阅读说明：本技术 一种纳米花状mos2/酸改性沥青焦活性炭钠离子电池负极材料及制备方法 (Nanometer flower-shaped MOS2Acid modified asphalt coke active carbon sodium ion battery negative electrode material and preparation method thereof ) 是由 许占位 王盈 刘鑫悦 陆凡宇 严皓 任宇川 张姿纬 黄剑锋 于 2021-09-16 设计创作，主要内容包括：本发明公开了一种纳米花状M-(O)S-(2)/酸改性沥青焦活性炭钠离子电池负极材料及制备方法,属于钠离子电池负极材料制备技术领域,制备方法首先采用硝酸溶液水浴热处理方法对活性炭进行改性得到酸改性活性炭,再以酸改性活性炭为导电基底,四水合钼酸铵为钼源,硫脲为硫源和还原剂,向去离子水中加入四水合钼酸铵、硫脲和酸改性活性炭搅拌均匀,最后转移至水热釜中进行水热处理,制得纳米花状M-(O)S-(2)/酸改性沥青焦活性炭钠离子电池负极材料,制备方法操作简单、成本较低、产率高且具有良好的重现性。经本发明方法制备的M-(O)S-(2)/FAC钠离子电池负极材料具有优异的循环稳定性。(The invention discloses a nanometer flower-shaped M O S 2 Acid modified asphalt coke active carbon sodium ion battery cathode material and preparation method thereof, belonging to the technical field of sodium ion battery cathode material preparationModifying activated carbon, taking acid modified activated carbon as a conductive substrate, ammonium molybdate tetrahydrate as a molybdenum source and thiourea as a sulfur source and a reducing agent, adding ammonium molybdate tetrahydrate, thiourea and the acid modified activated carbon into deionized water, uniformly stirring, and finally transferring to a hydrothermal kettle for hydrothermal treatment to obtain the nano flower-shaped M O S 2 The acid modified asphalt coke active carbon sodium ion battery cathode material has the advantages of simple preparation method operation, low cost, high yield and good reproducibility. M prepared by the process of the invention O S 2 The negative electrode material of the/FAC sodium-ion battery has excellent cycling stability.)

1. Nanometer flower-shaped M_OS₂The preparation method of the acid modified asphalt coke activated carbon sodium ion battery negative electrode material is characterized by comprising the following steps:

1) transferring the activated carbon into a nitric acid solution by adopting a water bath heating method, heating to 50-100 ℃ while stirring, and preserving heat for 6-30 hours to obtain modified activated carbon;

2) adding 1.31-2.51 g of ammonium molybdate tetrahydrate, 1.89-3.23 g of thiourea and 0.06-0.71 g of modified activated carbon into 60mL of deionized water, uniformly stirring, transferring to a hydrothermal kettle, and carrying out hydrothermal reaction for 12-36 h at 180-210 ℃;

3) after the hydrothermal reaction is finished, naturally cooling to room temperature to obtain the nano flower-shaped M_OS₂Acid modified asphalt coke active carbon sodium ion battery cathode material.

2. A nanoflower-like M according to claim 1_OS₂The preparation method of the acid modified asphalt coke activated carbon sodium ion battery negative electrode material is characterized in that the concentration of a nitric acid solution in the step 1) is 1-5 mol/L.

3. A nanoflower-like M according to claim 1_OS₂The preparation method of the acid modified asphalt coke activated carbon sodium ion battery cathode material is characterized in that the product is washed and dried after heating and heat preservation in the step 1).

4. A nanoflower-like M according to claim 1_OS₂The preparation method of the acid modified asphalt coke activated carbon sodium ion battery cathode material is characterized in that the stirring in the step 1) and the step 2) is magnetic stirring.

5. A nanoflower-like M according to claim 1_OS₂The preparation method of the acid modified asphalt coke activated carbon sodium ion battery negative electrode material is characterized in that the precipitate is purified and dried after being cooled to room temperature in the step 3).

6. A nanoflower-like M according to claim 5_OS₂The preparation method of the acid modified asphalt coke activated carbon sodium ion battery cathode material is characterized in that the purification comprises washing with ultrapure water and absolute ethyl alcohol respectively for a plurality of times.

