Resin-based self-activated porous carbon material as well as preparation method and application thereof

Abstract

The invention relates to the technical field of lithium battery negative electrode materials, and particularly discloses a resin-based self-activated porous carbon material and a preparation method and application thereof.The preparation method comprises the following steps that a diphenol monomer, a diphenol monomer containing thioether bonds, formaldehyde or polyaldehyde and a catalyst A are subjected to a condensation polymerization reaction, and phenolic resin is obtained; and carbonizing the phenolic resin to obtain the resin-based self-activated porous carbon material. The phenolic resin is synthesized by utilizing the diphenol monomer containing the thioether bond, so that a thioether alkane side chain is introduced into the phenolic resin, and in the carbonization process of the phenolic resin, because the thioether bond is extremely easy to decompose at high temperature to generate gas, a phenolic resin framework can be subjected to pore forming; the prepared resin-based self-activated porous carbon material has high specific surface area and pore volume, controllable design of the internal pore structure of the resin-based porous carbon can be realized by controlling the structure and modification proportion of the thioether alkane side chain, and ideal pore distribution is obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of anode materials for lithium batteries, and particularly to a resin-based self-activated porous carbon material, a preparation method thereof, and an application thereof. Background Art

[0002] As the main power battery in the fields of new energy vehicles, portable electronic devices, etc., the improvement of the energy density of lithium batteries has always been the focus of research. Silicon materials have a theoretical specific capacity as high as 4200 mAh / g and are considered the most promising candidates to replace traditional graphite anode materials. However, during the charge and discharge process, silicon materials will undergo a huge volume expansion, resulting in the pulverization and shedding of electrode materials, seriously affecting the cycle life and safety performance of the battery.

[0003] At present, the preparation of porous silicon-carbon anode materials by chemical vapor deposition is considered an effective way to solve the volume expansion problem of silicon anode materials. This method uses porous carbon as the carrier of the silicon source, and introduces silane gas into the pores of the porous carbon under high-temperature conditions, so that the silicon source is deposited in the pores of the porous carbon to form a silicon-carbon composite material. The pore structure of the porous carbon provides a buffer space for the expansion of silicon, effectively suppressing the pulverization of silicon particles. However, it is difficult to avoid the generation of ultramicropores (pore diameter < 0.7 nm) in the porous carbon materials prepared by existing physical activation, alkali activation and other methods. This ultramicropore structure will affect the insertion and extraction of lithium ions, reducing the initial Coulomb efficiency and rate performance of the battery. Therefore, developing a resin-based self-activated porous carbon material with a customizable pore structure size and avoiding the generation of ultramicropore structure is of great significance for improving the electrochemical performance of porous silicon-carbon anode materials. Summary of the Invention

[0004] Based on this, the purpose of the present invention is to provide a resin-based self-activated porous carbon material, a preparation method thereof, and an application thereof. By controlling the structure and modification ratio of the thioether alkane side chain, the controllable design of the internal pore structure of the resin-based porous carbon can be realized, and an ideal pore distribution can be obtained to meet the specific requirements of the silicon-carbon anode material for the pore structure.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions: The present invention first provides a preparation method of a resin-based self-activated porous carbon material, which includes the following steps: Performing a polycondensation reaction on a diphenol monomer, a diphenol monomer containing a thioether bond, formaldehyde or polyaldehyde, and a catalyst A to obtain a phenolic resin; Carbonizing the phenolic resin to obtain the resin-based self-activated porous carbon material.

[0006] As a further improvement of the above solution of the present invention, the preparation method of the diphenol monomer containing a thioether bond is as follows: 2,5-dihydroxybenzenethiol and a haloalkane are added to a solvent, and a catalyst B is added for reaction, followed by post-treatment to obtain the diphenol monomer containing a thioether bond.

[0007] As a further improvement of the above solution of the present invention, the molar ratio of 2,5-dihydroxybenzenethiol to the haloalkane is 1:1 - 1.5, and the mass of the catalyst B is 3% - 5% of the sum of the masses of 2,5-dihydroxybenzenethiol and the haloalkane; and / or, the haloalkane is at least one of bromohexane, bromobutane, and bromooctane; and / or, the catalyst B is at least one of potassium hydroxide, sodium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, and potassium bicarbonate; and / or, the solvent is ethanol.

