An electrospun Ti3C2T x Composite S-doped V₂O₅ self-supporting film materials, their preparation methods and applications

Abstract

This invention discloses an electrospun Ti3C2T x Composite S-doped V₂O₅ self-supporting film material, its preparation method, and its application. The method includes: Step 1, dissolving 0.5–2.0 g of PAN in 10 mL of DMF, stirring magnetically to obtain solution C, and adding 0.4–1.6 g of C to solution C. 10 H 14 Stir at 0.5°C for 1 hour to obtain solution D. Add 0.15–0.6 g of sulfur powder to solution D at 50°C and stir for 12 hours to obtain a dark green solution E. Add 5–20 mg of Ti3C2T to solution E. x MXene nanosheets were stirred until homogeneous to obtain a black spinning solution. Step 2: The spinning solution was first loaded into the syringe of an electrospinning machine to complete the spinning process, obtaining an electrospinning precursor. After vacuum drying, it was placed in a muffle furnace at 180–210°C and calcined for 2 hours. Then, under an argon atmosphere, the temperature was increased from room temperature to 600–700°C at a heating rate of 2°C / min, and annealed for 2 hours to obtain Ti3C2T. x Composite S-doped V2O5 self-supporting film materials have good structural stability, high power density and specific capacity, and can promote the rapid charging and discharging of ammonium-ion batteries.

Description

Technical Field

[0001] This invention relates to aqueous ammonium-ion battery cathode materials, specifically an electrospun Ti3C2T... x Composite S-doped V₂O₅ self-supporting film materials, their preparation methods, and applications. Background Technology

[0002] With the over-exploitation and rapid consumption of fossil fuels, energy issues and environmental degradation have become a major concern. Developing clean, inexpensive, and environmentally friendly energy storage components to alleviate the current energy crisis is of great significance for developing the national economy and achieving sustainable development. Ammonium ion batteries, as an emerging energy storage component, are considered one of the effective approaches. Research shows that: ① Compared to lithium-ion batteries, NH4+... + The battery has a higher power density and can achieve rapid charging and discharging; ②NH4 + Batteries are green, pollution-free, and environmentally friendly, and have application value in the field of power energy.

[0003] Ti3C2T x As one of the most attractive two-dimensional materials currently available, it has shown great potential in the field of next-generation high-performance capacitor electrodes due to its abundant surface functional groups, metallic-level conductivity, high specific surface area, and good hydrophilicity, and has received widespread attention in recent years. However, when applied as a cathode material for aqueous ammonium-ion batteries, it is prone to interlayer adhesion leading to agglomeration and lacks good NH4+ properties. + Storage performance; meanwhile, V₂O₅ is a typical layered structure material, and the weak hydrogen bonds between the layers facilitate reversible ion insertion / extraction, resulting in a high theoretical specific capacity. However, the adsorption capacity of V₂O₅ cathode for ammonium ions is limited, and in NH₄⁺... + During the insertion / extraction process, structural degradation is prone to occur, leading to NH4 + Poor storage performance can be addressed by replacing the O sites in the V₂O₅ cathode with S doping, which can effectively reduce the dependence of V₂O₅ on NH₄⁺. + The adsorption energy barrier is reduced, which enhances the adsorption capacity of V2O5 cathode for ammonium ions, promotes the contact between ammonium ions in the electrolyte and the cathode material interface, and accelerates the diffusion process of ammonium ions.

