Rhenium disulfide-nitrogen-doped porous carbon composite material, preparation method and application thereof

Abstract

The application discloses a rhenium disulfide-nitrogen doped porous carbon composite material and a preparation method and application thereof. The preparation method of the rhenium disulfide-nitrogen doped porous carbon composite material comprises the following steps: (1) adding a rhenium source, thiourea and sodium chloride into a folic acid solution and uniformly mixing to obtain a mixed solution, wherein the rhenium source is at least one of ammonium perrhenate and potassium perrhenate; (2) performing freeze drying on the mixed solution to obtain a mixed dry powder; (3) performing heat treatment and sulfuration treatment on the mixed dry powder under an inert atmosphere and at a certain temperature; and (4) performing washing and freeze drying on the product obtained in the step (3) to obtain the rhenium disulfide-nitrogen doped porous carbon composite material. The rhenium disulfide-nitrogen doped porous carbon composite material prepared by the method has good conductivity and low volume expansion effect, and is not prone to agglomeration or accumulation.

Description

Technical Field

[0001] This invention belongs to the field of composite material technology, and particularly relates to a rhenium disulfide-nitrogen doped porous carbon composite material, its preparation method and application. Background Technology

[0002] In contemporary society, energy has undoubtedly become one of the world's major issues, attracting widespread attention. Finding novel materials with exceptional energy storage and utilization capabilities has become a crucial task for scientists. Supercapacitors, as a new type of energy storage device, possess advantages such as long lifespan and high energy density, attracting significant research interest. The active electrode materials of supercapacitors greatly influence the electrochemical performance of energy storage devices; therefore, finding electrode materials with novel structures is a key issue in the development of supercapacitors.

[0003] Transition metal sulfides have attracted considerable attention as pseudocapacitive electrode materials for energy storage, similar to battery-type materials. Rhenium disulfide (ReS2) stands out as a promising pseudocapacitive electrode material due to its high specific capacitance. However, the high surface energy of rhenium disulfide nanoparticles makes them prone to aggregation or accumulation during use, significantly reducing their usable active surface area and thus decreasing their specific capacitance. Furthermore, the poor conductivity of rhenium disulfide and the volume expansion effect caused by prolonged charge-discharge cycles can easily lead to pulverization of the electrode material, resulting in poor cycle life and rate capability.

[0004] Therefore, there is an urgent need for a rhenium disulfide-nitrogen-doped porous carbon composite material, its preparation method, and its application, in order to address the shortcomings of existing technologies. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing rhenium disulfide-nitrogen-doped porous carbon composite material. The rhenium disulfide-nitrogen-doped porous carbon composite material prepared by this method has good electrical conductivity and low volume expansion effect, and is not prone to agglomeration or accumulation.

[0006] Another objective of this invention is to provide a rhenium disulfide-nitrogen-doped porous carbon composite material, which has good electrical conductivity and low volume expansion effect, and is not prone to agglomeration or accumulation.

[0007] Another object of the present invention is to provide an application of rhenium disulfide-nitrogen doped porous carbon composite material in supercapacitors, lithium-ion battery electrode materials or photocatalysts.

[0008] To achieve the above objectives, this invention provides a method for preparing rhenium disulfide-nitrogen-doped porous carbon composite materials, comprising the following steps:

[0009] (1) Add rhenium source, thiourea and sodium chloride to folic acid solution and mix evenly to obtain a mixture, wherein the rhenium source is at least one of ammonium perperurate and potassium perperurate;

[0010] (2) The mixture is freeze-dried to obtain a mixed dry powder;

[0011] (3) The mixed dry powder is subjected to heat treatment and vulcanization treatment in an inert atmosphere and at a certain temperature;

[0012] (4) The product obtained in step (3) is washed and freeze-dried to obtain rhenium disulfide-nitrogen doped porous carbon composite material.

