain a uniform and stable sulfide solid electrolyte slurry.

[0064] Slurry characteristics: grayish-white uniform paste, without obvious granular texture, and no stratification or sedimentation after standing for 24 hours.

[0065] Example 2-2 This embodiment adds a heating polymerization step to the basic embodiment 2-1: S1-S4: Same as Example 2-1.

[0066] S5. Heating polymerization: Transfer the slurry obtained in step S4 to a heating container, heat it to 100°C under argon protection and keep it for 3 hours to allow the modified perfluoropolyether oil to polymerize in situ and form a gel-like particle structure.

[0067] Slurry properties: A grayish-white gel-like paste with certain viscoelasticity. After exposure to air at 35℃ for 4 hours, the H2S release was <0.5ppm, the inhibition rate was >99.9%, and the ionic conductivity was 9.5×10⁻⁶. -4 S / cm.

[0068] Example 2-3 The specific steps of the raw material ratio and preparation process in this embodiment are as follows: Raw material ratio: 18g (20.2%) of modified perfluoropolyether oil (product of Examples 1-2); 70g (78.6%) of Li6PS5Cl electrolyte (D50=0.5μm); 1g (1.2%) of LiTFSI; 0.05g (0.06%) of TMS-SH.

[0069] Slurry preparation process: S1, stir at 150 rpm for 150 min. S2, stir for 10 min. S3, 3g per batch, 3 min interval. S4, stir at 400 rpm for 3 h.

[0070] Examples 2-4 This embodiment adds a heating polymerization step to the basis of embodiment 2-3: S1-S4 are the same as in embodiment 2-3; S5, heating polymerization: keep at 90℃ for 2 hours.

[0071] Examples 2-5 The raw material ratio and slurry preparation process in this embodiment are as follows: Raw material ratio: Modified perfluoropolyether oil (product of Examples 1-3) 30g (27.3%); Li3PS4 electrolyte (D50=2μm) 78g (70.9%); LiTFSI 2g (1.8%); TMS-SH 0.15g (0.14%).

[0072] Slurry preparation process: S1, stir at 250 rpm for 210 min. S2, stir for 20 min. S3, 7 g per batch, 7 min interval. S4, stir at 600 rpm for 5 h.

[0073] Examples 2-6 This embodiment adds a heating polymerization step to the basis of embodiments 2-5: S1-S4 are the same as in embodiments 2-5; S5, heating polymerization: keep at 110℃ for 4 hours.

[0074] Examples 2-7 This embodiment uses a mixture of two sulfide electrolytes: Raw material ratio: Modified perfluoropolyether oil (product of Example 1-1) 22g (23.6%); Li6PS5Cl electrolyte 35g + Li3PS4 electrolyte 35g (total 75.1%); LiTFSI 1.2g (1.3%); TMS-SH 0.08g (0.09%). The slurry preparation process is the same as in Example 2-1.

[0075] Examples 2-8 The raw material ratio and slurry preparation process in this embodiment are as follows: Raw material ratio: 25g (25%) of modified perfluoropolyether oil (product of Examples 1-4); 73g (73%) of Li6PS5Cl electrolyte (D50=1.2μm); 1.8g (1.8%) of LiTFSI; 0.12g (0.12%) of TMS-SH.

[0076] Slurry preparation process: S1, stir at 200 rpm for 180 min. S2, stir for 15 min. S3, 5 g per batch, 5 min interval. S4, stir at 500 rpm for 4 h.

[0077] Examples 2-9 This embodiment adds a heating polymerization step to the basis of embodiments 2-8: S1-S4 are the same as in embodiments 2-8; S5, heating polymerization: keep at 100℃ for 3 hours.

[0078] Example 2-10 This embodiment uses Li3PS4 alone: Raw material ratio: 20g modified perfluoropolyether oil (product of Example 1-1); 70g Li3PS4 electrolyte (D50=1μm); 1.5g LiTFSI; 0.1g TMS-SH. The slurry preparation process is the same as in Example 2-1.

[0079] Example 2-11 This embodiment uses LiFSI lithium salt and perfluorooctylthiol suspension stabilizer additive: Raw material ratio: 20g of modified perfluoropolyether oil (product of Example 1-1); 70g of Li6PS5Cl electrolyte (D50=1μm); 1.5g of lithium difluorosulfonylimide (LiFSI); 0.1g of perfluorooctyl mercaptan.

[0080] The slurry preparation process is the same as in Example 2-1, except that LiFSI dissolves faster than LiTFSI, and the stirring time can be shortened to 150 min.

[0081] Example 2-12 This embodiment adds a heating polymerization step to the basis of embodiment 2-11: S1-S4 are the same as in embodiment 2-11; S5, heating polymerization: keep at 100℃ for 3 hours.

[0082] Properties of the polymerized slurry: a grayish-white gel-like paste; after exposure to air at 35℃ for 4 hours, the H2S release was <0.3ppm, the inhibition rate was >99.9%, and the ionic conductivity was 9.8×10⁻⁶. -4 S / cm.

[0083] Example 2-13 This embodiment uses lithium salt LiBF4 and dodecyl mercaptan suspension stabilizer additive: Raw material ratio: 20g modified perfluoropolyether oil; 70g Li6PS5Cl electrolyte; 1.5g lithium tetrafluoroborate (LiBF4); 0.1g dodecyl mercaptan.

[0084] The slurry preparation process is the same as in Example 2-1, but the stirring time for dissolving LiBF4 needs to be extended to 200 min.

[0085] Example 2-14 This embodiment adds a heating polymerization step to the basis of embodiments 2-13: S1-S4 are the same as in embodiments 2-13; S5, heating polymerization: keep at 100℃ for 3 hours.

