Preparation method and application of high-power-density all-solid-state supercapacitor negative electrode material

Abstract

The application relates to a preparation method and application of a high-power-density all-solid-state supercapacitor negative material, and the method is characterized in that Ti3AlC2 and double fluorine salt are used as raw materials to in-situ synthesize multi-layer Ti3C2(OH) with hexagonal holes through high pressure x F y Then, carbon quantum dots are used as microwave sensitizing agents to prepare few-layer / single-layer products through a microwave-assisted chemical exfoliation method; the products are assembled into all-solid-state supercapacitors together with ZnMn2O4 positive electrodes and Zn3(PO4)2 solid-state electrolytes. Through the double innovation of double fluorine salt high-pressure in-situ pore forming and carbon quantum dot microwave sensitization exfoliation, the ion diffusion rate of the material is increased to 3-5 times that of traditional Ti3C2, and the electronic transmission efficiency is increased to 4-6 times, the prepared capacitor has a power density of greater than or equal to 6000 W / kg, can support a rescue unmanned aerial vehicle to realize a maximum load of 40-50 kg, 3-5 seconds from 0 to 120 km / h acceleration, and solve the problems of load limitation and lagging of mobile response caused by traditional materials.

Description

Technical Field

[0001] This invention belongs to the technical field of all-solid-state supercapacitor electrode materials, and relates to a preparation method and application of a high power density all-solid-state supercapacitor anode material, particularly to a preparation method of a high power density all-solid-state supercapacitor anode material, and the application of this anode material in a high-load rescue drone power system. Background Technology

[0002] As core equipment in the field of emergency rescue, rescue drones can perform functions such as personnel detection in complex terrain, delivery of rescue supplies, and emergency communication relay. Their core flight performance and operational capabilities are directly determined by the performance of the power system. All-solid-state supercapacitors have become the preferred power source for high-payload rescue drones due to their advantages such as high power density, long cycle life, wide operating temperature range, and no risk of electrolyte leakage. The power density of supercapacitors is dominated by the electron transport efficiency and ion diffusion rate of the electrode materials.

[0003] Ti3C2, a material in the MXene series, has become a research hotspot for supercapacitor anode materials due to its excellent conductivity, abundant surface functional groups, and two-dimensional layered structure. However, traditional Ti3C2-based anode materials suffer from problems such as severe interlayer stacking, short ion transport paths, and low differential charge density, which limit their power density and make it difficult to exceed 4000 W / kg. Rescue drones equipped with all-solid-state supercapacitors made of this type of material can only achieve a payload of 25-30 kg, and their maneuverability is slow, requiring 8-10 seconds to accelerate from 0 to 120 km / h. In complex rescue scenarios such as mountains and urban ruins, they are prone to problems such as delayed attitude adjustment, failure to avoid obstacles, and missed rescue windows.

[0004] To improve the power density of Ti3C2-based anode materials, current methods often employ single etching to prepare few-layer / monolayer Ti3C2. However, this method suffers from drawbacks such as poor pore formation, insufficient nanosheet exfoliation, and limited improvement in electron transport capability. Furthermore, the poor compatibility between the positive and negative electrode materials and the solid electrolyte in traditional all-solid-state supercapacitors further restricts the power output of the power system. Therefore, developing a Ti3C2-based anode material with high electron transport efficiency, high ion diffusion rate, and high compatibility with both the positive and negative electrodes and the solid electrolyte is crucial for addressing the limitations of payload and maneuverability in high-payload rescue drones. Summary of the Invention

[0005] The technical problem to be solved by this invention is to provide a method for preparing and applying a high power density all-solid-state supercapacitor anode material. This method prepares a few-layer / monolayer Ti3C2(OH) with a hexagonal porous structure by high-pressure in-situ pore formation with difluoride salt and microwave-assisted exfoliation with carbon quantum dots sensitized by the process. x F yThis significantly improves the electron transport efficiency and ion diffusion rate of the material; at the same time, a highly matched all-solid-state device system is designed to achieve a power density of ≥6000W / kg for the power system, effectively supporting the high payload and high maneuverability response requirements of rescue drones.

[0006] The technical solution of this invention is: A method for preparing a negative electrode material for a high power density all-solid-state supercapacitor, the specific steps of which are as follows: Step 1: High-pressure in-situ synthesis of hexagonal porous multilayer Ti3C2(OH) x F y (HP-ML-Ti3C2(OH,F)) Ti3AlC2 powder and a mixture of difluoride salt powder were added to a high-pressure reactor at a molar ratio of 1:4 to 1:6. The difluoride salt was a mixture of NH4HF2 and NaHF2 powder at a mass ratio of 1:1 to 1:2. Deionized water was added to make the solid-liquid mass-volume ratio 1:50 to 1:80 g / mL. After sealing, the reactor was heated to 180℃ to 220℃ and reacted at a constant temperature and pressure of 3.0MPa to 5.0MPa for 12h to 20h. After the reaction was completed, the reactor was naturally cooled to room temperature, centrifuged, washed, dried, and ground to obtain HP-ML-Ti3C2(OH,F) powder. Step 2: Prepare a carbon quantum dot-sensitized microwave-assisted etching system NH4F, choline chloride, and oxalic acid were dissolved in deionized water at a mass ratio of 2:3:1 to prepare an etching solution with a total concentration of 1.0 mol / L to 1.5 mol / L. Carbon quantum dots were added to the etching solution at a mass ratio of 0.5% to 1.0% of the total mass of the etching solution. The solution was ultrasonically dispersed for 20 to 30 minutes to obtain a microwave-assisted etching system sensitized with carbon quantum dots. Step 3: Microwave-assisted chemical exfoliation to prepare hexagonal porous few-layer / monolayer Ti3C2(OH) x F y The HP-ML-Ti3C2(OH,F) powder prepared in step one was added to the etching system in step two at a solid-liquid mass-to-volume ratio of 1:100 to 1:150 g / mL. After stirring at room temperature for 30 to 60 minutes, the mixture was transferred to a microwave synthesizer and subjected to microwave exfoliation reaction at a power of 400 W to 600 W, a frequency of 2.45 GHz, and a temperature of 100 °C to 140 °C for 30 to 60 minutes. After the reaction, the mixture was centrifuged, washed until the pH value was 6 to 7, freeze-dried, and graded and ground to obtain hexagonal porous few-layer Ti3C2(OH) powder. x F y (HP-FL-Ti3C2(OH,F)) and hexagonal porous monolayer Ti3C2(OH) x F y(HP-SL-Ti3C2(OH,F)) powder is used to obtain the negative electrode material of the all-solid-state supercapacitor.