[0004] In summary, the Ti3C2T is expected to be a success. x Combined with S-doped V₂O₅, to prepare NH₄⁺ with high stability. + The composite material of the battery, however, if simply Ti3C2T x Physically bonded with S-doped V₂O₅ in NH₄ + Ti3C2T during battery charging and discharging x S-doped V₂O₅ is prone to pulverization and structural degradation, while Ti₃C₂Tx S-doped V₂O₅ easily detaches from the current collector, and V₂O₅ readily dissolves in the electrolyte, leading to reduced material capacity and a continuous decline in cycle stability. Therefore, it is difficult to fully utilize the high ion diffusion and metallic conductivity of Mxenes, as well as the high specific capacity of S-doped V₂O₅. Thus, it is necessary to explore a method that can effectively utilize Ti₃C₂T₅. x A novel method for the efficient integration of Mxenes and S-doped V₂O₅ yields highly stable aqueous NH₄⁺ without compromising the high ion diffusion of Mxenes or the high specific capacity of S-doped V₂O₅. + Battery electrode materials. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide an electrospun Ti3C2T x Composite S-doped V2O5 self-supporting film material, its preparation method and application. The material has good structural stability, high power density and high areal specific capacity, which can promote the rapid charge and discharge of aqueous ammonium ion batteries.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] An electrospun Ti3C2T x The preparation method of composite S-doped V₂O₅ self-supporting film material includes the following steps:

[0008] Step 1: Prepare spinning solution

[0009] Dissolve 0.5–2.0 g of PAN in 10 mL of DMF and stir magnetically to obtain solution C. Add 0.4–1.6 g of C to solution C. 10 H 14 Stir at 0.5°C for 1 hour to obtain solution D. Add 0.15–0.6 g of sulfur powder to solution D at 50°C and stir for 12 hours to obtain a dark green solution E. Add 5–20 mg of Ti3C2T to solution E. x MXene nanosheets were stirred until homogeneous to obtain a black spinning solution;

[0010] Step 2: Preparation of Ti3C2T x Composite S-doped V₂O₅ self-supporting film material

[0011] First, the spinning solution is loaded into the syringe of the electrospinning machine to complete the spinning process, obtaining the electrospinning precursor. After vacuum drying, it is placed in a muffle furnace at 180–210 °C and calcined for 2 hours. Then, under an argon atmosphere, the temperature is increased from room temperature to 600–700 °C at a heating rate of 2 °C / min, and annealed for 2 hours to obtain Ti3C2T. xComposite S-doped V2O5 self-supporting film material.

[0012] Furthermore, the Ti3C2T in step 1 x MXene nanosheets were prepared by the following method:

[0013] Add 2–4 g of LiF to 30–50 mL of 9 mol / L HCl solution and stir thoroughly to obtain solution A. Slowly add 1–3 g of Ti3AlC2 to solution A and stir for 24 h in a 50°C water bath to obtain reaction solution B. Centrifuge and wash reaction solution B repeatedly until the pH of the supernatant is 5–6. Then, wash repeatedly with ultrasound until the pH of the supernatant is neutral. Separate the precipitate, vacuum dry, and obtain a black powder of Ti3C2T. x MXene nanosheets.

[0014] Furthermore, the vacuum drying temperature is 60–80°C.

[0015] Furthermore, in step 1, PAN, DMF, and C 10 H 14 O5V, sulfur powder and Ti3C2T x The ratio of MXene nanosheets is 1g:10mL:0.8g:0.3g:10mg.

[0016] Furthermore, in step 2, the parameters of the electrospinning machine are set as follows: the distance from the needle tip to the collector is 14-17 cm, the applied voltage is 17-20 kV, and the spinning speed is 1.3-1.8 mL / min.

[0017] Furthermore, in step 2, the vacuum drying temperature is 60°C and the time is 12 hours.

[0018] A Ti3C2T x Composite S-doped V2O5 self-supporting film material.

[0019] A Ti3C2T x Composite S-doped V₂O₅ self-supporting film material as aqueous NH₄ + Applications of battery cathode materials.