[0008] As a further improvement of the above solution of the present invention, the reaction is carried out at 60 - 70 °C for 2 - 3 h, and the post-treatment sequentially includes filtration, washing, and drying. The washing is carried out by washing with deionized water several times, and the drying is carried out at 80 - 90 °C for 10 - 14 h.

[0009] As a further improvement of the above solution of the present invention, the molar ratio of the diphenol monomer containing a thioether bond, the diphenol monomer, formaldehyde or polyaldehyde is 1:0.5 - 2:1.5 - 3; the mass of the catalyst A is 3% - 5% of the sum of the masses of the diphenol monomer containing a thioether bond, the diphenol monomer, formaldehyde or polyaldehyde; the polyaldehyde is at least one of malondialdehyde, succinaldehyde, glutaraldehyde, 2-hydroxypentanedial, and malealdehyde; the catalyst A is at least one of hydrochloric acid and oxalic acid.

[0010] As a further improvement of the above solution of the present invention, the polycondensation reaction is carried out at 80 - 90 °C for 4 - 6 h.

[0011] As a further improvement of the above solution of the present invention, the carbonization is carried out under a protective atmosphere. First, the temperature is raised to 170 - 180 °C and held for 2 - 3 h, then the temperature is raised at a heating rate of 1 °C / min - 10 °C / min to 450 - 500 °C and held for 4 - 6 h, and then the temperature is raised at a heating rate of 1 °C / min - 10 °C / min to 800 - 900 °C and held for 4 - 6 h.

[0012] The present invention also provides a resin-based self-activating porous carbon material, which is prepared by using the preparation method described above.

[0013] The present invention also provides an application of the resin-based self-activating porous carbon material described above, which is used for preparing the anode material of a lithium battery.

[0014] As a further improvement of the above solution of the present invention, the preparation of the lithium battery anode material includes the following steps: under a protective atmosphere, first perform silicon deposition on the resin-based self-activated porous carbon material by chemical vapor deposition using a silicon source gas; then perform carbon coating on the resin-based self-activated porous carbon material by chemical vapor deposition using a carbon source gas, and thus obtain the lithium battery anode material; the silicon source gas is at least one of silane, disilane, dichlorosilane, silicon tetrachloride, dichlorosilane dihydride, trichlorosilane, the temperature of the silicon deposition is 450-480 °C, and the time is 2-4 h; the carbon source gas is at least one of acetylene, methane, propane, cyclohexane, the temperature of the carbon coating is 560-580 °C, and the time is 2-4 h.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention synthesizes phenolic resin using a diphenol monomer containing a thioether bond, thereby introducing a thioether alkane side chain into the phenolic resin. During the carbonization process of the phenolic resin, since the thioether bond is extremely easy to decompose and generate gas at high temperature, it can create pores in the phenolic resin skeleton, promote the formation of micropores and mesopores, thereby increasing the specific surface area. Compared with the traditional physical activation or alkali activation methods, the method of the present invention effectively avoids the problem of the generation of inherent ultra-microporous structures during the preparation of porous carbon materials; at the same time, the flexible alkane molecular chain helps to relieve the structural stress during the carbonization process, reduce pore collapse, and obtain a more uniform pore size distribution. The prepared resin-based self-activated porous carbon material has a high specific surface area and pore volume. The doping of sulfur atoms can form sulfur-carbon bonds or sulfur-oxygen bonds, providing additional adsorption sites and catalytic active sites, and enhancing the application potential of the material in electrochemical energy storage or catalysis.

[0016] By controlling the structure and modification ratio of the thioether alkane side chain, the present invention can realize the controllable design of the internal pore structure of the resin-based porous carbon, obtain an ideal pore distribution, meet the specific requirements of the silicon-carbon anode material for the pore structure, and provide a solution for the customized design of porous structure carbon materials such as porous carbon and supercapacitor carbon.