[0007] Furthermore, the Ti3AlC2 powder in step one has a particle size of 200-300 mesh, a drying temperature of 60-80℃, and a drying time of 12-16 hours.

[0008] Furthermore, the carbon quantum dots mentioned in step two are carbon quantum dots with a particle size of 5nm to 10nm synthesized by hydrothermal synthesis of citric acid-ethylenediamine.

[0009] Furthermore, the centrifugation speed in steps one and three is 8000 r / min to 10000 r / min, and the centrifugation time is 10 min to 15 min; in step three, the freeze-drying temperature is -40℃ to -60℃, and the freeze-drying time is 24 h to 36 h; the graded grinding is carried out through 200 mesh and 500 mesh standard sieves to separate the few-layer and single-layer products.

[0010] Furthermore, during the graded grinding process, the material remaining on the 200-mesh standard sieve is a small layer of Ti3C2(OH). x F y The undersize material on a 500-mesh standard sieve is a single layer of Ti3C2(OH). x F y The few-layer Ti3C2(OH) x F y It consists of 2 to 10 layers of Ti3C2(OH) x F y The hexagonal porous structure formed by stacked nanosheets, wherein the monolayer Ti3C2(OH) x F y (A monolayer of Ti3C2(OH)) x F y The hexagonal porous structure formed by nanosheets.

[0011] Application of a negative electrode material obtained by the above preparation method in an all-solid-state supercapacitor.

[0012] Furthermore, the few-layer Ti3C2(OH) x F y And monolayer Ti3C2(OH) x F y Mix them in a mass ratio of 1:1 to 2:1 as negative electrode active materials, and assemble them with ZnMn2O4 positive electrode material and Zn3(PO4)2 solid electrolyte to form an all-solid-state supercapacitor.

[0013] Further, the negative electrode preparation steps are as follows: the negative electrode active material, acetylene black and PVDF are mixed in a mass ratio of 8:1:1, NMP is added to make a slurry, which is uniformly coated on the surface of titanium foil, rolled flat and then vacuum dried at 80℃~100℃ for 12h~16h to obtain the negative electrode. The positive electrode preparation steps are as follows: ZnMn2O4, acetylene black and PVDF are mixed in a mass ratio of 8:1:1, NMP is added to make a slurry, which is then uniformly coated on the surface of titanium foil, rolled flat and then vacuum dried at 80℃~100℃ for 12h~16h to obtain the positive electrode.

[0014] Furthermore, the all-solid-state supercapacitor is applied to power systems with high power density requirements, such as high-load rescue drones, new energy vehicles, and energy storage power stations, where the power density of the power system is ≥6000W / kg.

[0015] Furthermore, when applied to the power system of high-load rescue drones, the drone equipped with this capacitor has a maximum payload capacity of 40-50 kg and a maneuver response time of 3-5 seconds to accelerate from 0 to 120 km / h.

[0016] Beneficial effects of the present invention This invention, through process innovation and device system design, achieves a significant increase in the power density of the negative electrode material of all-solid-state supercapacitors, and compared with existing technologies, it has the following core beneficial effects: 1. High-pressure in-situ pore formation with difluoride salts to improve intrinsic material properties: Using NH4HF2 and NaHF2 difluoride salts as fluorine sources, they react in situ with Ti3AlC2 under high pressure to form hexagonal porous multilayer Ti3C2(OH)2. x F y The hexagonal porous structure increases the specific surface area and ion transport channels of the material, while also improving the differential charge density, which increases the ion diffusion rate to 3 to 5 times that of traditional Ti3C2, laying the material foundation for improving power density. 2. Carbon quantum dot-sensitized microwave exfoliation for efficient layering: Using carbon quantum dots as microwave sensitizers, combined with an NH4F + choline chloride + oxalic acid composite etching system, multilayer Ti3C2(OH) is achieved through microwave-assisted chemical exfoliation. x F y The efficient stripping process resulted in few-layer / monolayer products with no significant agglomeration, and the electron transport efficiency was increased to 4 to 6 times that of traditional Ti3C2, solving the problem of insufficient stripping by a single etching method. 3. High-matching all-solid-state device system for high-efficiency power output: A high-matching system of HP-FL / HP-SL-Ti3C2(OH,F) anode, ZnMn2O4 cathode, and Zn3(PO4)2 solid electrolyte was designed. The three components have low interfacial impedance and high ion conduction matching, which effectively avoids power loss caused by interfacial polarization. The power density of the prepared all-solid-state supercapacitor is ≥6000W / kg, which is much higher than the 4000W / kg of traditional materials. 4. Precisely match the needs of high-payload rescue drones and enhance rescue operation capabilities: The rescue drone equipped with the all-solid-state supercapacitor of this invention has increased its maximum payload capacity from 25-30kg to 40-50kg, and can carry more rescue supplies and detection equipment; the maneuver response time is shortened from 8-10 seconds to 3-5 seconds, and it can quickly adjust its attitude and avoid obstacles in complex terrain, effectively seize the rescue window, and greatly improve the efficiency and success rate of emergency rescue operations. Attached Figure Description

