阅读说明：本技术 一种氧化钒/氧化锰复合碳纳米管笼及其制备方法和应用 (Vanadium oxide/manganese oxide composite carbon nanotube cage and preparation method and application thereof ) 是由 向楷雄 雷嘉豪 陈晗 周伟 殷振国 张爱 范宪楷 于 2021-08-12 设计创作，主要内容包括：本发明涉及储能材料技术领域,提供了一种氧化钒/氧化锰复合碳纳米管笼及其制备方法和应用。本发明以碳纳米管笼的限域空间构造为基础,利用限域反应在碳纳米管笼内形成氧化钒填充层,随后利用碳纳米管笼的骨架结构,通过原位转化得到与氧化钒层相互交联的氧化锰层,构造出以氧化钒和氧化锰相间排列的复合碳纳米管笼。本发明制备的氧化钒/氧化锰复合碳纳米管笼电化学性能优异,将其应用于水系锌离子电池中,所得电池的循环稳定性好,容量保持率高。(The invention relates to the technical field of energy storage materials, and provides a vanadium oxide/manganese oxide composite carbon nanotube cage and a preparation method and application thereof. The method is based on the limited domain space structure of the carbon nanotube cage, a vanadium oxide filling layer is formed in the carbon nanotube cage by utilizing the limited domain reaction, then a manganese oxide layer which is mutually crosslinked with the vanadium oxide layer is obtained by utilizing the framework structure of the carbon nanotube cage through in-situ conversion, and the composite carbon nanotube cage which is arranged by the vanadium oxide and the manganese oxide at intervals is constructed. The vanadium oxide/manganese oxide composite carbon nanotube cage prepared by the method has excellent electrochemical performance, and when the vanadium oxide/manganese oxide composite carbon nanotube cage is applied to a water-system zinc ion battery, the obtained battery has good cycle stability and high capacity retention rate.)

1. A preparation method of a vanadium oxide/manganese oxide composite carbon nanotube cage is characterized by comprising the following steps:

mixing a carbon source, a vanadium source, a binder and water, and carrying out spheroidization on the obtained mixed solution to obtain a spheroidized material;

carbonizing the spheroidized material to obtain a vanadium oxide/carbon nanotube cage composite material;

and mixing the vanadium oxide/carbon nanotube cage composite material, potassium permanganate and water to perform hydrothermal reaction to obtain the vanadium oxide/manganese oxide composite carbon nanotube cage.

2. The production method according to claim 1, wherein the carbon source comprises a carbon material and/or a fibrous carbon source material.

3. The method according to claim 1, wherein the carbon material comprises one or more of graphene, carbon nanotubes and carbon nanofibers; the fibrous carbon source material comprises one or more of cotton, calamus, catkin and cellulose.

4. The method according to claim 1, wherein the binder comprises one or more of sucrose, glucose, fructose, carboxymethyl cellulose, polyethylene glycol and phenolic resin.

5. The preparation method according to claim 1, 2 or 4, wherein the weight ratio of the carbon source to the vanadium source is 1 (0.5-5); the dosage ratio of the vanadium source to the binder is 1 (0.05-0.3).

6. The production method according to claim 1, wherein the spheroidizing method is an ultrasonic spray method or an electrospinning method; the ultrasonic spraying method comprises the following steps: carrying out ultrasonic spraying on the mixed solution, and introducing the atomized liquid into a tubular furnace for heat treatment to obtain a spheroidized material; the temperature of the heat treatment is 300-500 ℃, and the time is 12-48 h;

the electrospinning method comprises the following steps: and (3) loading the mixed solution into an injector of an electrostatic spinning device, aligning a spray head with a circular receiving plate, and carrying out horizontal, longitudinal and oblique alternate spinning while the circular receiving plate rotates to obtain the spheroidized material on the circular receiving plate.

7. The method according to claim 1, wherein the carbonization treatment is carried out at a temperature of 600 to 750 ℃ for 2 to 3 hours.

8. The preparation method of the composite material of the vanadium oxide/carbon nanotube cage according to claim 1, wherein the mass ratio of the vanadium oxide/carbon nanotube cage composite material to potassium permanganate is 1 (1-10); the temperature of the hydrothermal reaction is 150-200 ℃, and the time is 2-24 h.

9. The process according to any one of claims 1 to 8The prepared vanadium oxide/manganese oxide composite carbon nanotube cage is characterized in that the vanadium oxide is V₂O₅Or VO₂The manganese oxide is MnO₂。

10. The use of the vanadium oxide/manganese oxide composite carbon nanotube cage of claim 9 in an aqueous zinc-ion battery positive electrode material.