7. A nanoflower-like M according to claim 5_OS₂The preparation method of the acid modified asphalt coke active carbon sodium ion battery negative electrode material is characterized in that the drying comprises vacuum drying at 70 DEG CDrying for 12-36 h.

8. Nanometer flower-shaped M_OS₂Acid modified asphalt coke active carbon sodium ion battery cathode material, characterized in that the nano flower-shaped M of any one of claims 1 to 7 is adopted_OS₂The acid modified asphalt coke active carbon sodium ion battery cathode material is prepared by the preparation method.

9. A nanoflower M according to claim 8_OS₂The acid modified asphalt coke active carbon sodium ion battery cathode material is characterized by being in a nanometer flower shape, the size of the nanometer flower shape is 100-150 nm, and M is_OS₂The nano-sheet grows on the surface of the acid modified asphalt coke active carbon in situ at the current density of 1Ag^-1At the lower cycle, the initial reversible capacity is 416.9mAh g^-1After 100 cycles, the reversible capacity is maintained at 280.6mAh g^-1The coulombic efficiency reaches 99.2 percent.

Technical Field

The invention belongs to the technical field of preparation of sodium-ion battery electrode materials, and particularly relates to a nanometer flower-shaped M_OS₂Acid modified asphalt coke active carbon sodium ion battery cathode material and preparation method thereof.

Background

Large-scale application of lithium ion batteries is limited due to scarcity of lithium resources. Sodium ion batteries are an object of interest because of their high storage capacity of sodium, a family element, and low cost, as compared to lithium. Molybdenum disulfide (MoS)₂) Has S-Mo-S sandwich layered structure, atoms in the layers are combined through covalent bonds, weak van der Waals force exists between the layers, ion embedding and ion releasing are facilitated, and the theoretical specific capacity of the material is higher (670mAh g)^-1) However, MoS₂Has the defects of poor conductivity, poor cycle performance caused by easy superposition in the charging and discharging process and the like. Thus, the composition with the carbon material is to improve MoS₂An important measure of the stacking of the sheets, pitch coke Activated Carbon (AC), which has a large specific surface area and excellent electrical conductivity, is a good support.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a nano flower-shaped M_OS₂The acid modified asphalt coke active carbon sodium ion battery cathode material and the preparation method thereof have the advantages of low cost, simple preparation, short period and high repeatabilityThe method has the advantages of environmental protection and safety, and is beneficial to large-scale production; the prepared material has high specific capacity and excellent cycling stability when being used for a sodium ion battery.

In order to achieve the above purpose, the invention provides a nano flower-shaped M_OS₂The preparation method of the acid modified asphalt coke activated carbon sodium ion battery negative electrode material comprises the following steps:

1) transferring the activated carbon into a nitric acid solution by adopting a water bath heating method, heating to 50-100 ℃ while stirring, and preserving heat for 6-30 hours to obtain modified activated carbon;

2) adding 1.31-2.51 g of ammonium molybdate tetrahydrate, 1.89-3.23 g of thiourea and 0.06-0.71 g of modified activated carbon into 60mL of deionized water, uniformly stirring, transferring to a hydrothermal kettle, and carrying out hydrothermal reaction for 12-36 h at 180-210 ℃;

3) after the hydrothermal reaction is finished, naturally cooling to room temperature to obtain the nano flower-shaped M_OS₂Acid modified asphalt coke active carbon sodium ion battery cathode material.

Preferably, the concentration of the nitric acid solution in the step 1) is 1-5 mol/L.

Preferably, the product is washed and dried after the heating and heat preservation in the step 1).

Preferably, the stirring in step 1) and step 2) is magnetic stirring.

Preferably, the precipitate is purified and dried after cooling to room temperature in the step 3).

Preferably, the purification comprises washing several times with ultrapure water and anhydrous ethanol, respectively.

Preferably, the drying comprises vacuum drying at 70 ℃ for 12-36 h.

