Electrospinning Ti3C2Tx composite S doped V2O5 self-supporting membrane material as well as preparation method and application thereof

Abstract

The invention discloses an electrostatic spinning Ti3C2Tx composite S doped V2O5 self-supporting membrane material and a preparation method and application thereof.The method comprises the steps that 1, 0.5 g to 2.0 g of PAN is dissolved in 10 mL of DMF, magnetic stirring is conducted, a solution C is obtained, 0.4 g to 1.6 g of C10H14O5V is added into the solution C, stirring is conducted for 1 h, a solution D is obtained, 0.15 g to 0.6 g of sulfur powder is added into the solution D at 50 DEG C, stirring is conducted for 12 h, a dark green solution E is obtained, 5 mg to 20 mg of Ti3C2Tx MXene nanosheets are added into the dark green solution E, stirring is conducted to be uniform, and a mixed solution is obtained; a black spinning solution is obtained; and 2, filling the spinning solution into an injector of an electrostatic spinning machine, completing a spinning process to obtain an electrostatic spinning precursor, carrying out vacuum drying, putting the electrostatic spinning precursor into a muffle furnace at 180-210 DEG C, calcining for 2 hours, heating from room temperature to 600-700 DEG C at a heating rate of 2 DEG C / min in an argon atmosphere, and annealing for 2 hours to obtain the Ti3C2Tx composite S-doped V2O5 self-supporting membrane material, namely the Ti3C2Tx composite S-doped V2O5 self-supporting membrane material. The material has good structural stability, high power density and specific capacity, and can promote rapid charging and discharging of the ammonium ion battery.

Description

Technical Field

[0001] The present invention relates to an aqueous ammonium ion battery positive electrode material, in particular to an electrostatically spun Ti 3 C 2 T x Composite S-doped V 2 O 5 Self-supporting film material and preparation method and application thereof. Background Art

[0002] With the over-exploitation and rapid consumption of fossil energy, energy problems and environmental degradation have attracted much attention. The development of clean, low-cost and environmentally friendly energy storage components to alleviate the current energy crisis in society is of great significance for the development of the national economy and the realization of sustainable development. Ammonium ion batteries, as emerging energy storage components, are considered to be one of the effective ways. Studies have shown that: ① Compared with lithium-ion batteries, NH 4 + The battery has a higher power density and can achieve rapid charge and discharge; ②NH 4 + The battery is green, pollution-free and environmentally friendly, and has application value in the field of power energy.

[0003] Ti 3 C 2 T x As one of the most attractive two-dimensional materials, it has shown great potential in the new generation of high-performance capacitor electrodes due to its rich surface functional groups, metal-level conductivity, high specific surface area and good hydrophilicity. However, when it is used as a positive electrode material for aqueous ammonium ion batteries, it is prone to interlayer adhesion and agglomeration, and does not have good NH 4 + Storage performance; at the same time, V 2 O 5 It is a typical layered structure material. The weak hydrogen bonds between the layers are conducive to the reversible insertion / extraction of ions, and it has a high theoretical specific capacity. However, V 2 O 5 The positive electrode has limited adsorption capacity for ammonium ions and 4 + During the embedding / removal process, structural degradation is likely to occur, resulting in NH 4 + The storage effect is not good, and S doping is used to replace V 2 O 5 The O site in the positive electrode can effectively reduce V 2 O 5 For NH 4 + The adsorption energy barrier increases V 2 O 5The positive electrode's adsorption capacity for ammonium ions promotes the interface contact between the ammonium ions in the electrolyte and the positive electrode material, accelerating the diffusion process of ammonium ions.

