CN112723334B - A method for preparing nitrogen-doped carbon materials by using fluorine-containing polymers - Google Patents

Abstract

The invention relates to a method for preparing a nitrogen-doped carbon material by utilizing fluorine-containing macromolecules, which comprises the steps of placing a precursor material of the fluorine-containing macromolecules in an ammonia atmosphere, and calcining at 360-1200 ℃ to obtain the nitrogen-doped carbon material; the fluorine-containing high polymer precursor material is a polymer with relative molecular mass of 1000-1000 ten thousand and partial hydrogen substituted by fluorine. The nitrogen-doped carbon material can be obtained at a lower temperature, and due to the isoelectronic exchange of fluorine and nitrogen species, the doping of nitrogen elements can be greatly promoted, so that the nitrogen content in the nitrogen-doped carbon material obtained by the method can reach more than 10%, and the controllable doping of the nitrogen content and the type on the conductive carbon felt can be realized by regulating and controlling the reaction temperature.

Description

A method for preparing nitrogen-doped carbon materials by using fluorine-containing polymers

technical field

The invention relates to a method for preparing nitrogen-doped carbon materials by utilizing fluorine-containing polymers, in particular to a new mechanism for utilizing fluorine-containing polymers to remove fluorine during carbonization and decomposition at high temperature in an ammonia atmosphere to promote nitrogen doping A porous structure is formed to obtain a carbon material with high nitrogen doping content and abundant pore structure, which belongs to the field of material preparation.

Background technique

Nitrogen-doped carbon materials and their composites are functional materials with a wide range of uses and have attracted much attention, and they are hot research materials in academia and industry. However, there are still many bottlenecks in the current research that cannot be broken through: for example, the type of nitrogen in nitrogen-doped carbon materials has a great influence on its functionalization, but how to control the synthesis is still difficult; Most of the limitations of the preparation methods can only be used to prepare nitrogen-doped carbon materials in small quantities in the laboratory, but cannot achieve large-scale industrial preparation; and how to realize nitrogen-doped carbon materials with high specific surface area and ordered pore structure is still a big problem. Difficulty; how to achieve uniform loading of metal carbon/nitrogen/fluorine/oxide on nitrogen-doped carbon when fabricating composites remains difficult.

Direct pyrolysis of nitrogen-rich precursors is a simple and commonly used method for preparing nitrogen-doped carbon materials, which can achieve relatively uniform nitrogen doping. Generally, this method can achieve graphitization of carbon materials at a higher temperature (>900°C), thereby achieving high electrical conductivity of the material, but since nitrogen-doped carbon materials tend to lose nitrogen at temperatures higher than 750°C, Therefore, the nitrogen content of the general nitrogen-doped carbon material obtained by this method is difficult to exceed 7%, and it is difficult to control the desired nitrogen-doped type.

SUMMARY OF THE INVENTION

In view of the above problems, the purpose of the present invention is to provide a carbon material doped with high nitrogen content (nitrogen-doped carbon material), a conductive carbon felt supported by nitrogen-doped carbon material, and a preparation method and application thereof.

In the first aspect, the present invention provides a method for preparing a nitrogen-doped carbon material by using a fluorine-containing polymer. The fluorine-containing polymer precursor material is placed in an ammonia gas atmosphere, and calcined at 360°C to 1200°C to obtain the obtained carbon material. The nitrogen-doped carbon material; the fluorine-containing polymer precursor material is a polymer in which part of the hydrogen with a relative molecular mass between 10 million and 10 million is replaced by fluorine.

In the present invention, fluorine-containing polymer materials are used for the first time to prepare nitrogen-doped carbon materials. High temperature carbonization (360-1200°C) in a tube furnace of ammonia gas (1mL/min-10000mL/min) can obtain nitrogen-doped carbon materials with porous structure. This enables nitrogen-doped carbon materials to be obtained at a lower temperature, and since the isoelectron exchange of fluorine and nitrogen species can greatly promote the doping of nitrogen elements, the nitrogen-doped carbon materials obtained by this method are The nitrogen content can reach more than 10%, and the controllable doping of nitrogen content and type can be realized by adjusting the reaction temperature.

Preferably, before calcination, a templating agent is also added, and the templating agent is selected from at least one of mesoporous silica, molecular sieve, and magnesium oxide; the mass ratio of the templating agent to the fluorine-containing polymer precursor material is (0.1-5): 1; and after calcination, the template agent is removed with an etchant. Preferably, by mixing the fluorine-containing polymer material with some templating agents (such as mesoporous silica, molecular sieve, magnesium oxide, etc.) in advance, and then nitriding at a high temperature in an ammonia gas atmosphere at a certain temperature, the obtained product is then acidified. The nitrogen-doped carbon material with ordered pore structure can be obtained by washing and removing the template agent.

Preferably, the fluorine-containing polymer precursor material is selected from polyvinylidene fluoride (PVDF), polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP), polyvinyl fluoride (PVF), polyperfluoroalkoxy (PFA) resin, at least one of polychlorotrifluoroethylene (PCTFE), ethylene-chlorotrifluoroethylene copolymer (ECTFE) and ethylene-tetrafluoroethylene (ETFE) copolymer, preferably polyvinylidene fluoride PVDF .

Preferably, the ammonia gas atmosphere is ammonia gas or a mixed gas containing ammonia gas;

When selecting an open container for calcination, the gas flow rate of the ammonia gas atmosphere is 1-10000 mL/min, preferably 300 mL/min;

When selecting a closed container for calcination, the pressure of the ammonia gas atmosphere is 0.1-100 MPa.

Preferably, the calcination temperature is 700°C.

Preferably, the heating rate of the calcination is 0.1-100°C/min, preferably 20°C/min.

Preferably, the calcination time is 1 minute to 10 hours, preferably 4 hours.

In a second aspect, the present invention provides a method for preparing a nitrogen-doped carbon material-supported conductive carbon felt, comprising:

(1) mixing a fluorine-containing polymer precursor material and a solvent to obtain a mixed solution, wherein the fluorine-containing polymer precursor material is a polymer in which part of the hydrogen with a relative molecular mass between 10 million and 10 million is replaced by fluorine;

(2) soak the conductive carbon felt in the obtained mixed solution for 0.1 to 24 hours, then dry it, place it in an ammonia gas atmosphere, and calcine it at 360 to 1200° C. to obtain the conductive carbon supported by the nitrogen-doped carbon material. felt.

