Fe < 3 + > doped nanobelt structure VO2 (B) / V3O5 heterojunction material as well as preparation method and application thereof

Abstract

The invention discloses a Fe < 3 + > doped nanobelt structure VO2 (B) / V3O5 heterojunction material and a preparation method and application thereof.The method comprises the following steps that 3 mmol to 5 mmol of V2O5 is added into 25 mL to 35 mL of deionized water, 7.5 mL to 12.5 mL of H2O2 is dropwise added, a clear dark red solution A is obtained, 0.15 mmol to 0.25 mmol of FeCl3. 6H2O and 40.5 mg to 67.6 mg of PEG-4000 are added into the solution A and fully stirred till complete dissolution, a mixed solution B is obtained, then the mixed solution B is transferred to a high-pressure reaction kettle, the temperature of the high-pressure reaction kettle is increased, and the Fe < 3 + > doped nanobelt structure VO2 (B) / V3O5 heterojunction material is obtained. The preparation method comprises the following steps: putting a high-pressure reaction kettle into a drying oven, reacting at 150-200 DEG C for 24-48 hours, and then sequentially cleaning and drying to obtain the powdery Fe < 3 + >-doped nanobelt structure VO2 (B) / V3O5 heterojunction material which has good structural stability, high power density and high area specific capacity and can promote rapid charging and discharging of an aqueous ammonium ion battery.

Description

Technical Field

[0001] The present invention relates to an aqueous ammonium ion battery positive electrode material, specifically a Fe 3+ Doped nanobelt structured VO2(B) / V3O5 heterojunction material, 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, 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: on the one hand, compared with lithium-ion batteries, NH4 + The battery has a higher power density and can achieve fast charge and discharge; on the other hand, NH4 + The battery is green, pollution-free and environmentally friendly, and has application value in the field of power energy.

[0003] VO2(B) has metal-level conductivity, high specific surface area and good hydrophilicity. It shows great potential in the new generation of high-performance battery electrodes and has received extensive attention in recent years. However, when it is used as the positive electrode material of aqueous ammonium ion batteries, the diffusion process of ammonium ions easily leads to the collapse of the interlayer structure and does not have good NH4 + Storage cycle stability performance; V3O5 material has a good tunnel structure, which can meet the needs of ion diffusion during the charge and discharge process of ammonium ion batteries. However, due to its structure and low ion diffusion rate, the V3O5 material with tunnel structure cannot accommodate more ammonium ions in the system, resulting in NH4 + The storage effect is not good; therefore, it is expected to combine the two to construct VO2(B) / V3O5 heterojunction materials and increase NH4 at the heterojunction + The adsorption sites for storage can improve the storage efficiency of ammonium ions. However, the weak hydrogen bonds between the layers of the VO2(B) / V3O5 heterojunction material are prone to degradation during the insertion / extraction of ammonium ions, which affects the ammonium storage effect of the heterojunction material. Therefore, it is necessary to continue to modify the VO2(B) / V3O5 heterojunction material to improve its structural stability, so as to obtain a more suitable material for aqueous NH4 + Composite materials for batteries. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention aims to provide a Fe 3+Doped nanobelt structured VO2(B) / V3O5 heterojunction material, preparation method and application thereof. The prepared VO2(B) / V3O5 heterojunction material has good structural stability, high power density and high area specific capacity, and can promote rapid charging and discharging of aqueous ammonium ion batteries.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A Fe 3+ The preparation method of the doped nanobelt structure VO2(B) / V3O5 heterojunction material comprises the following steps:

[0007] First, 3-5 mmol V2O5 was added to 25-35 mL deionized water, and then 7.5-12.5 mL H2O2 was added dropwise to obtain a clear dark red solution A. Then, 0.15-0.25 mmol FeCl3·6H2O and 40.5-67.6 mg PEG-4000 were added to solution A and stirred until completely dissolved to obtain a mixed solution B. Then, the mixed solution B was transferred to a high-pressure reactor, and the high-pressure reactor was placed in an oven and reacted at 150-200°C for 24-48 hours, and then washed and dried in sequence to obtain powdered Fe 3+ Doped nanoribbon structured VO2(B) / V3O5 heterojunction materials.

