CN103855365B - Lithium-air battery positive pole uses the porous carbon materials of N doping - Google Patents

Abstract

The invention relates to a nitrogen-doped porous carbon material for the positive electrode of a lithium-air battery, which is characterized in that: the nitrogen-doped porous carbon material has a hierarchical pore structure interpenetrating, and N is uniformly doped in the C skeleton, wherein N It accounts for 0.2-15% of the atomic ratio of carbon materials. The graded pores include mass transfer pores and deposition pores. The deposition pores account for 40-95% of the total pore volume, and the mass transfer pores account for 4-55% of the total pore volume; the carbon The material is used as an electrode material for lithium-air batteries, which can maximize the space utilization of carbon materials in the process of charging and discharging, and effectively improve the energy density and power density of lithium-air batteries. The invention has the advantages of simple preparation process, wide source of materials, controllable pore structure of the hierarchical pore carbon material in various control modes, and easy realization of nitrogen doping mode.

Description

Nitrogen-doped porous carbon material for lithium-air battery cathode

technical field

The invention belongs to the field of energy storage batteries, and in particular relates to a carbon material doped with nitrogen and having hierarchical pore distribution, which is applied to the positive electrode of a lithium-air battery and has high energy density and power density.

Background technique

The rapid development of electric vehicles and mobile electronic devices urgently requires the development of batteries with higher energy density. At present, although the laboratory specific energy of lithium-ion batteries has reached 250Wh/kg, it is difficult to increase the specific energy due to the limitation of the further improvement of the specific capacity of the positive electrode material, and the way to increase the specific energy by increasing the charging voltage will be Aggravating the safety problem, it is imperative to develop a new electrochemical energy storage system. In the new energy storage system, the lithium-air battery is a secondary battery with metal lithium as the negative electrode and the air electrode as the positive electrode. Metal lithium as the negative electrode material has the lowest theoretical voltage, and its theoretical specific capacity is as high as 3,862mAh/g, while oxygen as the positive electrode active material can be obtained directly from the air. Therefore, lithium-air batteries have extremely high specific capacity and specific capacity. energy. Taking lithium as the standard, its theoretical specific energy density can reach 11,140Wh/Kg, which has great application prospects in civil and military fields.

At present, lithium-air batteries mainly use various carbon materials as positive electrode materials, and prepare air electrodes by mixing PTFE, PVDF, Nafion and other binders. As shown in Figure 1, it is a simulation diagram of the discharge reaction process of the positive electrode of the lithium-air battery. The discharge reaction proceeds on the solid-liquid two-phase interface between the liquid electrolyte solution and the carbon material. The surface of the carbon material generates a solid insoluble product-lithium oxide. As the reaction progresses, the solid product accumulates to block the internal pores and cause the discharge to terminate.

As the place where the electrochemical reaction occurs, the physical parameters of the carbon material pore structure, such as specific surface area, pore volume, and pore size distribution, have an important impact on battery performance, especially the charge and discharge capacity. Tran et al. showed that the capacity of the electrode is determined by the amount of lithium oxide in the large-sized pores that do not affect the material transport. The micropores and some mesopores of carbon materials will be blocked by the lithium oxide formed at the initial stage of discharge, and the surface of these pores will not be able to pass through air and electrolyte again, so they will no longer participate in the electrochemical reaction, resulting in the termination of discharge. However, during the discharge process of carbon materials composed entirely of macropore sizes, due to the poor conductivity of lithium oxide, the accumulation thickness of discharge products on the pore walls is limited, the central part of the macropores cannot be utilized, and the pores cannot be fully utilized. Use the space. Therefore, how to construct a carbon material with a suitable pore structure to facilitate the transmission of electrolyte and air in the porous structure, thereby accelerating the electrode reaction rate and increasing the effective use of pores is an urgent problem to be solved.