In the present invention, a fluorine-containing polymer material is used for the first time to prepare a conductive carbon felt of a nitrogen-doped carbon material. ) carbonization at high temperature (360-1200°C) in a tube furnace with ammonia gas (1mL/min-10000mL/min) passing through, and nitrogen-doped carbon materials with porous structure can be obtained. This enables nitrogen-doped carbon materials to be obtained at a lower temperature, and since the isoelectron exchange of fluorine and nitrogen species can greatly promote the doping of nitrogen elements, the nitrogen-doped carbon materials obtained by this method are The nitrogen content can reach more than 10%, and the controllable doping of the nitrogen content and type on the conductive carbon felt can be realized by adjusting the reaction temperature.

Preferably, the solvent is selected from at least one of N-methylpyrrolidone, chloroform, water and ethanol; the concentration of the mixed solution is 5-100 mg/mL.

Preferably, a templating agent is also added to the mixed solution, and the templating agent is selected from at least one of mesoporous silica, molecular sieve, and magnesium oxide; the mass ratio of the templating agent to the fluorine-containing polymer precursor material is is (0.1-5): 1; and after calcination, the template agent is removed with an etchant. Preferably, by mixing the fluorine-containing polymer material with some templating agents (such as mesoporous silica, molecular sieve, magnesium oxide, etc.) in advance, and then nitriding at a high temperature in an ammonia gas atmosphere at a low temperature, the obtained product is reused Nitrogen-doped carbon materials with an ordered pore structure can be obtained by removing the template agent by etching methods such as pickling.

Preferably, the fluorine-containing polymer precursor material is selected from polyvinylidene fluoride (PVDF), polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP), polyvinyl fluoride (PVF), polyperfluoroalkoxy At least one of (PFA) resin, polychlorotrifluoroethylene (PCTFE), ethylene-chlorotrifluoroethylene copolymer (ECTFE), and ethylene-tetrafluoroethylene (ETFE) copolymer, preferably polyvinylidene fluoride PVDF .

Preferably, the ammonia gas atmosphere is ammonia gas or a mixed gas containing ammonia gas; when an open container is selected for calcination, the gas flow rate of the ammonia gas atmosphere is 1-10000mL/min, preferably 300mL/min; When selecting a closed container for calcination, the pressure of the ammonia gas atmosphere is 0.1-100 MPa. Taking polyvinylidene fluoride, namely PVDF as an example, it is carbonized at high temperature (360℃-1200℃) in a tube furnace with ammonia gas (1mL/min～10000mL/min), and a porous structure can be obtained. Nitrogen-doped carbon material.

Preferably, the calcination temperature is 700°C.

Preferably, the heating rate of the calcination is 0.1-100°C/min, preferably 20°C/min.

Preferably, the calcination time is 1 minute to 10 hours, preferably 4 hours.

In a third aspect, the present invention provides a nitrogen-doped carbon material prepared according to the above-mentioned method for preparing a nitrogen-doped carbon material by using a fluorine-containing polymer, wherein the atomic doping amount of nitrogen in the nitrogen-doped carbon material is 1 %˜15%; the conductivity of the nitrogen-doped carbon material is 1˜100 mS/cm.

In a fourth aspect, the present invention provides a nitrogen-doped carbon material-supported conductive carbon felt prepared according to the above method, comprising: a conductive carbon felt, and a nitrogen-doped carbon material supported on the conductive carbon felt, the nitrogen The loading amount of the doped carbon material is 1wt%-70wt%; the atomic doping amount of nitrogen element in the nitrogen-doped carbon material is 1%-15at%.

In a fifth aspect, the present invention provides an application of the above nitrogen-doped carbon material in the preparation of supercapacitors, lithium-ion batteries, catalytic materials, drying materials and metal-air batteries.

In a sixth aspect, the present invention provides an application of the above-mentioned nitrogen-doped carbon material-supported conductive carbon felt in the preparation of supercapacitors, lithium-ion batteries, catalytic materials, drying materials and metal-air batteries.

Compared with the prior art, the present invention has the following beneficial effects:

Since the fluorine-containing polymer material is decomposed by carbonization (pyrolysis), the fluorine element is removed to promote the doping of nitrogen element, and finally a carbon material with high nitrogen doping content and rich pore structure is obtained;

The variety of precursors used is rich: Since the key to this method lies in the new isoelectron exchange mechanism of fluorine and nitrogen species, only polymer materials containing fluorine and their composite materials can be used as precursor materials, even some discarded ones. Fluoroplastic products, so the cost is low and it can be prepared on a large scale, realizing environmental protection and waste utilization, and the reaction conditions are relatively mild, and high nitrogen doping content (>10%) can be obtained at a lower temperature (<500°C). The porous carbon material (specific surface area can reach more than 1000m ² /g) is energy-saving and environmentally friendly, suitable for industrialized mass production, and nitrogen-doped carbon materials with different nitrogen contents can be obtained by controlling the reaction temperature and time, or by adding some template agents. A nitrogen-doped carbon material containing an ordered pore structure is obtained;

Based on the new mechanism that fluorine is removed to promote nitrogen doping during carbonization and decomposition of fluorine-containing polymers at high temperature in ammonia atmosphere, and a porous structure is formed to obtain carbon materials with high nitrogen doping content and rich pore structure, which can be used to solve the problem. Large-scale and inexpensive production of high-performance nitrogen-doped porous carbon materials for supercapacitors, lithium-ion batteries, and electrocatalytic oxygen reduction.

Description of drawings

FIG. 1 shows a transmission electron microscope photograph of a nitrogen-doped carbon material with a disordered porous structure prepared according to the template-free method of the present invention. From the transmission electron microscope image, it can be seen that the prepared nitrogen-doped carbon material has a porous structure. of amorphous carbon;

FIG. 2 shows a transmission electron microscope photo with an ordered mesoporous structure prepared by the mesoporous silica template method of the present invention. It can be seen from the transmission electron microscope image that the prepared nitrogen-doped carbon material is amorphous carbon and Has an ordered porous structure;

Fig. 3 shows the transmission electron microscope photo with hollow pore structure prepared according to the magnesium oxide template method of the present invention, it can be seen from the transmission electron microscope picture that the prepared nitrogen-doped carbon material is amorphous carbon and has a hollow porous structure;

FIG. 4 shows the powder X-ray diffraction spectrum of the nitrogen-doped carbon material with ordered mesoporous structure and disordered porous structure prepared according to the method of the present invention. It can be seen from the spectrum that the product has no obvious effect within the test range. Diffraction peaks, indicating that the material is amorphous carbon;

Fig. 5 shows the small-angle powder X-ray diffraction spectra of nitrogen-doped carbon materials with ordered mesoporous structure and template mesoporous silica SBA-15 prepared according to the method of the present invention. It has obvious small-angle diffraction peaks, indicating its ordered mesoporous structure;

