A carbon-free sulfur composite electrode and a preparation method of a high-temperature all-solid-state battery

Abstract

The application relates to a carbon-free sulfur composite electrode and a preparation method of a high-temperature full-solid-state battery, and belongs to the field of lithium ion batteries. x The electrode preparation method is that elemental sulfur and M The NPS3 material is ground, mixed, sealed in a quartz tube and heated to prepare a composite powder material, a sulfide solid-state electrolyte is added to the powder material and ground to obtain a carbon-free sulfur composite positive electrode material; the carbon-free sulfur composite positive electrode material is dispersed in a circular mold and hot-pressed to obtain a full-solid-state carbon-free sulfur composite electrode. The battery preparation method is that, in the mold, a sulfide solid-state electrolyte powder is dispersed on the surface of the composite electrode, and after hot pressing, a full-solid-state carbon-free sulfur composite electrode layer and a solid-state electrolyte layer are obtained; a high-melting-point lithium boron, lithium aluminum or lithium silicon alloy sheet is attached to the surface of the solid-state electrolyte layer, and after hot pressing, a full-solid-state battery composite core is obtained; and the battery composite core is sealed in a high-temperature-resistant solid-state battery mold and pressurized to obtain a high-temperature full-solid-state battery. The application is used for preparing a carbon-free sulfur composite electrode and a high-temperature full-solid-state battery.

Description

Technical Field

[0001] This invention belongs to the field of lithium-ion battery technology, specifically relating to a carbon-sulfur-free composite electrode and a method for preparing a high-temperature all-solid-state battery. Background Technology

[0002] With the increasing applications of electric vehicles, portable electronic devices, and drones, the demand for lithium-ion batteries is growing rapidly. All-solid-state batteries, using solid electrolytes, exhibit advantages such as high-temperature resistance, non-flammability, non-volatility, and non-corrosiveness, successfully overcoming the flammability and explosiveness issues of liquid batteries. This allows all-solid-state batteries to not only have a longer cycle life but also significantly improve energy density and safety, making them an inevitable trend in the future development of lithium-ion batteries.

[0003] Sulfur, an abundant and inexpensive element in the Earth's crust, boasts environmentally friendly properties and a higher theoretical specific capacity compared to traditional oxide cathode materials. Therefore, lithium-sulfur batteries exhibit extremely high energy density. However, the shuttling effect of soluble polysulfides encountered during charge and discharge severely limits their cycle life. To address this issue, the development of all-solid-state lithium-sulfur batteries, utilizing inorganic solid electrolytes instead of liquid electrolytes, holds promise for fundamentally overcoming the polysulfide shuttling phenomenon and thus improving the cycle stability of lithium-sulfur batteries.

[0004] However, the poor ionic and electronic conductivity and slow reaction kinetics of solid-state sulfur cathodes result in low utilization of active materials, limiting the specific energy of solid-state lithium-sulfur batteries. Therefore, a large amount of conductive carbon is typically added to the composite electrode to compensate for the lack of electron transport and reaction sites. However, due to the ionic insulation of conductive carbon and its induction of electrolyte decomposition, the internal resistance of the all-solid-state sulfur composite electrode usually increases rapidly during cycling, leading to rapid degradation of the all-solid-state lithium-sulfur battery. Therefore, there is an urgent need to develop all-solid-state lithium-sulfur batteries with carbon-free sulfur composite electrodes to improve the utilization of active materials and cycle stability, thereby promoting the development of this field. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing a carbon-sulfur-free composite electrode and a high-temperature all-solid-state battery. The high-temperature all-solid-state battery prepared using this carbon-sulfur-free composite electrode has the characteristics of high utilization of active materials, low internal resistance, good chemical stability, and high temperature resistance.