In addition, nitrogen-doped carbon materials have shown excellent oxygen reduction activity in fuel cells and can partially replace noble metal Pt/C catalysts. Studies have shown that doping nitrogen atoms changes the microstructure and surface electronic state of carbon nanomaterials. Through N-O or C-O "dual site (dualsite) adsorption", it can weaken the O-O bond in oxygen molecules, which is conducive to the reduction reaction.

At present, there are a few reports on the application of nitrogen-doped carbon nanotubes and nitrogen-doped graphene materials in lithium-air batteries. The results show that nitrogen doping can cause carbon edge defects, effectively increasing the exposure of this part of the active site, and Promote the oxygen reduction reaction and effectively improve the discharge capacity and discharge voltage of the lithium-air battery. However, the above-mentioned materials are not conducive to large-scale commercial preparation and application due to their complicated preparation methods, high cost, and high experimental conditions, and still cannot meet the material requirements of lithium-air batteries.

Contents of the invention

The object of the present invention is to provide an electrode carbon material for a lithium-air battery and a preparation method thereof.

In order to achieve the above object, the technical scheme adopted in the present invention is as follows,

A nitrogen-doped porous carbon material for the positive electrode of a lithium-air battery, the nitrogen-doped porous carbon material has a hierarchical pore structure interpenetrating, N is uniformly doped in the C skeleton, and the atomic ratio of N to the carbon material is 0.2- 15%, graded pores include mass transfer pores and deposition pores, deposition pores account for 40-95% of the total pore volume, mass transfer pores account for 4-55% of the total pore volume, and the rest are pores with a diameter less than 5nm, deposition pores The pore diameter is 5~90nm, the mass transfer hole diameter is 0.1~6um, the distance between the mass transfer holes is 0.1~8um, the mass transfer holes are connected to each other through the deposition holes, and the total pore volume of the carbon material is 0.5~5cm ³ /g.

The carbon material is prepared by a sol-gel method combined with an activation method or a sol-gel method combined with a foaming method.

The sol-gel method combined with the activation method is preferred.

The specific preparation method is as follows:

A sol-gel method combined with activation method

The sol-gel method combined with the activation method includes catalytic activation during the carbonization process, or post-activation of the carbon material prepared by the sol-gel method, one or both of which are used in combination.

The catalytic activation in the sol-gel carbonization process and the _NH3 heat treatment activation method in the post-activation are preferred.

The sol-gel method is prepared by catalytic activation in the carbonization process as follows: disperse resorcinol in a solvent, then add metal salt or metal hydroxide to continue dissolving and dispersing, then add formaldehyde solution dropwise, 30~ Stir and mix evenly at 80°C until the reaction forms a gel; vacuum dry and age the gel at 60-100°C for _3-10 days, take it out and grind it to obtain a solid powder; Remove metal salts or metal hydroxides, filter and dry to obtain porous carbon materials, in which the NH ₃ intake flow rate is controlled at 2~100ml/min.

The metal salt or metal hydroxide contains Fe, Co, Ni, Cu, Ag, Pt, Pd, Au, Ir, Ru, Nb, Y, Rh, Cr, Zr, Ce, Ti, Mo, Mn, Zn , W, Sn, La and V of one or more metal salts or metal hydroxides; metal salts are metal nitrates, carbonates, sulfates, acetates, halides, dinitroso di One or more of amine salts, acetylacetonates, or macrocyclic complexes, porphyrin compounds, and phthalocyanine compounds. Nitrates and acetates of Fe, Co, Ni, Cu, Mo, Mn, and Mo are preferred.