[0017] The preparation method of the present invention is simple and efficient, without complex processes such as composite of multiple carbon sources or multi-step activation and doping. The preparation process is simple and the cost is low; the prepared resin-based porous carbon material has a high specific surface area and pore volume, and can meet the higher requirements of high-energy density lithium-ion batteries for anode materials. Description of the Drawings

[0018] Figure 1 It is the SEM image of the resin-based self-activated porous carbon material prepared in Example 1 of the present invention; Figure 2 It is the SEM image of the porous carbon material prepared in the comparative example; Figure 3This is a comparison chart of pore size / pore integral volume of the porous carbon materials prepared in Example 1 of the present invention and the comparative example; Figure 4 This is a pore size distribution chart of the resin-based self-activated porous carbon material prepared in Example 1 of the present invention; Figure 5 This is a pore size distribution chart of the porous carbon material prepared in the comparative example. Detailed implementation manners

[0019] For ease of understanding the present invention, the present invention will be described more comprehensively below in conjunction with specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided so that the disclosure of the present invention can be understood more thoroughly and comprehensively.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the description of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0021] Example 1 This example provides a resin-based self-activated porous carbon material, and its preparation method includes the following steps: S1. 2,5-Dihydroxybenzenethiol and bromohexane are added to an ethanol solvent in a molar ratio of 1:1, and stirred to dissolve them fully; then sodium hydroxide is slowly added as a catalyst, and the amount of sodium hydroxide is 5% of the sum of the masses of 2,5-dihydroxybenzenethiol and bromohexane, and the temperature is raised to 60 °C and reacted for 2 h; after the reaction is completed, it is washed 3 times with deionized water, filtered, and dried at 80 °C for 12 h to obtain a diphenol monomer containing a thioether bond, and its structural formula is:

[0022] The reaction mechanism of this step is: R-S-Na + R′Br ─→ R-S-R′ + NaBr, which is a nucleophilic substitution reaction, and the reaction equation is:

[0023] S2. The diphenol monomer containing a thioether bond, resorcinol, and formaldehyde prepared in step S1 are added to an ethanol solvent in a molar ratio of 1:1:2, stirred evenly, and then oxalic acid is added as a catalyst (the amount of oxalic acid is 5% of the sum of the masses of the diphenol monomer containing a thioether bond, resorcinol, and formaldehyde), and the temperature is raised to 90 °C and reacted for 4 h to obtain a phenolic resin; S3. Under a nitrogen atmosphere, heat the phenolic resin obtained in step S2 to 180 °C first and hold for 2 h for curing, then heat it to 500 °C at a heating rate of 1 °C / min and hold for 4 h for self-activation, and then heat it to 900 °C at a heating rate of 5 °C / min and carbonize for 4 h to obtain the resin-based self-activated porous carbon material.

[0024] Example 2 This example presents a resin-based self-activated porous carbon material, and its preparation method includes the following steps: S1. Add 2,5-dihydroxybenzenethiol and bromobutane in a molar mass ratio of 1:1.2 to an ethanol solvent, stir to dissolve it fully; then slowly add sodium hydroxide as a catalyst, and the dosage of sodium hydroxide is 3% of the total mass of 2,5-dihydroxybenzenethiol and bromobutane, heat to 70 °C and react for 3 h; after the reaction, wash with deionized water 3 times, filter, and dry at 90 °C for 10 h to obtain the diphenol monomer containing a thioether bond. S2. Add the diphenol monomer containing a thioether bond, m-dihydroxybenzene, and malonaldehyde prepared in step S1 in a molar ratio of 1:0.8:1.8 to an ethanol solvent, stir evenly, then add hydrochloric acid as a catalyst (the dosage of hydrochloric acid is 3% of the sum of the masses of the diphenol monomer containing a thioether bond, m-dihydroxybenzene, and formaldehyde), heat to 85 °C and react for 5 h to obtain the phenolic resin. S3. Under a nitrogen atmosphere, heat the phenolic resin obtained in step S2 to 170 °C first and hold for 2 h for curing, then heat it to 500 °C at a heating rate of 1 °C / min and hold for 4 h for self-activation, and then heat it to 850 °C at a heating rate of 5 °C / min and carbonize for 4 h to obtain the resin-based self-activated porous carbon material.