[0086] Example 2-15 This embodiment uses LiDFOB lithium salt and MPTMS suspension stabilizer additive: Raw material ratio: 20g modified perfluoropolyether oil; 70g Li6PS5Cl electrolyte; 1.5g lithium difluorooxalate borate (LiDFOB); 0.1g mercaptopropyltrimethoxysilane (MPTMS). The slurry preparation process is the same as in Example 2-1.

[0087] Example 2-16 This embodiment adds a heating polymerization step to the basis of embodiments 2-15: S1-S4 are the same as in embodiments 2-15; S5, heating polymerization: keep at 100℃ for 3 hours.

[0088] Example 2-17 The specific steps of the raw material ratio and preparation process in this embodiment are as follows: Raw material ratio: 15g (15.0%) of modified perfluoropolyether oil (product of Examples 1-2); 83g of Li6PS5Cl electrolyte (D50=0.5μm); 1g (1.0%) of LiTFSI; 0.05g (0.05%) of TMS-SH.

[0089] Slurry preparation process: S1, stir at 150 rpm for 150 min. S2, stir for 10 min. S3, 3g per batch, 3 min interval. S4, stir at 400 rpm for 3 h.

[0090] Slurry properties: Grayish-white homogeneous paste, no stratification or sedimentation after standing for 24 hours. H2S release <3.5ppm, inhibition rate >99%, ionic conductivity 9.0×10⁻⁶. -4 S / cm, viscosity 10.2 Pa·s.

[0091] Example 2-18 The specific steps of the raw material ratio and preparation process in this embodiment are as follows: Raw material ratio: Modified perfluoropolyether oil (product of Examples 1-3) 30g (30.0%); Li6PS5Cl electrolyte (D50=2μm) 68g (68.0%); LiTFSI 2g (2.0%); TMS-SH 0.15g (0.15%).

[0092] Slurry preparation process: S1, stir at 250 rpm for 210 min. S2, stir for 20 min. S3, 7 g per batch, 7 min interval. S4, stir at 600 rpm for 5 h.

[0093] Slurry properties: Grayish-white homogeneous paste, high viscosity but good flowability. H2S release <2.5ppm, inhibition rate >99%, ionic conductivity 8.5×10⁻⁶.-4 S / cm, viscosity 15.8 Pa·s, stable.

[0094] III. Preparation of Dry-Process Positive Electrode Example 3-1 This embodiment provides a solid-state battery cathode sheet prepared using a dry process, the specific steps of which are as follows: Raw material preparation: 200g of positive electrode material NCM811; 3g of binder PTFE; 2.5g of conductive agent conductive carbon black (SP); 50g of electrolyte slurry from Example 2-1; current collector is carbon-coated aluminum foil.

[0095] Film production process: S1. Adhesive fiberization: PTFE is placed in a high-speed shearing machine for fiberization treatment to form a fibrous adhesive with a network structure.

[0096] S2. Mixing and Ball Milling: NCM811, SP, fibrous PTFE, and electrolyte slurry are added to a ball mill jar and milled at 300 rpm for 2 hours using zirconia ball milling beads to obtain a mixture. The modified perfluoropolyether oil acts as a lubricant, making the dry mixing process more uniform and smooth.

[0097] S3. Roll forming: The mixture is spread on carbon-coated aluminum foil and repeatedly rolled 5-8 times using an 85℃ hot roller press to reduce the mixture to 100μm and achieve a compaction density of 3.3g / cm³. 3 .

[0098] S4. Thermal curing: The electrode is placed in a vacuum drying oven and dried at 115°C for 3 hours to allow the modified perfluoropolyether oil to undergo thermal polymerization and curing, forming a cross-linked gel-like ion conduction network between the positive electrode active material and the sulfide electrolyte, thus obtaining a dry-process positive electrode.

[0099] Note: The dry process uses an electrolyte slurry that has not been heated and polymerized (as in Example 2-1). The modified perfluoropolyether oil is used as a lubricant at this stage. After the sheet is made, it is polymerized in situ through a thermosetting step.

[0100] Example 3-2 The specific steps of the raw material ratio and preparation process in this embodiment are as follows: Raw material ratio: NCM811 200g; PTFE 2g; SP 2g; electrolyte slurry from Examples 2-3 40g; current collector is carbon-coated aluminum foil.

[0101] Film preparation process: S1-S2 are the same as in Example 3-1. S3, hot rolling temperature 80℃, thinning to 80μm, compaction density 3.0g / cm³. 3 S4. Dry at 100℃ for 2 hours.

[0102] Example 3-3 The specific steps of the raw material ratio and preparation process in this embodiment are as follows: Raw material ratio: NCM811 200g; PTFE 4g; SP 3g; electrolyte slurry from Examples 2-5 60g; current collector is carbon-coated aluminum foil.

[0103] Film preparation process: S1-S2 are the same as in Example 3-1. S3, hot rolling temperature 90℃, thinning to 120μm, compaction density 3.5g / cm³. 3 S4, dry at 120℃ for 4 hours.

[0104] Examples 3-4 This embodiment uses a slurry composed of LiFSI and perfluorooctyl mercaptan: Raw material ratio: NCM811 200g; PTFE 3g; SP 2.5g; electrolyte slurry from Example 2-11 50g; current collector is carbon-coated aluminum foil. The sheet preparation process is the same as in Example 3-1.

[0105] Examples 3-5 This embodiment uses lithium iron phosphate (LFP) cathode material and Ketjen Black conductive agent: Raw material ratio: LiFePO4 (LFP) 200g; PTFE 3g; Ketjen Black (KB) 3g; electrolyte slurry of Example 2-1 50g; current collector is carbon-coated aluminum foil.

[0106] The film preparation process is the same as in Example 3-1, except that LFP has a lower conductivity, requiring the use of Ketjen black, which has a high specific surface area, as a conductive agent. S3, hot rolling temperature 85℃, thinned to 100μm, compaction density 2.4g / cm³. 3 (LFP has a lower density than ternary materials).