The carbon material prepared by the sol-gel method is post-activated, including one or more of the following methods:

(1) Physical activation method: disperse resorcinol in a solvent, then add formaldehyde solution dropwise, stir and mix evenly at 30~80°C until the reaction forms a gel; vacuum dry and age the gel at 60~100°C for 3~ After 10 days of treatment, take it out, crush and grind it to obtain solid powder; after carbonization under high-temperature NH ₃ atmosphere, pass in water vapor, CO ₂ , and one or more of the compounds that can generate one of the above two gases to activate; The activation temperature is controlled at 400~1300°C, the activation time is controlled at 10min~5h, and the intake flow of NH ₃ , water vapor or CO ₂ is controlled at 2~100ml/min;

(2) NH ₃ heat treatment activation method: disperse resorcinol in the solvent, then add formaldehyde solution dropwise, stir and mix evenly at 30~80°C until the reaction forms a gel; vacuum dry and age the gel at 60~100°C After 3-10 days of treatment, take it out, crush and grind it to obtain solid powder; after carbonization by high temperature N ₂ or Ar, the obtained carbon material is activated by heat treatment in NH ₃ atmosphere. The heat treatment temperature is controlled at 400~1300°C, the time is controlled at 10min~6h, and the intake flow of _N2 or Ar, _NH3 is controlled at 2~100ml/min;

(3) Chemical activation method: disperse resorcinol in a solvent, then add formaldehyde solution dropwise, stir and mix evenly at 30~80°C until the reaction forms a gel; vacuum dry and age the gel at 60~100°C for 3~ After 10 days of treatment, take it out, crush and grind to obtain solid powder; after carbonization under high-temperature _NH3 atmosphere, grind and mix the activation reagent and the carbon material prepared by the sol-gel method evenly. The activation reagent is 10-300% of the mass of the carbon material. The activation temperature is controlled at 300-900°C, and the activation time is controlled at 10min-5h; after activation, the carbon material is washed with deionized water and dried; the NH ₃ intake flow is controlled at 2-100ml/min; the activation reagent includes alkali The activating reagent KOH, the acid activating reagent H ₃ PO ₄ , and the salt activating reagent are ZnCl ₂ , K ₂ CO ₃ or Na ₂ CO ₃ .

B sol-gel method combined with foaming method

The carbon material is prepared by the sol-gel method combined with the foaming method as follows: disperse resorcinol and foaming agent in a solvent, then add formaldehyde solution dropwise, stir and mix evenly at 30-80°C until the reaction Form a gel; vacuum dry and age the gel at 60-100°C for 3-10 days, take it out, crush and grind it to obtain a solid powder; after carbonization in a high-temperature NH ₃ atmosphere, remove the foaming agent with acid or alkali, and filter , drying, that is, porous carbon materials; wherein the NH ₃ intake flow is controlled at 2~100ml/min.

The whipping agent is citric acid, calcium carbonate, magnesium carbonate, sodium bicarbonate, sodium carbonate, ammonium carbonate, ammonium bicarbonate, ammonium nitrite, sodium lauryl sulfate, cetyltrimethylammonium bromide , one or more foaming agents of fatty alcohol polyoxyethylene ether sodium sulfate, n-pentane, n-hexane, n-heptane, petroleum ether, animal and vegetable protein foaming agents. Citric acid, ammonium carbonate, ammonium bicarbonate, sodium bicarbonate, calcium carbonate are preferred.

Beneficial effects of the present invention:

1. During the preparation of carbon materials, a hierarchical pore structure doped with nitrogen is constructed, which are used for the deposition of discharge products and the mass transfer of oxygen and electrolyte. The carbon materials can be used as lithium-air battery electrodes to maximize the In addition, the introduction of nitrogen causes defects on the carbon edge and introduces more active sites for oxygen reduction reactions. Considering comprehensively, this new type of carbon material can greatly improve the space utilization of the electrode, so that the pores of each pore size can perform their duties. At the same time, nitrogen doping has catalytic activity, which can effectively improve the discharge specific capacity, voltage platform and rate discharge capacity of the battery. Improve the energy density and power density of the battery.

2. The preparation method of nitrogen-doped hierarchical pore carbon material is simple and easy, the source of raw materials is wide and the price is low, the preparation process is mild and environmentally friendly, there is no strong acid and strong alkali, and it is easy to scale up to realize the mass preparation of the product, which meets the requirements of lithium-air batteries for positive electrodes. Material requirements to promote the commercial application of lithium-air batteries.