[0025] Example 3 This example presents a resin-based self-activated porous carbon material, and its preparation method includes the following steps: S1. Add 2,5-dihydroxybenzenethiol and bromooctane in a molar mass ratio of 1:1.5 to an ethanol solvent, stir to dissolve it fully; then slowly add sodium hydroxide as a catalyst, and the dosage of sodium hydroxide is 4% of the total mass of 2,5-dihydroxybenzenethiol and bromooctane, heat to 65 °C and react for 2.5 h; after the reaction, wash with deionized water 3 times, filter, and dry at 85 °C for 14 h to obtain the diphenol monomer containing a thioether bond. S2. Add the diphenol monomer containing a thioether bond, m-dihydroxybenzene, and formaldehyde prepared in step S1 in a molar ratio of 1:0.5:1.5 to an ethanol solvent, stir evenly, then add hydrochloric acid as a catalyst (the dosage of hydrochloric acid is 4% of the sum of the masses of the diphenol monomer containing a thioether bond, m-dihydroxybenzene, and formaldehyde), heat to 80 °C and react for 6 h to obtain the phenolic resin. S3. Under a nitrogen atmosphere, heat the phenolic resin obtained in step S2 to 180 °C first and hold for 2 h for curing, then heat it to 500 °C at a heating rate of 1 °C / min and hold for 4 h for self-activation, and then heat it to 800 °C at a heating rate of 5 °C / min and carbonize for 4 h to obtain a resin-based self-activated porous carbon material.

[0026] Example 4 This example presents a resin-based self-activated porous carbon material, and its preparation method includes the following steps: S1. Add 2,5-dihydroxybenzenethiol and octyl bromide into an ethanol solvent at a molar mass ratio of 1:1.5, stir to dissolve them fully; then slowly add sodium hydroxide as a catalyst, and the dosage of the catalyst is 4% of the total mass of 2,5-dihydroxybenzenethiol and octyl bromide, heat to 65 °C and react for 2.5 h; after the reaction, wash with deionized water 3 times, filter, and dry at 85 °C for 14 h to obtain a diphenol monomer containing a thioether bond; S2. Add the diphenol monomer containing a thioether bond, resorcinol, and formaldehyde prepared in step S1 into an ethanol solvent at a molar ratio of 1:2:3, stir evenly, then add hydrochloric acid as a catalyst (the dosage of hydrochloric acid is 4% of the sum of the masses of the diphenol monomer containing a thioether bond, resorcinol, and formaldehyde), heat to 80 °C and react for 6 h to obtain a phenolic resin; S3. Under a nitrogen atmosphere, heat the phenolic resin obtained in step S2 to 180 °C first and hold for 2 h for curing, then heat it to 500 °C at a heating rate of 1 °C / min and hold for 4 h for self-activation, and then heat it to 800 °C at a heating rate of 5 °C / min and carbonize for 4 h to obtain a resin-based self-activated porous carbon material.

[0027] Example 5 This example presents a resin-based self-activated porous carbon material, and its preparation method includes the following steps: S1. Add 2,5-dihydroxybenzenethiol and hexyl bromide into an ethanol solvent at a molar mass ratio of 1:1, stir to dissolve them fully; then slowly add sodium hydroxide as a catalyst, and the dosage of sodium hydroxide is 5% of the total mass of 2,5-dihydroxybenzenethiol and hexyl bromide, heat to 60 °C and react for 2 h; after the reaction, wash with deionized water 3 times, filter, and dry at 80 °C for 12 h to obtain a diphenol monomer containing a thioether bond; S2. Add the diphenol monomer containing a thioether bond, resorcinol, and formaldehyde prepared in step S1 into an ethanol solvent at a molar ratio of 1:1:2, stir evenly, then add oxalic acid as a catalyst (the dosage of oxalic acid is 5% of the sum of the masses of the diphenol monomer containing a thioether bond, resorcinol, and formaldehyde), heat to 90 °C and react for 4 h to obtain a phenolic resin; S3. Under a nitrogen atmosphere, first heat the phenolic resin obtained in step S2 to 180 °C and hold for 2 h for curing, then heat it at a heating rate of 5 °C / min to 500 °C and hold for 4 h for self-activation, and then heat it at a heating rate of 5 °C / min to 900 °C for carbonization for 4 h to obtain a resin-based self-activated porous carbon material.

