Preparation method of anatase phase VTiO4
By preparing anatase phase VTiO4, the problem of insufficient specific capacity and energy density of anatase phase TiO2 electrode materials was solved, and the application of high-performance lithium-ion storage electrode materials was realized.
Patent Information
- Application Number
- CN202311203881.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-09-19
- Publication Date
- 2025-09-23
- Estimated Expiration
- 2043-09-19
AI Technical Summary
Existing anatase phase TiO2 electrode materials have low specific capacity and energy density in electrochemical reactions, making it difficult to meet the performance requirements of lithium-ion storage devices.
Anatase phase VTiO4 is prepared by a preparation method, which includes adding lithium fluoride and VTiAlC powder into a hydrochloric acid aqueous solution, undergoing hydrothermal reaction, centrifugal washing and vacuum drying, and finally obtaining anatase phase VTiO4 under annealing treatment.
The prepared anatase phase VTiO4 material exhibits high specific capacity and high energy density, has excellent mass specific capacitance and cycle stability, and can maintain good performance especially at high current density.
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Figure CN117263243B_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of lithium ion storage materials, and in particular relates to a preparation method and application of anatase phase VTiO4. Background Art
[0002] Faced with global environmental degradation and energy shortages, the storage and application of clean, renewable energy is essential for sustainable human development. Among various electrochemical energy storage devices, lithium-ion storage devices are widely favored by scientists due to their low self-discharge, wide operating temperature range, and safety and environmental friendliness. Currently, they are widely used in portable smart devices and electric vehicles. Among the components of lithium-ion storage devices, electrode materials are the core and key. The performance of electrode materials directly determines the key performance characteristics of lithium-ion storage devices, such as charge-discharge capacity, capacity retention at high currents, energy density, power density, and cycling stability. Therefore, the development of electrode materials with excellent performance and environmental friendliness is crucial.
[0003] In the process of exploring new electrode materials, anatase titanium oxide (TiO2) has the characteristics of being environmentally friendly, low cost, highly stable in cycles, and safe, which are conducive to its application in large-scale lithium-ion storage. However, since only one electron in TiO2 participates in the reversible redox process in the electrochemical reaction, its specific capacity and energy density are relatively low. Vanadium ions have variable valence states (+2, +3, +4, and +5) during the lithiation / delithiation process, and can undergo additional redox reactions at lower potentials. Therefore, anatase vanadium titanium oxide (VTiO4) has a high specific capacity and high energy density relative to anatase TiO2. In addition, V 4+ The size of the ion and Ti 4+ The similarity leads to the high structural stability of V in TiO2. Therefore, VTiO4 is a very promising high-performance lithium-ion storage electrode material. Summary of the Invention
[0004] Based on the above technical background, the present invention provides a method for preparing anatase-phase VTiO4 and its application. The preparation method is simple, low-cost, economical, environmentally friendly, and highly reproducible, and has broad application prospects.
[0005] The technical solution adopted by the present invention is: a method for preparing anatase phase VTiO4, the preparation method comprising the following steps:
[0006] Step 1: Precursor VTiCT x Preparation
[0007] Lithium fluoride was added to the hydrochloric acid aqueous solution and stirred to fully dissolve to obtain a reactant. VTiAlC powder was added to the reactant and stirred to dissolve. The solution was transferred to a polytetrafluoroethylene hydrothermal reactor and heated at 30 o C~ 55 o C and stirred for 20 h to 60 h to obtain the reactant (precursor VTiCT x );
[0008] Step 2: Precursor VTiCT x Preparation of nanosheet suspension
[0009] The reactant obtained in step 1 (precursor VTiCT x ) for centrifugal washing, and then use dilute hydrochloric acid solution, lithium chloride aqueous solution, ethanol solution and deionized water for high-speed centrifugal washing several times. The muddy material after washing is collected by low-speed centrifugation. The upper suspension is VTiCT x Nanosheet suspension;
[0010] Step 3: Preparation of anatase phase VTiO4
[0011] VTiCT x The suspension was concentrated by high-speed centrifugation, and the concentrated VTiCT x The suspension was transferred to a polytetrafluoroethylene hydrothermal reactor and heated at 150 o C~250 o C for 10 h to 30 h to obtain a reactant, which is then vacuum dried for 10 h to 20 h. The powder is taken out and annealed in a furnace for 2 h to 10 h to obtain anatase phase VTiO4.