[0020] Compared with the prior art, the present invention has the following technical effects:

[0021] This invention utilizes an electrospinning method to spin Ti3C2T x Nanosheets and S-doped V₂O₅ materials are integrated onto a C-fiber membrane to construct an integrated Ti₃C₂T xThe / S-V2O5@CNF membrane material anchors S-V2O5 within carbon nanofibers (CNF), preventing direct contact between V2O5 and the electrolyte and mitigating the defect of V2O5 easily dissolving in the electrolyte during charge and discharge. Simultaneously, Ti3C2T... x S-V₂O₅ is embedded in a CNF film via electrospinning, forming chemical bonds between them. This ensures structural stability during charge and discharge processes. Furthermore, stress during charging can be moderately released through carbon nanofibers, preventing structural degradation. Therefore, this method not only stabilizes Ti₃C₂T₂... x The structure of S-V2O5 material effectively prevents the structural degradation of S-V2O5 caused by stress accumulation during charging and discharging, as well as the degradation of Ti3C2T. x Nanosheet aggregation retains the high ion diffusion and metallic conductivity of Mxenes as well as the high specific capacity of S-doped V₂O₅, while also increasing the specific surface area of ​​the material and enhancing its resistance to NH₄⁺. + The storage effect is good. In summary, the integrated Ti3C2T prepared by this invention... x / S-V2O5@CNF membrane material possesses high power density and high areal specific capacity, making it suitable for use with aqueous NH4+. + When used as a positive electrode material for batteries, it can promote rapid charging and discharging of aqueous ammonium ion battery systems and exhibits excellent electrochemical performance. In addition, the preparation method of this invention is simple, low-cost, and has high economic value. Attached Figure Description

[0022] Figure 1 The Ti3C2T prepared in Example 1 of this invention x XRD pattern of composite S-doped V₂O₅ self-supporting film material;

[0023] Figure 2 The Ti3C2T prepared in Example 1 of this invention x SEM image of composite S-doped V₂O₅ self-supporting film material;

[0024] Figure 3 The Ti3C2T prepared in Example 1 of this invention x NH4 assembled from composite S-doped V2O5 self-supporting film materials + Batteries, constant current charge-discharge spectra at different current densities;

[0025] Figure 4 The NH4 assembly of the S-doped V2O5 self-supporting film material prepared in Comparative Example 1 of this invention + Batteries, constant current charge-discharge spectra at different current densities;

[0026] Figure 5 Comparative Example 2 of this invention prepared Ti3C2T xNH4 assembled from composite V2O5 self-supporting membrane materials + Batteries, constant current charge and discharge spectra at different current densities. Detailed Implementation

[0027] The specific content of the present invention will be further explained in detail below with reference to the embodiments.

[0028] Examples 1-5 used LiF, Ti3AlC2, polyacrylonitrile (PAN), DMF, S powder, and C. 10 H 14 O5V are all analytical grade.

[0029] Example 1

[0030] Step 1: Preparation of Ti3C2T x MXene nanosheets

[0031] 2g of LiF was added to 40mL of 9mol / L HCl solution and stirred thoroughly to obtain solution A. 2g of Ti3AlC2 was slowly added to solution A, and the mixture was stirred for 24 hours in a 50℃ water bath to obtain reaction solution B. Reaction solution B was transferred to centrifuge tubes and centrifuged repeatedly at 4000rpm until the pH of the supernatant reached 6. The supernatant was then repeatedly washed with ultrasound until the pH was neutral, separating the precipitate. The precipitate was then vacuum dried at 70℃ to obtain a black powder, Ti3C2T. x MXene nanosheets;

[0032] Step 2: Prepare spinning solution

[0033] Dissolve 1.0 g PAN in 10 mL DMF and stir magnetically to obtain solution C. Add 0.8 g C to solution C. 10 H 14 Stir at 0.5°C for 1 hour to obtain solution D. Add 0.3 g of sulfur powder to solution D at 50°C and stir for 12 hours to obtain a dark green solution E. Add 10 mg of Ti3C2T to solution E. x MXene nanosheets were stirred until homogeneous to obtain a black spinning solution;

[0034] Step 3: Preparation of Ti3C2T x Composite S-doped V₂O₅ self-supporting film material