[0107] Examples 3-6 This embodiment uses LFP cathode material, carbon nanotube conductive agent, and graphite-coated aluminum foil current collector: Raw material ratio: 200g LiFePO4; 3g PTFE; 2g carbon nanotubes (CNT); 50g electrolyte slurry from Examples 2-11; current collector is graphite-coated aluminum foil.

[0108] The preparation process is the same as in Example 3-1, with a compaction density of 2.4 g / cm³. 3 .

[0109] Examples 3-7 This embodiment uses NCA cathode material, SP+CNT composite conductive agent, and graphene-coated aluminum foil current collector: Raw material ratio: NCA 200g; PTFE 3g; SP 2g + CNT 0.5g; electrolyte slurry from Example 2-1 50g; current collector is graphene-coated aluminum foil.

[0110] The preparation process is the same as in Example 3-1, with a compaction density of 3.4 g / cm³. 3 The combination of SP and CNT offers both point contact and line contact conductivity modes.

[0111] Examples 3-8 This embodiment uses NCA cathode material, graphene conductive agent, and carbon nanotube coated aluminum foil current collector: Raw material ratio: NCA 200g; PTFE 3g; graphene 2.5g; electrolyte slurry (after heating and polymerization) from Examples 2-12 50g; current collector is carbon nanotube coated aluminum foil.

[0112] The preparation process is the same as in Example 3-1, with a compaction density of 3.4 g / cm³. 3 .

[0113] Examples 3-9 The raw material ratio and film-making process in this embodiment Raw material ratio: NCM811 220g; PTFE 3g; SP 2.5g; electrolyte slurry from Example 2-1 55g; current collector is carbon-coated aluminum foil.

[0114] Film preparation process: S1-S2 are the same as in Example 3-1. S3, hot rolling temperature 85℃, thinning to 110μm, compaction density 3.3g / cm³. 3 S4, dry at 115℃ for 3 hours.

[0115] Electrode performance: The electrode has a flat and uniform appearance, with no obvious cracks or detachment, and the compaction density meets the standard.

[0116] IV. Preparation of wet-process positive electrode sheets Example 4-1 This embodiment provides a solid-state battery cathode sheet prepared using a wet process, the specific steps of which are as follows: Raw material preparation: 200g of positive electrode material NCM811; 3g of binder PVDF; 2.5g of conductive agent SP; 50g of electrolyte slurry from Example 2-2 (after heating and polymerization); 140g of solvent NMP; current collector is carbon-coated aluminum foil.

[0117] Note: The wet process must use electrolyte slurry that has been polymerized by heating (as in Example 2-2). If slurry that has not been polymerized by heating is used, solidification will occur during the electrode drying process, resulting in NMP solvent residue in the electrode and affecting battery performance.

[0118] Film production process: S1. Preparation of positive electrode slurry: Dissolve PVDF in NMP to form a gel (solid content of about 8%), then add NCM811, SP and the electrolyte slurry after heating and polymerization in sequence, and stir and disperse at 30 rpm and 1500 rpm for 2 hours to obtain a uniform positive electrode slurry.

[0119] S2. Coating: The positive electrode slurry is coated onto the carbon-coated aluminum foil using a doctor blade coating method to form a wet film, with the thickness of the wet film controlled to be approximately 350 μm.

[0120] S3. Drying and Rolling: The coated current collector is placed in a vacuum environment and dried at 115℃ for 7 hours to fully remove the NMP solvent. It is then rolled to reduce the thickness to 100μm, with a compaction density of 3.3g / cm³. 3 This yields a wet-process positive electrode.

[0121] Example 4-2 The specific steps of the raw material ratio and preparation process in this embodiment are as follows: Raw material ratio: NCM811 200g; PVDF 2g; SP 2g; electrolyte slurry from Examples 2-4 40g; NMP 120g; current collector is carbon-coated aluminum foil.

[0122] Preparation process: S1-S2 are the same as in Example 4-1. S3: Dry at 100℃ for 6 hours, roll-press to 80μm, compaction density 3.0g / cm³. 3 .

[0123] Example 4-3 The specific steps of the raw material ratio and preparation process in this embodiment are as follows: Raw material ratio: NCM811 200g; PVDF 4g; SP 3g; electrolyte slurry from Examples 2-6 60g; NMP 160g; current collector is carbon-coated aluminum foil.

[0124] Preparation process: S1-S2 are the same as in Example 4-1. S3: Dry at 120℃ for 8 hours, roll-press to 120μm, compaction density 3.5g / cm³. 3 .

[0125] Example 4-4 This embodiment uses a polymerization slurry composed of LiFSI and perfluorooctyl mercaptan: Raw material ratio: NCM811 200g; PVDF 3g; SP 2.5g; electrolyte slurry from Examples 2-12 50g; NMP 140g; current collector is carbon-coated aluminum foil. The sheet preparation process is the same as in Example 4-1.

[0126] Examples 4-5 This embodiment uses LFP cathode material, Ketjen Black conductive agent, and graphite-coated aluminum foil current collector: Raw material ratio: LiFePO4 (LFP) 200g; PVDF 3g; Ketjen Black 3g; electrolyte slurry of Example 2-2 50g; NMP 140g; current collector is graphite coated aluminum foil.

[0127] The preparation process is the same as in Example 4-1, with the film rolled to 100μm and a compaction density of 2.4g / cm³. 3 .

[0128] Examples 4-6 This embodiment uses NCA cathode material, SP+CNT composite conductive agent, and graphene-coated aluminum foil current collector: Raw material ratio: NCA 200g; PVDF 3g; SP 2g + CNT 0.5g; electrolyte slurry from Examples 2-12 50g; NMP 140g; current collector is graphene-coated aluminum foil.

[0129] The preparation process is the same as in Example 4-1, with a compaction density of 3.4 g / cm³. 3 .

[0130] Examples 4-7 The raw material ratio and tablet preparation process in this embodiment are as follows: Raw material ratio: NCM811 220g; PVDF 3g; SP 2.5g; electrolyte slurry from Example 2-2 55g; NMP 150g; current collector is carbon-coated aluminum foil.