Fig. 6 shows the small-angle powder X-ray diffraction spectrum of the nitrogen-doped carbon material with disordered porous structure prepared according to the method of the present invention. The material does not have a periodic ordered structure;

7 shows the nitrogen adsorption and desorption isotherms of the porous nitrogen-doped carbon material prepared according to the method of the present invention. From the shape of the curve, it can be seen that the material has mesoporous and microporous structures, and the specific surface area is 960 m ² g ⁻¹ ;

8 shows the Raman spectrum of the nitrogen-doped carbon material prepared according to the method of the present invention, from which it can be seen that the material contains a large amount of sp2 carbon and defect structures;

FIG. 9 shows the photoelectron spectrum (XPS) of N1s of the nitrogen-doped carbon material prepared according to the method of the present invention. From the spectrum, it can be seen that the material contains a large amount of nitrogen content of 10.8 wt %, and the type of nitrogen is pyrrole. type nitrogen and pyridine type nitrogen;

10 shows the cyclic voltammetry curve of the nitrogen-doped carbon material prepared according to the method of the present invention as a supercapacitor electrode material, the test shows that the material has typical electrochemical behavior of supercapacitors, and a pseudocapacitive redox peak appears ;

11 shows the constant current charge-discharge curve of the nitrogen-doped carbon material prepared by the method of the present invention as a supercapacitor electrode material, and the calculation shows that the material has a mass specific capacity as high as 500F g ⁻¹ ;

Figure 12 shows the cycle performance diagram of the nitrogen-doped carbon material prepared according to the method of the present invention as a negative electrode material for lithium ion batteries, and the calculation shows that the material has a mass specific capacity as high as 800mAh g ^-1 ;

13 shows a photo of a large-area conductive carbon felt supported by a nitrogen-doped carbon material prepared according to the method of the present invention, indicating that the material has the prospect of macro-scale preparation and application;

Figure 14 shows the linear scan curve of the nitrogen-doped carbon material prepared according to the method of the present invention as a catalyst for electrocatalytic oxygen reduction (ORR) reaction. By comparison with a commercial platinum carbon (20%) catalyst, it can be found that the carbon material prepared by the present invention Nitrogen-doped carbon materials have similar catalytic properties;

Figure 15 shows the galvanostatic charge-discharge curve of the black amorphous porous nitrogen-doped carbon material prepared in Comparative Example 1, and the calculation from the figure shows that the material only has a mass specific capacity of 120F g ^-1 ;

FIG. 16 shows the cyclic voltammetry curve of the black amorphous porous nitrogen-doped carbon material prepared in Comparative Example 1. It can be seen from the figure that it has a typical electrochemical behavior of a supercapacitor, and a pseudocapacitive redox peak appears.

Detailed ways

The present invention is further described below through the following embodiments, and it should be understood that the following embodiments are only used to illustrate the present invention, but not to limit the present invention.

In the present disclosure, fluorine-containing polymer precursor materials (polymers in which part of the hydrogen is replaced by fluorine, the molecular weight can be 10 million to 10 million), under high temperature (≥360°C) and oxygen-free conditions, hydrogen and fluorine will be converted into hydrogen fluoride. form out and carbonize. The inventors carried out pyrolysis treatment (or calcination, high temperature carbonization, etc.) in an ammonia gas atmosphere for the first time. Since hydrogen fluoride and ammonia gas are isoelectronics, the desorption of fluorine will promote the combination of nitrogen and carbon at the desorption site of fluorine. , so as to promote the doping of nitrogen into the carbon material formed after the fluorine is removed. This process is called isoelectronic exchange of fluorine and nitrogen species, and a nitrogen-doped carbon material with a porous structure is obtained. This process can take place at a lower temperature (≥360 °C), which makes nitrogen-doped carbon materials available at lower temperatures, and can greatly promote nitrogen due to the isoelectron exchange of fluorine and nitrogen species. The nitrogen content in the nitrogen-doped carbon material obtained by this method can reach more than 10%, and the nitrogen types can be pyrrole-type nitrogen and pyridine-type nitrogen.

In an optional embodiment, the fluorine-containing polymer precursor material is selected from the group consisting of polyvinylidene fluoride (PVDF), polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP), polyvinyl fluoride (PVF), polyperfluoroalkane At least one of oxy (PFA) resin, polychlorotrifluoroethylene (PCTFE), ethylene-chlorotrifluoroethylene copolymer (ECTFE), and ethylene-tetrafluoroethylene (ETFE) copolymer, preferably polyvinylidene fluoride Vinyl PVDF. It should be noted that the fluorine-containing polymer material used in the present invention can be directly purchased commercial powder, and can also be various waste pipes, membranes, components, etc. made of fluorine-containing polymer to realize the waste utilization of fluorine-containing polymer, The morphology is preferably powdery.

In alternative embodiments, a fluoropolymer precursor material and a templating agent (eg, mesoporous silica, molecular sieves, magnesia, clay, kaolin, etc.) may be mixed prior to calcination to achieve carbon materials adjustment of pore size and porosity. After calcination, the template agent is removed by acid washing, and a nitrogen-doped carbon material with an ordered pore structure can be obtained. Further preferably, the fluoropolymer precursor material and the templating agent can be directly mixed. Alternatively, the fluorine-containing polymer precursor material is first mixed with a solvent (for example, at least one of N-methylpyrrolidone, chloroform, water and ethanol, etc.), and then a templating agent is added to obtain a mixed slurry. After centrifugation and drying, a homogeneous mixture of the fluorine-containing polymer precursor material and the templating agent is obtained.

In an alternative embodiment, the temperature range of the pyrolysis treatment may be 360-1200°C. The heating rate of the pyrolysis treatment may be 0.1 to 100° C./min. The holding time for the pyrolysis treatment is 1 minute to 10 hours. Further preferred reaction conditions are: the reaction temperature is 700°C, the heating rate is 20°C/min, and the temperature is maintained for 4 hours.

In an optional embodiment, the ammonia gas atmosphere can be realized by continuously feeding ammonia gas or other mixed gas containing ammonia gas into the ammonia gas flow tube furnace (open container), and the gas flow rate ranges from 1 to 10000mL/ min, preferably 300 mL/min. Alternatively, ammonia gas or other mixed gas containing ammonia gas is passed into the airtight container containing the precursor material, and the pressure is in the range of 0.1-100 MPa, preferably 0.2 MPa.