[0017] Figure 1 This is a process flow diagram of the preparation of the all-solid-state supercapacitor negative electrode material and device in Embodiment 3 of the present invention; Figure 2 This refers to the microwave-assisted chemical exfoliation method used in Example 3 of the present invention to prepare hexagonal porous few-layer / monolayer Ti3C2(OH) material. x F y Schematic diagram; Figure 3 This is a SEM image of a hexagonal porous few-layer Ti3C2(OH,F) nanosheet prepared by microwave-assisted chemical exfoliation in Example 3 of the present invention. The scale bar is 1 μm. It can be seen that the interlayer spacing of the Ti3C2(OH,F) nanosheets is 20-50 nm, and there is no obvious aggregation. Figure 4 The CV curve of the all-solid-state supercapacitor assembled with the negative electrode material in Embodiment 3 of the present invention is shown. The scan rate is 100mV / s. The curve has redox peaks, indicating that it has pseudocapacitive characteristics. Figure 5 This is a comparison diagram of the differential charge density between the hexagonal porous few-layer / monolayer Ti3C2(OH,F) and the conventional Ti3C2 in Embodiment 3 of the present invention. The red area is the electron enrichment area, and the electron enrichment area of ​​the hexagonal porous few-layer / monolayer Ti3C2(OH,F) is 3 to 4 times that of the conventional Ti3C2. Figure 6 This is a bar chart showing the power density of all-solid-state supercapacitors in Examples 1-3 and Comparative Examples 1-3 of the present invention. The power density of the examples is 6200-7100W / kg, and that of the comparative examples is 3800-4900W / kg. Detailed Implementation

[0018] The technical solution of the present invention will be described in detail below through specific embodiments. These embodiments are only for explaining the present invention and are not intended to limit the scope of protection of the present invention. The raw materials used in the present invention are all commercially available conventional raw materials, with no special requirements. Example

[0019] 1. High-pressure in-situ synthesis of hexagonal porous multilayer Ti3C2(OH) x F y (HP-ML-Ti3C2(OH,F)) Ti3AlC2 powder (200-300 mesh) and a mixture of difluoride salt powder (NH4HF2:NaHF2 = 1:1-1:2, mass ratio) were added to a high-pressure reactor at a molar ratio of 1:4-1:6. Deionized water was added to achieve a solid-liquid mass-to-volume ratio of 1:50-1:80 g / mL. After sealing the reactor, the temperature was increased to 180-220°C at a rate of 5°C / min, and the reaction was carried out under constant temperature and pressure of 3.0-5.0 MPa for 12-20 hours. After the reaction, the mixture was allowed to cool naturally to room temperature at a rate of 2-3°C / min. The reactor is a stainless steel reactor lined with polytetrafluoroethylene. During the reaction, the difluorosalt dissociates into hydrated cations and adsorbs onto the negatively charged Ti3AlC2 nanosheets. At the same time, the released H2 impacts the vacancy defects of Ti3AlC2, forming a standard hexagonal porous structure in situ. After centrifugation at 8000r / min~10000r / min for 10min~15min, the supernatant is removed, and the mixture is washed 3~5 times alternately with deionized water and anhydrous ethanol. After drying at 60℃~80℃ for 12h~16h, the mixture is ground to obtain HP-ML-Ti3C2(OH,F) powder. 2. Preparation of a microwave-assisted etching system sensitized with carbon quantum dots NH4F, choline chloride, and oxalic acid were dissolved in deionized water at a mass ratio of 2:3:1 to prepare an etching solution with a total concentration of 1.0 mol / L to 1.5 mol / L. 0.5% to 1.0% (total mass of the etching solution) of carbon quantum dots (preferably carbon quantum dots synthesized hydrothermally from citric acid and ethylenediamine, with a mass ratio of citric acid to ethylenediamine of 4:1, subjected to hydrothermal reaction at 180°C for 6 hours, and centrifuged and washed to obtain carbon quantum dots with a particle size of 5 nm to 10 nm) were added to the etching solution. The solution was then ultrasonically dispersed at 300 W for 20 to 30 minutes to obtain a microwave-assisted etching system sensitized with carbon quantum dots. Carbon quantum dots, as a microwave sensitizer, can improve the absorption efficiency of microwave energy and promote the exfoliation of Ti3C2 nanosheets. 3. Microwave-assisted chemical exfoliation for the preparation of hexagonal porous few-layer / monolayer Ti3C2(OH) x F y The HP-ML-Ti3C2(OH,F) powder prepared in step 1 was added to the above etching system at a solid-liquid mass-to-volume ratio of 1:100 to 1:150 g / mL. The mixture was magnetically stirred at room temperature for 30 to 60 minutes to ensure thorough dispersion. The solution was then transferred to a microwave synthesizer and subjected to microwave-assisted chemical exfoliation at a power of 400 W to 600 W, a frequency of 2.45 GHz, and a temperature of 100 °C to 140 °C for 30 to 60 minutes. After the reaction, the mixture was centrifuged at 8000 r / min to 10000 r / min for 10 to 15 minutes, washed until the pH of the dispersion reached 6 to 7, and then freeze-dried at -40 °C to -60 °C for 24 to 36 hours. The resulting product was then graded and ground through 200-mesh and 500-mesh standard sieves. The material remaining on the 200-mesh standard sieve was hexagonal porous few-layer Ti3C2(OH). x F y (HP-FL-Ti3C2(OH,F)) (2-10 layers of stacked nanosheets), the undersize material on a 500-mesh standard sieve is a hexagonal porous monolayer Ti3C2(OH). x F y (HP-SL-Ti3C2(OH,F)) (single-layer nanosheet) is the negative electrode material of the all-solid-state supercapacitor of this invention.