Technical Field

The invention belongs to the technical field of energy storage materials, and particularly relates to a vanadium oxide/manganese oxide composite carbon nanotube cage and a preparation method and application thereof.

Background

The water system zinc ion batteries (AZIBs) as a new battery energy storage technology have the advantages of high safety, low price, high energy density, environmental friendliness, easiness in manufacturing and the like, are rapidly developed in recent years, attract people's wide attention, and are considered to be energy storage devices with great development prospects in the next-generation energy storage technology. The electrolyte adopted by the water-based zinc ion battery is water-based electrolyte, and the water-based electrolyte has the advantages of high ionic conductivity, high energy density and power density and easiness in preparation, and the safety of the battery is better ensured compared with non-water-based electrolyte. The metal zinc as the cathode has the advantages of low equilibrium potential and high overpotential for reaction with hydrogen, is a metal element with the highest energy capable of being stabilized in an aqueous solution, and has the advantages of abundant resources, low price, no toxicity, easiness in treatment and the like. Therefore, the zinc ion water system battery is an ideal green battery system, and has ideal application potential and wide development prospect in a large-scale energy storage system.

The anode is used as a crucial link of the water-based zinc ion battery, the overall performance of the battery is influenced, however, the zinc ion is higher in charge and molecular weight compared with lithium ion, and the solvation effect is severe, so that the anode material capable of effectively storing zinc at the present stage is less, and the anode material of the water-based zinc ion battery commonly used at present is a vanadium-based compound, a manganese-based compound, a prussian blue-based compound and the like, but the anode materials are poor in electrochemical performance and low in capacity retention rate.

Disclosure of Invention

In view of the above, the invention provides a vanadium oxide/manganese oxide composite carbon nanotube cage and a preparation method and application thereof. The vanadium oxide/manganese oxide composite carbon nanotube cage provided by the invention can avoid the dissolution of vanadium oxide and manganese oxide, and can be used as a positive electrode material of a water-based zinc ion battery, so that the cycle stability and the capacity retention rate of the battery can be improved.

In order to achieve the above object, the present invention provides the following technical solutions:

a preparation method of a vanadium oxide/manganese oxide composite carbon nanotube cage comprises the following steps:

mixing a carbon source, a vanadium source, a binder and water, and carrying out spheroidization on the obtained mixed solution to obtain a spheroidized material;

carbonizing the spheroidized material to obtain a vanadium oxide/carbon nanotube cage composite material;

and mixing the vanadium oxide/carbon nanotube cage composite material, potassium permanganate and water to perform hydrothermal reaction to obtain the vanadium oxide/manganese oxide composite carbon nanotube cage.

Preferably, the carbon source comprises a carbon material and/or a fibrous carbon source material.

Preferably, the carbon material comprises one or more of graphene, carbon nanotubes and carbon nanofibers; the fibrous carbon source material comprises one or more of cotton, calamus, catkin and cellulose.

Preferably, the binder comprises one or more of sucrose, glucose, fructose, carboxymethyl cellulose, polyethylene glycol and phenolic resin.

Preferably, the weight ratio of the carbon source to the vanadium source is 1 (0.5-5); the dosage ratio of the vanadium source to the binder is 1 (0.05-0.3).

Preferably, the spheroidizing method is an ultrasonic spray method or an electrostatic spinning method; the ultrasonic spraying method comprises the following steps: carrying out ultrasonic spraying on the mixed solution, and introducing the atomized liquid into a tubular furnace for heat treatment to obtain a spheroidized material; the temperature of the heat treatment is 300-500 ℃, and the time is 12-48 h;

the electrospinning method comprises the following steps: and (3) loading the mixed solution into an injector of an electrostatic spinning device, aligning a spray head with a circular receiving plate, and carrying out horizontal, longitudinal and oblique alternate spinning while the circular receiving plate rotates to obtain the spheroidized material on the circular receiving plate.

Preferably, the temperature of the carbonization treatment is 600-750 ℃, and the heat preservation time is 2-3 h.

Preferably, the mass ratio of the vanadium oxide/carbon nanotube cage composite material to the potassium permanganate is 1 (1-10); the temperature of the hydrothermal reaction is 150-200 ℃, and the time is 2-24 h.