[0131] Preparation process: S1-S2 are the same as in Example 4-1. S3: Dry at 115℃ for 7 hours, roll-press to 110μm, compaction density 3.3g / cm³. 3 .

[0132] Electrode performance: The electrode has a flat and uniform appearance, with no obvious cracks or detachment, and the compaction density meets the standard.

[0133] V. Preparation of All-Solid-State Batteries Example 5-1 This embodiment provides a method for preparing an all-solid-state battery, using a dry-process cathode sheet. The specific steps are as follows: Raw material preparation: The positive electrode sheet is the dry positive electrode sheet obtained in Example 3-1; the electrolyte slurry is the slurry in Example 2-1; the negative electrode sheet is a lithium-copper composite strip with a copper foil thickness of 8μm and a lithium layer thickness of 10μm (single-sided composite).

[0134] Preparation process: S1. Electrolyte layer coating: The electrolyte slurry is coated onto the surface of the dry positive electrode using a casting method and a doctor blade coating method is used, with the doctor blade height controlled at 50μm.

[0135] S2. In-situ polymerization: The coated positive electrode sheet is placed in a vacuum oven and heated at 100°C for 3 hours to allow the modified perfluoropolyether oil in the slurry to undergo in-situ thermal polymerization, forming an integrated structure of positive electrode-electrolyte layer.

[0136] S3. Roll forming: Roll forming is performed on the integrated structure to control the total thickness to approximately 135μm.

[0137] S4. Stacking Assembly: The integrated positive electrode and negative electrode are stacked according to the designed number of layers (in this embodiment, it is a single-layer structure with a theoretical capacity of 1Ah), and the tabs are welded and aluminum-plastic film is encapsulated to obtain a soft-pack battery.

[0138] S5. Isostatic Pressure Treatment: The pouch cell is placed in a temperature isostatic pressure apparatus and subjected to isostatic pressure treatment at 50℃ and 50MPa. The pressurization time is 5min, the pressurization gradient is 10MPa / min, the holding time is 5min, and the depressurization gradient is 10MPa / min, to obtain an all-solid-state battery.

[0139] Example 5-2 This embodiment uses a wet-process positive electrode: the positive electrode is the wet-process positive electrode obtained in Example 4-1; the electrolyte slurry is the slurry from Example 2-1; the negative electrode is the same as in Example 5-1. The preparation process is the same as in Example 5-1.

[0140] Example 5-3 The specific steps of the raw material ratio and preparation process in this embodiment are as follows: Raw material preparation: The positive electrode sheet is the dry positive electrode sheet obtained in Example 3-2; the electrolyte slurry is the slurry in Example 2-3; the copper foil thickness of the negative electrode sheet is 6μm and the lithium layer thickness is 8μm.

[0141] Preparation process: S1, scraper height 40μm. S2, heating at 90℃ for 2h. S3, total thickness 120μm. S5, 40℃, 40MPa, pressurization time 3min, pressurization gradient 8MPa / min, holding time 3min, depressurization gradient 8MPa / min.

[0142] Example 5-4 The specific steps of the raw material ratio and preparation process in this embodiment are as follows: Raw material preparation: The positive electrode sheet is the dry positive electrode sheet obtained in Example 3-3; the electrolyte slurry is the slurry in Example 2-5; the copper foil thickness of the negative electrode sheet is 10μm and the lithium layer thickness is 12μm.

[0143] Preparation process: S1, scraper height 60μm. S2, heating at 110℃ for 4h. S3, total thickness 150μm. S5, 60℃, 60MPa, pressurization time 7min, pressurization gradient 12MPa / min, holding time 7min, depressurization gradient 12MPa / min.

[0144] Example 5-5 This embodiment uses a wet cathode: the cathode sheet is the wet cathode sheet obtained in Example 4-1; the electrolyte slurry is the slurry from Examples 2-8; the negative electrode has a copper foil thickness of 8 μm and a lithium layer thickness of 10 μm. The preparation process is the same as in Example 5-1.

[0145] Examples 5-6 This embodiment uses a mixed electrolyte: the positive electrode is the dry-processed positive electrode obtained in Example 3-1; the electrolyte slurry is the slurry from Examples 2-7; and the negative electrode is the same as in Example 5-1. The preparation process is the same as in Example 5-1.

[0146] Examples 5-7 This embodiment uses Li3PS4 electrolyte: the positive electrode is the dry-processed positive electrode obtained in Example 3-1; the electrolyte slurry is the slurry from Example 2-10; the negative electrode is the same as in Example 5-1. The preparation process is the same as in Example 5-1.

[0147] Examples 5-8 This embodiment uses a LiFSI + perfluorooctylthiol combination (dry cathode): the cathode sheet is the dry cathode sheet obtained in Examples 3-4; the electrolyte slurry is the slurry from Examples 2-11; the anode sheet is the same as in Example 5-1. The preparation process is the same as in Example 5-1.

[0148] Examples 5-9 This embodiment uses a LiFSI + perfluorooctylthiol combination (wet cathode): the cathode sheet is the wet cathode sheet obtained in Example 4-4; the electrolyte slurry is the slurry from Example 2-11; the anode sheet is the same as in Example 5-1. The preparation process is the same as in Example 5-1.

[0149] Examples 5-10 This embodiment uses a LiBF4 + dodecyl mercaptan combination: the positive electrode is the dry-process positive electrode obtained in Example 3-1; the electrolyte slurry is the slurry from Example 2-13; and the negative electrode is the same as in Example 5-1. The preparation process is the same as in Example 5-1.

[0150] Examples 5-11 This embodiment uses a LiDFOB+MPTMS combination (wet cathode): the cathode sheet is the wet cathode sheet obtained in Example 4-1; the electrolyte slurry is the slurry from Example 2-15; the anode sheet is the same as in Example 5-1. The preparation process is the same as in Example 5-1.