[0020] This invention also discloses the application of the above-mentioned negative electrode material in an all-solid-state supercapacitor, specifically: HP-FL-Ti3C2(OH,F) and HP-SL-Ti3C2(OH,F) are mixed at a mass ratio of 1:1 to 2:1 as the negative electrode active material, and combined with ZnMn2O4 positive electrode material and Zn3(PO4)2 solid electrolyte, and the all-solid-state supercapacitor is assembled according to the following steps: 1. Preparation of negative electrode sheet: The negative electrode active material, acetylene black and PVDF are mixed in a mass ratio of 8:1:1. NMP is added and stirred slowly until a uniform slurry is formed. The slurry is uniformly coated on the surface of titanium foil (coating area 4cm×30cm). After being rolled flat, it is vacuum dried at 80℃~100℃ for 12h~16h to obtain the negative electrode sheet. 2. Preparation of positive electrode sheet: ZnMn2O4, acetylene black and PVDF are mixed in a mass ratio of 8:1:1. NMP is added and stirred slowly until a uniform slurry is formed. The slurry is uniformly coated on the surface of titanium foil (coating area 4cm×30cm). After being rolled flat, it is vacuum dried at 80℃~100℃ for 12h~16h to obtain the positive electrode sheet. 3. Device assembly: The negative electrode, Zn3(PO4)2 solid electrolyte membrane (thickness 150μm~180μm) and positive electrode are aligned and stacked in sequence, and hot-pressed at 10MPa~15MPa pressure and 60℃~80℃ for 30min~60min. After encapsulation, an all-solid-state supercapacitor is obtained.

[0021] The all-solid-state supercapacitor prepared by this invention is specifically designed for the power system of high-load rescue drones. The power system has a power density of ≥6000W / kg and can support the rescue drone to achieve a maximum load capacity of 40-50kg and a high-speed maneuver response of 3-5 seconds from 0 to 120km / h.

[0022] Example 1 1. High-pressure in-situ synthesis of HP-ML-Ti3C2(OH,F) 10 g of 200 mesh Ti3AlC2 powder and a mixture of difluoride salt powder (NH4HF2:NaHF2 = 1:1, mass ratio) were added to a high-pressure reactor at a molar ratio of 1:4. Deionized water was added to make the solid-liquid (based on the solid phase) mass-to-volume ratio of Ti3AlC2 powder and difluoride salt mixture 1:50 g / mL. After sealing, the temperature was increased to 180℃ at a heating rate of 5℃ / min and reacted at 3.0 MPa for 12 h. After natural cooling at a rate of 2-3℃ / min, the mixture was centrifuged at 8000 r / min for 10 min, washed three times alternately with deionized water and anhydrous ethanol, dried at 60℃ for 12 h, and ground to obtain HP-ML-Ti3C2(OH,F) powder. 2. Preparation of carbon quantum dot sensitized etching system An etching solution with a total molar concentration of 1.0 mol / L was prepared by dissolving NH4F, choline chloride, and oxalic acid in deionized water at a mass ratio of 2:3:1. 0.5% (by mass of the etching solution) of carbon quantum dots (preferably carbon quantum dots synthesized hydrothermally from citric acid and ethylenediamine, with a mass ratio of citric acid to ethylenediamine of 4:1, subjected to hydrothermal reaction at 180℃ for 6 hours, and centrifuged and washed to obtain carbon quantum dots with a particle size of 5 nm) was added. The mixture was then ultrasonically dispersed at 300 W for 20 minutes at room temperature to obtain the etching system. 3. Microwave-assisted exfoliation for the preparation of few-layer / monolayer products HP-ML-Ti3C2(OH,F) powder was added to the etching system at a solid-liquid mass-to-volume ratio of 1:100 g / mL. After stirring at room temperature for 30 min, the mixture was transferred to a microwave synthesizer and microwaved at 400 W, 2.45 GHz, and 100 °C for 30 min. The mixture was then centrifuged at 8000 r / min for 10 min, washed until pH=6, and freeze-dried at -40 °C for 24 h. The mixture was then graded and ground through 200-mesh and 500-mesh standard sieves. The material remaining on the 200-mesh sieve was a hexagonal porous, few-layer Ti3C2(OH) powder. x F y (HP-FL-Ti3C2(OH,F)) (2-10 layers of stacked nanosheets), the undersize material on a 500-mesh standard sieve is a hexagonal porous monolayer Ti3C2(OH). x F y(HP-SL-Ti3C2(OH,F)) (monolayer nanosheets) yielded HP-FL-Ti3C2(OH,F) and HP-SL-Ti3C2(OH,F); 4. Assembly and Application of All-Solid-State Supercapacitors HP-FL-Ti3C2(OH,F) and HP-SL-Ti3C2(OH,F) were mixed at a mass ratio of 1:1 to serve as the negative electrode active material. Negative electrode preparation: Negative electrode active material, acetylene black, and PVDF are mixed in a mass ratio of 8:1:1. N-methylpyrrolidone (NMP) is added and stirred slowly to form a uniform slurry with a solid content of 15%wt. The slurry is uniformly coated on the surface of titanium foil (coating area 4cm×30cm), rolled flat, and then vacuum dried at 80℃~100℃ for 12h to obtain the negative electrode. Positive electrode preparation: ZnMn2O4, acetylene black, and PVDF are mixed in a mass ratio of 8:1:1. N-methylpyrrolidone (NMP) is added and stirred slowly to form a uniform slurry with a solid content of 15%wt. The slurry is uniformly coated on the surface of titanium foil (coating area 4cm×30cm), rolled flat, and then vacuum dried at 80℃~100℃ for 12h to obtain the positive electrode. Device assembly: The negative electrode, Zn3(PO4)2 solid electrolyte membrane (150-180μm thick), and positive electrode were sequentially aligned and stacked, and then hot-pressed at 10MPa pressure and 60℃ for 30 minutes. After encapsulation, an all-solid-state supercapacitor was obtained. This capacitor was applied to the power system of a rescue drone, and its performance was tested.