3. The pore structure of nitrogen-doped hierarchical pore carbon materials can be adjusted and adjusted in various ways; the ways of N doping are diverse and easy to realize. The methods of introducing or generating N-containing structures on the surface of the carbon support include: in-situ doping of N, including carbonization under NH ₃ atmosphere; and post-doping of N, such as heat treatment in NH ₃ after carbonization of porous carbon materials.

4. The pore structure of nitrogen-doped hierarchically porous carbon materials can be adjusted, ranging from micron to nanometer, in a wide range and in various ways;

5. The advantages of the sol-gel method combined with the activation method are: using the three-dimensional network structure formed by the sol-gel method, carbon materials with excellent electrical conductivity and micropores and small mesoporous properties can be formed, and the network structure can be modified by activation. The pores are further expanded to form pores with larger pore diameters, and finally form a N-containing carbon material with a hierarchical pore structure ranging from mesopores to macropores, which meets the needs of the battery discharge process. Among them, the catalytic activation method can easily realize the doping of metal/metal oxide at the same time during the preparation process, and it can play a catalytic role in the charge and discharge process when applied to lithium-air batteries, reduce charge and discharge polarization, and improve battery energy efficiency.

6. The advantages of the sol-gel method combined with the foaming method are: the three-dimensional network structure formed by the sol-gel method can be used to form a carbon material with excellent electrical conductivity and micropores and small mesopores, and by adding a foaming agent, it can be Foaming forms pores with a larger pore size, and the added foaming agent decomposes during the carbonization process, and does not require pickling or alkali cleaning. Finally, a N-containing carbon material with a hierarchical pore structure ranging from mesopores to macropores is formed to meet the needs of the battery discharge process.

Description of drawings

Fig. 1 is the simulation diagram of electrode reaction process;

Fig. 2 is the comparison of the surface morphology of the hierarchical porous carbon material prepared by the sol-gel method combined with the catalytic activation method and the commercial carbon powder material in Example 1, A is the hierarchical porous carbon material (HPC-N) doped with N, B is commercialized KB600 toner.

detailed description

Example 1

Nitrogen-doped porous carbon materials with hierarchical pore structure were prepared by sol-gel method combined with catalytic activation method. Dissolve 6.16g of resorcinol in 10mL of deionized water to form a transparent solution; add 0.29g of nickel nitrate hexahydrate to the above transparent solution, mix and dissolve evenly to obtain a solution; add dropwise 9.08g of formaldehyde to the above stirring solution The solution was further stirred and mixed evenly, and continuously stirred in an environment of 20°C until the reaction formed a gel; the gel was transferred to a vacuum drying oven for 7 days of vacuum drying and aging treatment at 70°C, and then crushed and ground to obtain a solid powder; the solid The powder was carbonized in NH ₃ at 900°C for 3 hours, washed with an appropriate amount of 1M HCl to remove nickel oxide, filtered and dried to obtain the carbon material.

The positive electrode material structure prepared in Example 1 has a large number of deposition pores with a diameter of 10 to 40 nanometers, and graded pores with mass transfer pores of 0.1 to 0.5 microns. The distance between the mass transfer pores is about 1 μm, and the mass transfer pores penetrate the deposition pores. ; The carbon material has a honeycomb network pore structure (Scanning electron microscopy results shown in Figure 2). In addition, the BET results show that the prepared carbon material has a concentrated pore distribution around 20nm, the total pore volume of the carbon material is 0.9cm ³ /g, and the deposited pores account for 85% of the total pore volume. Among them, the X-ray photoelectron spectroscopy analysis in HPC-N shows that nitrogen accounts for 1.8% of the carbon material atomic ratio.