[0006] The present invention provides a carbon-sulfur-free composite electrode, wherein the traditional carbon material is not used as the electrode conductive agent, and M is selected which has both ionic and electronic conductivity. xNPS3 (where N in the metallic N powder is one of Ni, Fe, or Co, and M in the MCl material is one of Li, Na, or Cu, with x = 0.01-0.5), sulfur-containing positive electrode active materials can be obtained through M... x NPS3 gains lithium ions and electrons, undergoing a redox reaction directly on its surface. Furthermore, M x The NPS3 material and the sulfide solid electrolyte have high chemical stability, avoiding side reactions inside the electrode. Therefore, this carbon-free sulfur composite electrode has low internal impedance.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A method for preparing a carbon-sulfur-free composite electrode, the method comprising the following steps:

[0009] Step 1: According to elemental sulfur and M x The mass ratio of NPS3 material is 1:0.1-1. Weigh elemental sulfur and M. x NPS3 material was ground and mixed evenly, then sealed in a high-temperature resistant quartz tube under an inert atmosphere and heated at 100-750℃ for 1-48 hours.

[0010] Step 2: Add sulfide solid electrolyte to the powder material obtained in Step 1, with a mass ratio of powder material to sulfide solid electrolyte of 1:0.1-1; and grind for 1-24 hours to obtain carbon-sulfur-free composite cathode material;

[0011] Step 3: Disperse the carbon-sulfur-free composite cathode material obtained in Step 2 evenly in a circular mold, and hot press it at 90℃ and 200MPa for 2-60 minutes to obtain a fully solid-state carbon-sulfur-free composite electrode.

[0012] Furthermore, in step one, the M... x NPS3 material is prepared by vacuum solid-state sintering of a mixture of metallic N powder, red phosphorus powder, elemental sulfur powder, and MCl material in a quartz tube at a sintering temperature of 750℃ for 12-120 hours; the N in the metallic N powder is one of Ni, Fe, and Co, and the M in the MCl material is one of Li, Na, and Cu, with x = 0.01-0.5.

[0013] Furthermore, the molar ratio of the metallic N powder, red phosphorus powder, elemental sulfur powder, and MCl material is 1:1:3:0.01-0.5.

[0014] Furthermore, in step two, the sulfide solid electrolyte is LGPS or Li7P3S. 11, β-Li3PS4, Li7P2S8I, Li4PS4I, Li6PS5Cl x Li6PS5I y Li6PS5Br z One of them, where x, y, z = 0-1.

[0015] A method for preparing a high-temperature all-solid-state battery, the high-temperature all-solid-state battery comprising a positive electrode layer, a solid electrolyte layer, and a negative electrode layer, wherein the positive electrode layer comprises an all-solid-state carbon-sulfur-free composite electrode prepared by the method described above; the method for preparing the high-temperature all-solid-state battery comprises the following steps:

[0016] Step 1: In the mold used to prepare the all-solid-state carbon-sulfur-free composite electrode, uniformly disperse 5-100 mg / cm³ of the mixture on the surface of the all-solid-state carbon-sulfur-free composite electrode. 2 Sulfide solid electrolyte powder is hot-pressed at 90℃ and 300MPa for 2-60 minutes to obtain an all-solid carbon-sulfur-free composite electrode layer and a solid electrolyte layer.

[0017] Step 2: High-melting-point lithium boron, lithium aluminum, or lithium silicon alloy sheets are attached as negative electrode layers to the surface of the solid electrolyte layer. After hot pressing at 60°C and 50MPa for 2-60 minutes, an all-solid-state battery composite cell is obtained.

[0018] Step 3: Seal the all-solid-state battery composite cells in a high-temperature resistant solid-state battery mold and pressurize them to 0.5-100MPa to obtain a high-temperature all-solid-state battery.

[0019] Furthermore, in step one, the thickness of the all-solid carbon-sulfur-free composite electrode layer is 10-100 μm, and the thickness of the solid electrolyte layer is 10-100 μm.

[0020] Furthermore, in step one, the sulfide solid electrolyte powder is the same electrolyte used in the all-solid carbon-sulfur-free composite electrode.

[0021] Furthermore, in step two, the thickness of the negative electrode layer is 10-100 μm.