[0013] Compared with existing technologies, this invention uses folic acid, rhenium source, thiourea, and sodium chloride as raw materials. The mixture of these raw materials is then freeze-dried, forming a layer containing folic acid, rhenium source, and thiourea on the surface of sodium chloride microcrystals. In subsequent heat treatment and sulfidation, folic acid undergoes thermal decomposition to form nitrogen-doped carbon sheets, and thiourea decomposes to release hydrogen sulfide. The hydrogen sulfide, along with rhenium disulfide (ReS2) generated in situ by ammonium perperurate or potassium perperurate, is loaded onto the nitrogen-doped carbon sheets. After washing to remove the sodium chloride and create pores, a rhenium disulfide-nitrogen-doped porous carbon composite material is obtained. In this way, the rhenium disulfide nanoparticles are highly dispersed in the carbon network, avoiding agglomeration and exposing more active sites, which is beneficial for improving the specific capacitance of the composite material. Simultaneously, the confinement effect of the carbon material effectively mitigates the volume expansion effect of the rhenium disulfide nanoparticles during charge and discharge, enhancing the cycle stability of the composite material. Furthermore, the tight bonding with the conductive carbon material improves the overall conductivity of the composite material, which is beneficial for improving its rate performance. Therefore, the present invention uses folic acid as a carbon and nitrogen source, ammonium perperurate or potassium perperurate as a rhenium source, thiourea as a sulfur source, and sodium chloride as a pore-forming agent. Then, by freeze drying combined with heat treatment and sulfidation technology, a rhenium disulfide-nitrogen doped porous carbon composite material with good electrical conductivity, low volume expansion effect, and is not prone to agglomeration is prepared.

[0014] Preferably, the folic acid solution of the present invention has a molar concentration of 0.01 to 2.5 mol / L, the rhenium source has a molar concentration of 0.01 to 0.5 mol / L, and the molar ratio of folic acid solution to rhenium source is 1 to 5:1.

[0015] Preferably, the molar ratio of sodium chloride to rhenium source in this invention is 50–200:1.

[0016] Preferably, the molar ratio of thiourea to rhenium source in this invention is 5 to 10:1. Specifically, the structure and size of the rhenium disulfide-nitrogen-doped porous carbon composite material can be further controlled by changing the molar ratio of folic acid to rhenium source, the molar ratio of sodium chloride to rhenium source, and the molar ratio of thiourea to rhenium source.

[0017] Preferably, step (1) of the present invention further includes: dissolving folic acid in a certain amount of water, and then adding a certain amount of concentrated ammonia until the folic acid is completely dissolved to obtain a folic acid solution.

[0018] Preferably, the freeze-drying time in step (2) of the present invention is 10 to 16 hours. More preferably, the freeze-drying time is 12 hours.

[0019] Preferably, in step (3) of the present invention, the temperature of heat treatment and vulcanization is 500-700°C, and the time of heat treatment and vulcanization is 1-4 hours. Specifically, the present invention can also control the structure and size of the composite material by changing the temperature and time of heat treatment and vulcanization.

[0020] Preferably, step (4) of the present invention includes repeatedly washing the obtained product with water until sodium chloride is completely removed.

[0021] To achieve the above objectives, the present invention provides a rhenium disulfide-nitrogen-doped porous carbon composite material, which is obtained by the above-described preparation method of the rhenium disulfide-nitrogen-doped porous carbon composite material.

[0022] Compared with the prior art, the rhenium disulfide-nitrogen doped porous carbon composite material provided by the present invention is prepared by using folic acid as the carbon source and nitrogen source, ammonium perrhenate or potassium perrhenate as the rhenium source, thiourea as the sulfur source, and sodium chloride as the pore-forming agent, and then freeze-drying combined with heat treatment and sulfidation technology. Therefore, the composite material has better electrical conductivity and lower volume expansion effect, and is not prone to agglomeration or accumulation.

[0023] To achieve the above objectives, the present invention provides an application of the above-mentioned rhenium disulfide-nitrogen-doped porous carbon composite material in supercapacitors, lithium-ion battery electrode materials, or photocatalysts.

[0024] Compared with the prior art, the rhenium disulfide-nitrogen doped porous carbon composite material of the present invention has better conductivity and lower volume expansion effect, and is not prone to agglomeration. Therefore, when this composite material is applied to supercapacitors, lithium-ion battery electrode materials, and photoelectrocatalysts, it can achieve higher specific capacitance, better cycle stability and better rate performance. Attached Figure Description

[0025] Figure 1 The charge-discharge curve of the rhenium disulfide-nitrogen-doped porous carbon composite material prepared in Example 1 of the present invention is shown at a current density of 1 A / g.