[0012] Furthermore, the density of the hydrochloric acid aqueous solution in step 1 is 1.18 g mL -1 3.0 g of lithium fluoride was added to 25 mL of hydrochloric acid aqueous solution to prepare a reactant, and 1.0 g to 1.5 g of VTiAlC powder was added to the reactant to obtain a reactant.
[0013] Furthermore, the density of the dilute hydrochloric acid solution in step 2 is 1.10 g mL -1 , dilute hydrochloric acid aqueous solution is 20~25 mL, and the density of lithium chloride aqueous solution is 1.05 g mL -1 , the lithium chloride aqueous solution is 100~150 mL.
[0014] Furthermore, in step 2, the dilute hydrochloric acid aqueous solution, lithium chloride aqueous solution, ethanol solution and deionized water are respectively washed by high-speed centrifugation for 3 to 5 times.
[0015] Furthermore, the high-speed centrifugation in step 2 is centrifugation at a speed greater than 9000 rpm for 3 to 5 min; and the low-speed centrifugation is centrifugation at a speed of 3000 to 4000 rpm for 3 to 5 min.
[0016] Furthermore, in step 3, VTiCT x Suspension concentration is 3~6 mg mL -1 .
[0017] Furthermore, the temperature for vacuum drying the reactants in step 3 is 80 o C~90 o C.
[0018] Furthermore, in step 3, at 430 o C~470 o The powder was annealed at 4000 ℃ and high purity argon was passed through.
[0019] Furthermore, the prepared anatase phase VTiO4 is used as a lithium ion storage electrode material.
[0020] The beneficial effects of the present invention are as follows: a preparation method of anatase phase VTiO4 and its application are provided. The preparation method is simple, low-cost, economical, environmentally friendly, and highly reproducible. The application prospects are broad, and the material has excellent mass specific capacitance and cycle stability. When the current density is 0.05 A g -1 When the mass specific capacitance can reach 330 mAh g -1 , and at 5.00 A g -1 The mass specific capacity shows almost no attenuation after 1000 cycles at a high current density. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 is a transmission electron microscope image of anatase phase VTiO4 in the present invention;
[0022] Figure 2 It is the X-ray diffraction spectrum of anatase phase VTiO4 and anatase phase TiO2, where 1 represents anatase phase VTiO4 and 2 represents anatase phase TiO2;
[0023] Figure 3 This is the rate performance diagram of anatase phase VTiO4 at different current densities;
[0024] Figure 4 Anatase phase VTiO4 at 5.00 A g -1 Cyclic curves at current density of . Implementation Method Example
[0025] A method for preparing anatase phase VTiO4, the preparation method comprising the following steps:
[0026] Step 1: Precursor VTiCT x Preparation
[0027] Add 3.0 g of lithium fluoride to 25 mL of hydrochloric acid solution and stir to fully dissolve it to prepare the reactant. The density of hydrochloric acid solution is 1.18 g mL -1 ; Then 1.0 g of VTiAlC powder was added to the reactant, stirred and dissolved, and the solution was transferred to a polytetrafluoroethylene hydrothermal reactor and heated at 30 o C and stirred for 20 h to obtain the reactant (precursor VTiCT x ).