[0035] First, the spinning solution was loaded into a 10 mL syringe, which was then placed in an electrospinning machine. The distance from the needle tip to the current collector was set to 15 cm, the applied voltage to 18 kV, and the spinning speed to 1.5 mL / min. Spinning was then initiated. After the spinning process was completed, the electrospinning precursor was obtained. This precursor was then placed in a vacuum drying oven at 60 °C for 12 h, and then transferred to a muffle furnace at 200 °C for calcination for 2 h. Next, under an Ar atmosphere, the temperature was increased from room temperature to 650 °C at a rate of 2 °C / min, and annealed for 2 h to obtain Ti3C2T. x Composite S-doped V₂O₅ self-supporting film material, also known as self-supporting Ti₃C₂T x / S-V2O5@CNF membrane.

[0036] Example 2

[0037] Step 1: Preparation of Ti3C2T x MXene nanosheets

[0038] 4g of LiF was added to 50mL of 9mol / L HCl solution and stirred thoroughly to obtain solution A. 3g of Ti3AlC2 was slowly added to solution A, and the mixture was stirred for 24 hours in a 50℃ water bath to obtain reaction solution B. Reaction solution B was transferred to centrifuge tubes and centrifuged repeatedly at 4000rpm until the pH of the supernatant reached 5. The supernatant was then repeatedly washed with ultrasound until the pH was neutral, separating the precipitate. The precipitate was then vacuum dried at 60℃ to obtain a black powder, Ti3C2T. x MXene nanosheets;

[0039] Step 2: Prepare spinning solution

[0040] Dissolve 1.5g of PAN in 10mL of DMF and stir magnetically to obtain solution C. Add 1.2g of C to solution C. 10 H 14 Stir at 0.5°C for 1 hour to obtain solution D. Add 0.45 g of sulfur powder to solution D at 50°C and stir for 12 hours to obtain a dark green solution E. Add 15 mg of Ti3C2T to solution E. x MXene nanosheets were stirred until homogeneous to obtain a black spinning solution;

[0041] Step 3: Preparation of Ti3C2T x Composite S-doped V₂O₅ self-supporting film material

[0042] First, the spinning solution was loaded into a 10 mL syringe, which was then placed in an electrospinning machine. The distance from the needle tip to the collector was set to 16 cm, the applied voltage to 17 kV, and the spinning speed to 1.3 mL / min. Spinning was then initiated. After the spinning process was completed, the electrospinning precursor was obtained. This precursor was then placed in a vacuum drying oven at 60 °C for 12 h, and then transferred to a muffle furnace at 210 °C for calcination for 2 h. Next, under an Ar atmosphere, the temperature was increased from room temperature to 650 °C at a rate of 2 °C / min, and annealed for 2 h to obtain self-supporting Ti3C2T. x / S-V2O5@CNF membrane.

[0043] Example 3

[0044] Step 1: Preparation of Ti3C2T x MXene nanosheets

[0045] 3g LiF was added to 30mL of 9mol / L HCl solution and stirred thoroughly to obtain solution A. 1.5g Ti3AlC2 was slowly added to solution A, and the mixture was stirred for 24h in a water bath at 50℃ to obtain reaction solution B. Reaction solution B was transferred to a centrifuge tube and centrifuged repeatedly at 4000rpm until the pH of the supernatant was 6. The supernatant was then repeatedly washed with ultrasound until the pH was neutral, and the precipitate was separated. The precipitate was then vacuum dried at 80℃ to obtain a black powder, Ti3C2T. x MXene nanosheets;

[0046] Step 2: Prepare spinning solution

[0047] Dissolve 2.0 g of PAN in 10 mL of DMF and stir magnetically to obtain solution C. Add 1.6 g of C to solution C. 10 H 14 Stir at 0.5°C for 1 hour to obtain solution D. Add 0.6 g of sulfur powder to solution D at 50°C and stir for 12 hours to obtain a dark green solution E. Add 20 mg of Ti3C2T to solution E. x MXene nanosheets were stirred until homogeneous to obtain a black spinning solution;