[0028] Comparative Example This comparative example presents a resin-based porous carbon material, and its preparation method includes the following steps: S1. Add resorcinol and oxalic acid to deionized water at a molar ratio of 1:0.01, heat to 50 °C, and then slowly dropwise add 37% formaldehyde aqueous solution while stirring at a stirring speed of 200 r / min. The dropping is completed in 1 h. The molar ratio of formaldehyde to resorcinol is 1.5:1 to obtain a prepolymer solution; S2. Slowly dropwise add 4 wt% potassium hydroxide aqueous solution to the prepolymer solution while stirring at a stirring speed of 800 r / min. The dropping is completed in 1 h. Then take 37% formaldehyde aqueous solution and complete the dropping in 30 min. The molar ratio of formaldehyde to resorcinol in step S1 is 0.5:1; heat to 70 °C and hold for 8 h for cross-linking reaction to obtain a gel; place the obtained gel in an oven at 100 °C for drying to obtain a dried material; S3. Under a nitrogen atmosphere, keep the dried material at 700 °C for carbonization for 3 h; introduce carbon dioxide and nitrogen (the volume ratio of carbon dioxide to nitrogen is 1:5), heat to 800 °C and hold for activation for 5 h, and then cool to room temperature, followed by grinding, classification, shaping, and screening to obtain a porous carbon material with a particle size D50 of 5 - 8 μm.

[0029] Test Example (1) Use a scanning electron microscope to characterize the porous carbon materials prepared in Example 1 and the comparative example to obtain Figure 1 and Figure 2 . From Figure 1 , Figure 2 , it can be seen that there are no loose macropores on the surface of the porous carbon material prepared in Example 1, while obvious loose macropores exist on the surface of the porous carbon material prepared in the comparative example; this shows that the method of the present invention can avoid the formation of macropore structures on the surface of the porous carbon.

[0030] (2) Test the pore volume, average pore diameter, and specific surface area of the porous carbon materials prepared in Examples 1 - 5 and the comparative example: The test instrument is a V-Sorb X800TP specific surface area and pore size analyzer, and the test method: The test gas is nitrogen, and degassing is carried out at 300 °C for 6 h. The results are shown in Table 1, Figures 3 - 5 as shown.

[0031] Table 1 Test results of pore volume, pore diameter, and specific surface area

[0032] It can be seen from the results in Table 1 that: Comparing Examples 1-3 with the comparative examples, it can be seen that by controlling the molar ratio of the diphenol monomer containing a thioether bond, the pore volume, specific surface area, and pore diameter of the porous carbon material can be regulated, and the ultramicropore ratio of the porous carbon materials in Examples 1-3 is much lower than that of the comparative examples; this shows that by controlling the structure and modification ratio of the thioalkane side chain in the present invention, the controllable design of the internal pore structure of the resin-based porous carbon can be realized, and an ideal pore distribution can be obtained; Comparing with Example 3, it can be seen that in Example 4, by reducing the molar ratio of the diphenol monomer with a thioether bond, the pore diameter of the self-activated porous carbon can be controlled below 1 nm; at the same time, comparing with the comparative examples, it can be found that in Example 4, even when the average pore diameter of the porous carbon is reduced, the ultramicropore ratio can still be effectively controlled; From the test results of Example 1 and Example 5, it can be seen that the heating rate can also be used as one of the means to regulate the pore volume and pore diameter. If the heating rate is too fast, it will cause the pore diameter of the self-activated porous carbon to become larger. This is because the functional group C-O bond of the phenolic resin and the C-S-C bond of the thioether group break concentratedly, and the gas escapes simultaneously during activation, resulting in an increase in the pore diameter of the porous carbon; From Figure 3 it can be seen that the ultramicropore volume ratio of the porous carbon prepared in Example 1 below 0.7 nm is significantly lower than that of the comparative example; from Figure 4 , Figure 5 it can be seen that by comparing the pore diameter distributions of Example 1 and the comparative example, the pore diameter distribution of the porous carbon prepared in the present invention is narrower and more uniform.

[0033] Application Example The porous carbon materials prepared in Examples 1-5 and the comparative example were respectively used to prepare the anode materials for lithium batteries. The method was as follows: Take the porous carbon material and place it in a fluidized bed chemical vapor deposition device, and introduce a mixed gas of silane (SiH 4 ) and argon (the volume ratio of silane to argon is 1:4), and carry out chemical vapor deposition at 460 °C for 3 h; then flush the device with argon for 30 min, introduce a mixed gas of acetylene and argon (the volume ratio of acetylene to argon is 1:2), and carry out chemical vapor deposition at 570 °C for 3 h to obtain the anode materials for lithium batteries.