[0026] Figure 2 The image shows the XRD pattern of the rhenium disulfide-nitrogen-doped porous carbon composite material prepared in Example 1 of the present invention.

[0027] Figure 3 This is a scanning electron microscope image of the rhenium disulfide-nitrogen-doped porous carbon composite material prepared in Example 1 of the present invention.

[0028] Figure 4 The charge-discharge curve of the rhenium disulfide-nitrogen-doped porous carbon composite material prepared in Example 2 of the present invention is shown at a current density of 1 A / g.

[0029] Figure 5 This is a scanning electron microscope image of the rhenium disulfide-nitrogen-doped porous carbon composite material prepared in Example 2 of the present invention.

[0030] Figure 6 This is a charge-discharge curve of the rhenium disulfide material prepared in Comparative Example 1 of the present invention at a current density of 1 A / g.

[0031] Figure 7 This is a scanning electron microscope image of the rhenium disulfide material prepared in Comparative Example 1 of the present invention.

[0032] Figure 8 This is a scanning electron microscope image of the rhenium disulfide-nitrogen-doped porous carbon composite material prepared in Comparative Example 2 of the present invention. Detailed Implementation

[0033] To better illustrate the purpose, technical solution, and beneficial effects of this invention, the invention will be further described below with reference to specific embodiments. It should be noted that the methods described below are further explanations of this invention and should not be construed as limiting it.

[0034] Example 1

[0035] This embodiment provides a method for preparing rhenium disulfide-nitrogen-doped porous carbon composite material, the steps of which include:

[0036] (1) Dissolve 3 mmol of folic acid in 30 mL of deionized water under stirring, and then add 6 drops of concentrated ammonia until the folic acid is completely dissolved to obtain a folic acid solution. Under continuous stirring, add 1 mmol of ammonium perrhenate, 5 mmol of thiourea and 100 mmol of sodium chloride to the folic acid solution and mix evenly to obtain a mixed solution.

[0037] (2) Freeze the mixture with liquid nitrogen and then freeze-dry it for 12 hours to obtain a mixed dry powder;

[0038] (3) Place the mixed dry powder in a quartz boat, place it in the middle of a tube furnace, and perform heat treatment and sulfidation treatment at 600°C for 2 hours under a nitrogen atmosphere.

[0039] (4) The product obtained in step (3) is washed with water three times until sodium chloride is completely removed, and then freeze-dried for 12 hours to obtain rhenium disulfide-nitrogen doped porous carbon composite material.

[0040] 6.25 mg of acetylene black and 50 mg of the rhenium disulfide-nitrogen-doped porous carbon composite material prepared above were mixed and ground. Then, 6.25 mg of polyvinylidene fluoride and an appropriate amount of N-methylpyrrolidone (NMP) were added and ultrasonically dispersed for 30 min. After dispersion, the mixture was coated on the surface of nickel foam and vacuum dried at 60 °C for 12 hours to obtain an electrode sheet. The obtained electrode was used as the working electrode, a platinum sheet electrode as the counter electrode, and a saturated calomel electrode as the reference electrode. Capacitance performance was tested using 2 mol / L potassium hydroxide solution as the electrolyte. Figure 1 The galvanostatic charge-discharge curves show that its specific capacity is 940 F / g at 1 A / g. Simultaneously, XRD tests were performed on the rhenium disulfide-nitrogen-doped porous carbon composite material prepared in Example 1, and the results are shown in [Figure 1]. Figure 2 ,Depend on Figure 2 It can be seen that the positions and intensities of the diffraction peaks of rhenium disulfide are consistent with those of the standard diffraction card (JCPDS 89-0341) for triclinic rhenium disulfide. Furthermore, scanning electron microscopy was performed on the rhenium disulfide-nitrogen-doped porous carbon composite material prepared in Example 1, and the results are as follows: Figure 3 As shown, it is a three-dimensional porous structure composed of nanosheets with relatively uniform size and morphology, and its surface structure is distributed with many rhenium disulfide nanoparticles with an average diameter of about 18 nanometers. Elemental analysis shows that the mass content of rhenium disulfide in the composite material is 49.78%.