[0151] Examples 5-12 This embodiment uses LFP positive electrode material and Ketjen Black conductive agent (dry process positive electrode): the positive electrode sheet is the dry process positive electrode sheet obtained in Examples 3-5; the electrolyte slurry is the slurry in Example 2-1; the negative electrode sheet is the same as in Example 5-1. The preparation process is the same as in Example 5-1.

[0152] Examples 5-13 This embodiment uses LFP positive electrode material, Ketjen Black conductive agent, and graphite-coated aluminum foil current collector (wet process positive electrode, LiFSI + perfluorooctyl mercaptan combination): the positive electrode sheet is the wet process positive electrode sheet obtained in Examples 4-5; the electrolyte slurry is the slurry in Examples 2-11; the negative electrode sheet is the same as in Example 5-1. The preparation process is the same as in Example 5-1.

[0153] Examples 5-14 This embodiment uses NCA positive electrode material and SP+CNT composite conductive agent (dry process positive electrode): the positive electrode sheet is the dry process positive electrode sheet obtained in Examples 3-7; the electrolyte slurry is the slurry in Example 2-1; the negative electrode sheet is the same as in Example 5-1. The preparation process is the same as in Example 5-1.

[0154] Examples 5-15 This embodiment uses NCA positive electrode material, SP+CNT composite conductive agent, and graphene-coated aluminum foil current collector (wet process positive electrode, LiFSI+perfluorooctyl mercaptan combination): the positive electrode sheet is the wet process positive electrode sheet obtained in Examples 4-6; the electrolyte slurry is the slurry in Examples 2-11; the negative electrode sheet is the same as in Example 5-1. The preparation process is the same as in Example 5-1.

[0155] VI. Comparative Example Comparative Example 1 This comparative example provides a sulfide solid electrolyte without modified perfluoropolyether oil, which is used directly in the form of Li6PS5Cl powder (blank control).

[0156] The positive electrode sheet is prepared using a conventional wet process: 200g of NCM811, 3g of PVDF, 2.5g of SP and 50g of sulfide electrolyte powder are directly mixed in 140g of NMP, coated, dried and rolled to obtain the positive electrode sheet.

[0157] All-solid-state battery fabrication: The positive electrode sheet is stacked with a separately prepared sulfide electrolyte membrane (dry-pressed, about 50 μm thick) and a negative electrode sheet, and then isostatically pressed to obtain an all-solid-state battery.

[0158] Comparative Example 2 This comparative example uses unmodified K-type perfluoropolyether oil (without epoxy and cyano end groups) as a solvent, and the rest of the formulation and process are the same as in Example 2-1.

[0159] Results: During the slurry preparation process, it was found that the unmodified perfluoropolyether oil could not dissolve the LiTFSI lithium salt and had poor compatibility with the sulfide electrolyte, resulting in obvious stratification after standing.

[0160] Comparative Example 3 This comparative example uses a modified perfluoropolyether oil with epoxy end groups introduced only at one end (while retaining carboxyl or hydroxyl groups at the other end). The rest of the formulation and process are the same as in Example 2-1.

[0161] Comparative Example 4 This comparative example uses a modified perfluoropolyether oil with a cyano end group introduced only at one end (while retaining a carboxyl or hydroxyl group at the other end). The rest of the formulation and process are the same as in Example 2-1.

[0162] Comparative Example 5 This comparative example does not contain the suspension stabilizer TMS-SH; the rest of the formulation and process are the same as in Example 2-1.

[0163] Results: Significant sedimentation occurred in the slurry after standing for 24 hours, and a transparent oil layer precipitated on the upper layer, indicating that the suspension stabilizer additive is crucial to the stability of the slurry.

[0164] Comparative Example 6 The modified perfluoropolyether oil in this comparative example contains 10 wt%, and the remaining formulations and processes are adjusted proportionally according to Example 2-1.

[0165] Results: The slurry had poor fluidity, making coating difficult, and it settled after standing.

[0166] Comparative Example 7 The modified perfluoropolyether oil in this comparative example has a content of 35 wt%, and the remaining formulations and processes are adjusted proportionally according to Example 2-1.

[0167] Result: The ionic conductivity of the slurry decreased significantly, resulting in poor battery performance.

[0168] Comparative Example 8 The lithium salt LiTFSI content in this comparative example is 0.5 wt%, and the remaining formulations and processes are adjusted proportionally according to Example 2-1.

[0169] Comparative Example 9 The lithium salt LiTFSI content in this comparative example is 3wt%, and the remaining formulations and processes are adjusted proportionally according to Example 2-1.

[0170] Comparative Example 10 This comparative example uses a Li6PS5Cl electrolyte with a D50 of 5μm, and the rest of the formulation and process are the same as in Example 2-1.

[0171] VII. Performance Testing Test method: 1. H2S release test: Take 5g of slurry sample and place it in a sealed test chamber. Expose it to an air atmosphere of 35℃ and 50% relative humidity for 4-6 hours. Use a portable H2S detector (detection range 0-1000ppm, accuracy 0.1ppm) to continuously monitor the released H2S concentration, record the cumulative release amount, and calculate the H2S inhibition rate = (release amount of blank sample - release amount of example) / release amount of blank sample × 100%.

[0172] 2. Ionic Conductivity Test: Using the blocked electrode method, the slurry or electrolyte sample (13 mm in diameter, approximately 0.5 mm thick) is sandwiched between two polished stainless steel discs, and a pressure of 5 MPa is applied. AC impedance testing is performed using an electrochemical workstation (CHI660E) with a frequency range of 0.1 Hz to 1 MHz, an amplitude of 10 mV, and a test temperature of 25℃. The volume resistance is calculated based on the semicircle diameter in the impedance spectrum, and the ionic conductivity is then calculated using σ = L / (R × A).

