阅读说明：本技术 一种钒氧酸镁纳米材料的制备方法及其产品和应用 (Preparation method of magnesium vanadyl acid nano material, product and application thereof ) 是由 崔大祥 吴晓燕 林琳 王敬锋 于 2020-12-28 设计创作，主要内容包括：本发明提供一种钒氧酸镁纳米片材料的制备方法及其产品和应用,本发明提供一种钒氧酸镁纳米片材料的制备方法,偏钒酸盐和可溶性镁盐溶于去离子水；向上述溶液加入强酸,控制pH在2.0左右,磁力搅拌至均匀,将溶液转入反应釜中,180～200℃反应18～24 h,自然冷至室温；第四步：将产物经过离心,60～80℃烘箱干燥,得最终产物钒氧酸镁纳米片材料。本发明方法获得的产品具有较大的比表面积和较好的导电性,能够阻止电解液对材料的腐蚀发生副反应,进而可以提高材料的电化学性能。解决了在镁离子电池循环过程中比容量衰减相对较快电化学性能相对较差的问题。并且制备方法简单,工艺条件容易实现,能量消耗低,且制备无污染。(The invention provides a preparation method of a magnesium vanadyl oxide nanosheet material, a product and an application thereof, and the invention provides the preparation method of the magnesium vanadyl oxide nanosheet material, wherein metavanadate and soluble magnesium salt are dissolved in deionized water; adding strong acid into the solution, controlling the pH to be about 2.0, magnetically stirring until the solution is uniform, transferring the solution into a reaction kettle, reacting for 18-24 h at 180-200 ℃, and naturally cooling to room temperature; the fourth step: and centrifuging the product, and drying the product in an oven at the temperature of 60-80 ℃ to obtain the final product magnesium vanadyl oxide nanosheet material. The product obtained by the method has larger specific surface area and better conductivity, can prevent the electrolyte from corroding the material to generate side reaction, and further can improve the electrochemical performance of the material. The problem that the specific capacity is attenuated relatively fast and the electrochemical performance is relatively poor in the circulation process of the magnesium ion battery is solved. And the preparation method is simple, the process conditions are easy to realize, the energy consumption is low, and the preparation is pollution-free.)

1. A preparation method of a magnesium vanadyl acid nanosheet material is characterized by comprising the following steps of,

the first step is as follows: dissolving 6-12 mmol of metavanadate and 1-2 mmol of soluble magnesium salt in deionized water, magnetically stirring at 80 ℃ for 1-2 hours until the salt is completely dissolved, and marking as a solution A;

the second step is that: adding 2-8 mmol of strong acid into the solution A, controlling the pH to be about 2.0, and magnetically stirring until the solution is uniform, wherein the solution is marked as a solution B;

the third step: transferring the solution B into a reaction kettle, reacting for 18-24 h at 180-200 ℃, and naturally cooling to room temperature;

the fourth step: and centrifuging the product, and drying the product in an oven at the temperature of 60-80 ℃ to obtain the final product magnesium vanadyl oxide nanosheet material.

2. The method according to claim 1, wherein the metavanadate is one or a combination of ammonium metavanadate, sodium metavanadate and potassium metavanadate.

3. The method of claim 1, wherein the magnesium vanadate is selected from the group consisting of magnesium chloride, magnesium bromide, magnesium sulfate, and combinations thereof.

4. The method of claim 1, wherein the strong acid is one or a combination of hydrochloric acid, hydrobromic acid, or sulfuric acid.

5. Magnesium vanadyl nanosheet material characterized by being prepared according to the method of any one of claims 1 to 4.

6. The use of the magnesium vanadyl acid nanosheet material of claim 5 in the preparation of a magnesium electrical positive electrode material.

Technical Field

The invention relates to the technical field of magnesium ion battery materials, in particular to a preparation method of a magnesium vanadyl acid nano material, a product and application thereof.