In an embodiment of the present invention, the atomic doping amount of nitrogen in the nitrogen-doped carbon material prepared by the above method is 1% to 15%. The conductivity of the nitrogen-doped carbon material is 1-100 mS/cm. Moreover, the size of the pores of the obtained nitrogen-doped carbon material is micropores and mesopores, and the nitrogen-doped carbon material directly prepared from the fluorine-containing polymer material has a disordered porous structure. However, by mixing fluorine-containing polymer materials with some templating agents (such as mesoporous silica, molecular sieves, magnesium oxide) and then placing them in an ammonia atmosphere for high-temperature calcination, the product is etched to remove the templating agent. Heterocarbon materials have highly ordered microporous or mesoporous structures. The method is simple and effective, has excellent performance, and does not require tedious post-treatment processes, and the obtained product can be widely used in new energy fields such as supercapacitors, lithium-ion batteries, and electrocatalytic oxygen reduction.

In one embodiment of the present invention, using conductive carbon felt as the base material, and using the high-temperature carbonization process of the fluorine-containing polymer precursor material, the nitrogen-doped carbon material is directly grown on the conductive carbon felt in situ to obtain nitrogen-doped carbon. Material-loaded conductive carbon felts have a wide range of applications in supercapacitors, lithium-ion batteries, catalytic materials, drying materials, and metal-air batteries. The following exemplifies the preparation method of the nitrogen-doped carbon material-supported conductive carbon felt.

Preparation of mixed slurry. The fluorine-containing polymer precursor material and the solvent are mixed to obtain a mixed solution. The above-mentioned fluorine-containing polymer precursor material is a polymer in which part of the hydrogen with a relative molecular mass between 10 million and 10 million is replaced by fluorine. Wherein, the solvent is at least one selected from at least one of N-methylpyrrolidone, chloroform, water and ethanol. The concentration of the mixed solution may be 5-100 mg/mL. Preferably, a templating agent is also added to the mixed solution. The templating agent is selected from at least one of mesoporous silica, molecular sieve, and magnesium oxide. The mass ratio of the template agent to the fluorine-containing polymer precursor material may be (0.1-5):1. After calcination, an etchant (acid solution corresponding to the template) is used to remove the template.

The conductive carbon felt is soaked in the obtained mixed solution for 0.1 to 24 hours, dried, and then placed in an ammonia gas atmosphere for high-temperature carbonization. The high-temperature carbonization process is basically the same as the calcination process of nitrogen-doped carbon materials.

In summary, the obtained nitrogen-doped carbon material and nitrogen-doped carbon material-supported conductive carbon felt can be used as materials for supercapacitors, lithium-ion batteries, catalysis, and metal-air batteries, and can also adsorb pollutants for use in air/water quality Purification, or adsorption of water molecules in the air and used as a desiccant.

Sample Characterization

The morphology and ultrastructural information of the samples were collected by transmission electron microscopy. The sample structure information was collected by X-ray diffractometer. The pore structure information of the samples was collected using a specific surface area tester. X-ray photoelectron spectroscopy was used to analyze the chemical composition, element valence and content of the material. The conductivity of the material was tested using the four-probe method.

The following further examples are given to illustrate the present invention in detail. It should also be understood that the following examples are only used to further illustrate the present invention, and should not be construed as limiting the protection scope of the present invention. Some non-essential improvements and adjustments made by those skilled in the art according to the above content of the present invention belong to the present invention. scope of protection. The specific process parameters and the like in the following examples are only an example of a suitable range, that is, those skilled in the art can make selections within the suitable range through the description herein, and are not intended to be limited to the specific numerical values exemplified below.

Example 1

Weigh 0.5g of polyvinylidene fluoride (PVDF) powder sample, spread it evenly in a corundum porcelain boat, and then place it in a tubular atmosphere furnace, then connect both ends of the tubular atmosphere furnace with special flanges and pass ammonia into it. The flow rate of ammonia gas is 300mL/min, and in the subsequent calcination process, ammonia gas is continuously fed in at this flow rate, and the tail gas is absorbed by sulfuric acid solution to prevent atmospheric pollution. The heating rate of ℃/min is heated to 700 ℃, and then the heating is stopped after 4 hours of insulation, and the temperature is naturally lowered. After the temperature drops to room temperature, the ammonia gas is stopped and the flow rate of argon is 300 mL/min. After at least 60 minutes Stop, take out the corundum porcelain boat containing the product to obtain black amorphous porous nitrogen-doped carbon material powder, the transmission electron microscope picture and X-ray powder diffraction of the product are shown in accompanying drawings 1, 4 and 6. The product has a nitrogen content of 10%, a specific surface area of 960 m ² /g, a capacity of 300 F/g as a supercapacitor material, and a capacity of 520 mAh/g ^-1 as a negative electrode material for lithium batteries.

Example 2

Weigh 0.5g of polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) powder sample, spread it evenly in a corundum porcelain boat, and then place it in a tubular atmosphere furnace. The blue is connected and fed with ammonia gas. The flow rate of ammonia gas is 300mL/min. During the subsequent calcination process, ammonia gas is continuously fed with this flow rate. The tail gas is absorbed by sulfuric acid solution to prevent atmospheric pollution. After ventilating at room temperature for at least 60 minutes Turn on the programmed heating, heat up to 700°C at a heating rate of 20°C/min, stop heating after 4 hours of heat preservation, cool down naturally, stop feeding ammonia after the temperature drops to room temperature, and feed argon with a flow rate of 300mL/min , stop after at least 60 minutes, and take out the corundum porcelain boat containing the product to obtain a black amorphous porous nitrogen-doped carbon material powder. The nitrogen content of the product is 10% and the specific surface area is 1030m ² /g, as The capacity of the supercapacitor material is 320F/g, and the capacity of the lithium battery negative electrode material is 450mAh/g.

Example 3:

Weigh 0.5g of polyvinylidene fluoride (PVDF) powder sample and 0.5g of mesoporous silica SBA-15 for mixing and ball milling for 4 hours. The mixed sample powder is evenly spread in a corundum porcelain boat, and then placed in a tubular atmosphere furnace , then connect the two ends of the tubular atmosphere furnace with special flanges and pass ammonia gas, the flow rate of ammonia gas is 300mL/min, and continue to pass ammonia gas at this flow rate during the subsequent calcination process, and the tail gas is absorbed by sulfuric acid solution To prevent air pollution, turn on the program heating after ventilating at room temperature for at least 60 minutes, and heat up to 700°C at a heating rate of 20°C/min, then stop heating after holding for 4 hours, cool down naturally, and stop feeding ammonia when the temperature drops to room temperature The black mesoporous silica SBA-15-ordered mesoporous carbon material composite can be obtained by taking out the corundum porcelain boat containing the product and passing it into the argon gas with a flow rate of 300 mL/min for at least 60 minutes. The material was placed in 50 mL of 15% hydrofluoric acid, stirred for 24 hours, and filtered to remove the mesoporous silica. The obtained product was an amorphous ordered mesoporous nitrogen-doped carbon material powder, and the product contained The nitrogen content is 11%, the specific surface area is 1530m ² /g, the capacity as a supercapacitor material is 450F/g, and the capacity as a lithium battery negative electrode material is 600mAh/g.