[0173] 3. Slurry stability test: Take 50g of slurry and place it in a transparent sealed glass bottle. Let it stand for 7 days under an argon atmosphere at 25℃. Observe and record whether there are phenomena such as stratification, sedimentation, or precipitation every day.

[0174] 4. Slurry viscosity test: The slurry viscosity was tested using a rotational viscometer (NDJ-8S) at 25℃, with rotor model 4# and rotation speed of 60rpm.

[0175] 5. Full battery performance test: (1) Initial Coulombic Efficiency: After the battery is placed in a constant temperature chamber at 25°C for 12 hours, it is charged at a constant current rate of 0.1C to 4.25V, and then charged at a constant voltage rate until the current drops to 0.02C to cut off; it is then discharged at a constant current rate of 0.1C to 2.5V. Initial Coulombic Efficiency = Initial Discharge Capacity / Initial Charge Capacity × 100%.

[0176] (2) Rate performance: Constant current discharge was performed at 0.2C and 2C rates to 2.5V, and the discharge capacity was recorded.

[0177] (3) Cycle life: Cyclic tests were conducted under the conditions of 0.5C constant current and constant voltage charging (cutoff voltage 4.25V, cutoff current 0.05C) and 1C constant current discharging (cutoff voltage 2.5V), and the number of cycles when the capacity decayed to 80% and 70% of the initial capacity was recorded.

[0178] (4) Clamping force influence test: The above battery performance test was conducted under clamping force conditions of 50kg, 70kg, 90kg and 200kg respectively to evaluate the battery’s sensitivity to external pressure.

[0179] The test results are shown in Table 2-8 below: Table 2. Test results of H2S release performance and ionic conductivity of sulfide solid electrolyte slurry Table 3 Performance of Dry-Processed Positive Electrode Table 4 Performance of wet-process cathode sheets Table 5. Test results of electrical performance of all-solid-state batteries (theoretical capacity 1Ah soft pack, 50kg clamping force). Table 6. Effect of clamping force on the performance of all-solid-state batteries (Example 5-1 Dry cathode sheet) Table 7 Comparative Slurry Performance Test Results Table 8 Comparative all-solid-state battery performance (50kg clamping force) Test Result Analysis 1. H2S release performance analysis As shown in Table 2, after exposure to air at 35°C for 4 hours, the H2S release of the slurries from Examples 2-1 to 2-16 was less than 3.5 ppm, with an H2S inhibition rate greater than 99%. Among these, the H2S release of the examples treated with heat polymerization (such as 2-2, 2-4, 2-6, 2-9, 2-12, 2-14, and 2-16) was further reduced to below 0.5 ppm, with an inhibition rate greater than 99.9% and an ionic conductivity reaching 9.0 × 10⁻⁶. -4 Up to 1.0×10 -3 S / cm.

[0180] In contrast, Comparative Example 1 (pure sulfide electrolyte powder) exhibited an H2S release exceeding 1000 ppm with an inhibition rate below 30%; Comparative Example 2 (unmodified perfluoropolyether oil) also showed an H2S release exceeding 800 ppm. This clearly demonstrates that modified perfluoropolyether oil provides excellent protection for sulfide electrolytes, effectively preventing contact between moisture and oxygen and the sulfide electrolyte, thus preventing the hydrolysis of PS bonds.

[0181] Comparative Example 3 (containing only epoxy end groups) and Comparative Example 4 (containing only cyano end groups) also showed some air stability (inhibition rates of 95% and 92%, respectively), but their performance was significantly worse than that of the examples containing both epoxy and cyano end groups. This indicates that the synergistic effect of the two end groups is the key to achieving excellent air stability.

[0182] 2. Effects of different lithium salts and suspension stabilizers on slurry properties As can be seen from Table 2, the slurries using different lithium salts all exhibit excellent performance: (1) LiTFSI: Ionic conductivity 9.0-9.8×10 -4 S / cm indicates a preferred lithium salt; (2) LiFSI: Ionic conductivity reaches 1.0 × 10⁻⁶ -3 S / cm is the highest among all lithium salts; (3) LiBF4: Ionic conductivity 9.0-9.2×10 -4 S / cm, excellent thermal stability; (4) LiDFOB: Ionic conductivity 9.2-9.5×10 -4 It has a strength of S / cm and good film-forming properties.

[0183] All four suspension stabilizers (TMS-SH, perfluorooctyl mercaptan, dodecyl mercaptan, and MPTMS) can effectively prevent the aggregation and sedimentation of sulfide electrolyte particles. Among them, perfluorooctyl mercaptan has the best compatibility with perfluoropolyether oil and the best dispersion effect.

[0184] 3. Battery performance with different cathode materials As shown in Table 5, batteries using different cathode materials exhibit distinct performance characteristics: (1) NCM811: initial efficiency 88-89.5%, 70% cycle life 220-245 times, high energy density, making it a preferred positive electrode active material; (2) LFP: First efficiency up to 95.5-95.8%, 70% cycle life 350-380 times, cycle life is significantly better than ternary materials, especially suitable for energy storage applications; (3) NCA: First-time efficacy 88.2-88.8%, 70% cycle 220-235 times, high energy density, comparable to NCM811.

[0185] 4. The effect of different conductive agents Table 3-5 shows the effects of different conductive agents on the performance of the positive electrode and the battery: (1) Conductive carbon black (SP): It is the preferred conductive agent. The addition amount is 2-3g / 200g of positive electrode material, and the effect is stable. (2) Carbon nanotubes (CNTs): Adding 2g / 200g of cathode material is sufficient to achieve good conductivity; (3) Graphene: Added at 2.5g / 200g of cathode material, with excellent conductivity; (4) Ketjen Black (KB): Particularly suitable for low conductivity cathode materials such as LFP, with an addition amount of 3g / 200g cathode material; (5) SP+CNT composite: It has both point contact and line contact conductivity modes and is suitable for high-rate applications.