[0004] In summary, it is expected that Ti 3 C 2 T x and S doped V 2 O 5 Combined to prepare NH 4 + Composite materials for batteries, however, if Ti 3 C 2 T x and S doped V 2 O 5 Physical bonding, in NH 4 + During battery charging and discharging, Ti 3 C 2 T x and S doped V 2 O 5 It is easy to powder and structural deterioration, and Ti 3 C 2 T x and S doped V 2 O 5 Easy to fall off from the current collector, V 2 O 5 It is easy to dissolve in the electrolyte, resulting in a decrease in material capacity and a continuous decrease in cycle stability, so it is difficult to play the role of high ion diffusion and metal-level conductivity of Mxenes and S-doped V 2 O 5 Therefore, it is necessary to explore a method that can convert Ti 3 C 2 T x Mxenes and S-doped V 2 O 5 A new method for efficient integration without affecting the high ion diffusion of Mxenes and S-doped V 2 O 5 Under the condition of high specific capacity, highly stable aqueous NH 4 + Battery electrode materials. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention aims to provide an electrospinning Ti 3 C 2 T x Composite S-doped V 2 O 5The invention relates to a self-supporting membrane material, a preparation method and an application thereof. The material has good structural stability, high power density and high area specific capacity, and can promote the rapid charging and discharging of aqueous ammonium ion batteries.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] An electrospun Ti 3 C 2 T x Composite S-doped V 2 O 5 The method for preparing a self-supporting film material comprises the following steps:

[0008] Step 1: Prepare spinning solution

[0009] Dissolve 0.5-2.0 g PAN in 10 mL DMF and stir magnetically to obtain solution C. Add 0.4-1.6 g C 10 H 14 O 5 V, stirred for 1 hour to obtain solution D, added 0.15-0.6 g sulfur powder to solution D at 50°C, stirred for 12 hours to obtain dark green solution E, added 5-20 mg Ti 3 C 2 T x MXene nanosheets are stirred evenly to obtain a black spinning solution;

[0010] Step 2: Preparation of Ti 3 C 2 T x Composite S-doped V 2 O 5 Self-supporting membrane materials

[0011] First, the spinning solution was loaded into the syringe of the electrospinning machine to complete the spinning process to obtain the electrospinning precursor. After vacuum drying, it was placed in a muffle furnace at 180-210°C and calcined for 2h. Then, in an argon atmosphere, the temperature was raised from room temperature to 600-700°C at a heating rate of 2°C / min and annealed for 2h to obtain Ti 3 C 2 T x Composite S-doped V 2 O 5 Self-supporting film material.

[0012] Furthermore, the Ti in step 1 3 C 2 T x MXene nanosheets were prepared by the following method:

[0013] Add 2-4 g LiF to 30-50 mL 9 mol / L HCl solution and stir thoroughly to obtain solution A. Add 1-3 g Ti 3 AlC 2 Solution A was slowly added, and stirred for 24 h in a water bath at 50 °C to obtain a reaction solution B. The reaction solution B was repeatedly centrifuged and washed until the pH value of the supernatant was 5-6, and then repeatedly washed with ultrasound until the pH value of the supernatant was neutral. The precipitate was separated and vacuum dried to obtain black powder Ti 3 C 2 T x MXene nanosheets.

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

[0015] Furthermore, in the step 1, PAN, DMF, C 10 H 14 O 5 V, sulfur powder and Ti 3 C 2 T x The ratio of MXene nanosheets is 1g:10mL:0.8g:0.3g:10mg.

[0016] Furthermore, the parameters of the electrospinning machine in step 2 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 h.

[0018] A Ti 3 C 2 T x Composite S-doped V 2 O 5 Self-supporting film material.

[0019] A Ti 3 C 2 T x Composite S-doped V 2 O 5 Self-supporting membrane materials as aqueous NH 4 + Application of battery positive electrode materials.

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

[0021] The present invention utilizes the electrostatic spinning method to 3 C 2 T xNanosheets and S-doped V 2 O 5 The material is integrated on the C fiber membrane to build an integrated Ti 3 C 2 T x / SV 2 O 5 @CNF membrane material, SV 2 O 5 Anchored inside carbon nanofibers (CNFs), V 2 O 5 Direct contact with electrolyte to ease the charge and discharge process V 2 O 5 The defect of being easily soluble in the electrolyte, and Ti 3 C 2 T x and SV 2 O 5 Through the electrospinning method, it is embedded in the CNF membrane, and a chemical bond is formed between the two. The structure is stable during the charge and discharge process. Moreover, the stress during the charging process can be slowly released through the carbon nanofibers, and it is not easy to deteriorate the structure. It can be seen that it can not only stabilize Ti 3 C 2 T x and SV 2 O 5 The structure of the material effectively prevents SV caused by material stress enrichment during the charge and discharge process 2 O 5 Structural deterioration and Ti 3 C 2 T x The nanosheets agglomerate, thereby retaining the high ion diffusion and metallic-level conductivity of Mxenes and the S-doped V 2 O 5 The high specific capacity and increased specific surface area of ​​the material enhance the NH 4 + In summary, the integrated Ti prepared by the present invention 3 C 2 T x / SV 2 O 5 @CNF membrane material has high power density and high area specific capacity. 4 + When used as a positive electrode material for a battery, the rapid charge and discharge of an aqueous ammonium ion battery system can be promoted, and the battery has excellent electrochemical performance. In addition, the preparation method of the invention is simple, low in cost, and has high economic value. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 : Ti prepared in Example 1 of the present invention3 C 2 T x Composite S-doped V 2 O 5 XRD pattern of the free-standing film material;