Example 4

Weigh 0.5g of polyvinylidene fluoride (PVDF) powder sample and 1g of mesoporous silica SBA-15 for mixing and ball milling for 4 hours. The mixed sample powder is evenly spread in a corundum porcelain boat, and then placed in a tube atmosphere furnace. Then, the two ends of the tubular atmosphere furnace are connected with special flanges and ammonia gas is introduced. The flow rate of ammonia gas is 300mL/min. During the subsequent calcination process, ammonia gas is continuously introduced at this flow rate. The tail gas is absorbed by sulfuric acid solution to prevent Atmospheric pollution, ventilate for at least 60 minutes at room temperature, turn on the heating program, and heat up to 700°C at a heating rate of 20°C/min, then stop heating after holding for 4 hours, cool down naturally, and stop feeding ammonia gas when the temperature drops to room temperature And pass argon with a flow rate of 300mL/min, stop after at least 60 minutes, take out the corundum porcelain boat with the product to get black mesoporous silica SBA-15-ordered mesoporous carbon material composite , the material was placed in 50 mL of 15% hydrofluoric acid, stirred for 24 hours, and filtered to remove the mesoporous silica. The resulting product was an amorphous ordered mesoporous nitrogen-doped carbon material powder. The product was TEM Image, X-ray powder diffraction, small angle X-ray powder diffraction, nitrogen adsorption and desorption isotherms, Raman spectroscopy, photoelectron spectroscopy (XPS), and electrochemical performance as electrodes for supercapacitors and lithium-ion batteries, electrocatalytic oxygen reduction reaction performance As shown in Figures 2, 4, 5, 7-12, and 14, the nitrogen content is 11%, the specific surface area is 1630m ² /g, the capacity as a supercapacitor material is 500F/g, and the capacity as a lithium battery negative electrode material is 800mAh/g g.

Example 5

0.5g of polyvinylidene fluoride (PVDF) powder sample was weighed and mixed with 2g of light magnesium oxide powder for ball milling for 4 hours. The mixed sample powder was evenly spread in a corundum porcelain boat, and then placed in a tube atmosphere furnace. The two ends of the atmosphere furnace are connected with special flanges and fed with ammonia gas. The flow rate of ammonia gas is 300mL/min. During the subsequent calcination process, ammonia gas is continuously fed at this flow rate. The tail gas is absorbed by sulfuric acid solution to prevent atmospheric pollution. After ventilating at normal temperature for at least 60 minutes, turn on the program heating, and heat up to 700 °C at a heating rate of 20 °C/min. Then, stop heating after holding for 4 hours, and cool down naturally. After the temperature drops to room temperature, stop feeding ammonia gas and feed it. Argon gas with a flow rate of 300 mL/min lasted for at least 60 minutes and then stopped. The corundum porcelain boat containing the product was taken out to obtain a black ordered mesoporous carbon-magnesium oxide composite. The material was placed in 50 mL with a concentration of 6 mol. After stirring in sodium hydroxide for 24 hours, filtering and washing, and then repeatedly washing with 1 mol/L dilute hydrochloric acid to remove magnesium oxide, the obtained product is amorphous hollow porous nitrogen-doped carbon material powder. The transmission electron microscope picture of the product is as attached As shown in Figure 3, the nitrogen content is 7%, the specific surface area is 1010m ² /g, the capacity as a supercapacitor material is 400F/g, and the capacity as a lithium battery negative electrode material is 560mAh/g.

Example 6

Weigh 2g of polyvinylidene fluoride (PVDF) powder sample and dissolve it in 100mL of N-methylpyrrolidone (NMP) to prepare a 20mg m/L PVDF/NMP solution, and take 2g of light magnesium oxide powder into the above solution. Mixing and stirring for 6 hours, high-speed centrifugation was used for solid-liquid separation after sonication for 6 hours, and the supernatant liquid was removed to obtain a PVDF-magnesium oxide mixture. and then placed in a tubular atmosphere furnace, and then the two ends of the tubular atmosphere furnace were connected with special flanges and fed with ammonia gas. Entering ammonia gas, the exhaust gas is absorbed by sulfuric acid solution to prevent air pollution. After ventilating at room temperature for at least 60 minutes, turn on the program heating, and heat up to 700 °C at a heating rate of 20 °C/min. After the temperature dropped to room temperature, the ammonia gas was stopped and the argon gas with a flow rate of 300 mL/min was passed in. After at least 60 minutes, the stop was stopped. The corundum porcelain boat containing the product was taken out to obtain a black ordered mesoporous carbon- Magnesium oxide complex, put this material into 50mL of sodium hydroxide with a concentration of 6mol/L and stir for 24 hours, filter and wash, and then repeatedly rinse with 1mol/L of dilute hydrochloric acid to remove the magnesium oxide therein, and the resulting product is an amorphous hollow polyamide. The amorphous ordered mesoporous nitrogen-doped carbon material powder has a nitrogen content of 7%, a specific surface area of 1010m ² /g, a capacity of 420F/g as a supercapacitor material, and a capacity of 610mAh/g as a lithium battery anode material.

Example 7

Weigh 2g of polyvinylidene fluoride (PVDF) powder sample and dissolve it in 100mL of N-methylpyrrolidone (NMP) to prepare a 20mg m/L PVDF/NMP solution, take 2g of mesoporous silica SBA-15 powder Mixing and stirring for 6 hours in the above solution, high-speed centrifugation was used for solid-liquid separation after sonication for 6 hours, and the supernatant liquid was removed to obtain a PVDF-magnesium oxide mixture. In the corundum porcelain boat, it was then placed in a tubular atmosphere furnace, and then the two ends of the tubular atmosphere furnace were connected with special flanges and ammonia gas was introduced. The flow rate of ammonia gas was 300mL/min, and in the subsequent calcination process This flow rate is continuously fed with ammonia gas, and the exhaust gas is absorbed by sulfuric acid solution to prevent atmospheric pollution. After ventilating at normal temperature for at least 60 minutes, turn on the program heating, and heat up to 700 °C at a heating rate of 20 °C/min, and then stop heating after 4 hours of heat preservation. , Cool down naturally, stop feeding ammonia gas and argon gas with a flow rate of 300 mL/min after the temperature drops to room temperature, and stop after at least 60 minutes. Take out the corundum porcelain boat containing the product to get black mesopores Silica SBA-15-ordered mesoporous carbon material composite, the material was put into 50 mL of 15% hydrofluoric acid, stirred for 24 hours, filtered to remove the mesoporous silica, and the obtained product was amorphous The ordered mesoporous nitrogen-doped carbon material powder has a nitrogen content of 12%, a specific surface area of 1010m ² /g, a capacity of 550F/g as a supercapacitor material, and a capacity of 840mAh/g as a lithium battery anode material.