[0048] Step 3: Preparation of Ti3C2T x Composite S-doped V₂O₅ self-supporting film material

[0049] First, the spinning solution was loaded into a 10 mL syringe, which was then placed in an electrospinning machine. The distance from the needle tip to the collector was set to 17 cm, the applied voltage to 20 kV, and the spinning speed to 1.8 mL / min. Spinning was then initiated. After the spinning process was completed, the electrospinning precursor was obtained. This precursor was then placed in a vacuum drying oven at 60 °C for 12 h, and then transferred to a muffle furnace at 180 °C for calcination for 2 h. Next, under an Ar atmosphere, the temperature was increased from room temperature to 600 °C at a rate of 2 °C / min, and annealed for 2 h to obtain self-supporting Ti3C2T. x / S-V2O5@CNF membrane.

[0050] Example 4

[0051] Step 1: Preparation of Ti3C2T x MXene nanosheets

[0052] 3.5 g of LiF was added to 45 mL of 9 mol / L HCl solution and stirred thoroughly to obtain solution A. 2.5 g of Ti3AlC2 was slowly added to solution A, and the mixture was stirred for 24 h in a 50°C water bath to obtain reaction solution B. Reaction solution B was transferred to a centrifuge tube and centrifuged repeatedly at 4000 rpm until the pH of the supernatant reached 5. The supernatant was then repeatedly washed with ultrasound until the pH was neutral, separating the precipitate. The precipitate was then vacuum dried at 75°C to obtain a black powder, Ti3C2T. x MXene nanosheets;

[0053] Step 2: Prepare spinning solution

[0054] Dissolve 0.5 g PAN in 10 mL DMF and stir magnetically to obtain solution C. Add 0.4 g C to solution C. 10 H 14 Stir at 0.5°C for 1 hour to obtain solution D. Add 0.15 g of sulfur powder to solution D at 50°C and stir for 12 hours to obtain a dark green solution E. Add 5 mg of Ti3C2T to solution E. x MXene nanosheets were stirred until homogeneous to obtain a black spinning solution;

[0055] Step 3: Preparation of Ti3C2T x Composite S-doped V₂O₅ self-supporting film material

[0056] First, the spinning solution was loaded into a 10 mL syringe, which was then placed in an electrospinning machine. The distance from the needle tip to the collector was set to 15 cm, the applied voltage to 19 kV, and the spinning speed to 1.6 mL / min. Spinning was then initiated. After the spinning process was completed, the electrospinning precursor was obtained. This precursor was then placed in a vacuum drying oven at 60 °C for 12 h, and then transferred to a muffle furnace at 190 °C for calcination for 2 h. Next, under an Ar atmosphere, the temperature was increased from room temperature to 700 °C at a rate of 2 °C / min, and annealed for 2 h to obtain self-supporting Ti3C2T. x / S-V2O5@CNF membrane.

[0057] Example 5

[0058] Step 1: Preparation of Ti3C2T x MXene nanosheets

[0059] 2.5 g LiF was added to 35 mL of 9 mol / L HCl solution and stirred thoroughly to obtain solution A. 1 g Ti3AlC2 was slowly added to solution A, and the mixture was stirred for 24 h in a 50°C water bath to obtain reaction solution B. Reaction solution B was transferred to centrifuge tubes and centrifuged repeatedly at 4000 rpm until the pH of the supernatant reached 6. The supernatant was then repeatedly washed with ultrasound until the pH was neutral, separating the precipitate. The precipitate was then vacuum dried at 65°C to obtain a black powder, Ti3C2T. x MXene nanosheets;