[0023] Example 2 1. High-pressure in-situ synthesis of HP-ML-Ti3C2(OH,F) 10 g of 250 mesh Ti3AlC2 powder and a mixture of difluoride salt powder (NH4HF2:NaHF2 = 1:1.5, mass ratio) were added to a high-pressure reactor at a molar ratio of 1:5. Deionized water was added to make the solid-liquid (based on the solid phase) mass-to-volume ratio of Ti3AlC2 powder and difluoride salt mixture 1:65 g / mL. After sealing, the temperature was increased to 200℃ at a rate of 5℃ / min, and the reaction was carried out at a pressure of 4.0 MPa for 16 h. After natural cooling at a rate of 2-3℃ / min, the mixture was centrifuged at 9000 r / min for 12 min, washed 4 times alternately with deionized water and anhydrous ethanol, dried at 70℃ for 14 h, and ground to obtain HP-ML-Ti3C2(OH,F) powder. 2. Preparation of carbon quantum dot sensitized etching system An etching solution with a total molar concentration of 1.2 mol / L was prepared by dissolving NH4F, choline chloride, and oxalic acid in deionized water at a mass ratio of 2:3:1. 0.75% (by mass of the etching solution) of carbon quantum dots (preferably carbon quantum dots synthesized hydrothermally from citric acid and ethylenediamine, with a mass ratio of citric acid to ethylenediamine of 4:1, subjected to hydrothermal reaction at 180°C for 6 hours, and centrifuged and washed to obtain carbon quantum dots with a particle size of 8 nm) was added. The solution was then ultrasonically dispersed at 300 W for 25 minutes at room temperature to obtain the etching system. 3. Microwave-assisted exfoliation for the preparation of few-layer / monolayer products HP-ML-Ti3C2(OH,F) powder was added to the etching system at a solid-liquid mass-to-volume ratio of 1:125 g / mL. After stirring at room temperature for 45 min, the mixture was transferred to a microwave synthesizer and microwaved at 500 W, 2.45 GHz, and 120 °C for 45 min. The mixture was then centrifuged at 9000 r / min for 12 min, washed until pH=6.5, and freeze-dried at -50 °C for 30 h. The mixture was then graded and ground through 200-mesh and 500-mesh standard sieves. The material remaining on the 200-mesh sieve was a hexagonal porous, few-layer Ti3C2(OH) powder. x F y (HP-FL-Ti3C2(OH,F)) (2-10 layers of stacked nanosheets), the undersize material on a 500-mesh standard sieve is a hexagonal porous monolayer Ti3C2(OH). x F y (HP-SL-Ti3C2(OH,F)) (monolayer nanosheets) yielded HP-FL-Ti3C2(OH,F) and HP-SL-Ti3C2(OH,F); 4. Assembly and Application of All-Solid-State Supercapacitors HP-FL-Ti3C2(OH,F) and HP-SL-Ti3C2(OH,F) were mixed at a mass ratio of 1.5:1 as the negative electrode active material; The negative electrode was prepared in a ratio of 8:1:1, the positive electrode was prepared in a ratio of 8:1:1 using ZnMn2O4, and then combined with a Zn3(PO4)2 solid electrolyte membrane. The mixture was hot-pressed at 12MPa and 70℃ for 45min and then encapsulated to obtain an all-solid-state supercapacitor. Negative electrode preparation: Negative electrode active material, acetylene black, and PVDF are mixed in a mass ratio of 8:1:1. N-methylpyrrolidone (NMP) is added and stirred slowly to form a uniform slurry with a solid content of 15%wt. The slurry is uniformly coated on the surface of titanium foil (coating area 4cm×30cm), rolled flat, and then vacuum dried at 80℃~100℃ for 14h to obtain the negative electrode. Positive electrode preparation: ZnMn2O4, acetylene black, and PVDF are mixed in a mass ratio of 8:1:1. N-methylpyrrolidone (NMP) is added and stirred slowly to form a uniform slurry with a solid content of 15%wt. The slurry is uniformly coated on the surface of titanium foil (coating area 4cm×30cm), rolled flat, and then vacuum dried at 80℃~100℃ for 14h to obtain the positive electrode. Device assembly: The negative electrode, Zn3(PO4)2 solid electrolyte membrane (150-180μm thick), and positive electrode were sequentially aligned and stacked, and then hot-pressed at 12MPa pressure and 70℃ for 45min. After encapsulation, an all-solid-state supercapacitor was obtained. This capacitor was applied to the power system of a rescue drone, and its performance was tested.