[0028] Step 2: Precursor VTiCT x Preparation of nanosheet suspension
[0029] The reactant obtained in step 1 (precursor VTiCT x ) for centrifugal washing, and then washed three times with dilute hydrochloric acid solution, lithium chloride aqueous solution, ethanol solution and deionized water by high-speed centrifugation; the density of dilute hydrochloric acid aqueous solution is 1.10g mL -1 , dilute hydrochloric acid aqueous solution is 20 mL, and the density of lithium chloride aqueous solution is 1.05 g mL -1 , lithium chloride aqueous solution is 100mL, high-speed centrifugation is centrifugation at a speed of 10000 rpm for 3 min; the muddy material after washing is collected by low-speed centrifugation, and the low-speed centrifugation is centrifugation at a speed of 3000 rpm for 3 min. The suspension is VTiCT x Nanosheet suspension.
[0030] Step 3: Preparation of anatase phase VTiO4
[0031] VTiCT x The suspension was concentrated by centrifugation at 10,000 rpm for 30 min (high-speed centrifugation). x The concentration of the suspension is 3 mg mL -1 , the concentrated VTiCT x The suspension was transferred to a polytetrafluoroethylene hydrothermal reactor and heated at 150 o C for 10 h to obtain the reactant, which was then vacuum dried for 10 h at a temperature of 80 o C, take out the powder and put it in the furnace at 430 oThe powder was annealed at 4000 ℃ and high-purity argon was passed through for 2 hours. Finally, anatase phase VTiO4 was obtained. Example
[0032] A method for preparing anatase phase VTiO4, the preparation method comprising the following steps:
[0033] Step 1: Precursor VTiCT x Preparation
[0034] Add 3.0 g of lithium fluoride to 25 mL of hydrochloric acid solution and stir to fully dissolve it to prepare the reactant. The density of hydrochloric acid solution is 1.18 g mL -1 ; Then 1.5 g of VTiAlC powder was added to the reactant, stirred and dissolved, and the solution was transferred to a polytetrafluoroethylene hydrothermal reactor at 55 o C and stirred for 60 h to obtain the reactant (precursor VTiCT x ).
[0035] Step 2: Precursor VTiCT x Preparation of nanosheet suspension
[0036] The reactant obtained in step 1 (precursor VTiCT x ) for centrifugal washing, and then washed five times with dilute hydrochloric acid solution, lithium chloride aqueous solution, ethanol solution and deionized water by high-speed centrifugation; the density of dilute hydrochloric acid aqueous solution is 1.10 g mL -1 , dilute hydrochloric acid aqueous solution is 25 mL, and the density of lithium chloride aqueous solution is 1.05 g mL -1 , lithium chloride aqueous solution is 150mL, high-speed centrifugation is centrifugation at a speed greater than 9000 rpm for 5 minutes; the muddy material after washing is collected by low-speed centrifugation, and the low-speed centrifugation is centrifugation at a speed of 4000 rpm for 5 minutes. The suspension is VTiCT x Nanosheet suspension.
[0037] Step 3: Preparation of anatase phase VTiO4
[0038] VTiCT x The suspension was concentrated by centrifugation at 10,000 rpm for 30 min (high-speed centrifugation). x The concentration of the suspension is 6 mg mL -1 , the concentrated VTiCT x The suspension was transferred to a polytetrafluoroethylene hydrothermal reactor and heated at 250 oC for 30 h to obtain the reactant, which was then vacuum dried for 20 h at a temperature of 90 o C, take out the powder and put it in the furnace at 470 o The powder was annealed at 4000 ℃ and high-purity argon was passed through for 10 h. Finally, anatase phase VTiO4 was obtained. Example
[0039] A method for preparing anatase phase VTiO4, the preparation method comprising the following steps:
[0040] Step 1: Precursor VTiCT x Preparation
[0041] Add 3.0 g of lithium fluoride to 25 mL of hydrochloric acid solution and stir to fully dissolve it to prepare the reactant. The density of hydrochloric acid solution is 1.18 g mL -1 ; Then 1.25 g of VTiAlC powder was added to the reactant, stirred and dissolved, and the solution was transferred to a polytetrafluoroethylene hydrothermal reactor at 43 o C and stirred for 40 h to obtain the reactant (precursor VTiCT x ).