[0023] Figure 2 : Ti prepared in Example 1 of the present invention 3 C 2 T x Composite S-doped V 2 O 5 SEM images of the self-supporting membrane material;

[0024] Figure 3 : Ti prepared in Example 1 of the present invention 3 C 2 T x Composite S-doped V 2 O 5 NH assembled from self-supporting membrane materials 4 + Battery, constant current charge and discharge spectrum at different current densities;

[0025] Figure 4 : S-doped V prepared in Comparative Example 1 of the present invention 2 O 5 NH assembled from self-supporting membrane materials 4 + Battery, constant current charge and discharge spectrum at different current densities;

[0026] Figure 5 : Ti prepared in Comparative Example 2 of the present invention 3 C 2 T x Composite V 2 O 5 NH assembled from self-supporting membrane materials 4 + Battery, constant current charge and discharge spectrum at different current densities. DETAILED DESCRIPTION

[0027] The specific contents of the present invention are further explained in detail below in conjunction with embodiments.

[0028] LiF and Ti used in Examples 1 to 5 3 AlC 2 , polyacrylonitrile PAN, DMF, S powder, C 10 H 14 O 5 V was of analytical grade.

[0029] Example 1

[0030] Step 1: Preparation of Ti3 C 2 T x MXene nanosheets

[0031] 2g LiF was added to 40mL 9mol / L HCl solution and stirred thoroughly to obtain solution A. 2g Ti 3 AlC 2 Solution A was slowly added, and stirred for 24 hours in a water bath at 50°C to obtain reaction solution B. The reaction solution B was transferred to a centrifuge tube, and centrifuged and washed repeatedly at 4000 rpm using a centrifuge until the pH value of the supernatant reached 6. Ultrasonic cleaning was then performed repeatedly until the pH value of the supernatant reached neutrality, and the precipitate was separated and vacuum dried at 70°C to obtain black powdered Ti 3 C 2 T 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 10 H 14 O 5 V, stirred for 1 h to obtain solution D, 0.3 g of sulfur powder was added to solution D at 50 °C, stirred for 12 h to obtain dark green solution E, 10 mg of Ti was added to the dark green solution E 3 C 2 T x MXene nanosheets are stirred evenly to obtain a black spinning solution;

[0034] Step 3: Preparation of Ti 3 C 2 T x Composite S-doped V 2 O 5 Self-supporting membrane materials

[0035] First, the spinning solution was loaded into a 10 mL syringe, and the syringe was placed in an electrospinning machine. At the same time, the distance from the needle tip to the collector was set to 15 cm, the applied voltage was set to 18 kV, the spinning speed was set to 1.5 mL / min, and spinning was started. 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 for 12 h, and then transferred to a muffle furnace at 200 ° C for calcination for 2 h. Then, in an Ar atmosphere, the temperature was raised from room temperature to 650 ° C at a heating rate of 2 ° C / min, and annealed for 2 h to obtain Ti 3 C 2 T x Composite S-doped V 2 O5 Self-supporting film material, also known as self-supporting Ti 3 C 2 T x / SV 2 O 5 @CNF membrane.