[0024] Example 3 1. High-pressure in-situ synthesis of HP-ML-Ti3C2(OH,F) 10 g of 300 mesh Ti3AlC2 powder and a mixture of difluoride salt powder (NH4HF2:NaHF2=1:2, mass ratio) were added to a high-pressure reactor at a molar ratio of 1:6. Deionized water was added to make the solid-liquid (based on the solid phase) mass-to-volume ratio of Ti3AlC2 powder and difluoride salt mixture 1:80 g / mL. After sealing, the temperature was increased to 220℃ at 5℃ / min, and the reaction was carried out at 5.0 MPa for 20 h. After natural cooling at 2-3℃ / min, the mixture was centrifuged at 10000 r / min for 15 min, washed 5 times alternately with deionized water and anhydrous ethanol, dried at 80℃ for 16 h, and ground to obtain HP-ML-Ti3C2(OH,F) powder. 2. Preparation of carbon quantum dot sensitized etching system An etching solution with a total molar concentration of 1.5 mol / L was prepared by dissolving NH4F, choline chloride, and oxalic acid in deionized water at a mass ratio of 2:3:1. 1.0% (by mass of the etching solution) of carbon quantum dots (preferably carbon quantum dots synthesized hydrothermally from citric acid and ethylenediamine, with a mass ratio of citric acid to ethylenediamine of 4:1, subjected to hydrothermal reaction at 180℃ for 6 h, and centrifuged and washed to obtain carbon quantum dots with a particle size of 10 nm) was added. The mixture was then ultrasonically dispersed at 300 W for 30 min at room temperature to obtain the etching system. 3. Microwave-assisted exfoliation for the preparation of few-layer / monolayer products HP-ML-Ti3C2(OH,F) powder was added to the etching system at a solid-liquid mass-to-volume ratio of 1:150 g / mL. After stirring at room temperature for 60 min, the mixture was transferred to a microwave synthesizer and microwaved at 600 W, 2.45 GHz, and 140 °C for 60 min. The mixture was then centrifuged at 10000 r / min for 15 min, washed until pH=7, and freeze-dried at -60 °C for 36 h. The mixture was then graded and ground through 200-mesh and 500-mesh standard sieves. The material passing through the 200-mesh sieve was hexagonal porous few-layer Ti3C2(OH)x F y (HP-FL-Ti3C2(OH,F)) (2-10 layers of stacked nanosheets), the undersize material on a 500-mesh standard sieve is a hexagonal porous monolayer Ti3C2(OH). x F y (HP-SL-Ti3C2(OH,F)) (monolayer nanosheets) yielded HP-FL-Ti3C2(OH,F) and HP-SL-Ti3C2(OH,F); 4. Assembly and Application of All-Solid-State Supercapacitors HP-FL-Ti3C2(OH,F) and HP-SL-Ti3C2(OH,F) were mixed at a mass ratio of 2:1 to serve as the negative electrode active material. Negative electrode preparation: Negative electrode active material, acetylene black, and PVDF are mixed in a mass ratio of 8:1:1. N-methylpyrrolidone (NMP) is added and stirred slowly to form a uniform slurry with a solid content of 15%wt. The slurry is uniformly coated on the surface of titanium foil (coating area 4cm×30cm), rolled flat, and then vacuum dried at 80℃~100℃ for 16h to obtain the negative electrode. Positive electrode preparation: ZnMn2O4, acetylene black, and PVDF are mixed in a mass ratio of 8:1:1. N-methylpyrrolidone (NMP) is added and stirred slowly to form a uniform slurry with a solid content of 15%wt. The slurry is uniformly coated on the surface of titanium foil (coating area 4cm×30cm), rolled flat, and then vacuum dried at 80℃~100℃ for 16h to obtain the positive electrode. Device assembly: The negative electrode, Zn3(PO4)2 solid electrolyte membrane (150-180μm thick), and positive electrode were sequentially aligned and stacked, and then hot-pressed at 15MPa pressure and 80℃ for 60min. After encapsulation, an all-solid-state supercapacitor was obtained. This capacitor was applied to the power system of a rescue drone, and its performance was tested.

[0025] Figure 1 This is a process flow diagram of the fabrication process of the all-solid-state supercapacitor anode material and device in Example 3. This dual innovation of high-pressure in-situ pore formation with difluoride salt and microwave exfoliation with carbon quantum dots not only increases the specific capacitance of the anode material, but also improves the electron transport efficiency and ion diffusion rate of the anode material. Figure 2 This refers to the microwave-assisted chemical exfoliation method used in Example 3 to prepare hexagonal porous few-layer / monolayer Ti3C2(OH)2. x F y Schematic diagram. This provides a new approach for the efficient delamination and peeling of layered materials. Figure 3The image shown in Example 3 is a SEM image of a hexagonal porous multilayer Ti3C2(OH,F) fabricated into a hexagonal porous few-layer Ti3C2(OH,F) by microwave-assisted chemical exfoliation. The large interlayer spacing and high delamination and exfoliation efficiency lay the structural foundation for improving the specific capacitance of the anode material and the diffusion of energy storage ions. Figure 4 This is the CV curve of the all-solid-state supercapacitor assembled with the negative electrode material in Embodiment 3 of this invention. The large specific capacitance indicates that the negative electrode material has a high ion diffusion rate. Figure 5 This is a comparison of the differential charge density of HP-FL / HP-SL-Ti3C2(OH,F) and conventional Ti3C2 in Example 3. Through two-dimensional differential charge density analysis, red represents the probability of electron presence. Compared to conventional Ti3C2, the red area is larger, indicating electron enrichment in Ti3C2HP-FL / HP-SL-Ti3C2(OH,F), resulting in stronger electron transport efficiency.

[0026] Comparative Example 1 (In-situ hole formation without high pressure, direct etching of Ti3AlC2) 1. Preparation of carbon quantum dot sensitized etching system An etching solution with a total molar concentration of 1.5 mol / L was prepared by dissolving NH4F, choline chloride, and oxalic acid in deionized water at a mass ratio of 2:3:1. 1.0% (by mass of the etching solution) of carbon quantum dots (preferably carbon quantum dots synthesized hydrothermally from citric acid and ethylenediamine, with a mass ratio of citric acid to ethylenediamine of 4:1, subjected to hydrothermal reaction at 180℃ for 6 h, and centrifuged and washed to obtain carbon quantum dots with a particle size of 10 nm) was added. The mixture was then ultrasonically dispersed at 300 W for 30 min at room temperature to obtain the etching system. 2. Microwave-assisted exfoliation for the preparation of few-layer / monolayer products Ti3AlC2 powder was added to the etching system at a solid-liquid mass-to-volume ratio of 1:150 g / mL. After stirring at room temperature for 60 min, the mixture was transferred to a microwave synthesizer and microwaved at 600 W, 2.45 GHz, and 140 °C for 60 min. After centrifugation at 10000 r / min for 15 min, the mixture was washed until pH=7 and freeze-dried at -60 °C for 36 h. The mixture was then graded and ground through 200 mesh and 500 mesh standard sieves. The material on the 200 mesh sieve was hexagonal porous few-layer nanosheets, and the material below the 500 mesh standard sieve was monolayer nanosheets.