The invention also provides a nano flower-shaped M_OS₂Acid modified asphalt coke active carbon sodium ion battery cathode material adopting nano flower-shaped M_OS₂The acid modified asphalt coke active carbon sodium ion battery cathode material is prepared by the preparation method. The material is in a nanometer flower shape, the size is 100-150 nm, and M is_OS₂The nano-sheet grows in situ on the acid modified asphalt coke active carbonSurface at a current density of 1Ag^-1At the lower cycle, the initial reversible capacity is 416.9mAh g^-1After 100 cycles, the reversible capacity is maintained at 280.6mAh g^-1The coulombic efficiency reaches 99.2 percent.

Compared with the prior art, the preparation method comprises the steps of firstly modifying the activated carbon by adopting a nitric acid solution water-bath heat treatment method to obtain acid-modified activated carbon (FAC), then adding ammonium molybdate tetrahydrate, thiourea and a reducing agent into deionized water by taking the FAC as a conductive substrate, taking ammonium molybdate tetrahydrate as a molybdenum source and thiourea as a sulfur source and a reducing agent, uniformly stirring, and finally transferring the mixture into a hydrothermal kettle for hydrothermal treatment to obtain the nano flower-shaped M_OS₂The negative electrode material of the FAC sodium ion battery is prepared by enriching active functional groups such as carboxyl, carbonyl and the like on the surface of active carbon through nitric acid modification treatment, taking acid modified active carbon (FAC) as a template, and utilizing the large specific surface area, high conductivity and abundant functional groups on the surface of the FAC to induce MoS₂And growing in situ to improve the conductivity and stability of the material. This modification of the chemical structure can improve MoS₂And FAC, thereby stabilizing the structure, and taking the acid modified asphalt coke active carbon as a conductive substrate, namely supporting M_OS₂Avoidance of M_OS₂The structure collapse is easy to occur in the charge and discharge process, the volume change in the charge and discharge process is relieved, the integral conductivity of the material is improved, the electron transfer is facilitated, and the MoS is improved₂Sodium storage Properties of/FAC. The preparation method has the advantages of simple operation, low cost, short period, high yield, good reproducibility, environmental protection, safety and good product consistency, and is beneficial to industrial production.

Prepared nano flower-shaped M_OS₂The acid modified asphalt coke active carbon sodium ion battery cathode material is in a nanometer flower shape, and the size is about 100-150 nm. M_OS₂The nano-sheet grows on the surface of FAC in situ, thereby effectively preventing M_OS₂And (3) stacking. M_OS₂The synergistic effect with FAC is favorable to the transfer of reaction electrons, so increasing M_OS₂Sodium storage stability of/FAC. At a current density of 1A g^-1At the time of lower circulation, the nano flower-like M is measured_OS₂The initial reversible capacity of the negative electrode material of the/FAC sodium-ion battery is 416.9mAh g^-1The capacity is increased firstly as the charging and discharging process is carried out, which is the activation process, then the capacity is kept stable, and the reversible capacity is still kept at 280.6mAh g after 100 cycles of circulation^-1The coulombic efficiency reaches 99.2 percent. M prepared by the process of the invention_OS₂the/FAC negative electrode material shows high specific capacity and excellent cycling stability, and can be widely used as a negative electrode material of a sodium ion battery.

Drawings

FIG. 1 shows a nano-flower M prepared in example 3 of the present invention_OS₂XRD (X-ray diffraction) pattern of negative electrode material of FAC (sodium ion battery);

FIG. 2 shows a nano-flower M prepared in example 3 of the present invention_OS₂SEM image of/FAC sodium ion battery cathode material.

FIG. 3 shows a nanoflower M prepared in example 3 of the present invention_OS₂FAC Material and M of comparative example_OS₂And (3) comparing the cycle performance of the sodium-ion battery with the negative electrode made of the material.