[0036] Example 2

[0037] Step 1: Preparation of Ti 3 C 2 T x MXene nanosheets

[0038] 4g LiF was added into 50mL 9mol / L HCl solution and stirred thoroughly to obtain solution A. 3g Ti 3 AlC 2 Solution A was slowly added, and stirred for 24 hours in a water bath at 50°C to obtain reaction solution B. The reaction solution B was transferred to a centrifuge tube, and centrifuged and washed repeatedly at 4000 rpm using a centrifuge until the pH value of the supernatant was 5. Ultrasonic cleaning was then repeated until the pH value of the supernatant was neutral, and the precipitate was separated and vacuum dried at 60°C to obtain black powdered Ti 3 C 2 T x MXene nanosheets;

[0039] Step 2: Prepare spinning solution

[0040] Dissolve 1.5 g PAN in 10 mL DMF and stir magnetically to obtain solution C. Add 1.2 g C 10 H 14 O 5 V, stirred for 1 h to obtain solution D, 0.45 g of sulfur powder was added to solution D at 50 °C, stirred for 12 h to obtain dark green solution E, 15 mg of Ti was added to the dark green solution E 3 C 2 T x MXene nanosheets are stirred evenly to obtain a black spinning solution;

[0041] Step 3: Preparation of Ti 3 C 2 T x Composite S-doped V 2 O 5 Self-supporting membrane materials

[0042] First, the spinning solution was loaded into a 10 mL syringe, and the syringe was placed in an electrospinning machine. At the same time, the distance from the needle tip to the collector was set to 16 cm, the applied voltage was set to 17 kV, the spinning speed was set to 1.3 mL / min, and spinning was started. 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 for 12 h, and then transferred to a muffle furnace at 210 ° C for calcination for 2 h. Then, in an Ar atmosphere, the temperature was raised from room temperature to 650 ° C at a heating rate of 2 ° C / min, and annealed for 2 h to obtain a self-supporting Ti 3 C 2 T x / SV 2 O 5 @CNF membrane.

[0043] Example 3

[0044] Step 1: Preparation of Ti 3 C 2 T x MXene nanosheets

[0045] 3g LiF was added to 30mL 9mol / L HCl solution and stirred thoroughly to obtain solution A. 1.5g Ti 3 AlC 2 Solution A was slowly added, and stirred for 24 hours in a water bath at 50°C to obtain reaction solution B. The reaction solution B was transferred to a centrifuge tube, and centrifuged and washed repeatedly at 4000 rpm using a centrifuge until the pH value of the supernatant was 6. Ultrasonic cleaning was then repeated until the pH value of the supernatant was neutral, and the precipitate was separated and vacuum dried at 80°C to obtain black powdered Ti 3 C 2 T x MXene nanosheets;

[0046] Step 2: Prepare spinning solution

[0047] Dissolve 2.0 g PAN in 10 mL DMF and stir magnetically to obtain solution C. Add 1.6 g C 10 H 14 O 5 V, stirred for 1 h to obtain solution D, 0.6 g of sulfur powder was added to solution D at 50 °C, stirred for 12 h to obtain dark green solution E, 20 mg of Ti was added to the dark green solution E 3 C 2 T x MXene nanosheets are stirred evenly to obtain a black spinning solution;

[0048] Step 3: Preparation of Ti 3 C2 T x Composite S-doped V 2 O 5 Self-supporting membrane materials

[0049] First, the spinning solution was loaded into a 10 mL syringe, and the syringe was placed in an electrospinning machine. At the same time, the distance from the needle tip to the collector was set to 17 cm, the applied voltage was set to 20 kV, the spinning speed was set to 1.8 mL / min, and spinning was started. 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 for 12 h, and then transferred to a muffle furnace at 180 ° C for calcination for 2 h. Then, in an Ar atmosphere, the temperature was raised from room temperature to 600 ° C at a heating rate of 2 ° C / min, and annealed for 2 h to obtain a self-supporting Ti 3 C 2 T x / SV 2 O 5 @CNF membrane.