The invention also provides a vanadium oxide/manganese oxide composite carbon nanotube cage prepared by the preparation method in the scheme, wherein the vanadium oxide is V₂O₅Or VO₂The manganese oxide is MnO₂。

The invention also provides application of the vanadium oxide/manganese oxide composite carbon nanotube cage in the anode material of the water-based zinc ion battery.

The invention provides a preparation method of a vanadium oxide/manganese oxide composite carbon nanotube cage, which comprises the following steps: mixing a carbon source, a vanadium source, a binder and water, and carrying out spheroidization on the obtained mixed solution to obtain a spheroidized material; carbonizing the spheroidized material to obtain a vanadium oxide/carbon nanotube cage composite material; and mixing the vanadium oxide/carbon nanotube cage composite material, potassium permanganate and water to perform hydrothermal reaction to obtain the vanadium oxide/manganese oxide composite carbon nanotube cage. According to the method, a limited space structure of a carbon nanotube cage is taken as a basis, a vanadium oxide internal filling layer is formed in the carbon nanotube cage by utilizing a limited space reaction, then a manganese oxide layer which is mutually crosslinked with the vanadium oxide layer is obtained by utilizing a framework structure of the carbon nanotube cage through in-situ conversion, and the composite carbon nanotube cage with the vanadium oxide and the manganese oxide arranged alternately is constructed. The method provided by the invention can obtain the vanadium oxide/manganese oxide composite carbon nanotube cage with excellent electrochemical performance, and when the vanadium oxide/manganese oxide composite carbon nanotube cage is applied to a water system zinc ion battery, the carbon nanotube cage can also inhibit the dissolution of vanadium oxide and manganese oxide in water system electrolyte, thereby improving the circulation stability and the capacity retention rate of the battery.

Drawings

FIG. 1 is an SEM image of a vanadium oxide/carbon nanotube cage composite prepared in example 1;

FIG. 2 shows the cell assembled in example 1 at 0.05Ag^-1Constant current charge-discharge characteristics under conditions;

FIG. 3 shows the cell assembled in example 1 at 0.1mV s^-1CV curve under the conditions.

Detailed Description

The invention provides a preparation method of a vanadium oxide/manganese oxide composite carbon nanotube cage, which comprises the following steps:

mixing a carbon source, a vanadium source, a binder and water, and carrying out spheroidization on the obtained mixed solution to obtain a spheroidized material;

carbonizing the spheroidized material to obtain a vanadium oxide/carbon nanotube cage composite material;

and mixing the vanadium oxide/carbon nanotube cage composite material, potassium permanganate and water to perform hydrothermal reaction to obtain the vanadium oxide/manganese oxide composite carbon nanotube cage.

According to the invention, a carbon source, a vanadium source, a binder and water are mixed, and the obtained mixed solution is subjected to spheroidization treatment to obtain a spheroidized material. In the present invention, the carbon source preferably includes a carbon material and/or a fibrous carbon source material; the carbon material preferably comprises one or more of graphene, carbon nanotubes and carbon nanofibers; the fibrous carbon source material preferably comprises one or more of cotton, calamus, catkin and cellulose.

In the present invention, the vanadium source is preferably ammonium vanadate (NH)₄VO₃) (ii) a The weight ratio of the carbon source to the vanadium source is preferably 1 (0.5-5), and more preferably 1 (1-3).

In the invention, the binder preferably comprises one or more of sucrose, glucose, fructose, carboxymethyl cellulose, polyethylene glycol and phenolic resin; the dosage ratio of the vanadium source to the binder is preferably 1 (0.05-0.3), and more preferably 1 (0.1-0.2).

In the invention, the water is preferably deionized water, and the carbon source, the vanadium source and the binder can be dissolved and dispersed uniformly without special requirements on the using amount of the water.

In the present invention, the mixing process of the carbon source, the vanadium source, the binder and the water is specifically preferably: stirring and mixing a carbon source, a vanadium source, a binder and water, and then carrying out ultrasonic dispersion to obtain a mixed solution; the stirring and mixing time is preferably 3-18 h, and the stirring and mixing can be carried out at room temperature without additional heating or cooling; the ultrasonic dispersion is preferably carried out in an electromagnetic sonicator or a cell debubbler.