[0027] This comparative example omits the high-pressure in-situ pore formation step with difluoride salts. Instead, Ti3AlC2 powder is directly added to the carbon quantum dot sensitized etching system of Example 3, and few-layer / single-layer Ti3C2 is prepared using the same microwave lift-off process. The remaining steps are the same as in Example 1. An all-solid-state supercapacitor is assembled and the relevant indicators of the UAV are tested.

[0028] Comparative Example 2 (Carbon-free quantum dot sensitization, conventional microwave exfoliation) 1. High-pressure in-situ synthesis of HP-ML-Ti3C2(OH,F) 10 g of 300 mesh Ti3AlC2 powder and a mixture of difluoride salt powder (NH4HF2:NaHF2=1:2, mass ratio) were added to a high-pressure reactor at a molar ratio of 1:6. Deionized water was added to make the solid-liquid (based on the solid phase) mass-to-volume ratio of Ti3AlC2 powder and difluoride salt mixture 1:80 g / mL. After sealing, the temperature was increased to 220℃ at 5℃ / min, and the reaction was carried out at 5.0 MPa for 20 h. After natural cooling at 2-3℃ / min, the mixture was centrifuged at 10000 r / min for 15 min, washed 5 times alternately with deionized water and anhydrous ethanol, dried at 80℃ for 16 h, and ground to obtain HP-ML-Ti3C2(OH,F) powder. 2. Preparation of a carbon-free quantum dot-sensitized etching system An etching solution with a total molar concentration of 1.5 mol / L was prepared by dissolving NH4F, choline chloride, and oxalic acid in deionized water at a mass ratio of 2:3:1. The solution was then ultrasonically dispersed at 300W for 30 min at room temperature to obtain the etching system. 3. Microwave-assisted exfoliation for the preparation of few-layer / monolayer products HP-ML-Ti3C2(OH,F) powder was added to the etching system at a solid-liquid mass-to-volume ratio of 1:150 g / mL. After stirring at room temperature for 60 min, the mixture was transferred to a microwave synthesizer and microwaved at 600 W, 2.45 GHz, and 140 °C for 60 min. The mixture was then centrifuged at 10000 r / min for 15 min, washed until pH=7, and freeze-dried at -60 °C for 36 h. The mixture was then graded and ground through 200 mesh and 500 mesh standard sieves. The material passing through the 200 mesh sieve was Ti3C2(OH,F), and the material passing through the 500 mesh standard sieve was monolayer Ti3C2(OH,F) (monolayer nanosheets).

[0029] In this comparative example, the addition of carbon quantum dots was omitted when preparing the etching system. The remaining preparation steps were the same as in Example 3, resulting in a few-layer / monolayer Ti3C2(OH,F) without carbon quantum dot sensitization. An all-solid-state supercapacitor was then assembled and the relevant indicators of the UAV were tested.

[0030] Comparative Example 3 (Traditional solid electrolyte, replacing Zn3(PO4)2) In this comparative example, the traditional Li3PO4 solid electrolyte was used to replace the Zn3(PO4)2 of the present invention. The remaining preparation and assembly steps were the same as in Example 3. The all-solid-state supercapacitor was assembled and the relevant indicators of the UAV were tested.

[0031] Figure 6The bar charts show the power density of the all-solid-state supercapacitors in Examples 1-3 and Comparative Examples 1-3. The highly matched all-solid-state device system achieves a power density of 6200-7100 W / kg, effectively supporting the high payload and high maneuverability requirements of rescue drones.

[0032] Performance testing Performance tests were conducted on the samples from Examples 1-3 and Comparative Examples 1-3. Test parameters included: specific capacitance of the negative electrode material, differential charge density, power density of the all-solid-state supercapacitor, and the maximum payload and maneuver response time (0→120 km / h) of the rescue drone equipped with the capacitor. The testing methods for each parameter were as follows: specific capacitance was tested using cyclic voltammetry (scan rate 100 mV / s) in a dual-electrode system with a 3 mol / L ZnSO4 electrolyte; differential charge density was calculated using VASP software based on first-principles calculations; power density was tested using a constant current charge-discharge method; the tested drone was a multi-rotor rescue drone (wheelbase 1.8 m), and the test environment was a windless environment at 25°C and an altitude below 500 m. The test results are shown in Table 1. Table 1. Correlation between device performance and UAV indicators of the embodiments of the present invention and the comparative examples. The test results show that the specific capacitance and differential charge density of the negative electrode materials prepared in Examples 1-3 of this invention are significantly higher than those in the comparative examples. The power density of the assembled all-solid-state supercapacitors is ≥6000W / kg, and the maximum payload of the rescue drone carried by the drone reaches 40-50kg, with the maneuver response time shortened to 3-5 seconds. In contrast, the power density of the comparative examples is significantly reduced due to the lack of high-voltage in-situ pore formation, carbon quantum dot sensitization, or the use of traditional solid electrolytes. The payload and maneuver response performance of the drone are also significantly reduced. This proves that the process innovation and device system design of this invention can effectively solve the core technical problems of high-payload rescue drones.

[0033] Industrial applicability The high power density all-solid-state supercapacitor anode material preparation method of the present invention is simple, highly controllable, and suitable for large-scale production. The prepared anode material has high compatibility with ZnMn2O4 cathode and Zn3(PO4)2 solid electrolyte. The assembled all-solid-state supercapacitor has a power density of ≥6000W / kg and can be directly applied to the power system of high-load rescue drones. It can also be extended to fields with high power density requirements such as drones, new energy vehicles, and energy storage power stations, and has broad industrial application prospects.