[0060] Step 2: Prepare spinning solution

[0061] Dissolve 1g of PAN in 10mL of DMF and stir magnetically to obtain solution C. Add 0.8g of C to solution C. 10 H 14 Stir at 0.5°C for 1 hour to obtain solution D. Add 0.3 g of sulfur powder to solution D at 50°C and stir for 12 hours to obtain a dark green solution E. Add 10 mg of Ti3C2T to solution E. x MXene nanosheets were stirred until homogeneous to obtain a black spinning solution;

[0062] Step 3: Preparation of Ti3C2T x Composite S-doped V₂O₅ self-supporting film material

[0063] First, the spinning solution was loaded into a 10 mL syringe, which was then placed in an electrospinning machine. The distance from the needle tip to the collector was set to 14 cm, the applied voltage to 17.5 kV, and the spinning speed to 1.4 mL / min. Spinning was then initiated. After the spinning process was completed, the electrospinning precursor was obtained. This precursor was then placed in a vacuum drying oven at 60 °C for 12 h, and then transferred to a muffle furnace at 210 °C for calcination for 2 h. Next, under an Ar atmosphere, the temperature was increased from room temperature to 600 °C at a rate of 2 °C / min, and annealed for 2 h to obtain self-supporting Ti3C2T. x / S-V2O5@CNF membrane.

[0064] Comparative Example 1

[0065] Step 1: Prepare spinning solution

[0066] Dissolve 1.0 g of PAN in 10 mL of DMF and stir magnetically to obtain solution C. Add 0.8 g of C to solution C. 10 H 14 O5V, stir for 1h to obtain solution D. Add 0.3g sulfur powder to solution D at 50℃ and stir for 12h to obtain dark green spinning solution;

[0067] Step 2: Preparation of S-doped V₂O₅ self-supporting film material

[0068] First, the spinning solution was loaded into a 10 mL syringe, which was then placed in an electrospinning machine. The distance from the needle tip to the collector was set to 15 cm, the applied voltage to 18 kV, and the spinning speed to 1.5 mL / min. Spinning was then started, and after the spinning process was completed, an electrospinning precursor was obtained. The electrospinning precursor was then placed in a vacuum drying oven at 60 °C and dried for 12 h. Then, it was transferred to a muffle furnace at 200 °C and calcined for 2 h. Next, under an Ar atmosphere, the temperature was increased from room temperature to 650 °C at a heating rate of 2 °C / min and annealed for 2 h to obtain an S-doped V₂O₅ self-supporting film material, also known as a self-supporting S-V₂O₅@CNF film.

[0069] Comparative Example 2

[0070] Step 1: Preparation of Ti3C2T x MXene nanosheets

[0071] 2g of LiF was added to 40mL of 9mol / L HCl solution and stirred thoroughly to obtain solution A. 2g of Ti3AlC2 was slowly added to solution A, and the mixture was stirred for 24 hours in a 50℃ water bath to obtain reaction solution B. Reaction solution B was transferred to centrifuge tubes and centrifuged repeatedly at 4000rpm until the pH of the supernatant reached 6. The supernatant was then repeatedly washed with ultrasound until the pH was neutral, separating the precipitate. The precipitate was then vacuum dried at 70℃ to obtain a black powder, Ti3C2T. x MXene nanosheets;

[0072] Step 2: Prepare spinning solution

[0073] Dissolve 1.0 g of PAN in 10 mL of DMF and stir magnetically to obtain solution C. Add 0.8 g of C to solution C. 10 H 14 Stir at 05°C for 1 hour to obtain solution D. Add 10 mg of Ti3C2T to solution D at 50°C. x MXene nanosheets were stirred until homogeneous to obtain a black spinning solution;

[0074] Step 3: Preparation of Ti3C2T x Composite V2O5 self-supporting membrane material

[0075] First, the spinning solution was loaded into a 10 mL syringe, which was then placed in an electrospinning machine. The distance from the needle tip to the current collector was set to 15 cm, the applied voltage to 18 kV, and the spinning speed to 1.5 mL / min. Spinning was then initiated. After the spinning process was completed, the electrospinning precursor was obtained. This precursor was then placed in a vacuum drying oven at 60 °C for 12 h, and then transferred to a muffle furnace at 200 °C for calcination for 2 h. Next, under an Ar atmosphere, the temperature was increased from room temperature to 650 °C at a rate of 2 °C / min, and annealed for 2 h to obtain Ti3C2T. x Composite V₂O₅ self-supporting membrane material, also known as self-supporting Ti₃C₂T x / V2O5@CNF membrane.