In the present invention, the spheroidizing method is preferably an ultrasonic spray method or an electrostatic spinning method; the ultrasonic spraying method preferably comprises: carrying out ultrasonic spraying on the mixed solution, and introducing the atomized liquid into a tubular furnace for heat treatment to obtain a spheroidized material; the temperature of the heat treatment is preferably 300-500 ℃, more preferably 320-480 ℃, and the time is preferably 12-48 hours, more preferably 15-40 hours; in a specific embodiment of the present invention, the time of the heat treatment is based on evaporating the atomized solution, and the heat treatment is preferably performed in a protective atmosphere; in a specific embodiment of the invention, the ultrasonic spraying is preferably carried out in an ultrasonic sprayer, and the sprayed atomized liquid is conveyed into a tubular furnace which is pre-filled with protective atmosphere and is pre-heated to the heat treatment temperature under the action of argon gas flow; in the embodiment of the invention, the temperature is preferably maintained at the heat treatment temperature for 2 hours after the atomized liquid is completely injected into the tube furnace.

After the heat treatment is finished, the spheroidized powder on the inner wall of the tubular furnace is preferably collected in a crucible and then placed in a blast drier for drying to obtain the spheroidized material; the drying temperature is preferably 60-150 ℃.

In the present invention, the electrospinning method preferably includes: and (3) loading the mixed solution into an injector of an electrostatic spinning device, aligning a spray head with a circular receiving plate, and carrying out horizontal, longitudinal and oblique alternate spinning while the circular receiving plate rotates to obtain the spheroidized material on the circular receiving plate. In the invention, the inner diameter of the spray head is preferably 0.5-5 mm, more preferably 1-4 mm, the distance between the spray head and the circular receiving plate is preferably 5-20 cm, more preferably 8-15 cm, the rotating speed of the circular receiving plate is preferably 5-20 r/min, more preferably 8-12 r/min, the voltage of electrostatic spinning is preferably 40-60 kV, more preferably 45-55 kV, and the spinning speed is preferably 2-50 cm/min, more preferably 5-40 cm/min.

After obtaining the spheroidized material, the spheroidized material is carbonized to obtain the vanadium oxide/carbon nanotube cage composite material. In the invention, the temperature of the carbonization treatment is preferably 600-750 ℃, more preferably 650-700 ℃, and the heat preservation time is preferably 2-3 h, more preferably 2.3-2.5 h; the heating rate for heating to the carbonization temperature is preferably 5 ℃/min; the carbonization treatment is preferably carried out in a tube furnace.

After the vanadium oxide/carbon nanotube cage composite material is obtained, the vanadium oxide/carbon nanotube cage composite material, potassium permanganate and water are mixed for hydrothermal reaction to obtain the vanadium oxide/manganese oxide composite carbon nanotube cage. In the invention, the mass ratio of the vanadium oxide/carbon nanotube cage composite material to the potassium permanganate is preferably 1 (1-10), and more preferably 1 (2-8); the water is preferably deionized water, the invention has no special requirement on the using amount of the water, can completely dissolve potassium permanganate, and can uniformly disperse the vanadium oxide/carbon nanotube cage composite material.

In the invention, the temperature of the hydrothermal reaction is preferably 150-200 ℃, more preferably 160-180 ℃, and the time is preferably 2-24 hours, more preferably 5-20 hours; the hydrothermal reaction is preferably carried out in a stainless steel reaction vessel.

After the hydrothermal reaction is finished, the obtained product liquid is preferably filtered, and the solid product is washed to be neutral by deionized water and then dried to obtain the vanadium oxide/manganese oxide composite carbon nanotube cage.

The invention also provides a vanadium oxide/manganese oxide composite carbon nanotube cage prepared by the preparation method in the scheme, wherein the vanadium oxide is V₂O₅Or VO₂The manganese oxide is MnO₂。

The invention also provides application of the vanadium oxide/manganese oxide composite carbon nanotube cage in the anode material of the water-based zinc ion battery. The present invention has no special requirement on the specific method for the application, and the method is well known to those skilled in the art.

The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention.

Example 1

0.175g of sucrose and 0.9625g of NH were mixed₄VO₃Mixing with 60ml deionized water, and adding carbon nanotubes, carbon nanotubes and NH to the solution₄VO₃The weight ratio of the components is 1:1.5, and the mixture is magnetically stirred for 17 hours at room temperature and then ultrasonically dispersed by using an electromagnetic ultrasonic device to obtain a mixed solution;

and transferring the mixed solution into an ultrasonic atomization machine, conveying the mixed solution into a tubular furnace for spheroidization in argon flow after atomization, wherein the spheroidization temperature is 400 ℃, the spheroidization is carried out until the atomized solution is evaporated to dryness, the time is about 24 hours, collecting spheroidized powder on the inner wall of the tubular furnace in a crucible, and drying the spheroidized powder in a blast drier at 80 ℃ to obtain the spheroidized material.