[0008] Furthermore, the ratio of V2O5 to H2O2 is 4mmol:10mL.

[0009] Furthermore, the ratio of V2O5 to FeCl3·6H2O is 4mmol:0.2mmol.

[0010] Furthermore, the mass ratio of the FeCl3·6H2O to PEG-4000 is 1:1.

[0011] Furthermore, the V2O5 and FeCl3·6H2O are both analytically pure.

[0012] Furthermore, the cleaning is performed by centrifugal washing with deionized water for 3 to 5 times.

[0013] Furthermore, the drying is carried out at 60 to 80° C. for 10 to 12 hours.

[0014] A Fe 3+ Doped nanoribbon structured VO2(B) / V3O5 heterojunction materials.

[0015] A Fe 3+ Doped nanoribbon structured VO2(B) / V3O5 heterojunction materials as aqueous NH4 + Application of battery positive electrode materials.

[0016] Compared with the prior art, the present invention has the following technical effects:

[0017] The present invention utilizes a hydrothermal method to Fe-treat VO2(B) / V3O5 heterojunction materials. 3+ Doping to generate Fe 3+ Doping nanobelt structure VO2(B) / V3O5 heterojunction materials has the following advantages: On the one hand, it can not only stabilize the structure of VO2(B) / V3O5 materials, effectively prevent the structural deterioration caused by stress enrichment of materials during the charge and discharge process, improve the structural stability of the materials, but also increase the specific surface area of ​​the materials, significantly increasing the composite material's resistance to NH4 + storage effect; on the other hand, Fe 3+ Doping not only widens the interlayer spacing, but also facilitates NH4 + insertion / extraction, and increased NH4 + ions adsorption active sites, thereby improving the NH4 + Storage performance; Therefore, the Fe prepared by the present invention 3+ Doped nanobelt structure VO2(B) / V3O5 heterojunction material has good structural stability, high power density and high area specific capacity, and is suitable for aqueous NH4 + When used as a positive electrode material for a battery, it can promote rapid charging and discharging of an aqueous ammonium ion battery system and 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

[0018] Figure 1 : Fe prepared in Example 1 of the present invention 3+ XRD pattern of doped nanobelt structure VO2(B) / V3O5 material;

[0019] Figure 2 : Fe prepared in Example 1 of the present invention 3+ TEM image of doped nanobelt structured VO2(B) / V3O5 material;

[0020] Figure 3 : Fe prepared in Example 1 of the present invention 3+ NH4 doped nanobelt structured VO2(B) / V3O5 materials assembled + Hybrid capacitor, constant current charge and discharge profiles at different current densities;

[0021] Figure 4 : NH4 assembled from nanobelt structure VO2(B) / V3O5 materials prepared in comparative example 1 of the present invention +Hybrid capacitor, constant current charge and discharge profiles at different current densities. DETAILED DESCRIPTION

[0022] The specific contents of the present invention are further explained in detail below in conjunction with embodiments.

[0023] The V2O5 and FeCl3·6H2O used in Examples 1 to 5 were both analytically pure.

[0024] Example 1

[0025] Step 1, add 4 mmol V2O5 to 30 mL deionized water, and then add 10 mL H2O2 dropwise to obtain a clear deep red solution A;

[0026] Step 2, add 0.2 mmol FeCl3·6H2O and 54 mg PEG-4000 to solution A, stir thoroughly until completely dissolved, and obtain a mixed solution B;

[0027] Step 3: Transfer the mixed solution B to a high-pressure reactor, place the high-pressure reactor in an oven, react at 150°C for 24 hours, then centrifuge and wash three times with deionized water, and dry at 60°C for 12 hours to obtain powdered Fe 3+ Doped nanoribbon structured VO2(B) / V3O5 heterojunction materials.