Example 8

Weigh 2g of polyvinylidene fluoride (PVDF) powder sample and dissolve it in 100mL of N-methylpyrrolidone (NMP) to make a 20mg/mL PVDF/NMP solution, and drop the solution onto conductive carbon felt (0.2g) , control the volume of the solution and the size of the conductive carbon felt to be 2cm×2cm, so that the PVDF loading amount is 6mg cm ^-2 . The conductive carbon felt was dried at 100°C for 12 hours and then taken out, spread evenly in a corundum porcelain boat, and then placed in a In the tubular atmosphere furnace, the two ends of the tubular atmosphere furnace are then connected with special flanges and fed with ammonia gas. The flow rate of ammonia gas is 300mL/min. Absorb with sulfuric acid solution to prevent air pollution, turn on programmed heating after ventilating at room temperature for at least 60 minutes, and heat up to 700 °C at a heating rate of 20 °C/min, then stop heating after holding for 4 hours, cool down naturally, and wait for the temperature to drop to room temperature Then stop feeding ammonia gas and pass argon gas with a flow rate of 300 mL/min for at least 60 minutes and then stop, and take out the corundum porcelain boat containing the product to obtain amorphous disordered porous nitrogen-doped carbon-supported conductive carbon Felt (wherein, the loading amount of nitrogen-doped carbon material is 1 mg cm ⁻² , and the atomic doping amount of nitrogen element in nitrogen-doped carbon material is 12 at%), and its capacity as a supercapacitor electrode is 1 F/cm ² .

Example 9

Weigh 20g of polyvinylidene fluoride (PVDF) powder sample and dissolve it in 200mL of N-methylpyrrolidone (NMP) to prepare a 100mg/mL PVDF/NMP solution, and soak it in a conductive carbon felt (20g) with a size of 20cm×20cm In the above solution for 12 hours, then the conductive carbon felt was dried at 100 ° C for 12 hours, taken out, evenly spread in a corundum porcelain boat, and then placed in a tubular atmosphere furnace, and then the two ends of the tubular atmosphere furnace were used for special purpose. Flange connection and pass ammonia gas, the flow rate of ammonia gas is 300mL/min, and continue to pass ammonia gas at this flow rate during the subsequent calcination process, the tail gas is absorbed by sulfuric acid solution to prevent atmospheric pollution, and ventilate at room temperature for at least 60 minutes Then turn on the program heating, heat up to 700°C at a heating rate of 20°C/min, then stop heating after holding for 4 hours, cool down naturally, stop feeding ammonia after the temperature drops to room temperature, and feed argon with a flow rate of 300mL/min After at least 60 minutes, it stopped, and the corundum porcelain boat containing the product was taken out to obtain a large-area conductive carbon felt supported by amorphous disordered porous nitrogen-doped carbon. The electrode capacity was 10F cm ^-2 . The loading amount of the nitrogen-doped carbon material is 20 mg cm ⁻² (converted to a mass content of 30 wt %), and the nitrogen element content in the nitrogen-doped carbon material is 11 at %.

Example 10

Weigh 0.5g of polyvinylidene fluoride (PVDF) powder sample, spread it evenly in a corundum porcelain boat, and then place it in a tubular atmosphere furnace, then connect both ends of the tubular atmosphere furnace with special flanges and pass ammonia into it. The flow rate of ammonia gas is 300mL/min, and in the subsequent calcination process, ammonia gas is continuously fed in at this flow rate, and the tail gas is absorbed by sulfuric acid solution to prevent atmospheric pollution. The heating rate of ℃/min is heated up to 360 ℃, and then the heating is stopped after holding for 4 hours, and the temperature is naturally lowered. After the temperature drops to room temperature, the ammonia gas is stopped and the argon gas with a flow rate of 300 mL/min is introduced. After lasting at least 60 minutes Stop, take out the corundum porcelain boat with the product to get black amorphous porous nitrogen-doped carbon material powder, the product has a nitrogen content of 3%, a specific surface area of 660m ² /g, and a capacity of 200F as a supercapacitor material. /g, the capacity as a lithium battery negative electrode material is 400mAh/g.

Example 11

Weigh 0.5g of polyvinylidene fluoride (PVDF) powder sample, spread it evenly in a corundum porcelain boat, and then place it in a tubular atmosphere furnace, then connect both ends of the tubular atmosphere furnace with special flanges and pass ammonia into it. The flow rate of ammonia gas is 300mL/min, and in the subsequent calcination process, ammonia gas is continuously fed in at this flow rate, and the tail gas is absorbed by sulfuric acid solution to prevent atmospheric pollution. The heating rate of ℃/min is heated up to 500 ℃, then the heating is stopped after holding for 4 hours, and the temperature is naturally lowered. After the temperature drops to room temperature, the ammonia gas is stopped and the argon gas with a flow rate of 300 mL/min is introduced. After at least 60 minutes Stop, take out the corundum porcelain boat with the product to get black amorphous porous nitrogen-doped carbon material powder, the product has a nitrogen content of 4%, a specific surface area of 870m ² /g, and a capacity of 240F as a supercapacitor material. /g, the capacity as a negative electrode material for lithium batteries is 460mAh/g.

Example 12

Weigh 0.5g of polyvinylidene fluoride (PVDF) powder sample, spread it evenly in a corundum porcelain boat, and then place it in a tubular atmosphere furnace, then connect both ends of the tubular atmosphere furnace with special flanges and pass ammonia into it. The flow rate of ammonia gas is 300mL/min, and in the subsequent calcination process, ammonia gas is continuously fed in at this flow rate, and the tail gas is absorbed by sulfuric acid solution to prevent atmospheric pollution. The heating rate of ℃/min is heated to 600 ℃, and then the heating is stopped after holding for 4 hours, and the temperature is naturally lowered. After the temperature drops to room temperature, the ammonia gas is stopped and the argon gas with a flow rate of 300 mL/min is introduced, and it lasts for at least 60 minutes. Stop, take out the corundum porcelain boat with the product to get black amorphous porous nitrogen-doped carbon material powder, the product has a nitrogen content of 5%, a specific surface area of 890m ² /g, and a capacity of 260F as a supercapacitor material. /g, the capacity as a lithium battery negative electrode material is 500mAh/g.