[0041] Example 2

[0042] This embodiment provides a method for preparing rhenium disulfide-nitrogen-doped porous carbon composite material, the steps of which include:

[0043] (1) Dissolve 1 mmol of folic acid in 30 mL of deionized water under stirring, and then add 5 drops of concentrated ammonia until the folic acid is completely dissolved to obtain a folic acid solution. Under continuous stirring, add 1 mmol of ammonium perrhenate, 5 mmol of thiourea and 50 mmol of sodium chloride to the folic acid solution and mix evenly to obtain a mixed solution.

[0044] (2) Freeze the mixture with liquid nitrogen and then freeze-dry it for 12 hours to obtain a mixed dry powder;

[0045] (3) Place the mixed dry powder in a quartz boat, place it in the middle of a tube furnace, and perform heat treatment and sulfidation treatment at 600°C for 2 hours under a nitrogen atmosphere.

[0046] (4) The product obtained in step (3) is washed with water three times until sodium chloride is completely removed, and then freeze-dried for 12 hours to obtain rhenium disulfide-nitrogen doped porous carbon composite material.

[0047] 6.25 mg of acetylene black and 50 mg of the rhenium disulfide-nitrogen-doped porous carbon composite material prepared above were mixed and ground. Then, 6.25 mg of polyvinylidene fluoride and an appropriate amount of N-methylpyrrolidone (NMP) were added and ultrasonically dispersed for 30 min. After dispersion, the mixture was coated on the surface of nickel foam and vacuum dried at 60 °C for 12 hours to obtain an electrode sheet. The obtained electrode was used as the working electrode, a platinum sheet electrode as the counter electrode, and a saturated calomel electrode as the reference electrode. Capacitance performance was tested using 2 mol / L potassium hydroxide solution as the electrolyte. Figure 4 The galvanostatic charge-discharge curves show that its specific capacity is 427 F / g at 1 A / g. XRD analysis of the rhenium disulfide-nitrogen-doped porous carbon composite material prepared in Example 2 showed that it was consistent with the standard diffraction card for triclinic rhenium disulfide. Furthermore, scanning electron microscopy (SEM) observation of the rhenium disulfide-nitrogen-doped porous carbon composite material prepared in Example 2 yielded the following results: Figure 5 As shown, it is a three-dimensional porous structure composed of nanosheets with relatively uniform size and morphology, and its surface structure is distributed with many rhenium disulfide nanoparticles with an average diameter of about 32 nanometers. Elemental analysis shows that the mass content of rhenium disulfide in the composite material is 64.67%.

[0048] Example 3

[0049] This embodiment provides a method for preparing rhenium disulfide-nitrogen-doped porous carbon composite material, the steps of which include:

[0050] (1) Dissolve 5 mmol of folic acid in 30 mL of deionized water under stirring, and then add 6 drops of concentrated ammonia until the folic acid is completely dissolved to obtain a folic acid solution. Under continuous stirring, add 1 mmol of potassium perrhenate, 8 mmol of thiourea and 170 mmol of sodium chloride to the folic acid solution and mix well to obtain a mixed solution.

[0051] (2) Freeze the mixture with liquid nitrogen and then freeze-dry it for 15 hours to obtain a mixed dry powder;

[0052] (3) Place the mixed dry powder in a quartz boat, place it in the middle of a tube furnace, and perform heat treatment and sulfidation treatment at 500°C for 4 hours under a nitrogen atmosphere.

[0053] (4) The product obtained in step (3) is washed with water five times until sodium chloride is completely removed, and then freeze-dried for 16 hours to obtain rhenium disulfide-nitrogen doped porous carbon composite material.

[0054] 6.25 mg of acetylene black and 50 mg of the rhenium disulfide-nitrogen-doped porous carbon composite material prepared above were mixed and ground. Then, 6.25 mg of polyvinylidene fluoride and an appropriate amount of N-methylpyrrolidone (NMP) were added and ultrasonically dispersed for 30 min. After dispersion, the mixture was coated on the surface of nickel foam and vacuum dried at 60 °C for 12 hours to obtain an electrode sheet. The obtained electrode was used as the working electrode, the platinum sheet electrode as the counter electrode, and the saturated calomel electrode as the reference electrode. The capacitance performance was tested using 2 mol / L potassium hydroxide solution as the electrolyte. Its specific capacitance at 1 A / g was 652 F / g.