[0022] Furthermore, in step three, the high-temperature resistant solid-state battery mold includes a PTFE insulating shell, two stainless steel current collectors, and two silicone rings; the two stainless steel current collectors are the positive electrode current collector and the negative electrode current collector, respectively. The all-solid-state battery composite cell is placed inside the PTFE insulating shell. The all-solid-state carbon-sulfur-free composite electrode layer of the all-solid-state battery composite cell is sealed with the positive electrode current collector and the negative electrode layer is sealed with the negative electrode current collector, respectively. The two silicone rings are installed inside the PTFE insulating shell, and the positive electrode current collector and the negative electrode current collector are threadedly connected to the inner wall of the PTFE insulating shell, respectively.

[0023] The advantages of this invention over the prior art are:

[0024] 1. This invention utilizes M x The dual ionic and electronic conductivity of NPS3 allows sulfur cathode materials to be directly applied in M... x The NPS3 surface undergoes a redox reaction, which increases the number of reaction sites and improves the utilization rate of the cathode material.

[0025] 2. This invention uses M x NPS3, as a conductive material in composite electrodes, avoids the introduction of conductive carbon materials, which would lead to the decomposition of sulfide electrolytes, thus improving the cycle stability of the battery.

[0026] 3. The high-temperature solid-state battery prepared by the present invention has stable high-temperature cycle characteristics. The carbon-sulfur-free composite cathode can eliminate the chemical reaction at the interface between traditional oxide cathode materials and sulfide electrolytes under high-temperature conditions. Therefore, the carbon-sulfur-free composite cathode also has a small internal resistance at high temperatures.

[0027] 4. The high-temperature solid-state battery prepared by the present invention uses a high-melting-point alloy as the negative electrode, which can avoid the melting and flow of lithium indium or lithium tin alloy negative electrodes commonly used in sulfide solid-state batteries at high temperatures, which can cause short circuits in the battery and improve the stability and safety of the battery at high temperatures. Attached Figure Description

[0028] Figure 1 S@Li obtained in Example 1 0.1 A schematic diagram of the redox reaction in FePS3 composite materials, in which... Figure 1 (a) is a carbon-sulfur composite electrode. Figure 1 (b) is a carbon-sulfur-free composite electrode;

[0029] Figure 2 This is a schematic diagram of the high-temperature resistant all-solid-state battery cell and mold obtained in Example 2.

[0030] Figure 3 S@Li obtained in Example 1 0.1 SEM image of FePS3 composite material.

[0031] Figure 4 The images show SEM cross-sectional views of the carbon-sulfur-free composite electrode obtained in Example 1 and the solid electrolyte layer obtained in Example 2.

[0032] Figure 5 S@Li obtained in Example 2 0.1 A schematic diagram of the cycle performance of an all-solid-state battery made of FePS3 composite material at 120°C.

[0033] The component names and reference numerals in the above figures are as follows:

[0034] Positive current collector 1, negative current collector 2, PTFE insulating shell 3, silicone ring 4, all-solid carbon-sulfur-free composite electrode layer 5, solid electrolyte layer 6, negative electrode layer 7. Detailed Implementation

[0035] Specific Implementation Method 1: This implementation method discloses a method for preparing a carbon-sulfur-free composite electrode, the method comprising the following steps:

[0036] Step 1: According to elemental sulfur and M x The mass ratio of NPS3 material is 1:0.1-1. Weigh elemental sulfur and M. x NPS3 material is ground (by hand or ball mill) and mixed evenly, then sealed in a high-temperature resistant quartz tube under an inert atmosphere (such as argon or nitrogen) and heated at 100-750℃ for 1-48 hours.

[0037] Step 2: Add sulfide solid electrolyte to the powder material obtained in Step 1, with a mass ratio of powder material to sulfide solid electrolyte of 1:0.1-1; and grind (hand-grind or ball-mill) for 1-24 hours to obtain carbon-sulfur-free composite cathode material;

[0038] Step 3: Disperse the carbon-sulfur-free composite cathode material obtained in Step 2 evenly in a circular mold, and hot press it at 90℃ and 200MPa for 2-60 minutes to obtain a fully solid-state carbon-sulfur-free composite electrode.