[0076] Depend on Figure 1 It can be seen that when 2θ is 6.1°, Ti3C2T is observed. x The (002) crystal plane diffraction peak of the material was observed at 2θ of 9.7°, 25.6°, and 50.2°, while the (001) and (010) crystal plane diffraction peaks of the S-doped V₂O₅ material were observed, indicating that Example 1 successfully prepared Ti₃C₂T. xThe composite S-doped V₂O₅ self-supporting film material exhibits improved performance due to the S doping within the V₂O₅ layer. This shifts the (020) crystal plane diffraction peak of V₂O₅ from quasi-10.4° to the left, reducing it to 9.7°. The increased interlayer spacing of V₂O₅ also facilitates the absorption of NH₄⁺. + In Ti3C2T x Embedding / de-embedding of / S-V2O5@CNF.

[0077] Depend on Figure 2 It can be seen that the surface of the S-doped V2O5 carbon fiber self-supporting film is coated with Ti3C2T x Nanosheet encapsulation to form an integrated Ti3C2T x The / S-V2O5@CNF self-supporting structure not only helps stabilize Ti3C2T x The structure of S-V2O5 materials can effectively prevent Ti3C2T x The nanosheets aggregate and have a larger specific surface area, enhancing their ability to resist NH4. + Storage performance.

[0078] Ti3C2T prepared in Example 1 x Composite S-doped V₂O₅ self-supporting film material, S-doped V₂O₅ self-supporting film material prepared in Comparative Example 1, and Ti₃C₂T prepared in Comparative Example 2 x Assembling NH4 with composite V2O5 self-supporting membrane material + The battery was tested, and its constant current charge-discharge capacity was measured. The results are as follows: Figures 3-5 As shown:

[0079] Depend on Figure 3 It can be seen that at a current density of 0.5 A·g -1 1A·g -1 2A·g -1 5A·g -1 10A·g -1 and 20A·g -1 Under the conditions, Ti3C2T prepared in Example 1 x NH4 assembled from composite S-doped V2O5 self-supporting film materials + The battery capacities are 555.2 mAh·g. -1 402.3mAh·g -1 316.5mAh·g -1 196.4 mAh·g -1 110.7mAh·g -1 and 54.2 mAh·g -1 ;

[0080] Depend on Figure 4 It can be seen that at a current density of 0.5 A·g -1 1A·g-1 2A·g -1 5A·g -1 10A·g -1 and 20A·g -1 Under the conditions, NH4 assembled from the S-doped V2O5 self-supporting film material prepared in Comparative Example 1 + The battery capacities are 540.1 mAh·g. -1 354.7mAh·g -1 216.9mAh·g -1 110.4mAh·g -1 56.8mAh·g -1 and 26.2mAh·g -1 ;

[0081] Depend on Figure 5 It can be seen that at a current density of 0.5 A·g -1 1A·g -1 2A·g -1 5A·g -1 10A·g -1 and 20A·g -1 Under the conditions, Ti3C2T prepared by Comparative Example 2 x NH4 assembled from composite V2O5 self-supporting membrane materials + The battery capacity is 162.2 mAh·g. -1 126.6mAh·g -1 103.1mAh·g -1 49.2mAh·g -1 22.2mAh·g -1 and 3.2mAh·g -1 .