Example 13

Weigh 0.5g of polyvinylidene fluoride (PVDF) powder sample, spread it evenly in a corundum porcelain boat, and then place it in a tubular atmosphere furnace, then connect both ends of the tubular atmosphere furnace with special flanges and pass ammonia into it. The flow rate of ammonia gas is 300mL/min, and in the subsequent calcination process, ammonia gas is continuously fed in at this flow rate, and the tail gas is absorbed by sulfuric acid solution to prevent atmospheric pollution. The heating rate of ℃/min is heated up to 1200 ℃, and then the heating is stopped after holding for 4 hours, and the temperature is naturally lowered. After the temperature drops to room temperature, the ammonia gas is stopped and the argon gas with a flow rate of 300 mL/min is introduced. After lasting at least 60 minutes Stop, take out the corundum porcelain boat with the product to get black amorphous porous nitrogen-doped carbon material powder, the product has a nitrogen content of 5%, a specific surface area of 1220m ² /g, and a capacity of 250F as a supercapacitor material. /g, the capacity as a lithium battery negative electrode material is 420mAh/g.

Example 14

Weigh 0.5g of polyvinylidene fluoride (PVDF) powder sample, spread it evenly in a corundum porcelain boat, and then place it in a tubular atmosphere furnace, then connect both ends of the tubular atmosphere furnace with special flanges and pass ammonia into it. The flow rate of ammonia gas is 300mL/min, and in the subsequent calcination process, ammonia gas is continuously fed in at this flow rate, and the tail gas is absorbed by sulfuric acid solution to prevent atmospheric pollution. The heating rate of ℃/min is heated to 700 ℃, and then the heating is stopped after holding for 2 hours, and the temperature is naturally lowered. After the temperature drops to room temperature, the ammonia gas is stopped and the flow rate of argon is 300 mL/min. After at least 60 minutes Stop, take out the corundum porcelain boat with the product to get black amorphous porous nitrogen-doped carbon material powder, the product has a nitrogen content of 6%, a specific surface area of 960m ² /g, and a capacity of 270F as a supercapacitor material. /g, the capacity as a lithium battery negative electrode material is 520mAh/g.

Example 15

Weigh 0.5g of polyvinylidene fluoride (PVDF) powder sample, spread it evenly in a corundum porcelain boat, and then place it in a tubular atmosphere furnace, then connect both ends of the tubular atmosphere furnace with special flanges and pass ammonia into it. The flow rate of ammonia gas is 100mL/min, and in the subsequent calcination process, ammonia gas is continuously fed at this flow rate, and the tail gas is absorbed by sulfuric acid solution to prevent atmospheric pollution. After ventilating at room temperature for at least 60 minutes, turn on the program heating, and use 20 The heating rate of ℃/min is heated to 700 ℃, and then the heating is stopped after 4 hours of insulation, and the temperature is naturally lowered. After the temperature drops to room temperature, the ammonia gas is stopped and the flow rate of argon is 300 mL/min. After at least 60 minutes Stop, take out the corundum porcelain boat with the product to get black amorphous porous nitrogen-doped carbon material powder, the product has a nitrogen content of 5%, a specific surface area of 760m ² /g, and a capacity of 220F as a supercapacitor material. /g, the capacity as a lithium battery negative electrode material is 480mAh/g.

Example 16

Weigh 0.5g of polyvinylidene fluoride (PVDF) powder sample, spread it evenly in a corundum porcelain boat, and then place it in a tubular atmosphere furnace, then connect both ends of the tubular atmosphere furnace with special flanges and pass ammonia into it. The flow rate of ammonia gas is 1000mL/min, and during the subsequent calcination process, ammonia gas is continuously fed at this flow rate, and the tail gas is absorbed by sulfuric acid solution to prevent atmospheric pollution. After ventilating at room temperature for at least 60 minutes, turn on the program heating, and heat at 20 The heating rate of ℃/min is heated to 700 ℃, and then the heating is stopped after 4 hours of insulation, and the temperature is naturally lowered. After the temperature drops to room temperature, the ammonia gas is stopped and the flow rate of argon is 300 mL/min. After at least 60 minutes Stop, take out the corundum porcelain boat containing the product to get black amorphous porous nitrogen-doped carbon material powder, the product has a nitrogen content of 5%, a specific surface area of 1260m ² /g, and a capacity of 320F as a supercapacitor material. /g, the capacity as a lithium battery negative electrode material is 680mAh/g.

Example 17

Weigh 0.5g of polyvinylidene fluoride (PVDF) powder sample, spread it evenly in a corundum porcelain boat, and then place it in a tubular atmosphere furnace, then connect both ends of the tubular atmosphere furnace with special flanges and pass ammonia into it. The flow rate of ammonia gas is 10mL/min, and during the subsequent calcination process, ammonia gas is continuously fed in at this flow rate, and the tail gas is absorbed by sulfuric acid solution to prevent atmospheric pollution. After ventilating at room temperature for at least 60 minutes, turn on the program heating, and use 20 The heating rate of ℃/min is heated to 700 ℃, and then the heating is stopped after 4 hours of insulation, and the temperature is naturally lowered. After the temperature drops to room temperature, the ammonia gas is stopped and the flow rate of argon is 300 mL/min. After at least 60 minutes Stop, take out the corundum porcelain boat with the product to get black amorphous porous nitrogen-doped carbon material powder, the product has a nitrogen content of 4%, a specific surface area of 1260m2/g, and a capacity of 120F/g as a supercapacitor material. g, as a lithium battery anode material with a capacity of 380mAh/g.

Example 18

Weigh 0.5g of polyvinylidene fluoride (PVDF) powder sample, then place it in the autoclave, then connect the two ends of the autoclave with a special excuse and pass ammonia gas, the flow rate of ammonia gas is 300mL/min, at room temperature Ventilate for at least 60 minutes to completely remove the air in the autoclave, the tail gas is absorbed by sulfuric acid solution to prevent atmospheric pollution, then close the air outlet and continue to feed ammonia gas into the autoclave until the pressure reaches 10MPa and then stop feeding Ammonia gas, turn on the heating program, heat up to 700°C at a heating rate of 20°C/min, stop heating after 4 hours of heat preservation, cool down naturally, open the gas outlet after the temperature drops to room temperature and slowly discharge the gas in the reactor, and the exhaust gas passes through the sulfuric acid The solution is absorbed to prevent atmospheric pollution. After returning to normal pressure, argon gas with a flow rate of 300 mL/min is introduced, and it is stopped after at least 60 minutes. After opening the autoclave, black amorphous porous nitrogen-doped carbon material powder can be obtained. The product has a nitrogen content of 15%, a specific surface area of 1160m2/g, a capacity of 520F/g as a supercapacitor material, and a capacity of 820mAh/g as a lithium battery negative electrode material.