[0042] Step 2: Precursor VTiCT x Preparation of nanosheet suspension
[0043] The reactant obtained in step 1 (precursor VTiCT x ) for centrifugal washing, and then washed four times with dilute hydrochloric acid solution, lithium chloride aqueous solution, ethanol solution and deionized water by high-speed centrifugation; the density of dilute hydrochloric acid aqueous solution is 1.10g mL -1 , dilute hydrochloric acid aqueous solution is 22 mL, and the density of lithium chloride aqueous solution is 1.05 g mL -1 , lithium chloride aqueous solution is 125mL, high-speed centrifugation is centrifugation at a speed greater than 9000 rpm for 4 min; the muddy material after washing is collected by low-speed centrifugation, and the low-speed centrifugation is centrifugation at a speed of 3500 rpm for 4 min. The suspension is VTiCT x Nanosheet suspension.
[0044] Step 3: Preparation of anatase phase VTiO4
[0045] VTiCT x The suspension was concentrated by centrifugation at 10,000 rpm for 30 min (high-speed centrifugation). x The concentration of the suspension is 4.5 mg mL -1, the concentrated VTiCT x The suspension was transferred to a polytetrafluoroethylene hydrothermal reactor and heated at 200 o C for 20 h to obtain the reactant, which was then vacuum dried for 15 h at a temperature of 85 o C, take out the powder and put it in the furnace at 450 o The powder was annealed at 4000 ℃ and high-purity argon was passed through for 6 h. Finally, anatase phase VTiO4 was obtained. Example
[0046] In the preparation method of anatase phase VTiO4
[0047] In step 1, the polytetrafluoroethylene hydrothermal reactor is sealed and stirred in a water bath. The reaction temperature can be selected to be 40 o C or 50 o C, the rotation speed can be 200 rpm or 400 rpm, and the reaction time can be 40 h or 50 h.
[0048] In step 3, VTiCT x The suspension was concentrated by high-speed centrifugation. x The concentration of the suspension is 3 mg / mL -1 , the concentrated VTiCT x The suspension was transferred to a polytetrafluoroethylene hydrothermal reactor and heated at 180 o C or 220 o After keeping the temperature at 450℃ for 15 hours, the reactant was obtained. The powder was taken out and placed in a furnace. o The powder is annealed at 4°C and high-purity argon is passed through. The annealing time can be 4 hours. Example
[0049] The anatase phase VTiO4 prepared in the above embodiment is used as a lithium ion storage electrode material.
[0050] Based on the above embodiments, Figure 1 The transmission electron microscope image of the prepared anatase phase VTiO4 shows that the VTiO4 has a granular morphology. Figure 2 This is the X-ray diffraction spectrum of anatase phase VTiO4. It can be seen from the figure that the X-ray diffraction spectrum of the synthetic product is similar to that of anatase TiO2. Figure 1 The results show that the anatase phase VTiO4 was successfully prepared.
[0051] The prepared anatase phase VTiO4 was used as a lithium ion storage electrode material, and the electrochemical tests were performed as follows:
[0052] Lithium-ion battery assembly:
[0053] The working electrode is made by uniformly mixing anatase phase VTiO4, conductive adhesive polyvinylidene fluoride and conductive agent acetylene black in a mass ratio of 8:1:1 to form a slurry, and then evenly coating the slurry on copper foil. Polypropylene film is used as the diaphragm, 1 mol L -1 LiPF6 was used as the electrolyte (the volume ratio of ethylene carbonate and diethyl carbonate was 1:1), the coated electrode was used as the working electrode, and the metal lithium sheet was used as the counter electrode to assemble into a button cell.
[0054] Electrochemical performance test:
[0055] The charge-discharge performance and cycle performance of the working electrode at different current densities were tested using a LAND CT2001A blue battery test system, and the assembled half-cell test voltage range was 0.01~3 V.