Claims

1. A method for preparing a negative electrode material for a high power density all-solid-state supercapacitor, characterized in that, The specific steps are as follows: Step 1: High-pressure in-situ synthesis of hexagonal porous multilayer Ti3C2(OH) x F y (HP-ML-Ti3C2(OH,F)) Ti3AlC2 powder and a mixture of difluoride salt powder were added to a high-pressure reactor at a molar ratio of 1:4 to 1:

6. The difluoride salt was a mixture of NH4HF2 and NaHF2 powder at a mass ratio of 1:1 to 1:

2. Deionized water was added to make the solid-liquid mass-volume ratio 1:50 to 1:80 g / mL. After sealing, the reactor was heated to 180℃ to 220℃ and reacted at a constant temperature and pressure of 3.0MPa to 5.0MPa for 12h to 20h. After the reaction was completed, the reactor was naturally cooled to room temperature, centrifuged, washed, dried, and ground to obtain HP-ML-Ti3C2(OH,F) powder. Step 2: Prepare a carbon quantum dot-sensitized microwave-assisted etching system NH4F, choline chloride, and oxalic acid were dissolved in deionized water at a mass ratio of 2:3:1 to prepare an etching solution with a total concentration of 1.0 mol / L to 1.5 mol / L. Carbon quantum dots were added to the etching solution at a mass ratio of 0.5% to 1.0% of the total mass of the etching solution. The solution was ultrasonically dispersed for 20 to 30 minutes to obtain a microwave-assisted etching system sensitized with carbon quantum dots. Step 3: Microwave-assisted chemical exfoliation to prepare hexagonal porous few-layer / monolayer Ti3C2(OH) x F y The HP-ML-Ti3C2(OH,F) powder prepared in step one was added to the etching system in step two at a solid-liquid mass-to-volume ratio of 1:100 to 1:150 g / mL. After stirring at room temperature for 30 to 60 minutes, the mixture was transferred to a microwave synthesizer and subjected to microwave exfoliation reaction at a power of 400 W to 600 W, a frequency of 2.45 GHz, and a temperature of 100 °C to 140 °C for 30 to 60 minutes. After the reaction, the mixture was centrifuged, washed until the pH value was 6 to 7, freeze-dried, and graded and ground to obtain hexagonal porous few-layer Ti3C2(OH) powder. x F y (HP-FL-Ti3C2(OH,F)) and hexagonal porous monolayer Ti3C2(OH) x F y (HP-SL-Ti3C2(OH,F)) powder is used to obtain the negative electrode material of the all-solid-state supercapacitor.

2. The preparation method according to claim 1, characterized in that, The Ti3AlC2 powder in step one has a particle size of 200-300 mesh, a drying temperature of 60-80℃, and a drying time of 12-16 hours.

3. The preparation method according to claim 1, characterized in that, The carbon quantum dots mentioned in step two are carbon quantum dots with a particle size of 5nm to 10nm synthesized by hydrothermal synthesis of citric acid-ethylenediamine.

4. The preparation method according to claim 1, characterized in that, The centrifugation speed in steps one and three is 8000 r / min to 10000 r / min, and the centrifugation time is 10 min to 15 min. In step three, the freeze-drying temperature is -40℃ to -60℃, and the freeze-drying time is 24 h to 36 h. The graded grinding is carried out through 200 mesh and 500 mesh standard sieves to separate the multilayer and single-layer products.

5. The preparation method according to claim 4, characterized in that, During graded grinding, the material remaining on a 200-mesh standard sieve is a small layer of Ti3C2(OH). x F y The undersize material on a 500-mesh standard sieve is a single layer of Ti3C2(OH). x F y The few-layer Ti3C2(OH) x F y It consists of 2 to 10 layers of Ti3C2(OH) x F y The hexagonal porous structure formed by stacked nanosheets, wherein the monolayer Ti3C2(OH) x F y (A monolayer of Ti3C2(OH)) x F y The hexagonal porous structure formed by nanosheets.

6. The application of a negative electrode material obtained by the preparation method according to any one of claims 1 to 5 in an all-solid-state supercapacitor.

7. The application according to claim 6, characterized in that, Few-layered Ti3C2(OH) x F y And monolayer Ti3C2(OH) x F y Mix them in a mass ratio of 1:1 to 2:1 as negative electrode active materials, and assemble them with ZnMn2O4 positive electrode material and Zn3(PO4)2 solid electrolyte to form an all-solid-state supercapacitor.

8. The application according to claim 6, characterized in that, The negative electrode preparation steps are as follows: the negative electrode active material, acetylene black and PVDF are mixed in a mass ratio of 8:1:1, NMP is added to make a slurry, which is uniformly coated on the surface of titanium foil, rolled flat and then vacuum dried at 80℃~100℃ for 12h~16h to obtain the negative electrode. The positive electrode preparation steps are as follows: ZnMn2O4, acetylene black and PVDF are mixed in a mass ratio of 8:1:1, NMP is added to make a slurry, which is then uniformly coated on the surface of titanium foil, rolled flat and then vacuum dried at 80℃~100℃ for 12h~16h to obtain the positive electrode.

9. The application according to claim 7, characterized in that, The all-solid-state supercapacitor is used in power systems with high power density requirements, such as high-load rescue drones, new energy vehicles, and energy storage power stations. The power density of the power system is ≥6000W / kg.

10. The application according to claim 9, characterized in that, When applied to the power system of high-load rescue drones, the drone equipped with this capacitor has a maximum payload capacity of 40-50 kg and a maneuver response time of 3-5 seconds from 0 to 120 km / h.

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