Example 19

Weigh 0.5g of polyvinylidene fluoride (PVDF) powder sample, spread it evenly in a corundum porcelain boat, and then place it in a tubular atmosphere furnace, then connect both ends of the tubular atmosphere furnace with special flanges and pass ammonia into it. A mixture of gas and argon, wherein the flow rate of ammonia gas is 10mL/min, and the flow rate of argon gas is 190mL/min, and in the subsequent calcination process, the mixture gas of ammonia gas and argon gas is continuously fed at this flow rate, and the tail gas passes through sulfuric acid The solution is absorbed to prevent air pollution. After ventilating at room temperature for at least 60 minutes, turn on the program heating, and heat up to 700 °C at a heating rate of 20 °C/min. A mixture of ammonia gas and argon gas was introduced, and argon gas with a flow rate of 300 mL/min was introduced, and stopped after at least 60 minutes. The black amorphous porous nitrogen-doped carbon was obtained by taking out the corundum porcelain boat containing the product. Material powder, the product has a nitrogen content of 5%, a specific surface area of 1160m ² /g, a capacity of 150F/g as a supercapacitor material, and a capacity of 420mAh/g as a lithium battery negative electrode material.

Comparative Example 1

Weigh 0.5g of polytetrafluoroethylene (PTFE) powder sample, spread it evenly in a corundum porcelain boat, and then place it in a tubular atmosphere furnace, then connect both ends of the tubular atmosphere furnace with special flanges and pass ammonia into it. The flow rate of ammonia gas is 300mL/min, and in the subsequent calcination process, ammonia gas is continuously fed in at this flow rate, and the tail gas is absorbed by sulfuric acid solution to prevent atmospheric pollution. The heating rate of ℃/min is heated to 700 ℃, and then the heating is stopped after 4 hours of insulation, and the temperature is naturally lowered. After the temperature drops to room temperature, the ammonia gas is stopped and the flow rate of argon is 300 mL/min. After at least 60 minutes Stop, take out the corundum porcelain boat with the product to get black amorphous porous nitrogen-doped carbon material powder. The nitrogen content of the product is 2%, the specific surface area is 860m ² /g, and the capacity as a supercapacitor material is only The capacity of 120F/g as a lithium battery anode material is only 230mAhg ^-1 .

Table 1 shows the performance parameters of the nitrogen-doped carbon materials prepared in Examples 1-19 of the present invention and Comparative Example 1:

Claims (12)

1. A method for preparing a nitrogen-doped carbon material by utilizing a fluorine-containing polymer, wherein the fluorine-containing polymer precursor material is placed in an ammonia gas atmosphere, and calcined at 360°C to 1200°C to obtain the nitrogen Doped carbon material; the fluorine-containing polymer precursor material is a polymer in which part of the hydrogen with a relative molecular mass between 10 million and 10 million is replaced by fluorine, and is selected from polyvinylidene fluoride (PVDF), polyvinylidene fluoride- At least one of hexafluoropropylene (PVDF-HFP), polyvinyl fluoride (PVF), ethylene-chlorotrifluoroethylene copolymer (ECTFE) and ethylene-tetrafluoroethylene (ETFE) copolymer; The atomic doping amount of nitrogen element in the nitrogen-doped carbon material is 4-15 at %; the conductivity of the nitrogen-doped carbon material is 1-100 mS/cm. 2. The method according to claim 1, characterized in that, before calcining, a templating agent is also added, and the templating agent is selected from at least one of mesoporous silica, molecular sieve, and magnesium oxide; the templating agent The mass ratio to the fluorine-containing polymer precursor material is (0.1-5): 1; and after calcination, an etchant is used to remove the template agent. 3. A method for preparing a nitrogen-doped carbon material-loaded conductive carbon felt, comprising: (1) Mixing a fluorine-containing polymer precursor material and a solvent to obtain a mixed solution, the fluorine-containing polymer precursor material is an organic polymer in which part of the hydrogen with a relative molecular mass between 10 million and 10 million is replaced by fluorine, Selected from polyvinylidene fluoride (PVDF), polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP), polyvinyl fluoride (PVF), ethylene-chlorotrifluoroethylene copolymer (ECTFE) and ethylene-tetrafluoroethylene (ETFE) ) at least one of the copolymers; (2) soak the conductive carbon felt in the obtained mixed solution for 0.1 to 24 hours, then dry it, place it in an ammonia gas atmosphere, and calcine it at 360°C to 1200°C to obtain the conductive carbon felt supported by the nitrogen-doped carbon material. carbon felt; The conductive carbon felt supported by the nitrogen-doped carbon material includes: a conductive carbon felt, and a nitrogen-doped carbon material supported on the conductive carbon felt, and the loading amount of the nitrogen-doped carbon material is 1 wt% to 70 wt %; the atomic doping amount of nitrogen element in the nitrogen-doped carbon material is 4% to 15 at%. 4. The method according to claim 3, wherein the solvent is selected from at least one of N-methylpyrrolidone, chloroform, water and ethanol; the concentration of the mixed solution is 5-100 mg/mL . 5. The method according to claim 3, wherein a templating agent is also added in the mixed solution, and the templating agent is selected from at least one of mesoporous silica, molecular sieve, and magnesium oxide; the templating agent The mass ratio to the fluorine-containing polymer precursor material is (0.1-5): 1; and after calcination, an etchant is used to remove the template agent. 6. The method according to any one of claims 1-5, wherein the ammonia atmosphere is ammonia or a mixed gas containing ammonia; When selecting an open container for calcination, the gas flow rate of the ammonia gas atmosphere is 1-10000 mL/min; When selecting a closed container for calcination, the pressure of the ammonia gas atmosphere is 0.1-100 MPa. 7 . The method according to claim 6 , wherein when an open container is selected for calcination, the gas flow rate of the ammonia gas atmosphere is 300 mL/min. 8 . 8. The method according to any one of claims 1-5, wherein the calcination temperature is 700°C. 9 . The method according to claim 1 , wherein the heating rate of the calcination is 0.1˜100° C./min; the calcination time is 1 minute˜10 hours. 10 . 10 . The method according to claim 9 , wherein the heating rate of the calcination is 20° C./min; and the calcination time is 4 hours. 11 . 11. Application of a nitrogen-doped carbon material prepared by the method according to claim 1 in the preparation of supercapacitors, lithium-ion batteries, catalytic materials, dry materials and metal-air batteries. 12 . The application of the nitrogen-doped carbon material-supported conductive carbon felt prepared by the method according to claim 3 in the preparation of supercapacitors, lithium-ion batteries, catalytic materials, dry materials and metal-air batteries. 13 .

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