Background

With the development of human society, the contradiction between the global shortage of energy resources and the increasing demand of people for energy is more and more acute. The development of battery systems with high energy density is a major goal of current power supply systems. Although lithium ion batteries having high specific energy and being environmentally friendly have been widely used in portable mobile appliances such as mobile phones and notebook computers, and in power sources for electric bicycles and electric vehicles. However, because the safety of the lithium ion battery is not well solved, the application of the lithium ion battery as a power battery still has much work to be done. Magnesium, one of the most abundant light metal elements on earth, is widely used in many fields due to its good physical and chemical properties. Much research is now done on secondary magnesium batteries, all based on secondary lithium ion batteries. Since magnesium and lithium are located diagonally in the periodic table of elements, the melting point of magnesium (648.8 ℃) is much higher than that of lithium (180.5 ℃) and there is no metal mobility of lithium, in addition to having similar atomic radius and chemical properties, so that the secondary magnesium battery is better in safety. Although the specific mass capacity was not as high as lithium (3862 mAh/g), it was also quite considerable (2205 mAh/g). In addition, the magnesium resource is very rich in China, the price of magnesium is far lower than that of lithium, and the magnesium is environment-friendly, so that secondary magnesium batteries are more and more concerned by people.

Magnesium vanadyl acid is taken as a magnesium ion battery material, and the material is considered to be a promising magnesium ion battery material. However, the magnesium vanadyl oxide nano material is easy to agglomerate, collapse and pulverize in the circulating process, so that the electrochemical performance of the material is poor.

Disclosure of Invention

In order to overcome the defect that the electrochemical performance of the material is poor due to the fact that the magnesium vanadyl oxide nano material is easy to agglomerate, collapse and pulverize in the circulating process, the invention aims to provide a preparation method of the magnesium vanadyl oxide nano material.

Yet another object of the present invention is to: provides a magnesium vanadyl oxide nanosheet material product prepared by the method.

Yet another object of the present invention is to: provides an application of the product.

The invention aims to realize the following scheme that the preparation method of the magnesium vanadyl oxide nanosheet material comprises the following steps,

the first step is as follows: dissolving 6-12 mmol of metavanadate and 1-2 mmol of soluble magnesium salt in deionized water, magnetically stirring at 80 ℃ for 1-2 hours until the salt is completely dissolved, and marking as a solution A;

the second step is that: adding 2-8 mmol of strong acid into the solution A, controlling the pH to be about 2.0, and magnetically stirring until the solution is uniform, wherein the solution is marked as a solution B;

the third step: transferring the solution B into a reaction kettle, reacting for 18-24 h at 180-200 ℃, and naturally cooling to room temperature;

the fourth step: and centrifuging the product, and drying the product in an oven at the temperature of 60-80 ℃ to obtain the final product magnesium vanadyl oxide nanosheet material.

On the basis of the scheme, the metavanadate is one or the combination of ammonium metavanadate, sodium metavanadate or potassium metavanadate.

The magnesium salt is one or the combination of magnesium chloride, magnesium bromide or magnesium sulfate.

The strong acid is one or the combination of hydrochloric acid, hydrobromic acid or sulfuric acid.

The invention also provides a magnesium vanadyl acid nanosheet material prepared according to any one of the methods.

The invention also provides application of the magnesium vanadyl acid nanosheet material in preparation of a magnesium electrode positive electrode material.

The product structure obtained by the method has larger specific surface area and better conductivity, can prevent the electrolyte from corroding the material to generate side reaction, and further can improve the electrochemical performance of the material. The average specific discharge capacity under the current density of 200 mA/g is about 268 mAh/g; the average specific discharge capacity under the current density of 400 mA/g is about 277 mAh/g; the average specific discharge capacity under the current density of 600 mA/g is about 260 mAh/g; the average specific discharge capacity at the current density of 800 mA/g is about 217 mAh/g. The problem that the specific capacity is attenuated relatively fast and the electrochemical performance is relatively poor in the circulation process of the magnesium ion battery is solved. And the preparation method is simple, the process conditions are easy to realize, the energy consumption is low, and the preparation is pollution-free.