[0055] Comparative Example 1

[0056] This comparative example provides a method for preparing rhenium disulfide material, the steps of which include:

[0057] (1) Add 1 mmol of ammonium perrhenate and 5 mmol of thiourea to 30 mL of deionized water under stirring, and mix well to obtain a mixture;

[0058] (2) Freeze the mixture with liquid nitrogen and then freeze-dry it for 12 hours to obtain a mixed dry powder;

[0059] (3) Place the mixed dry powder in a quartz boat, place it in the middle of a tube furnace, and perform heat treatment and sulfidation treatment at 600°C for 2 hours under a nitrogen atmosphere.

[0060] (4) The product obtained in step (3) is washed with water three times and then freeze-dried for 12 hours to obtain rhenium disulfide material.

[0061] 6.25 mg of acetylene black and 50 mg of the rhenium disulfide material prepared above were mixed and ground. Then, 6.25 mg of polyvinylidene fluoride and an appropriate amount of N-methylpyrrolidone (NMP) were added and ultrasonically dispersed for 30 min. After dispersion, the mixture was coated on the surface of nickel foam and vacuum dried at 60 °C for 12 hours to obtain an electrode sheet. The obtained electrode was used as the working electrode, a platinum sheet electrode as the counter electrode, and a saturated calomel electrode as the reference electrode. Capacitance performance was tested using a 2 mol / L potassium hydroxide solution as the electrolyte. Figure 6 The galvanostatic charge-discharge curves show that its specific capacity is 280 F / g at 1 A / g. XRD analysis of the rhenium disulfide material prepared in Comparative Example 1 also showed consistency with the standard diffraction card for triclinic rhenium disulfide. Furthermore, scanning electron microscopy (SEM) observation of the rhenium disulfide material prepared in Comparative Example 1 yielded the following results: Figure 7 As shown, it consists of nanoparticles clustered together.

[0062] Comparative Example 2

[0063] This invention provides a method for preparing rhenium disulfide-nitrogen-doped porous carbon composite materials, the steps of which include:

[0064] (1) Dissolve 1 mmol hexamethylenetetramine in 30 mL of deionized water under stirring, and then add 1 mmol ammonium perrhenate, 5 mmol thiourea and 50 mmol sodium chloride under continuous stirring, and mix well to obtain a mixture;

[0065] (2) Freeze the mixture with liquid nitrogen and then freeze-dry it for 12 hours to obtain a mixed dry powder;

[0066] (3) Place the mixed dry powder in a quartz boat, place it in the middle of a tube furnace, and perform heat treatment and sulfidation treatment at 600°C for 2 hours under a nitrogen atmosphere.

[0067] (4) The product obtained in step (3) is washed with water three times until sodium chloride is completely removed, and then freeze-dried for 12 hours to obtain rhenium disulfide-nitrogen doped porous carbon composite material.

[0068] 6.25 mg of acetylene black and 50 mg of the rhenium disulfide-nitrogen-doped porous carbon composite material prepared above were mixed and ground. Then, 6.25 mg of polyvinylidene fluoride and an appropriate amount of N-methylpyrrolidone (NMP) were added and ultrasonically dispersed for 30 min. After dispersion, the mixture was coated onto a nickel foam surface and vacuum dried at 60 °C for 12 hours to obtain an electrode sheet. The obtained electrode was used as the working electrode, a platinum sheet electrode as the counter electrode, and a saturated calomel electrode as the reference electrode. Capacitance performance was tested using 2 mol / L potassium hydroxide solution as the electrolyte. Its specific capacitance at 1 A / g was 313 F / g. Scanning electron microscopy was performed on the rhenium disulfide-nitrogen-doped porous carbon composite material prepared in Comparative Example 2. The results are as follows: Figure 8 As shown.

[0069] As can be seen from Examples 1-3, the present invention can further control the structure and size of the rhenium disulfide-nitrogen-doped porous carbon composite material by changing the molar ratio of folic acid to rhenium source, the molar ratio of sodium chloride to rhenium source, the molar ratio of thiourea to rhenium source, and the temperature and time of heat treatment and sulfidation treatment. This also shows that the present invention uses folic acid as the carbon and nitrogen source, ammonium perperurate or potassium perperurate as the rhenium source, thiourea as the sulfur source, and sodium chloride as the pore-forming agent. Then, by freeze drying combined with heat treatment and sulfidation technology, a rhenium disulfide-nitrogen-doped porous carbon composite material with good conductivity, low volume expansion effect, and is not prone to agglomeration can be obtained.