[0050] Example 4

[0051] Step 1: Preparation of Ti 3 C 2 T x MXene nanosheets

[0052] 3.5 g LiF was added to 45 mL 9 mol / L HCl solution and stirred thoroughly to obtain solution A. 2.5 g Ti 3 AlC 2 Solution A was slowly added, and stirred for 24 h in a water bath at 50°C to obtain reaction solution B. The reaction solution B was transferred to a centrifuge tube, and centrifuged and washed repeatedly at 4000 rpm using a centrifuge until the pH value of the supernatant was 5. Ultrasonic cleaning was then repeated until the pH value of the supernatant was neutral, and the precipitate was separated and vacuum dried at 75°C to obtain black powdered Ti 3 C 2 T 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 10 H 14 O 5 V, stirred for 1 h to obtain solution D, 0.15 g of sulfur powder was added to solution D at 50 °C, stirred for 12 h to obtain dark green solution E, 5 mg of Ti was added to the dark green solution E 3 C 2 Tx MXene nanosheets are stirred evenly to obtain a black spinning solution;

[0055] Step 3: Preparation of Ti 3 C 2 T x Composite S-doped V 2 O 5 Self-supporting membrane materials

[0056] First, the spinning solution was loaded into a 10 mL syringe, and the syringe was placed in an electrospinning machine. At the same time, the distance from the needle tip to the collector was set to 15 cm, the applied voltage was set to 19 kV, the spinning speed was set to 1.6 mL / min, and spinning was started. 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 for 12 h, and then transferred to a muffle furnace at 190 ° C for calcination for 2 h. Then, in an Ar atmosphere, the temperature was raised from room temperature to 700 ° C at a heating rate of 2 ° C / min, and annealed for 2 h to obtain a self-supporting Ti 3 C 2 T x / SV 2 O 5 @CNF membrane.

[0057] Example 5

[0058] Step 1: Preparation of Ti 3 C 2 T x MXene nanosheets

[0059] 2.5 g LiF was added to 35 mL 9 mol / L HCl solution and stirred thoroughly to obtain solution A. 1 g Ti 3 AlC 2 Solution A was slowly added, and stirred for 24 h in a water bath at 50°C to obtain reaction solution B. The reaction solution B was transferred to a centrifuge tube, and centrifuged and washed repeatedly at 4000 rpm using a centrifuge until the pH value of the supernatant reached 6. Ultrasonic cleaning was then repeated until the pH value of the supernatant reached neutrality, and the precipitate was separated and vacuum dried at 65°C to obtain black powdered Ti 3 C 2 T x MXene nanosheets;

[0060] Step 2: Prepare spinning solution

[0061] Dissolve 1 g of PAN in 10 mL of DMF and stir magnetically to obtain solution C. Add 0.8 g of C 10 H 14 O 5V, stirred for 1 h to obtain solution D, 0.3 g of sulfur powder was added to solution D at 50 °C, stirred for 12 h to obtain dark green solution E, 10 mg of Ti was added to the dark green solution E 3 C 2 T x MXene nanosheets are stirred evenly to obtain a black spinning solution;

[0062] Step 3: Preparation of Ti 3 C 2 T x Composite S-doped V 2 O 5 Self-supporting membrane materials

[0063] First, the spinning solution was loaded into a 10 mL syringe, and the syringe was placed in an electrospinning machine. At the same time, the distance from the needle tip to the collector was set to 14 cm, the applied voltage was set to 17.5 kV, the spinning speed was set to 1.4 mL / min, and spinning was started. 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 for 12 h, and then transferred to a muffle furnace at 210 ° C for calcination for 2 h. Then, in an Ar atmosphere, the temperature was raised from room temperature to 600 ° C at a heating rate of 2 ° C / min, and annealed for 2 h to obtain a self-supporting Ti 3 C 2 T x / SV 2 O 5 @CNF membrane.

[0064] Comparative Example 1

[0065] Step 1: Prepare spinning solution

[0066] Dissolve 1.0 g PAN in 10 mL DMF and stir magnetically to obtain solution C. Add 0.8 g C 10 H 14 O 5 V, stirred for 1 h to obtain solution D, 0.3 g of sulfur powder was added to solution D at 50 °C, stirred for 12 h to obtain a dark green spinning solution;

[0067] Step 2: Preparation of S-doped V 2 O 5 Self-supporting membrane materials

[0068] First, the spinning solution was loaded into a 10 mL syringe, and the syringe was placed in an electrospinning machine. At the same time, the distance from the needle tip to the collector was set to 15 cm, the applied voltage was set to 18 kV, the spinning speed was set to 1.5 mL / min, and spinning was started. 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 for 12 h, and then transferred to a muffle furnace at 200 ° C for calcination for 2 h. Then, in an Ar atmosphere, the temperature was raised from room temperature to 650 ° C at a heating rate of 2 ° C / min, and annealed for 2 h to obtain S-doped V 2 O 5 Self-supporting film material, also known as self-supporting SV 2 O 5 @CNF membrane.