Detailed Description

The present invention will be further explained with reference to the drawings and specific examples in the specification, and it should be understood that the examples described are only a part of the examples of the present application, and not all examples. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The invention provides a nano flower-shaped M_OS₂The preparation method of the acid modified asphalt coke activated carbon sodium ion battery negative electrode material specifically comprises the following steps:

1) transferring the activated carbon into a nitric acid solution with the concentration of 1-5 mol/L by adopting a water bath heating method, heating to 50-100 ℃ while magnetically stirring, preserving heat for 6-30 hours, washing and drying a product after heating and preserving heat to obtain modified activated carbon;

2) adding 1.31-2.51 g of ammonium molybdate tetrahydrate, 1.89-3.23 g of thiourea and 0.06-0.71 g of modified activated carbon into 60mL of deionized water, uniformly stirring by magnetic force, transferring to a hydrothermal kettle, and carrying out hydrothermal reaction for 12-36 h at 180-210 ℃;

3) after the hydrothermal reaction is finished, naturally cooling to room temperature, purifying and drying the precipitate to obtain the nano flower-shaped M_OS₂Acid modified asphalt coke active carbon sodium ion battery cathode material. Preferably, the purification comprises washing with ultrapure water and absolute ethanol, respectively, several times; the drying comprises vacuum drying at 70 ℃ for 12-36 h.

The invention also provides the nano flower-shaped M prepared by the method_OS₂Acid modified asphalt coke active carbon sodium ion battery cathode material in a nanometer flower shape with the size of 100-150 nm, M_OS₂The nano-sheet grows on the surface of the acid modified asphalt coke active carbon in situ at the current density of 1A g^-1At the lower cycle, the initial reversible capacity is 416.9mAh g^-1After 100 cycles, the reversible capacity is maintained at 280.6mAh g^-1The coulombic efficiency reaches 99.2 percent.

The present invention will be described in detail with reference to specific examples.

Example 1:

the method comprises the following steps:

1) transferring the activated carbon into a nitric acid aqueous solution with the concentration of 1mol/L, heating to 100 ℃ while magnetically stirring, preserving heat for 6 hours, and finally washing and drying to obtain acid modified activated carbon, which is marked as FAC;

2) adding 1.31g of ammonium molybdate tetrahydrate, 1.89g of thiourea and 0.06g of FAC into 60mL of deionized water, uniformly stirring by magnetic force, and finally transferring to a hydrothermal kettle for hydrothermal reaction at 180 ℃ for 36 hours;

3) after the hydrothermal reaction is finished, naturally cooling to room temperature, respectively washing the precipitate for 3 times by using ultrapure water and absolute ethyl alcohol, and performing vacuum drying at 70 ℃ for 12 hours to obtain the sodium-ion battery cathode material M_OS₂/FAC。

Example 2:

the method comprises the following steps:

1) transferring the activated carbon into a nitric acid aqueous solution with the concentration of 2mol/L, heating to 60 ℃ while magnetically stirring, preserving heat for 12 hours, and finally washing and drying to obtain acid modified activated carbon, which is marked as FAC;

2) adding 1.62g of ammonium molybdate tetrahydrate, 2.21g of thiourea and 0.09g of FAC into 60mL of deionized water, uniformly stirring by magnetic force, and finally transferring to a hydrothermal kettle for hydrothermal reaction at 190 ℃ for 30 hours;

3) after the hydrothermal reaction is finished, naturally cooling to room temperature, washing the precipitate for 3 times by using ultrapure water and absolute ethyl alcohol respectively, and performing vacuum drying at 70 ℃ for 18 hours to obtain the sodium-ion battery cathode material M_OS₂/FAC。

Example 3:

the method comprises the following steps:

1) transferring the activated carbon into a nitric acid aqueous solution with the concentration of 3mol/L, heating to 80 ℃ while magnetically stirring, preserving heat for 18 hours, and finally washing and drying to obtain acid modified activated carbon, which is marked as FAC;

2) adding 1.92g of ammonium molybdate tetrahydrate, 2.56g of thiourea and 0.18g of FAC into 60mL of deionized water, uniformly stirring by magnetic force, and finally transferring to a hydrothermal kettle for hydrothermal reaction at 200 ℃ for 24 hours;

3) after the hydrothermal reaction is finished, naturally cooling to room temperature, respectively washing the precipitate for 3 times by using ultrapure water and absolute ethyl alcohol, and performing vacuum drying at 70 ℃ for 24 hours to prepare the sodium-ion battery cathode material M_OS₂/FAC。

Referring to FIG. 1, it can be seen from FIG. 1 that the product obtained is M_OS₂the/FAC has diffraction pattern of each diffraction peak in XRD and MoS by comparing with standard card₂The diffraction peaks of the standard card corresponded, indicating better crystallinity and higher purity.