[0056] The mass specific capacitance of the anatase phase VTiO4 working electrode prepared in Example 3 at different current densities is shown in FIG. Figure 3 ,from Figure 3 It can be seen that 0.05 A g -1 At a current density of 1.5 Å, the mass specific capacitance of the anatase phase VTiO4 working electrode is as high as 330 mAhg -1 , which is much higher than the theoretical capacity of TiO2 (~168 mAh g -1 ), and at 5.00 A g -1 Even at a high current density of 140 mAh g -1 The mass specific capacitance of the anatase phase VTiO4 working electrode is shown in Figure 2. Figure 4 ,from Figure 4 It can be seen that at 5.00 A g -1 At a current density of 1000, the mass specific capacitance hardly decays during 1000 cycles, indicating that it has excellent cycle stability.
[0057] The anatase-phase VTiO4 preparation method described in the above embodiment solves the problem of the single nature of existing anatase-phase VTiO4 preparation methods, thereby developing a novel anatase-phase VTiO4 preparation method. The resulting anatase-phase VTiO4, as a lithium-ion storage electrode material, exhibits high mass-to-capacitance, excellent rate capability, and long cycle life.
Claims
1. A method for preparing anatase phase VTiO4, characterized in that: The preparation method comprises the following steps: Step 1: Precursor VTiCT x Preparation Lithium fluoride was added to the hydrochloric acid aqueous solution and stirred to fully dissolve to obtain a reactant. VTiAlC powder was added to the reactant and stirred to dissolve. The solution was transferred to a polytetrafluoroethylene hydrothermal reactor and heated at 30 o C~55 o C and stirred for 20 h to 60 h to obtain the reactant; Step 2: Precursor VTiCT x Preparation of nanosheet suspension The reactant obtained in step 1 was centrifugally washed, and then washed several times with dilute hydrochloric acid solution, lithium chloride aqueous solution, ethanol solution and deionized water by high-speed centrifugation. The muddy material after washing was centrifuged at low speed to collect the upper suspension. The suspension was VTiCT x Nanosheet suspension; Step 3: Preparation of anatase phase VTiO4 VTiCT x The suspension was concentrated by high-speed centrifugation, and the concentrated VTiCT x The suspension was transferred to a polytetrafluoroethylene hydrothermal reactor and heated at 150 o C~250 o C for 10 to 30 hours to obtain a reactant, which is then vacuum dried for 10 to 20 hours. The powder is taken out and annealed in a furnace for 2 to 10 hours to obtain anatase phase VTiO4. The density of the hydrochloric acid solution in step 1 is 1.18 g mL -1 3.0 g of lithium fluoride was added to 25 mL of hydrochloric acid aqueous solution to prepare a reactant, and 1.0 g to 1.5 g of VTiAlC powder was added to the reactant to obtain a reactant; The density of the dilute hydrochloric acid solution in step 2 is 1.10 g mL -1 , dilute hydrochloric acid aqueous solution is 20~25 mL, and the density of lithium chloride aqueous solution is 1.05 g mL -1 , lithium chloride aqueous solution is 100~150 mL; The dilute hydrochloric acid aqueous solution, lithium chloride aqueous solution, ethanol solution and deionized water in step 2 are respectively washed by high-speed centrifugation 3 to 5 times; The high-speed centrifugation in step 2 is centrifugation at a speed greater than 9000 rpm for 3 to 5 min; the low-speed centrifugation is centrifugation at a speed of 3000 to 4000 rpm for 3 to 5 min; In step 3, VTiCT x Suspension concentration is 3~6 mg mL -1 ; The temperature for vacuum drying the reactants in step 3 is 80 o C~90 o C; In step 3, at 430 o C~470 o The powder was annealed at 4000 ℃ and high purity argon was passed through.
2. The method for preparing anatase phase VTiO4 according to claim 1, characterized in that: The prepared anatase phase VTiO4 is used as a lithium ion storage electrode material.
Citation Information
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