[0069] Comparative Example 2

[0070] Step 1: Preparation of Ti 3 C 2 T x MXene nanosheets

[0071] 2g LiF was added to 40mL 9mol / L HCl solution and stirred thoroughly to obtain solution A. 2g Ti 3 AlC 2 Solution A was slowly added, and stirred for 24 hours in a water bath at 50°C to obtain reaction solution B. The reaction solution B was transferred to a centrifuge tube, and centrifuged and washed repeatedly at 4000 rpm using a centrifuge until the pH value of the supernatant reached 6. Ultrasonic cleaning was then performed repeatedly until the pH value of the supernatant reached neutrality, and the precipitate was separated and vacuum dried at 70°C to obtain black powdered Ti 3 C 2 T x MXene nanosheets;

[0072] Step 2: Prepare spinning solution

[0073] Dissolve 1.0 g PAN in 10 mL DMF and stir magnetically to obtain solution C. Add 0.8 g C 10 H 14 O 5 V, stirred for 1 h to obtain solution D, and 10 mg Ti was added to solution D at 50 °C. 3 C 2 T x MXene nanosheets are stirred evenly to obtain a black spinning solution;

[0074] Step 3: Preparation of Ti 3 C 2 T x Composite V 2O 5 Self-supporting membrane materials

[0075] First, the spinning solution was loaded into a 10 mL syringe, and the syringe was placed in an electrospinning machine. At the same time, the distance from the needle tip to the collector was set to 15 cm, the applied voltage was set to 18 kV, the spinning speed was set to 1.5 mL / min, and spinning was started. 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 for 12 h, and then transferred to a muffle furnace at 200 ° C for calcination for 2 h. Then, in an Ar atmosphere, the temperature was raised from room temperature to 650 ° C at a heating rate of 2 ° C / min, and annealed for 2 h to obtain Ti 3 C 2 T x Composite V 2 O 5 Self-supporting film material, also known as self-supporting Ti 3 C 2 T x / V 2 O 5 @CNF membrane.

[0076] Depend on Figure 1 It can be seen that at 2θ of 6.1°, Ti 3 C 2 T x The (002) crystal plane diffraction peaks of the material were observed at 2θ of 9.7°, 25.6°, and 50.2°. 2 O 5 The (001) and (010) diffraction peaks of the material indicate that Ti 3 C 2 T x Composite S-doped V 2 O 5 Self-supporting film material, due to S doping into V 2 O 5 , so that V 2 O 5 The (020) crystal plane diffraction peak shifts from quasi-10.4° to 9.7° to the left, V 2 O 5 The interlayer spacing becomes wider, which is beneficial to NH 4 + In Ti 3 C 2 T x / SV 2 O 5 @Embed / Escape in CNF.

[0077] Depend on Figure 2 It can be seen that S doped V 2 O5 The surface of the carbon fiber self-supporting membrane is coated with Ti 3 C 2 T x Nanosheets wrapped to form an integrated Ti 3 C 2 T x / SV 2 O 5 @CNF self-supporting structure not only helps to stabilize Ti 3 C 2 T x and SV 2 O 5 The structure of the material can effectively prevent Ti 3 C 2 T x The nanosheets are aggregated and have a larger specific surface area, which enhances the NH 4 + storage effect.