[0070] The capacitance of the rhenium disulfide-nitrogen-doped porous carbon composite materials in Examples 1-3 is superior to that in Comparative Example 1. This indicates that pure-phase rhenium disulfide nanoparticles are prone to aggregation or accumulation during use due to their high surface energy, resulting in a significant reduction in their usable active specific surface area and thus a decrease in specific capacitance. Furthermore, the poor conductivity of rhenium disulfide and the volume expansion effect caused by prolonged charge-discharge cycles can easily lead to pulverization of the electrode material, resulting in poor cycle life and rate capability.

[0071] Comparing Example 2 and Comparative Example 2, it can be seen that the capacitance of the rhenium disulfide-nitrogen doped porous carbon composite material prepared by using hexamethylenetetramine as the carbon and nitrogen source, ammonium perrhenate as the rhenium source, thiourea as the sulfur source, and sodium chloride as the pore-forming agent, combined with freeze-drying, heat treatment, and sulfidation techniques, is not good. This is because the carbon sheets derived from the heat treatment of hexamethylenetetramine are relatively large, making it difficult for the composite material to form a three-dimensional porous structure (e.g., ...). Figure 8 As shown in the figure, the specific surface area is small, which is not conducive to the improvement of electrochemical performance. This also shows that the choice of carbon and nitrogen source has a great influence on the structure of rhenium disulfide-nitrogen doped porous carbon composite material. That is, not all substances containing carbon and nitrogen sources can be used as raw materials for the preparation of rhenium disulfide-nitrogen doped porous carbon composite material of the present invention.

[0072] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles disclosed herein.

Claims

1. The application of a rhenium disulfide-nitrogen-doped porous carbon composite material in supercapacitors, characterized in that, The supercapacitor has a maximum specific capacitance of 940 F / g at 1 A / g. The rhenium disulfide-nitrogen-doped porous carbon composite material has an average diameter of 18 nm to 32 nm. The preparation method of the rhenium disulfide-nitrogen-doped porous carbon composite material includes the following steps: (1) Add rhenium source, thiourea and sodium chloride to folic acid solution and mix evenly to obtain a mixture, wherein the rhenium source is at least one of ammonium perperurate and potassium perperurate. Dissolve folic acid in a certain amount of water and add a certain amount of concentrated ammonia until the folic acid is completely dissolved to obtain the folic acid solution. (2) The mixture is freeze-dried to obtain a mixed dry powder; (3) The mixed dry powder is subjected to heat treatment and vulcanization treatment in an inert atmosphere and at a certain temperature; (4) The product obtained in step (3) is washed and freeze-dried to obtain rhenium disulfide-nitrogen doped porous carbon composite material.

2. The application of the rhenium disulfide-nitrogen-doped porous carbon composite material as described in claim 1 in supercapacitors, characterized in that, The folic acid solution has a molar concentration of 0.01~2.5 mol / L, the rhenium source has a molar concentration of 0.01~0.5 mol / L, and the molar ratio of the folic acid solution to the rhenium source is 1~5:

1.

3. The application of the rhenium disulfide-nitrogen-doped porous carbon composite material as described in claim 1 in supercapacitors, characterized in that, The molar ratio of sodium chloride to the rhenium source is 50~200:

1.

4. The application of the rhenium disulfide-nitrogen-doped porous carbon composite material as described in claim 1 in supercapacitors, characterized in that, The molar ratio of the thiourea to the rhenium source is 5~10:

1.

5. The application of the rhenium disulfide-nitrogen-doped porous carbon composite material as described in claim 1 in supercapacitors, characterized in that, The freeze-drying time in step (2) is 10 to 16 hours.

6. The application of the rhenium disulfide-nitrogen-doped porous carbon composite material as described in claim 1 in supercapacitors, characterized in that, The temperature of the heat treatment and vulcanization treatment in step (3) is 500~700℃, and the time of the heat treatment and vulcanization treatment is 1~4 hours.

7. The application of the rhenium disulfide-nitrogen-doped porous carbon composite material as described in claim 1 in supercapacitors, characterized in that, Step (4) involves repeatedly washing the resulting product with water until the sodium chloride is completely removed.

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