The N-doped hierarchical porous carbon material prepared in Example 1 is used as the positive electrode of a lithium-air battery, and its electrode load is 3 mg/cm ² _carbon . In the electrolyte composed of ether solvent, tested under the condition of 0.1mA/cm ² current density at room temperature and 99.99% purity O ₂ at 1 atm, the first cycle discharge capacity reached 6500mAh/g.

Comparative example:

Commercialized KB-600 carbon powder is used as the positive electrode of lithium-air battery. Under the same conditions, its first-cycle discharge capacity is only 3000mAh/g. The capacity of the hierarchical porous carbon material doped with N prepared in Example 1 is higher than that of commercial carbon powder KB -600 has been increased by 116%, and the discharge voltage platform has been increased.

Example 2

Nitrogen-doped porous carbon materials with hierarchical pore structure were prepared by sol-gel method combined with activation method. Dissolve 6.16g of resorcinol in 10mL of deionized water to form a transparent solution; add 0.808g of ferric nitrate to the above-mentioned transparent solution, mix and dissolve to obtain a uniform solution; add 9.08g of formaldehyde solution dropwise to the above-mentioned stirring solution, Stir and mix evenly, and continue to stir in an environment of 20°C until the reaction forms a gel; transfer the gel to a vacuum drying oven for 3 days of vacuum drying and aging treatment at 70°C, take it out, crush and grind to obtain a solid powder; put the solid powder in Carbonization treatment in NH ₃ at 1000° C. for 5 h, washing away iron oxide with an appropriate amount of 1M HCl, filtering and drying to obtain the carbon material.

Example 3

Nitrogen-doped porous carbon materials with hierarchical pore structure were prepared by sol-gel method combined with activation method. Dissolve 6.16g of resorcinol in 10mL of deionized water to form a transparent solution; add 0.2716g of cobalt nitrate hexahydrate to the above transparent solution, mix and dissolve to obtain a solution; add dropwise 9.08g of formaldehyde to the above stirring solution The solution was further stirred and mixed evenly, and continuously stirred in an environment of 20°C until the reaction formed a gel; the gel was transferred to a vacuum drying oven for 7 days of vacuum drying and aging treatment at 70°C, and then crushed and ground to obtain a solid powder; the solid The powder was carbonized in NH ₃ at 900°C for 3 hours, washed with an appropriate amount of 1M HCl to remove cobalt oxide, filtered and dried to obtain the carbon material.

Example 4

Nitrogen-doped porous carbon materials with hierarchical pore structure were prepared by sol-gel method combined with foaming method. Dissolve 6.16g of resorcinol in 10mL of deionized water to form a transparent solution; add 9.08g of formaldehyde solution and 1g of ammonium bicarbonate to the stirring solution, stir and mix evenly, and continue to stir at 20°C until React to form a gel; transfer the gel to a vacuum drying oven for 7 days of vacuum drying and aging treatment at 70°C, take it out and grind it to obtain a solid powder; treat the solid powder in NH ₃ at 850°C for 2 hours to obtain the carbon material .

Example 5

Nitrogen-doped porous carbon materials with hierarchical pore structure were prepared by sol-gel method combined with foaming method. Dissolve 6.16g of resorcinol in 10mL of deionized water to form a transparent solution; add 9.08g of formaldehyde solution and 1g of citric acid to the stirring solution, stir and mix evenly, and continue stirring at 20°C until the reaction Form a gel; transfer the gel to a vacuum drying oven for 7 days of vacuum drying and aging treatment at 70°C, take it out and grind it to obtain a solid powder; treat the solid powder in NH ₃ at 850°C for 2 hours to obtain the carbon material.