[0082] contrast Figures 3-5 It can be observed that the Ti3C2T prepared in Example 1... x NH4 assembled from composite S-doped V2O5 self-supporting film materials + The battery is compared with the S-doped V₂O₅ self-supporting film material prepared by Comparative Example 1 and the Ti₃C₂T prepared by Comparative Example 2. x NH4 assembled from composite V2O5 self-supporting membrane materials + For batteries, the higher specific capacity and power density demonstrate that the Ti3C2T prepared in Example 1 exhibits superior performance. x Composite S-doped V₂O₅ self-supporting film material as aqueous NH₄ + When used as a positive electrode material in batteries, it can accelerate the charging and discharging process of aqueous ammonium ion battery systems.

Claims

1. An electrospun Ti3C2T x The method for preparing composite S-doped V₂O₅ self-supporting film materials is characterized by, Includes the following steps: Step 1: Prepare spinning solution Dissolve 0.5–2.0 g of PAN in 10 mL of DMF and stir magnetically to obtain solution C. Add 0.4–1.6 g of C to solution C. 10 H 14 Stir at 0.5°C for 1 hour to obtain solution D. Add 0.15–0.6 g of sulfur powder to solution D at 50°C and stir for 12 hours to obtain a dark green solution E. Add 5–20 mg of Ti3C2T to solution E. x MXene nanosheets were stirred until homogeneous to obtain a black spinning solution; Step 2: Preparation of Ti3C2T x Composite S-doped V₂O₅ self-supporting film material First, the spinning solution is loaded into the syringe of the electrospinning machine to complete the spinning process, obtaining the electrospinning precursor. After vacuum drying, it is placed in a muffle furnace at 180–210 °C and calcined for 2 hours. Then, under an argon atmosphere, the temperature is increased from room temperature to 600–700 °C at a heating rate of 2 °C / min, and annealed for 2 hours to obtain Ti3C2T. x Composite S-doped V2O5 self-supporting film material.

2. The electrospun Ti3C2T according to claim 1 x The method for preparing composite S-doped V₂O₅ self-supporting film materials is characterized by, The Ti3C2T in step 1 x MXene nanosheets were prepared by the following method: Add 2–4 g of LiF to 30–50 mL of 9 mol / L HCl solution and stir thoroughly to obtain solution A. Slowly add 1–3 g of Ti3AlC2 to solution A and stir for 24 h in a 50°C water bath to obtain reaction solution B. Centrifuge and wash reaction solution B repeatedly until the pH of the supernatant is 5–6, then wash repeatedly with ultrasound until the pH of the supernatant is neutral. Separate the precipitate, vacuum dry, and obtain a black powder of Ti3C2T. x MXene nanosheets.

3. The electrospun Ti3C2T according to claim 2 x The method for preparing composite S-doped V₂O₅ self-supporting film materials is characterized by, The vacuum drying temperature is 60–80°C.

4. The electrospun Ti3C2T according to claim 1 x The method for preparing composite S-doped V₂O₅ self-supporting film materials is characterized by, In step 1, PAN, DMF, C 10 H 14 O5V, sulfur powder and Ti3C2T x The ratio of MXene nanosheets is 1g:10mL:0.8g:0.3g:10mg.

5. The electrospun Ti3C2T according to claim 1 x The method for preparing composite S-doped V₂O₅ self-supporting film materials is characterized by, In step 2, the parameters of the electrospinning machine are set as follows: the distance from the needle tip to the collector is 14-17 cm, the applied voltage is 17-20 kV, and the spinning speed is 1.3-1.8 mL / min.

6. The electrospun Ti3C2T according to claim 1 x The method for preparing composite S-doped V₂O₅ self-supporting film materials is characterized by, In step 2, the vacuum drying temperature is 60℃ and the time is 12h.

7. A Ti3C2T prepared by the method according to any one of claims 1 to 6 x Composite S-doped V2O5 self-supporting film material.

8. The Ti3C2T according to claim 7 x Composite S-doped V₂O₅ self-supporting film material as aqueous NH₄ + Applications of battery cathode materials.

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