[0186] 5. The influence of different current collectors Carbon-coated aluminum foil, graphite-coated aluminum foil, graphene-coated aluminum foil, and carbon nanotube-coated aluminum foil can all be used as positive electrode current collectors. (1) Carbon-coated aluminum foil: The carbon coating can reduce the interfacial resistance and improve the adhesion, making it a preferred current collector; (2) Graphite-coated aluminum foil: The graphite coating has good chemical stability and low interfacial impedance; (3) Graphene-coated aluminum foil: Excellent conductivity, large specific surface area, suitable for high-power applications; (4) Carbon nanotube coated aluminum foil: forms a three-dimensional conductive network with good electrical contact.

[0187] 6. Clamp force sensitivity analysis As shown in Table 6, the all-solid-state battery prepared in the embodiments of the present invention is not sensitive to clamping force. Taking Example 5-1 as an example, when the clamping force is increased from 50 kg to 200 kg (a 4-fold increase), the battery performance is only slightly improved: the first-cycle efficiency increases from 88.5% to 88.8%, the 0.2C capacity increases from 0.96 Ah to 0.97 Ah, the 2C capacity increases from 0.90 Ah to 0.91 Ah, and the 70% cycle life increases from 225 cycles to 238 cycles.

[0188] This demonstrates that the gel-like coating layer formed by the modified perfluoropolyether oil of the present invention can maintain good solid-solid interface contact under low external pressure conditions, overcoming the problem that traditional sulfide solid-state batteries require high-pressure (about 600 MPa) operation, and providing favorable conditions for the practical application of solid-state batteries.

[0189] In summary, this invention, through the introduction of modified perfluoropolyether oil, simultaneously solves the problems of air stability, space charge layer, and high-voltage operation in sulfide solid electrolytes. The multiple choices of lithium salts, suspension stabilizers, cathode materials, conductive agents, and current collectors provide flexibility for formulation optimization. The preparation process is simple, low-cost, and has good prospects for industrial application.

[0190] The above are merely specific embodiments of the present invention. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the protection scope of the present invention. All other details not described in detail belong to the prior art.

Claims

1. A method for preparing a sulfide solid electrolyte slurry, characterized in that, Includes the following steps: S1: Modified perfluoropolyether oil is prepared by using perfluoropolyether carboxylic acid as raw material, through acyl chloride reaction, cyano end group introduction, epoxy end group introduction and hydrogenation reduction treatment; wherein, the modified perfluoropolyether oil has perfluoropolyether oil as the skeleton structure and adopts an asymmetric end group design, with one end being an epoxy propylene ether group and the other end being a cyano group; S2: Under vacuum or inert gas protection, the modified perfluoropolyether oil is mixed with lithium salt and stirred at 150-250 rpm for 150-210 min to completely dissolve the lithium salt. S3: Add the suspension stabilizer to the mixture obtained in step S2 and continue stirring for 10-20 minutes to disperse it evenly; S4: Add the sulfide electrolyte powder to the mixture obtained in step S3 in batches, with an interval of 3-7 minutes between each batch; S5: After all the sulfide electrolyte powder has been added, increase the stirring speed to 400-600 rpm and continue stirring for 3-5 hours to obtain sulfide solid electrolyte slurry. The sulfide solid electrolyte slurry comprises the following components by mass percentage: 70%-80% sulfide electrolyte, 15%-30% modified perfluoropolyether oil, 1%-2% lithium salt, and 0.05%-0.15% suspension stabilizer additive; the sulfide electrolyte is selected from one or a combination of two of Li6PS5Cl or Li3PS4, and the particle size D50 is 0.5-2μm.

2. The preparation method according to claim 1, characterized in that, The preparation method of the modified perfluoropolyether oil in step S1 specifically includes the following steps: S101: Perfluoropolyether carboxylic acid with a number average molecular weight of 1500-2500 is reacted with thionyl chloride at 50-70℃ for 3-5h, and excess thionyl chloride is removed by vacuum distillation to obtain perfluoropolyether acyl chloride. S102: Under an inert atmosphere, 4-aminobenzyl cyanide and triethylamine catalyst are added to the perfluoropolyether acyl chloride and reacted at 70-90°C for 5-7 hours. A cyano end group is introduced at one end of the perfluoropolyether molecular chain through an amidation reaction, wherein the molar ratio of 4-aminobenzyl cyanide to perfluoropolyether acyl chloride is 1.0-1.2:

1. S103: Add epichlorohydrin to the product obtained in step S102 and react at 50-70℃ for 5-7h under potassium hydroxide catalysis. Introduce epichlorohydrin ether groups at the other end of the perfluoropolyether molecular chain through etherification reaction, wherein the molar ratio of epichlorohydrin to perfluoropolyether acyl chloride is 1.0-1.5:

1. S104: A modified perfluoropolyether oil is obtained by hydrogenation reduction treatment using a Pd / C catalyst under a hydrogen pressure of 0.3-0.7 MPa to control the functionality, wherein the molar ratio of epoxy groups to cyano groups is 1.0-1.5:1; the volatilization temperature of the modified perfluoropolyether oil is above 250℃, and the structural formula of the epoxy propylene ether group is -O-CH2-CH(-O-)-CH2.

3. The preparation method according to claim 1, characterized in that, The lithium salt is one or more of lithium bis(trifluoromethanesulfonyl)imide, lithium bis(fluorosulfonyl)imide, lithium tetrafluoroborate, and lithium difluorooxalate borate; the suspension stabilizing additive is one or more of trimethylsilylthiol, perfluorooctylthiol, dodecylthiol, and mercaptopropyltrimethoxysilane.