Example 6

Nitrogen-doped porous carbon materials with hierarchical pore structure were prepared by sol-gel method combined with foaming method. 6.16g of resorcinol was dissolved in 10mL of deionized water to form a transparent solution; 9.08g of formaldehyde solution and 1g of cetyltrimethylammonium bromide were added to the above stirring solution, and further stirred and mixed evenly, at 20 Stir continuously in an environment of ℃ until the reaction forms a gel; transfer the gel to a vacuum drying oven for 3 days of vacuum drying and aging treatment at 70 ℃, take it out and grind it to obtain a solid powder; treat the solid powder in NH ₃ at 1050 ℃ for 2 hours , to obtain the carbon material.

Claims (10)

1. The positive electrode of lithium-air battery uses nitrogen-doped porous carbon material, which is characterized in that: the nitrogen-doped porous carbon material has a hierarchical pore structure interpenetrating, and N is evenly doped in the C skeleton, wherein N accounts for 0.2-15% of C atoms in carbon materials, graded pores include mass transfer pores and deposition pores, deposition pores account for 40-95% of the total pore volume, mass transfer pores account for 4-55% of the total pore volume, and the rest are For pores with a pore diameter less than 5nm, the pore diameter of the deposition pores is 5-90nm, the pore diameter of the mass transfer pores is 0.1-6μm, the distance between the mass transfer pores is 0.1-8μm, the mass transfer pores are connected to each other through the deposition pores, and the total pore volume of the carbon material is 0.9 ~5 cm ³ /g. 2. The nitrogen-doped porous carbon material according to claim 1, characterized in that: the nitrogen-doped porous carbon material is prepared by a sol-gel method combined with an activation method or a sol-gel method combined with a foaming method . 3. The nitrogen-doped porous carbon material according to claim 2, characterized in that: the sol-gel method combined with the activation method comprises catalytic activation in the carbonization process, or after the carbon material obtained by the sol-gel method is Activation, one of the two or a combination of the two. 4. The nitrogen-doped porous carbon material according to claim 3, characterized in that: the sol-gel method is prepared by catalytic activation in the carbonization process as follows, resorcinol is dispersed in a solvent, Then add metal salt or metal hydroxide to continue dissolving and dispersing, then add formaldehyde solution dropwise, stir and mix evenly at 30~80°C until the reaction forms a gel; vacuum dry and age the gel at 60~100°C for 3~10 days, Take it out, pulverize and grind to obtain solid powder; after carbonization under high temperature NH ₃ atmosphere, remove metal salt or metal hydroxide with acid or alkali, filter and dry to obtain nitrogen-doped porous carbon material, in which NH ₃ gas The flow rate is controlled at 2~100mL/min. 5. The nitrogen-doped porous carbon material according to claim 4, characterized in that: the metal salt or metal hydroxide contains Fe, Co, Ni, Cu, Ag, Pt, Pd, Au, Ir, One or two or more metal salts or metal hydroxides of Ru, Nb, Y, Rh, Cr, Zr, Ce, Ti, Mo, Mn, Zn, W, Sn, La and V; the metal salt is nitric acid of metal One or more of salts, carbonates, sulfates, acetates, halides, dinitrosodiamine salts, acetylacetonates, or macrocyclic complexes, porphyrins, and phthalocyanines , wherein the metal salt or metal hydroxide accounted for the mass percentage of resorcinol ranges from 1 to 15%. 