[0039] Furthermore, in step one, the M... x NPS3 material is prepared by vacuum solid-state sintering of a mixture of metallic N powder, red phosphorus powder, elemental sulfur powder, and MCl material in a quartz tube at a sintering temperature of 750℃ for 12-120 hours; the N in the metallic N powder is one of Ni, Fe, and Co, and the M in the MCl material is one of Li, Na, and Cu, with x = 0.01-0.5.

[0040] Furthermore, the molar ratio of the metallic N powder, red phosphorus powder, elemental sulfur powder, and MCl material is 1:1:3:0.01-0.5.

[0041] Furthermore, in step two, the sulfide solid electrolyte is LGPS or Li7P3S. 11 , β-Li3PS4, Li7P2S8I, Li4PS4I, Li6PS5Cl x Li6PS5I y Li6PS5Br z One of them, where x, y, z = 0-1.

[0042] Specific Embodiment Two: This embodiment discloses a method for preparing a high-temperature all-solid-state battery. The high-temperature all-solid-state battery includes a positive electrode layer, a solid electrolyte layer 6, and a negative electrode layer 7. The positive electrode layer includes an all-solid-state carbon-sulfur-free composite electrode prepared by the method described in Specific Embodiment One. The method for preparing the high-temperature all-solid-state battery includes the following steps:

[0043] Step 1: In the mold used to prepare the all-solid-state carbon-sulfur-free composite electrode, uniformly disperse 5-100 mg / cm³ of the mixture on the surface of the all-solid-state carbon-sulfur-free composite electrode. 2 Sulfide solid electrolyte powder is hot-pressed at 90℃ and 300MPa for 2-60 minutes to obtain an all-solid carbon-sulfur-free composite electrode layer 5 (positive electrode layer) and a solid electrolyte layer 6 (electrolyte composite sheet).

[0044] Step 2: A high-melting-point lithium boron, lithium aluminum, or lithium silicon alloy sheet is attached as the negative electrode layer 7 to the surface of the solid electrolyte layer 6. After hot pressing at 60°C and 50MPa for 2-60 minutes, an all-solid-state battery composite cell is obtained.

[0045] Step 3: Seal the all-solid-state battery composite cells in a high-temperature resistant solid-state battery mold and pressurize them to 0.5-100MPa to obtain a high-temperature all-solid-state battery.

[0046] Furthermore, in step one, the thickness of the all-solid carbon-sulfur-free composite electrode layer 5 is 10-100 μm, and the thickness of the solid electrolyte layer 6 is 10-100 μm.

[0047] Furthermore, in step one, the sulfide solid electrolyte powder is the same electrolyte used in the all-solid carbon-sulfur-free composite electrode.

[0048] Furthermore, in step two, the thickness of the negative electrode layer 7 is 10-100 μm.

[0049] Furthermore, in step three, the high-temperature resistant solid-state battery mold includes a PTFE insulating shell 3, two stainless steel current collectors, and two silicone rings 4; the two stainless steel current collectors are the positive current collector 1 and the negative current collector 2, respectively. The all-solid-state battery composite cell is placed inside the PTFE insulating shell 3. The all-solid-state carbon-sulfur-free composite electrode layer 5 of the all-solid-state battery composite cell is sealed with the positive current collector 1 and the negative current collector 2 respectively through the silicone rings 4. The two silicone rings 4 are installed inside the PTFE insulating shell 3, and the positive current collector 1 and the negative current collector 2 are threadedly connected to the inner wall of the PTFE insulating shell 3 respectively.

[0050] The integrated high-temperature all-solid-state battery operates at a temperature of 100-150℃.