[0028] See also Figure 1 The XRD patterns of the samples show that the marked diffraction peaks point to the (001), (200), (110), (002), (-511), (312), (-404) crystal planes of VO2 (PDF#31-1438) and the (002), (-112), (020), (-310), (-312) crystal planes of V3O5 (PDF#38-1181), respectively, indicating that VO2(B) and V3O5 materials are successfully composited and VO2(B) / V3O5 heterojunction materials are successfully prepared. At the same time, the diffraction peaks at 25.2° and 29° corresponding to VO2 shift slightly to the left in the low-angle diffraction direction, indicating that Fe 3+ Successfully entered the layered structure of VO2, expanding the lattice spacing, and Fe 3+ The widening of the VO2 interlayer spacing caused by doping is beneficial to NH4 + Insertion / extraction.

[0029] See also Figure 2 SEM images of the VO2(B) / V3O5 heterojunction material show nanobelts with a width of about 100nm. The ultra-thin nanobelt VO2(B) / V3O5 heterojunction material has a larger specific surface area and more NH4 + Storage sites, enhancing the NH4 +storage effect.

[0030] Example 2

[0031] Step 1, add 4.4mmol V2O5 to 35mL deionized water, and then add 11mL H2O2 dropwise to obtain a clear deep red solution A;

[0032] Step 2, add 0.22mmol FeCl3·6H2O and 59.5mg PEG-4000 to solution A, stir thoroughly until completely dissolved, and obtain a mixed solution B;

[0033] Step 3: Transfer the mixed solution B to a high-pressure reactor, place the high-pressure reactor in an oven, react at 180°C for 36 hours, then centrifuge and wash three times with deionized water, and dry at 70°C for 10 hours to obtain powdered Fe 3+ Doped nanoribbon structured VO2(B) / V3O5 heterojunction materials.

[0034] Example 3

[0035] Step 1, add 5 mmol V2O5 to 25 mL deionized water, and then add 12.5 mL H2O2 dropwise to obtain a clear deep red solution A;

[0036] Step 2, add 0.25 mmol FeCl3·6H2O and 67.6 mg PEG-4000 to solution A, stir thoroughly until completely dissolved, and obtain a mixed solution B;

[0037] Step 3: Transfer the mixed solution B to a high-pressure reactor, place the high-pressure reactor in an oven, react at 170°C for 36 hours, then centrifuge and wash 4 times with deionized water, and dry at 70°C for 10 hours to obtain powdered Fe 3+ Doped nanoribbon structured VO2(B) / V3O5 heterojunction materials.

[0038] Example 4

[0039] Step 1, add 3 mmol V2O5 to 20 mL deionized water, and then add 7.5 mL H2O2 dropwise to obtain a clear deep red solution A;

[0040] Step 2, add 0.15 mmol FeCl3·6H2O and 40.5 mg PEG-4000 to solution A, stir thoroughly until completely dissolved, and obtain a mixed solution B;

[0041] Step 3: Transfer the mixed solution B to a high-pressure reactor, place the high-pressure reactor in an oven, react at 190°C for 48 hours, then centrifuge and wash 4 times with deionized water, and dry at 70°C for 11 hours to obtain powdered Fe3+ Doped nanoribbon structured VO2(B) / V3O5 heterojunction materials.

[0042] Example 5

[0043] Step 1, add 3.5mmol V2O5 to 27.5mL deionized water, and then add 8.75mL H2O2 dropwise to obtain a clear deep red solution A;

[0044] Step 2, add 0.18 mmol FeCl3·6H2O and 48.7 mg PEG-4000 to solution A, stir thoroughly until completely dissolved, and obtain a mixed solution B;

[0045] Step 3: Transfer the mixed solution B to a high-pressure reactor, place the high-pressure reactor in an oven, react at 200°C for 24 hours, then centrifuge and wash 5 times with deionized water, and dry at 60°C for 10 hours to obtain powdered Fe 3+ Doped nanoribbon structured VO2(B) / V3O5 heterojunction materials.

[0046] Comparative Example 1

[0047] Step 1, add 4 mmol V2O5 to 30 mL deionized water, and then add 10 mL H2O2 dropwise to obtain a clear deep red solution A;

[0048] Step 2: Transfer the mixed solution A to a high-pressure reactor, place the high-pressure reactor in an oven, react at 150°C for 24 hours, then centrifuge and wash three times with deionized water, and dry at 70°C for 10 hours to obtain a powdered nanobelt structured VO2(B) / V3O5 heterojunction material.