6. The nitrogen-doped porous carbon material according to claim 3, characterized in that: the carbon material prepared by the sol-gel method is post-activated and prepared by combining one or more of the following methods: (1) Physical activation method: disperse resorcinol in a solvent, then add formaldehyde solution dropwise, stir and mix evenly at 30~80°C until the reaction forms a gel; vacuum dry and age the gel at 60~100°C for 3~ After 10 days of treatment, take it out, crush and grind it to obtain solid powder; after carbonization under high-temperature NH ₃ atmosphere, pass in water vapor, CO ₂ , and one or more of the compounds that can generate one of the above two gases to activate; The activation temperature is controlled at 400~1300°C, the activation time is controlled at 10min~5h, and the intake flow of NH ₃ , water vapor or CO ₂ is controlled at 2~100mL/min; (2) NH ₃ heat treatment activation method: disperse resorcinol in the solvent, then add formaldehyde solution dropwise, stir and mix evenly at 30~80°C until the reaction forms a gel; vacuum dry and age the gel at 60~100°C After 3-10 days of treatment, take it out, crush and grind to obtain solid powder; after carbonization by high-temperature N ₂ or Ar, the obtained carbon material is activated by heat treatment under NH ₃ atmosphere, and the heat treatment temperature is controlled at 400-1300°C and the time is controlled at 10 minutes ~6h, N ₂ or Ar, NH ₃ intake flow is controlled at 2~100mL/min; ( 3 ) Chemical activation method: disperse resorcinol in a solvent, then add formaldehyde solution dropwise, stir and mix evenly at 30~80°C until the reaction forms a gel; vacuum dry and age the gel at 60~100°C for 3~ After 10 days of treatment, take it out, crush and grind to obtain solid powder; after carbonization under high-temperature _NH3 atmosphere, grind and mix the activation reagent and the carbon material prepared by the sol-gel method evenly. The activation reagent is 10-300% of the mass of the carbon material. The activation temperature is controlled at 300-900°C, and the activation time is controlled at 10min-5h; after activation, the carbon material is washed with deionized water and dried; the NH ₃ intake flow is controlled at 2-100mL/min; the activation reagent includes alkali The activating reagent KOH, the acid activating reagent H ₃ PO ₄ , and the salt activating reagent are ZnCl ₂ , K ₂ CO ₃ or Na ₂ CO ₃ . 7. The nitrogen-doped porous carbon material according to claim 4 or 6, characterized in that: the resorcinol and the solvent are in a ratio of 0.1 to 8ml solvent/1g resorcinol; the solvent is water, ethanol , isopropanol or ethylene glycol, the molar ratio of resorcinol to formaldehyde is 1:1 to 5:1, the mass concentration of the formaldehyde solution is 30 to 40%, and the carbonization temperature range is 500 to 1700°C. The time is controlled at 1~10h. 8. The porous carbon material according to claim 2, characterized in that: the nitrogen-doped porous carbon material is prepared by a sol-gel method in combination with a foaming method as follows: resorcinol and foaming The agent is dispersed in the solvent, then formaldehyde solution is added dropwise, stirred and mixed evenly at 30-80°C until the reaction forms a gel; the gel is vacuum-dried and aged at 60-100°C for 3-10 days, taken out, crushed and ground to obtain a solid Powder; after carbonization under high temperature NH ₃ atmosphere, remove foaming agent with acid or alkali, wash, filter and dry to obtain nitrogen-doped porous carbon material. 9. The porous carbon material according to claim 8, characterized in that: the resorcinol and solvent are in the ratio of 0.1 to 8ml solvent/1g resorcinol; the solvent is water, ethanol, isopropanol or ethanol Glycol, the molar ratio of resorcinol and formaldehyde is 1:1～5:1, and the mass concentration of described formaldehyde solution is 30～40%, and wherein NH _The inlet flow rate is controlled at 2～100mL/min, carbonization temperature The range is 500~1700℃, the carbonization time is controlled at 1~10h, and the mass percentage of foaming agent in resorcinol is in the range of 3~100%. 10. The porous carbon material according to claim 8, characterized in that: the blowing agent is citric acid, calcium carbonate, magnesium carbonate, sodium bicarbonate, sodium carbonate, ammonium carbonate, ammonium bicarbonate, ammonium nitrite, Sodium lauryl sulfate, cetyltrimethylammonium bromide, sodium fatty alcohol polyoxyethylene ether sulfate, n-pentane, n-hexane, n-heptane, petroleum ether, animal and vegetable protein foaming agent One or more foaming agents; the acid solution used to remove the foaming agent is 0.5-3M hydrochloric acid, sulfuric acid or nitric acid, and the alkali solution is 0.5-3M sodium hydroxide solution.