A preparation method, product and application of titanium dioxide coated magnesium vanadate

Abstract

The present invention discloses a method for preparing titanium dioxide-coated magnesium vanadate, a product thereof and an application thereof. Organic vanadium oxysalt cobalt and tetrabutyl titanate are dissolved in anhydrous ethanol for ultrasonic dispersion and then stirred. 10 mL of deionized water is added dropwise to the above suspension to form a sol; an organic magnesium salt is added to the above sol, and after continuous stirring, it is added to a 100 mL reactor, reacted at 160-200 °C for 10-15 h to obtain a TiO2-coated magnesium vanadate precursor, which is washed with deionized water for 3-5 times and dried in a vacuum oven at 60-80 °C; the TiO2-coated magnesium vanadate precursor is placed in a muffle furnace and calcined at 500-700 °C for 2-6 h to obtain titanium dioxide-coated magnesium vanadate. Titanium dioxide-coated magnesium vanadate can reduce the erosion of the electrolyte on the positive electrode material, thereby improving the electrochemical performance of the material. In addition, the preparation method is simple, the process conditions are easy to achieve, the energy consumption is low, and the preparation is pollution-free.

Description

Technical Field

[0001] The invention relates to a method for preparing a magnesium electric positive electrode material, and in particular to a method for preparing titanium dioxide-coated magnesium vanadate, a product thereof and an application thereof. Background Art

[0002] With the development of human society, the contradiction between the shortage of global energy resources and the increasing demand for energy has become increasingly acute. The development of a battery system with high energy density has become the main goal of the current power system. Although lithium-ion batteries with high specific energy and environmental friendliness have been widely used in portable mobile appliances such as mobile phones and laptops, as well as power sources for electric bicycles and electric vehicles. However, since the safety of lithium-ion batteries has not been properly resolved, there is still a lot of work to be done in the application of lithium-ion batteries as power batteries. Magnesium, one of the most abundant light metal elements on the earth, is widely used in many fields due to its good physical and chemical properties. Now there are many studies on secondary magnesium batteries, all based on secondary lithium-ion batteries. Since magnesium and lithium are in diagonal positions in the periodic table, in addition to their similar atomic radius and chemical properties, the melting point of magnesium (648.8 ℃) is much higher than that of lithium (180.5 ℃), and it is not as active as lithium metal, so secondary magnesium batteries are better in safety. Although the mass capacity is not as high as lithium (3862 mAh g -1 ) but still pretty impressive (2205 mAh g -1 ). In addition, my country has extremely rich magnesium resources, the price of magnesium is much lower than that of lithium, and magnesium is environmentally friendly, so secondary magnesium batteries are gaining more and more attention.

[0003] Magnesium sulfide is a cubic sulfide that is often used as a semiconductor with a wide energy band gap. It can also be used as a positive electrode material for magnesium-ion batteries. This material is considered to be a promising magnesium-ion positive electrode material. Summary of the invention

[0004] The present invention aims to provide a method for preparing titanium dioxide-coated magnesium vanadate.

[0005] Another object of the present invention is to provide a titanium dioxide-coated magnesium vanadate product prepared by the above method.

[0006] Another object of the present invention is to provide an application of the above product.

[0007] The object of the present invention is achieved by the following scheme: A method for preparing titanium dioxide-coated magnesium vanadate, characterized in that the specific steps of the method are:

[0008] (1) Dissolve the organic vanadium oxysalt and tetrabutyl titanate in 70 mL of anhydrous ethanol at a ratio of 100 mmol:1-3 mmol and perform ultrasonic dispersion for 30-60 min, then stir for 1-2 h.

[0009] (2) Add 10 mL of deionized water dropwise into the above suspension to form a sol.

[0010] (3) Add 100 mmol of organic magnesium salt to the above sol, stir continuously for 1-2 h, then add it into a 100 mL reactor and react at 160-200 °C for 10-15 h to obtain a TiO2-coated magnesium vanadate precursor. Wash it with deionized water for 3-5 times and dry it in a vacuum oven at 60-80 °C.

[0011] (4) The TiO2-coated magnesium vanadate precursor is placed in a muffle furnace and calcined at 500-700 °C for 2-6 h to obtain titanium dioxide-coated magnesium vanadate.

[0012] The lithium organic vanadium oxysalt is one of diacetylacetonate vanadium oxysalt, isopropoxide vanadium oxysalt or lactate vanadium oxysalt or a combination thereof.