Drawings

FIG. 1 is a graph of rate capability of magnesium vanadyl acid nanosheets material of example 1;

FIG. 2 is a graph of rate capability of magnesium vanadyl acid nanosheets material of example 2;

FIG. 3 is a graph of rate capability of magnesium vanadyl acid nanosheets material of example 3.

Detailed Description

The present invention is described in detail by the following specific examples, but the scope of the present invention is not limited to these examples.

Example 1

A magnesium vanadyl acid nanosheet material is prepared by the following steps:

the first step is as follows: dissolving 6 mmol of metavanadate and 1 mmol of soluble magnesium sulfate in deionized water, magnetically stirring for 1 h at 80 ℃ until the salts are completely dissolved, and marking as a solution A;

the second step is that: adding 2 mmol of strong acid sulfuric acid into the solution A, controlling the pH value to be about 2.0, and magnetically stirring until the solution is uniform, wherein the solution is marked as a solution B;

the third step: transferring the solution B into a reaction kettle, reacting for 24 hours at 180 ℃, and naturally cooling to room temperature;

the fourth step: and centrifuging the product, and drying the product in an oven at 80 ℃ to obtain the final product magnesium vanadyl oxide nanosheet material.

FIG. 1 is a graph of cycle performance of magnesium vanadyl acid nanosheets at different magnifications. The average specific discharge capacity under the current density of 200 mA/g is about 320 mAh/g; the average specific discharge capacity under the current density of 400 mA/g is about 271 mAh/g; the average specific discharge capacity under the current density of 600 mA/g is about 233 mAh/g; the average specific discharge capacity at 800 mA/g current density is about 182 mAh/g.

Example 2

The magnesium vanadyl acid nanosheet material is prepared by the following steps, which are similar to the steps in the examples:

the first step is as follows: dissolving 6 mmol of sodium metavanadate and 1 mmol of soluble magnesium chloride in deionized water, magnetically stirring for 2 hours at 80 ℃ until all salts are dissolved, and marking as a solution A;

the second step is that: adding 4 mmol of hydrochloric acid into the solution A, controlling the pH value to be about 2.0, and magnetically stirring until the solution is uniform, wherein the solution is marked as a solution B;

the third step: transferring the solution B into a reaction kettle, reacting for 18 h at 200 ℃, and naturally cooling to room temperature;

the fourth step: and centrifuging the product, and drying the product in an oven at 80 ℃ to obtain the final product magnesium vanadyl oxide nanosheet material.

FIG. 2 is a graph of cycle performance of magnesium vanadyl acid nanosheets at different magnifications. The average specific discharge capacity under the current density of 200 mA/g is about 273 mAh/g; the average specific discharge capacity under the current density of 400 mA/g is about 255 mAh/g; the average specific discharge capacity under the current density of 600 mA/g is about 214 mAh/g; the average specific discharge capacity at the current density of 800 mA/g is about 151 mAh/g.

Example 3

The magnesium vanadyl acid nanosheet material is prepared by the following steps, which are similar to the steps in the examples:

the first step is as follows: dissolving 12 mmol of potassium metavanadate and 2 mmol of soluble magnesium bromide in deionized water, magnetically stirring for 2 hours at 80 ℃ until all salts are dissolved, and marking as a solution A;

the second step is that: adding 4 mmol hydrobromic acid into the solution A, controlling the PH to be about 2.0, and stirring the solution A and the solution A uniformly by magnetic force to mark the solution A as solution B;

the third step: transferring the solution B into a reaction kettle, reacting for 18 h at 200 ℃, and naturally cooling to room temperature;

the fourth step: and centrifuging the product, and drying the product in an oven at 80 ℃ to obtain the final product magnesium vanadyl oxide nanosheet material.

FIG. 3 is a graph of cycle performance of magnesium vanadyl acid nanosheets at different magnifications. The average specific discharge capacity under the current density of 200 mA/g is about 268 mAh/g; the average specific discharge capacity under the current density of 400 mA/g is about 277 mAh/g; the average specific discharge capacity under the current density of 600 mA/g is about 260 mAh/g; the average specific discharge capacity at the current density of 800 mA/g is about 217 mAh/g.