[0051] Example 1:

[0052] This embodiment discloses a method for preparing a carbon-sulfur-free composite electrode, the method comprising the following steps:

[0053] Step 1: Weigh out metallic iron powder, red phosphorus powder, elemental sulfur powder, and LiCl material in a molar ratio of 1:1:3:0.1. Mix the above materials evenly and then vacuum seal them in a quartz tube. Sinter at 750℃ for 48 hours to obtain LiCl. 0.1 FePS3 material was ground into a uniform powder; elemental sulfur and Li were weighed in a mass ratio of 1:1. 0.1 FePS3 material was mixed evenly by hand or ball milling, then sealed in a high-temperature resistant quartz tube under an inert atmosphere (argon or nitrogen) and heated at 150°C for 10 hours to obtain S@Li. 0.1 FePS3 composite powder material;

[0054] Step 2: Weigh 1g of the S@Li obtained in Step 1 0.1 FePS3 composite powder material was mixed with an equal amount of Li3PS4 sulfide solid electrolyte and ball-milled at 300 rpm for 6 hours to obtain a carbon-sulfur-free composite cathode material, wherein S@Li 0.1 The mass ratio of FePS3 composite material to Li3PS4 sulfide is 1:1;

[0055] Step 3: Weigh 15mg of the carbon-sulfur-free composite cathode material obtained in Step 2, disperse it evenly in a circular mold with a diameter of 20mm, and hot-press it at 90℃ and 200MPa for 30 minutes to obtain a fully solid carbon-sulfur-free composite electrode.

[0056] Example 2:

[0057] This embodiment discloses a method for preparing a high-temperature all-solid-state battery, the method comprising the following steps:

[0058] Step 1: In the circular mold of Step 3 of Example 1, 100mg of Li3PS4 sulfide solid electrolyte powder is uniformly dispersed on the surface of the prepared all-solid carbon-sulfur-free composite electrode. After hot pressing at 90℃ and 300MPa for 30 minutes, the all-solid carbon-sulfur-free composite electrode layer 5 (positive electrode layer) and solid electrolyte layer 6 (electrolyte composite sheet) are obtained.

[0059] Step 2: A lithium boron alloy sheet with a diameter of 18 mm and a thickness of 30 μm is attached as the negative electrode layer 7 to the surface of the all-solid electrolyte layer 6 obtained in Step 1. After hot pressing at 60°C and 50 MPa for 30 minutes, an all-solid battery composite cell is obtained.

[0060] Step 3: Seal the all-solid-state battery composite cell assembly obtained in Step 2 into a high-temperature resistant solid-state battery mold, tighten the threads, and obtain a high-temperature all-solid-state battery.

[0061] Figure 1 The S@Li obtained in Example 1 of this embodiment 0.1 A schematic diagram of the redox reaction in FePS3 composite materials, as shown below. Figure 1 As shown, due to the extremely low ionic and electronic conductivity of sulfur and lithium sulfide, the redox reaction in the carbon-sulfur composite electrode only occurs at the three-phase interface, resulting in a large internal resistance. S@Li 0.1 Li in FePS3 composite electrode 0.1 FePS3 can simultaneously transport ions and electrons, increasing the area of ​​the sulfur redox reaction zone and improving ion transport and charge transfer within the solid electrode.

[0062] Figure 2 This is a schematic diagram of the high-temperature resistant all-solid-state battery cell and mold obtained in Example 2, as shown below. Figure 2 As shown, this high-temperature resistant all-solid-state battery is made of S@Li 0.1 The electrode is composed of FePS3 composite electrode, Li3PS4 solid electrolyte layer, and lithium boron alloy. Stainless steel is used as positive and negative current collectors, silicone ring is used as mold seal, and PTFE material is used as insulating shell.

[0063] Figure 3 The S@Li obtained in Example 1 of this embodiment 0.1 SEM images of FePS3 composite materials, as shown Figure 3 As shown, sulfur is uniformly dispersed in Li 0.1 FePS3 surface, forming S@Li 0.1 FePS3 composite material.

[0064] Figure 4 The images show SEM cross-sectional views of the carbon-sulfur-free composite electrode obtained in Example 1 and the solid electrolyte layer obtained in Example 2, as shown. Figure 4 As shown, dense S@Li is formed after hot pressing. 0.1 FePS3 composite electrode layer and sulfide solid electrolyte layer.