[0013] The lithium organic magnesium salt is one of magnesium diacetylacetonate, magnesium isopropoxide or magnesium lactate or a combination thereof.

[0014] The present invention provides titanium dioxide-coated magnesium vanadate, which is characterized in that it is prepared according to any of the above methods.

[0015] The invention provides application of titanium dioxide-coated magnesium vanadate in a magnesium ion battery.

[0016] Beneficial effects:

[0017] The present invention provides a preparation method of titanium dioxide coated magnesium vanadate, which can reduce the corrosion of electrolyte on positive electrode materials, thereby improving the electrochemical performance of the material. The preparation method is simple, the process conditions are easy to achieve, the energy consumption is low, and the preparation is pollution-free. DETAILED DESCRIPTION

[0018] The present invention is described in detail through the following specific examples, but the protection scope of the present invention is not limited to these embodiments.

[0019] Example 1

[0020] A titanium dioxide-coated magnesium vanadate is prepared according to the following steps:

[0021] (1) Dissolve diacetylacetonatovanadium oxysalt and tetrabutyl titanate in 70 mL of anhydrous ethanol at a ratio of 100 mmol:1 mmol and perform ultrasonic dispersion for 30 min, then stir for 1 h to obtain a suspension;

[0022] (2) Add 10 mL of deionized water dropwise into the above suspension to form a sol;

[0023] (3) Add 100 mmol of magnesium diacetylacetonate to the above sol, stir continuously for 1 h, then add it to a 100 mL reactor and react at 160 °C for 15 h to obtain a TiO2-coated magnesium vanadate precursor, wash it with deionized water three times, and dry it in a vacuum oven at 60 °C;

[0024] (4) The TiO2-coated magnesium vanadate precursor was calcined in a muffle furnace at 500°C for 6 h to obtain titanium dioxide-coated magnesium vanadate.

[0025] The electrochemical performance of the obtained titanium dioxide-coated magnesium vanadate at a current density of 100 mA / g is shown in Table 1.

[0026] Example 2

[0027] A titanium dioxide-coated magnesium vanadate is similar to Example 1 and is prepared according to the following steps:

[0028] (1) Dissolve vanadium oxyisopropoxide and tetrabutyl titanate in 70 mL of anhydrous ethanol at a ratio of 100 mmol:3 mmol and perform ultrasonic dispersion for 60 min, then stir for 1 h to obtain a suspension;

[0029] (2) Add 10 mL of deionized water dropwise into the above suspension to form a sol;

[0030] (3) Add 100 mmol of magnesium isopropoxide to the above sol, stir continuously for 1 h, then add it to a 100 mL reactor, react at 180 °C for 12 h to obtain a TiO2-coated magnesium vanadate precursor, wash the obtained TiO2-coated magnesium vanadate precursor with deionized water for 5 times, and dry it in a vacuum oven at 80 °C;

[0031] (4) The TiO2-coated magnesium vanadate precursor was calcined at 600°C in a muffle furnace for 3 h to obtain titanium dioxide-coated magnesium vanadate.

[0032] The electrochemical performance of the obtained titanium dioxide-coated magnesium vanadate at a current density of 100 mA / g is shown in Table 1.

[0033] Example 3

[0034] A titanium dioxide-coated magnesium vanadate is similar to Example 1 and is prepared according to the following steps:

[0035] (1) Vanadium lactate and tetrabutyl titanate were dissolved in 70 mL of anhydrous ethanol at a ratio of 100 mmol:3 mmol and ultrasonically dispersed for 30 min, then stirred for 1 h to obtain a suspension;

[0036] (2) Add 10 mL of deionized water dropwise into the above suspension to form a sol;

[0037] (3) Add 100 mmol of magnesium lactate to the above sol, stir continuously for 1 h, then add it into a 100 mL reactor, react at 200 °C for 10 h to obtain a TiO2-coated magnesium vanadate precursor, wash it with deionized water three times, and dry it in a vacuum oven at 80 °C;

[0038] (4) The TiO2-coated magnesium vanadate precursor was calcined in a muffle furnace at 700°C for 2 h to obtain titanium dioxide-coated magnesium vanadate.

[0039] The electrochemical performance of the obtained titanium dioxide-coated magnesium vanadate at a current density of 100 mA / g is shown in Table 1:

[0040] .