[0078] The Ti prepared in Example 1 3 C 2 T x Composite S-doped V 2 O 5 Self-supporting film material, S-doped V prepared in Comparative Example 1 2 O 5 Self-supporting film material and Ti prepared in Comparative Example 2 3 C 2 T x Composite V 2 O 5 Self-supporting membrane material assembly NH 4 + The battery was tested for constant current charge and discharge capacity. Figure 3 to Figure 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, the Ti prepared in Example 1 3 C 2 T x Composite S-doped V 2 O 5 NH assembled from self-supporting membrane materials 4 + The battery capacity is 555.2mAh·g -1 、402.3mAh·g-1 、316.5mAh·g -1 、196.4mAh·g -1 、110.7mAh·g -1 and 54.2mAh·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, the S-doped V prepared in Comparative Example 1 2 O 5 NH assembled from self-supporting membrane materials 4 + The battery capacity is 540.1mAh·g -1 、354.7mAh·g -1 、216.9mAh·g -1 、110.4mAh·g -1 、56.8mAh·g -1 and 26.2 mAh 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, the Ti prepared in Comparative Example 2 3 C 2 T x Composite V 2 O 5 NH assembled from self-supporting membrane materials 4 + 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 Figure 3 to Figure 5 It can be found that the Ti prepared in Example 1 3 C2 T x Composite S-doped V 2 O 5 NH assembled from self-supporting membrane materials 4 + The battery is relatively stable compared to the S-doped V prepared in Comparative Example 1. 2 O 5 Self-supporting film material and Ti prepared in Comparative Example 2 3 C 2 T x Composite V 2 O 5 NH assembled from self-supporting membrane materials 4 + The battery has a higher specific capacity and power density, indicating that the Ti prepared in Example 1 3 C 2 T x Composite S-doped V 2 O 5 Self-supporting membrane materials as aqueous NH 4 + When used as a positive electrode material for batteries, it can accelerate the charge and discharge process of aqueous ammonium ion battery systems.

Claims

1. An electrospun Ti3C2T x The method for preparing a composite S-doped V2O5 self-supporting film material is characterized in that: The steps include: Step 1: Prepare spinning solution Dissolve 0.5-2.0 g PAN in 10 mL DMF and stir magnetically to obtain solution C. Add 0.4-1.6 g C 10 H 14 O5V, stir for 1h to obtain solution D, add 0.15-0.6g sulfur powder to solution D at 50℃, stir for 12h to obtain dark green solution E, add 5-20mg Ti3C2T x MXene nanosheets are stirred evenly to obtain a black spinning solution; Step 2: Preparation of Ti3C2T x Composite S-doped V2O5 self-supporting film material First, the spinning solution was loaded into the syringe of the electrospinning machine to complete the spinning process to obtain the electrospinning precursor. After vacuum drying, it was placed in a muffle furnace at 180-210 ° C and calcined for 2 h. Then, in an argon atmosphere, the temperature was raised from room temperature to 600-700 ° C at a heating rate of 2 ° C / min, and annealed for 2 h to obtain Ti3C2T x Composite S-doped V2O5 self-supporting film material.

2. The electrospun Ti3C2T3 according to claim 1 x The method for preparing a composite S-doped V2O5 self-supporting film material is characterized in that: The Ti3C2T in step 1 x MXene nanosheets were prepared by the following method: 2-4 g LiF was added to 30-50 mL 9 mol / L HCl solution and stirred thoroughly to obtain solution A. 1-3 g Ti3AlC2 was slowly added to solution A and stirred for 24 h in a water bath at 50 °C to obtain reaction solution B. The reaction solution B was repeatedly centrifuged and washed until the pH value of the supernatant was 5-6, and then repeatedly washed with ultrasound until the pH value of the supernatant was neutral. The precipitate was separated and vacuum dried to obtain black powder Ti3C2T x MXene nanosheets.

3. The electrospun Ti3C2T3 according to claim 2 x The method for preparing a composite S-doped V2O5 self-supporting film material is characterized in that: The vacuum drying temperature is 60-80°C.

4. The electrospun Ti3C2T3 according to claim 1 x The method for preparing a composite S-doped V2O5 self-supporting film material is characterized in that: In the 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 Ti3C2T3 according to claim 1 x The method for preparing a composite S-doped V2O5 self-supporting film material is characterized in that: The parameters of the electrospinning machine in step 2 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 Ti3C2T3 according to claim 1 x The method for preparing a composite S-doped V2O5 self-supporting film material is characterized in that: The vacuum drying temperature in step 2 is 60° C. and the time is 12 h.

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 Ti3C2T3 according to claim 7 x Composite S-doped V2O5 self-supporting membrane material as aqueous NH4 + Application of battery positive electrode materials.

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