Referring to FIG. 2, it can be seen from the SEM image that M is produced_OS₂the/FAC is a nano flower-shaped structure with the particle size of 100-150 nm, the size distribution is uniform, and the dispersibility is good.

For comparison, preparation M was designed_OS₂Comparative example (c): adding 1.92g of ammonium molybdate tetrahydrate and 2.56g of thiourea into 60mL of deionized water, uniformly stirring by magnetic force, finally transferring the mixture into a hydrothermal kettle for hydrothermal reaction at 200 ℃ for 24 hours, and naturally cooling the mixture after the hydrothermal reaction is finishedCooling to room temperature, respectively washing the precipitate with ultrapure water and anhydrous ethanol for 3 times, and vacuum drying at 70 deg.C for 24 hr to obtain sodium ion battery cathode material M_OS₂。

Referring to FIG. 3, M can be seen_OS₂When the/FAC composite material is used as a negative electrode material of a sodium-ion battery, the phase ratio of M is compared with M_OS₂The cycling stability is improved at a current density of 1A g^-1At the time of lower circulation, the nano flower-like M is measured_OS₂The initial reversible capacity of the negative electrode material of the/FAC sodium-ion battery is 416.9mAh g^-1The capacity is increased firstly as the charging and discharging process is carried out, which is the activation process, then the capacity is kept stable, and the reversible capacity is still kept at 280.6mAh g after 100 cycles of circulation^-1The coulombic efficiency reaches 99.2 percent. Description of the circulation Properties the nanoflower MoS prepared according to the invention₂The acid modified asphalt coke activated carbon can be widely used as an excellent sodium ion battery cathode material.

Example 4:

the method comprises the following steps:

1) transferring the activated carbon into a nitric acid aqueous solution with the concentration of 4mol/L, heating to 50 ℃ while magnetically stirring, preserving heat for 24 hours, and finally washing and drying to obtain acid modified activated carbon, which is marked as FAC;

2) adding 2.23g of ammonium molybdate tetrahydrate, 2.89g of thiourea and 0.36g of FAC into 60mL of deionized water, uniformly stirring by magnetic force, and finally transferring to a hydrothermal kettle for hydrothermal reaction at 205 ℃ for 18 h;

3) after the hydrothermal reaction is finished, naturally cooling to room temperature, respectively washing the precipitate for 3 times by using ultrapure water and absolute ethyl alcohol, and performing vacuum drying at 70 ℃ for 30 hours to obtain the sodium-ion battery cathode material M_OS₂/FAC。

Example 5:

the method comprises the following steps:

1) transferring the activated carbon into an aqueous solution of nitric acid with the concentration of 5mol/L, heating to 70 ℃ while magnetically stirring, preserving heat for 30 hours, and finally washing and drying to obtain acid modified activated carbon, which is marked as FAC;

2) adding 2.51g of ammonium molybdate tetrahydrate, 3.23g of thiourea and 0.71g of FAC into 60mL of deionized water, uniformly stirring by magnetic force, and finally transferring to a hydrothermal kettle for hydrothermal reaction at 210 ℃ for 12 hours;

3) after the hydrothermal reaction is finished, naturally cooling to room temperature, washing the precipitate for 3 times by using ultrapure water and absolute ethyl alcohol respectively, and performing vacuum drying at 70 ℃ for 36 hours to obtain the sodium-ion battery cathode material M_OS₂/FAC。

In conclusion, the preparation method is novel in design idea, and the active functional group in the FAC is used for inducing MoS in the hydrothermal synthesis process₂Nucleation growth, not only can stabilize MoS₂Can also be used as an electron transmission framework to finally prepare the M in the shape of the nanometer flower_OS₂a/FAC composite. The method is simple and easy to control, has low cost and high repeatability, and is favorable for industrial production. The obtained nanometer flower-like M_OS₂the/FAC can be used as an excellent negative electrode material of the sodium-ion battery.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.