[0049] The Fe prepared in Example 1 and Comparative Example 1 were 3+ Doped nanobelt structured VO2(B) / V3O5 heterojunction materials and nanobelt structured VO2(B) / V3O5 heterojunction materials as aqueous NH4 + Battery positive electrode materials, assembling aqueous NH4 + Batteries, under the same conditions, the capacity of the batteries was tested respectively, and the results are as follows Figure 3 and Figure 4 As shown:

[0050] See also Figure 3 It can be seen that at a current density of 0.5A·g -1 , 1A·g -1 , 2A·g -1 , 3A g -1 , 4A g -1 and 5A·g -1 Under the conditions, the Fe prepared in Example 1 3+NH4 doped nanoribbon structured VO2(B) / V3O5 heterojunction materials assembled + The battery capacity is 285mAh g -1 、188.3、mAh·g -1 、136.7mAh·g -1 、118.3mAh·g -1 、108.3mAh·g -1 and 101.7 mAh g -1 ;

[0051] See also Figure 4 It can be seen that at a current density of 0.5A·g -1 , 1A·g -1 , 2A·g -1 , 3A g -1 , 4A g -1 and 5A·g -1 Under the conditions, NH4 + The battery capacity is 156.8mAh·g -1 、110.8mAh·g -1 、85mAh·g -1 、74.4mAh·g -1 、67.5mAh·g -1 and 63mAh·g -1 ;

[0052] By comparison Figure 3 and Figure 4 The experimental results show that the Fe prepared in Example 1 3+ Doped nanoribbon structured VO2(B) / V3O5 heterojunction materials as aqueous NH4 + When used as a positive electrode material for batteries, it can accelerate the charge and discharge process of aqueous ammonium ion battery systems and has high specific capacity and high power density.

Claims

1. A kind of Fe 3+ The method for preparing a doped nanobelt structure VO2(B) / V3O5 heterojunction material is characterized in that: The steps include: First, 3-5 mmol V2O5 was added to 25-35 mL deionized water, and then 7.5-12.5 mL H2O2 was added dropwise to obtain a clear dark red solution A. Then, 0.15-0.25 mmol FeCl3·6H2O and 40.5-67.6 mg PEG-4000 were added to solution A and stirred until completely dissolved to obtain a mixed solution B. Then, the mixed solution B was transferred to a high-pressure reactor, and the high-pressure reactor was placed in an oven and reacted at 150-200°C for 24-48 hours, and then washed and dried in sequence to obtain powdered Fe 3+ Doped nanoribbon structured VO2(B) / V3O5 heterojunction materials.

2. Fe according to claim 1 3+ The method for preparing a doped nanobelt structure VO2(B) / V3O5 heterojunction material is characterized in that: The ratio of V2O5 to H2O2 is 4mmol:10mL.

3. Fe according to claim 2 3+ The method for preparing a doped nanobelt structure VO2(B) / V3O5 heterojunction material is characterized in that: The ratio of V2O5 to FeCl3·6H2O is 4mmol:0.2mmol.

4. Fe according to claim 3 3+ The method for preparing a doped nanobelt structure VO2(B) / V3O5 heterojunction material is characterized in that: The mass ratio of the FeCl3·6H2O to PEG-4000 is 1:

1.

5. Fe according to claim 1 3+ The method for preparing a doped nanobelt structure VO2(B) / V3O5 heterojunction material is characterized in that: The V2O5 and FeCl3·6H2O are both analytically pure.

6. Fe according to claim 1 3+ The method for preparing a doped nanobelt structure VO2(B) / V3O5 heterojunction material is characterized in that: The cleaning is performed by centrifugation washing with deionized water for 3 to 5 times.

7. Fe according to claim 1 3+ The method for preparing a doped nanobelt structure VO2(B) / V3O5 heterojunction material is characterized in that: The drying is carried out at 60 to 80° C. for 10 to 12 hours.

8. A Fe prepared by the method according to any one of claims 1 to 7 3+ Doped nanoribbon structured VO2(B) / V3O5 heterojunction materials.

9. Fe according to claim 8 3+ Doped nanoribbon structured VO2(B) / V3O5 heterojunction materials as aqueous NH4 + Application of battery positive electrode materials.

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