And (3) putting the dried powder into a tubular furnace, and carrying out carbonization treatment under the protection of protective atmosphere, wherein the carbonization treatment temperature is 600 ℃, the heat preservation time is 2h, and the heating rate is 5 ℃/min, so as to obtain the vanadium oxide/carbon nanotube cage composite material.

Mixing the obtained vanadium oxide/carbon nanotube cage composite material with potassium permanganate according to the mass ratio of 1:2, placing the mixture in a stainless steel reaction kettle for reaction at 150 ℃ for 5 hours, taking out the product after the reaction is finished, filtering, washing the product with deionized water to be neutral, and drying the product to obtain the vanadium oxide/manganese oxide composite carbon nanotube cage.

FIG. 1 is an SEM image of the resulting vanadium oxide/carbon nanotube cage composite, and it can be seen from FIG. 1 that a large number of CNTs can be seen on the surface of the vanadium oxide/carbon nanotube cage composite, like a hair bulb. Some small flaky grains are implanted inside the hair ball, and the flaky grains are vanadium oxide.

And (3) electrochemical performance testing: mixing vanadium oxide/manganese oxide composite carbon nanotube cage, acetylene black and polyvinylidene fluoride with N-methyl pyrrolidone according to the mass ratio of 7:2:1 to form slurry, uniformly coating the slurry on a stainless steel foil, drying for 24 hours, and cutting into phi 14mm wafers; 3mol/L zinc sulfate solution is adopted as electrolyte, and a glass fiber film and a zinc foil are respectively adopted as a diaphragm and a counter electrode; assembling a CR2025 coin cell in a dry atmosphere, and performing charge and discharge tests by using a NEWARE cell test system; cyclic Voltammetry (CV) tests were performed using an electrochemical workstation (CHI 760E).

The results are shown in FIGS. 2-3, where FIG. 2 shows that the battery has a surface area of 0.05Ag^-1Constant current charge-discharge characteristics in the initial three cycles under the conditions; FIG. 3 shows the cell at 0.1mV s^-1CV curve under the conditions. As can be seen from the figures 2-3, the aqueous zinc ion battery assembled by the vanadium oxide/manganese oxide composite carbon nanotube cage has good electrochemical performance and excellent cycle stability.

In addition, in 0.05Ag^-15000 cycles of the battery were performed under the conditions, and the results showed that the capacity retention rate of the battery was 86%. The water-based zinc ion battery assembled by the vanadium oxide/manganese oxide composite carbon nanotube cage has higher capacity retention rate.

Example 2

The other steps are the same as the example 1, only the sucrose is changed into carboxymethyl cellulose, and the carbon nano tube is changed into graphene.

Example 3

Other conditions are the same as the example 1, only the carbon nano tube is changed into cotton, and after the mixed solution is obtained, the spheroidization is carried out by adopting an electrostatic spinning method, which comprises the following specific steps: loading the obtained mixed solution into an injector of an electrostatic spinning device, aligning a nozzle with a round receiving plate, and carrying out horizontal, longitudinal and oblique alternate spinning while the round receiving plate rotates to obtain a spheroidized material on the round receiving plate; the inner diameter of the nozzle is 2mm, the distance between the nozzle and the circular receiving plate is preferably 10cm, the rotating speed of the circular receiving plate is preferably 10r/min, the voltage of electrostatic spinning is preferably 50kV, and the spinning speed is preferably 10 cm/min.

The subsequent carbonization treatment and the like were carried out in the same manner as in example 1.

Example 4

Other conditions were the same as in example 3 except that the binder was changed to polyethylene glycol and the carbon material was changed to catkin.

SEM observation of the vanadium oxide/manganese oxide composite carbon nanotube cages obtained in examples 1 to 4 shows that the obtained materials are all in a cage structure, and flaky particles are contained in the cage structure.

Electrochemical tests on the vanadium oxide/manganese oxide composite carbon nanotube cages prepared in the embodiments 2 to 4 are performed according to the method in the embodiment 1, and the results show that the aqueous zinc ion battery assembled by using the vanadium oxide/manganese oxide composite carbon nanotube cage has excellent electrochemical performance and excellent cycle performance, and the capacity retention rate is more than 85% after 5000 cycles.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.