Claims

1. A method for preparing titanium dioxide-coated magnesium vanadate, characterized in that: The specific steps of this method are: (1) Dissolve the organic vanadium oxysalt and tetrabutyl titanate in 70 mL of anhydrous ethanol at a ratio of 100 mmol:1-3 mmol and perform ultrasonic dispersion for 30-60 min, then stir for 1-2 h to obtain a suspension; (2) Add 10 mL of deionized water dropwise into the above suspension to form a sol; (3) Add 100 mmol of organic magnesium salt to the above sol, stir continuously for 1-2 h, then add to a 100 mL reactor, react at 160-200 °C for 10-15 h to obtain a TiO2-coated magnesium vanadate precursor, wash with deionized water 3-5 times, and dry in a vacuum oven at 60-80 °C; (4) The TiO2-coated magnesium vanadate precursor is placed in a muffle furnace and calcined at 500-700°C for 2-6 h to obtain titanium dioxide-coated magnesium vanadate.

2. The method for preparing titanium dioxide-coated magnesium vanadate according to claim 1, characterized in that The organic vanadium oxysalt is one of diacetylacetonate vanadium oxysalt, isopropoxide vanadium oxysalt or lactate vanadium oxysalt or a combination thereof.

3. The method for preparing titanium dioxide-coated magnesium vanadate according to claim 1, characterized in that The organic magnesium salt is one of magnesium diacetylacetonate, magnesium isopropoxide and magnesium lactate or a combination thereof.

4. The method for preparing titanium dioxide-coated magnesium vanadate according to any one of claims 1 to 3, characterized in that: Prepare as follows: (1) Dissolve diacetylacetonatovanadium oxysalt and tetrabutyl titanate in 70 mL of anhydrous ethanol at a ratio of 100 mmol:1 mmol and perform ultrasonic dispersion for 30 min, then stir for 1 h to obtain a suspension; (2) Add 10 mL of deionized water dropwise into the above suspension to form a sol; (3) Add 100 mmol of magnesium diacetylacetonate to the above sol, stir continuously for 1 h, then add it to a 100 mL reactor and react at 160 °C for 15 h to obtain a TiO2-coated magnesium vanadate precursor, wash it with deionized water three times, and dry it in a vacuum oven at 60 °C; (4) The TiO2-coated magnesium vanadate precursor was calcined in a muffle furnace at 500°C for 6 h to obtain titanium dioxide-coated magnesium vanadate.

5. The method for preparing titanium dioxide-coated magnesium vanadate according to any one of claims 1 to 3, characterized in that: Prepare as follows: (1) Dissolve vanadium oxyisopropoxide and tetrabutyl titanate in 70 mL of anhydrous ethanol at a ratio of 100 mmol:3 mmol and perform ultrasonic dispersion for 60 min, then stir for 1 h to obtain a suspension; (2) Add 10 mL of deionized water dropwise into the above suspension to form a sol; (3) Add 100 mmol of magnesium isopropoxide to the above sol, stir continuously for 1 h, then add it to a 100 mL reactor, react at 180 °C for 12 h to obtain a TiO2-coated magnesium vanadate precursor, wash the obtained TiO2-coated magnesium vanadate precursor with deionized water for 5 times, and dry it in a vacuum oven at 80 °C; (4) The TiO2-coated magnesium vanadate precursor was calcined at 600°C in a muffle furnace for 3 h to obtain titanium dioxide-coated magnesium vanadate.

6. The method for preparing titanium dioxide-coated magnesium vanadate according to any one of claims 1 to 3, characterized in that: Prepare as follows: (1) Vanadium lactate and tetrabutyl titanate were dissolved in 70 mL of anhydrous ethanol at a ratio of 100 mmol:3 mmol and ultrasonically dispersed for 30 min, then stirred for 1 h to obtain a suspension; (2) Add 10 mL of deionized water dropwise into the above suspension to form a sol; (3) Add 100 mmol of magnesium lactate to the above sol, stir continuously for 1 h, then add it into a 100 mL reactor and react at 200 °C for 10 h to obtain a TiO2-coated magnesium vanadate precursor, wash it with deionized water three times, and dry it in a vacuum oven at 80 °C; (4) The TiO2-coated magnesium vanadate precursor was calcined in a muffle furnace at 700°C for 2 h to obtain titanium dioxide-coated magnesium vanadate.

7. A titanium dioxide-coated magnesium vanadate, characterized in that Prepared according to any one of claims 1 to 6.

8. Use of the titanium dioxide-coated magnesium vanadate according to claim 7 in a magnesium ion battery.