[0065] Figure 5 The S@Li obtained in Example 2 of this embodiment 0.1 Cycling performance of all-solid-state batteries made of FePS3 composite material at 120°C, such as Figure 5 As shown, carbon-free S@Li 0.1 The FePS3 composite electrode high-temperature battery exhibits a high initial discharge capacity (1245 mAh g). -1 After 35 cycles, the capacity retention rate of the first-generation battery is 96.7%; while the carbon-sulfur composite electrode battery has a lower discharge capacity, with a capacity retention rate of only 77.5% after 35 cycles.

[0066] Example 3:

[0067] This embodiment discloses a method for preparing a carbon-sulfur-free composite electrode, the method comprising the following steps:

[0068] Step 1: Weigh out nickel powder, red phosphorus powder, elemental sulfur powder, and CuCl material in a molar ratio of 1:1:3:0.05. Mix the above materials evenly and then vacuum seal them in a quartz tube. Sinter at 750℃ for 24 hours to obtain CuCl. 0.05 NiPS3 material was ground into a uniform powder; elemental sulfur and Cu were weighed in a mass ratio of 1:0.8. 0.05 NiPS3 material was mixed evenly by hand or ball milling, then sealed in a high-temperature resistant quartz tube under an inert atmosphere (argon or nitrogen) and heated at 150°C for 8 hours to obtain S@Cu. 0.05 NiPS3 composite powder material;

[0069] Step 2: Weigh 1.5 g of the S@Cu obtained in Step 1. 0.05 NiPS3 composite powder material, with an equal amount of Li7P3S added to it. 11 A sulfide solid electrolyte was ball-milled at 400 rpm for 5 hours to obtain a carbon-sulfur-free composite cathode material, in which S@Cu 0.05 NiPS3 composite material and Li7P3S 11 The mass ratio of sulfides is 1:1;

[0070] Step 3: Weigh 20mg of the carbon-sulfur-free composite cathode material obtained in Step 3, disperse it evenly in a circular mold with a diameter of 25mm, and hot press it at 90℃ and 200MPa for 20 minutes to obtain a fully solid carbon-sulfur-free composite electrode.

[0071] Example 4:

[0072] This embodiment discloses a method for preparing a high-temperature all-solid-state battery, the method comprising the following steps:

[0073] Step 1: In the circular mold of Step 3 in Example 3, 120 mg of Li7P3S is uniformly dispersed on the surface of the prepared all-solid-state carbon-sulfur-free composite electrode. 11 The sulfide solid electrolyte was hot-pressed at 90℃ and 300MPa for 15 minutes to obtain an all-solid carbon-free sulfur composite electrode layer 5 (positive electrode layer) and a solid electrolyte layer 6 (electrolyte composite sheet).

[0074] Step 2: A lithium-aluminum alloy sheet with a diameter of 22 mm and a thickness of 25 μm is attached to the surface of the solid electrolyte layer 6 obtained in Step 1. After hot pressing at 60°C and 50 MPa for 30 minutes, an all-solid-state battery composite cell is obtained.

[0075] Step 3: Seal the all-solid-state battery composite cell assembly obtained in Step 2 into a high-temperature resistant solid-state battery mold, tighten the threads, and obtain a high-temperature all-solid-state battery.

[0076] S@Cu obtained in Example 3 0.05 NiPS3 composite electrode, in Example 4, using the S@Cu obtained in Example 3. 0.05 NiPS3 composite electrode as positive electrode layer, Li7P3S 11 The high-temperature all-solid-state battery, using a sulfide solid electrolyte layer and a lithium-aluminum alloy as the negative electrode layer, exhibits a capacity of 1137 mAh g at 110°C. -1 It has a high initial discharge capacity and a capacity retention rate of 93.2% after 35 cycles.

[0077] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a carbon-sulfur-free composite electrode, characterized in that: The method includes the following steps: Step 1: According to elemental sulfur and M x The mass ratio of NPS3 material is 1:0.1-1. Weigh elemental sulfur and M. x NPS3 material was ground and mixed evenly, then sealed in a high-temperature resistant quartz tube under an inert atmosphere and heated at 100-750℃ for 1-48 hours; M... x NPS3 material is prepared by vacuum solid-state sintering of a mixture of metallic N powder, red phosphorus powder, elemental sulfur powder, and MCl material in a quartz tube at a sintering temperature of 750℃ for 12-120 hours. The N in the metallic N powder is one of Ni, Fe, or Co, and the M in the MCl material is one of Li, Na, or Cu, with x = 0.01-0.