4. The preparation method according to claim 1, characterized in that, The process also includes step S6: heating the slurry obtained in step S5 to 90-110℃ and maintaining it for 2-4 hours to allow the modified perfluoropolyether oil to polymerize in situ, forming a gel-like particle structure; after the slurry is heated and polymerized, it is exposed to air at 35℃ for 4-6 hours, and the H2S release is less than 0.5 ppm, the H2S inhibition rate is greater than 99.9%, and the ionic conductivity is 9.0 × 10⁻⁶. -4 Up to 1.0×10 -3 S / cm.

5. A method for preparing a positive electrode sheet, employing a dry process, characterized in that, Includes the following steps: S1: Polytetrafluoroethylene adhesive is fiberized to form a fibrous structure; S2: The positive electrode active material, conductive agent, and fibrous binder are mixed with the sulfide solid electrolyte slurry prepared by the method of claim 1 and ball-milled to obtain a mixture. The modified perfluoropolyether oil in the slurry acts as a lubricant in this stage. S3: The mixture is laid on the current collector and repeatedly rolled using a hot roller press at a temperature of 80-90℃ to reduce the mixture to the target thickness and form an electrode sheet; S4: Place the rolled electrode sheet in a vacuum environment and dry it at 100-120℃ for 2-4 hours to allow the modified perfluoropolyether oil in the slurry to undergo thermal polymerization and solidification, forming a cross-linked gel-like ion conduction network between the positive electrode active material and the sulfide electrolyte, thus obtaining a dry-process positive electrode sheet.

6. The preparation method according to claim 5, characterized in that, The positive electrode active material is one or more of nickel-cobalt-manganese ternary positive electrode material, lithium iron phosphate, and nickel-cobalt-aluminum ternary positive electrode material; the conductive agent is one or more of conductive carbon black, carbon nanotubes, graphene, and Ketjen black; the current collector is one or more of carbon-coated aluminum foil, graphite-coated aluminum foil, graphene-coated aluminum foil, and carbon nanotube-coated aluminum foil. By mass fraction, the positive electrode active material is 200-220 parts, the polytetrafluoroethylene binder is 2-4 parts, the conductive agent is 2-3 parts, and the sulfide solid electrolyte slurry is 40-60 parts; the hot rolling temperature in step S3 is 80-90℃, and the thickness of the electrode sheet after rolling is 80-120μm.

7. A method for preparing a positive electrode sheet, employing a wet process, characterized in that, Includes the following steps: S1. Polyvinylidene fluoride adhesive is dissolved in N-methylpyrrolidone solvent to form a glue solution, and then positive electrode active material, conductive agent and sulfide solid electrolyte slurry prepared by the method of claim 4 are added, and the mixture is stirred and dispersed evenly to obtain positive electrode slurry. S2. The positive electrode slurry is coated onto the current collector to form a wet film; S3. Place the coated current collector in a vacuum environment and dry it at 100-120℃ for 6-8 hours to fully remove the N-methylpyrrolidone solvent. Then roll it to the target thickness to obtain a wet cathode sheet.

8. The preparation method according to claim 7, characterized in that, The positive electrode active material is one or more of nickel-cobalt-manganese ternary positive electrode material, lithium iron phosphate, and nickel-cobalt-aluminum ternary positive electrode material; the current collector is one or more of carbon-coated aluminum foil, graphite-coated aluminum foil, graphene-coated aluminum foil, and carbon nanotube-coated aluminum foil. By mass fraction, the positive electrode active material is 200-220 parts, the polyvinylidene fluoride binder is 2-4 parts, the conductive agent is 2-3 parts, the sulfide solid electrolyte slurry is 40-60 parts, and the N-methylpyrrolidone solvent is 120-160 parts; the thickness of the rolled electrode sheet is 80-120 μm.

9. A method for preparing an all-solid-state battery, characterized in that, Includes the following steps: S1. The sulfide solid electrolyte slurry prepared by the method of claim 1 is coated onto the surface of the dry positive electrode sheet prepared by the method of claim 5 or 6 or the wet positive electrode sheet prepared by the method of claim 7 or 8 using a casting method, and the scraper height is controlled to be 40-60μm. S2. Place the coated positive electrode sheet in a vacuum environment and heat it at 90-110℃ for 2-4 hours to allow the modified perfluoropolyether oil in the slurry to undergo in-situ thermal polymerization, forming an integrated structure of positive electrode-electrolyte layer. S3. Roll-press the integrated positive electrode-electrolyte layer structure obtained in step S2 to control the total thickness to 120-150μm; S4. The integrated positive electrode and negative electrode are stacked according to the designed number of layers, and then the tabs are welded and packaged to obtain a soft-pack battery. The negative electrode is a lithium copper composite strip, which includes a copper foil substrate with a thickness of 6-10μm and a metallic lithium layer with a thickness of 8-12μm composite on one side of the copper foil substrate. S5. Place the pouch cell in a temperature isostatic press and perform isostatic pressing at a temperature of 40-60℃ and a pressure of 40-60MPa. The pressurization time is 3-7 minutes, the pressurization gradient is 8-12MPa / min, the holding time is 3-7 minutes, and the depressurization gradient is 8-12MPa / min to obtain an all-solid-state battery.

10. An all-solid-state battery, characterized in that, The all-solid-state battery is prepared by the preparation method described in claim 9. The all-solid-state battery includes a positive electrode, an electrolyte layer and a negative electrode. A gel-state ion-conducting layer is formed between the positive electrode and the electrolyte layer. The gel-state ion-conducting layer is composed of a cross-linked network structure formed by thermal polymerization of modified perfluoropolyether oil and a lithium salt. The cross-linked network structure includes a polyether network formed by ring-opening polymerization of epoxy propylene ether groups and a triazine ring structure formed by cyano trimerization. Under a clamping force of 50 kg, the all-solid-state battery has an initial coulombic efficiency of ≥88%, a 0.2C discharge capacity of ≥0.95 Ah, a 2C discharge capacity of ≥0.89 Ah, and a cycle test under 0.5C charging / 1C discharging conditions, with a cycle count of ≥220 when the capacity decays to 70%.

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