5. The molar ratio of the metallic N powder, red phosphorus powder, elemental sulfur powder, and MCl material is 1:1:3:0.01-0.

5. Step 2: Add sulfide solid electrolyte to the powder material obtained in Step 1, with a mass ratio of powder material to sulfide solid electrolyte of 1:0.1-1; and grind for 1-24 hours to obtain carbon-sulfur-free composite cathode material; Step 3: Disperse the carbon-sulfur-free composite cathode material obtained in Step 2 evenly in a circular mold, and hot press it at 90℃ and 200MPa for 2-60 minutes to obtain a fully solid-state carbon-sulfur-free composite electrode.

2. The method for preparing a carbon-sulfur-free composite electrode according to claim 1, characterized in that: In step two, the sulfide solid electrolyte is LGPS or Li7P3S. 11 , β-Li3PS4, Li7P2S8I, Li4PS4I, Li6PS5Cl x Li6PS5I y Li6PS5Br z One of them, where x, y, z = 0-1.

3. A method for preparing a high-temperature all-solid-state battery, characterized in that: The high-temperature all-solid-state battery includes a positive electrode layer, a solid electrolyte layer (6), and a negative electrode layer (7). The positive electrode layer includes an all-solid-state carbon-sulfur-free composite electrode prepared by the method described in any one of claims 1-2. The preparation method of the high-temperature all-solid-state battery includes the following steps: Step 1: In the mold used to prepare the all-solid-state carbon-sulfur-free composite electrode, uniformly disperse 5-100 mg / cm³ of the mixture on the surface of the all-solid-state carbon-sulfur-free composite electrode. 2 Sulfide solid electrolyte powder is hot-pressed at 90℃ and 300MPa for 2-60 minutes to obtain an all-solid carbon-sulfur-free composite electrode layer (5) and a solid electrolyte layer (6). Step 2: A high-melting-point lithium boron, lithium aluminum or lithium silicon alloy sheet is attached as the negative electrode layer (7) to the surface of the solid electrolyte layer (6). After hot pressing at 60°C and 50MPa for 2-60 minutes, an all-solid-state battery composite cell is obtained. Step 3: Seal the all-solid-state battery composite cells in a high-temperature resistant solid-state battery mold and pressurize them to 0.5-100MPa to obtain a high-temperature all-solid-state battery.

4. The method for preparing a high-temperature all-solid-state battery according to claim 3, characterized in that: In step one, the thickness of the all-solid carbon-sulfur-free composite electrode layer (5) is 10-100 μm, and the thickness of the solid electrolyte layer (6) is 10-100 μm.

5. The method for preparing a high-temperature all-solid-state battery according to claim 3, characterized in that: In step one, the sulfide solid electrolyte powder is the same as the electrolyte used in the all-solid carbon-sulfur-free composite electrode.

6. The method for preparing a high-temperature all-solid-state battery according to claim 3 or 4, characterized in that: In step two, the thickness of the negative electrode layer (7) is 10-100 μm.

7. The method for preparing a high-temperature all-solid-state battery according to claim 3, characterized in that: In step three, the high-temperature resistant solid-state battery mold includes a PTFE insulating shell (3), two stainless steel current collectors and two silicone rings (4); the two stainless steel current collectors are the positive current collector (1) and the negative current collector (2), the all-solid-state battery composite cell is placed inside the PTFE insulating shell (3), the all-solid-state carbon-sulfur-free composite electrode layer (5) of the all-solid-state battery composite cell is sealed with the positive current collector (1) and the negative current collector (2) respectively by silicone rings (4), the two silicone rings (4) are installed inside the PTFE insulating shell (3), and the positive current collector (1) and the negative current collector (2) are threaded to the inner wall of the PTFE insulating shell (3) respectively.

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