[0034] Then, the prepared anode materials for lithium batteries were respectively used to prepare CR2025 type button cells: Mix according to the weight ratio of the anode material for lithium battery, conductive agent (Super-P), binder (carboxymethyl cellulose sodium CMC), and polyacrylonitrile binder (LA133) of 80:10:8:2, add an appropriate amount of ultrapure water to make a slurry, coat it on a copper foil, and carry out vacuum drying and rolling to prepare a negative electrode sheet; the positive electrode uses a lithium metal sheet, and the electrolyte selects 1 mol / L LiPF 6The solvent of the solution (the solvent is a mixture of dimethyl carbonate DMC, diethyl carbonate DEC, and ethylene carbonate EC in a mass ratio of 1:1:1), and the separator uses a polypropylene microporous membrane to assemble a CR2025 type button cell. The obtained CR2025 type button cell is subjected to electrochemical performance testing on a Blue Electric battery testing system: under normal temperature conditions, constant current charge and discharge at 0.1C, and the charge and discharge voltage is limited to 0.005 - 1.5V. The results are shown in Table 2 below.

[0035] Table 2 Electrochemical Performance Results

[0036] As can be seen from Table 2: Compared with the comparative example, the porous carbon materials provided in Examples 1 - 4 of the present invention have better capacity performance and first efficiency performance at 0.8V. It can be seen that the silicon-carbon composite material prepared by the present invention has more excellent electrochemical performance; it shows that the controllable design of the internal pore structure of the resin-based porous carbon and the doping of sulfur atoms in the present invention are beneficial to improving the electrochemical performance of the silicon-carbon composite material.

[0037] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0038] The above-described embodiments only represent several implementation manners of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A method for preparing a resin-based self-activated porous carbon material, characterized in that: It includes the following steps: Carrying out polycondensation reaction of diphenol monomer, diphenol monomer containing thioether bond, formaldehyde or polyaldehyde, and catalyst A to obtain phenolic resin; The phenolic resin is carbonized to obtain a resin-based self-activated porous carbon material.

2. The method for preparing a resin-based self-activated porous carbon material according to claim 1, characterized in that: The preparation method of the diphenol monomer containing a thioether bond is as follows: 2,5-dihydroxythiophenol and halogenated alkane are added into a solvent, a catalyst B is added for reaction, and post-treatment is performed to obtain the diphenol monomer containing a thioether bond.

3. The method for preparing a resin-based self-activated porous carbon material according to claim 2, characterized in that: The molar ratio of the 2,5-dihydroxythiophenol to the halogenated alkane is 1:1-1.5, and the mass of the catalyst B is 3%-5% of the sum of the masses of the 2,5-dihydroxythiophenol and the halogenated alkane; and / or the halogenated alkane is at least one of hexyl bromide, butyl bromide, and octane bromide; and / or the catalyst B is at least one of potassium hydroxide, sodium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, and potassium bicarbonate; and / or the solvent is ethanol.

4. The method for preparing a resin-based self-activated porous carbon material according to claim 2, characterized in that: The reaction is carried out at 60-70° C. for 2-3 hours, and the post-treatment comprises filtering, washing and drying in sequence. The washing is carried out several times with deionized water, and the drying is carried out at 80-90° C. for 10-14 hours.

5. The method for preparing a resin-based self-activated porous carbon material according to claim 1, characterized in that: The molar ratio of the diphenol monomer containing a thioether bond, the diphenol monomer, formaldehyde or the polyaldehyde is 1:0.5-2:1.5-3; the mass of the catalyst A is 3%-5% of the sum of the masses of the diphenol monomer containing a thioether bond, the diphenol monomer, formaldehyde or the polyaldehyde; the polyaldehyde is at least one of malondialdehyde, succindialdehyde, glutaraldehyde, 2-hydroxyglutaraldehyde and maleic aldehyde; the catalyst A is at least one of hydrochloric acid and oxalic acid.

6. The method for preparing a resin-based self-activated porous carbon material according to claim 1, characterized in that: The polycondensation reaction is carried out at 80-90° C. for 4-6 hours.

7. The method for preparing a resin-based self-activated porous carbon material according to claim 1, characterized in that: The carbonization is carried out under a protective atmosphere, firstly heating to 170-180°C and keeping the temperature for 2-3h, then heating to 450-500°C at a heating rate of 1°C / min-10°C / min and keeping the temperature for 4-6h, and then heating to 800-900°C at a heating rate of 1°C / min-10°C / min and keeping the temperature for 4-6h.

8. A resin-based self-activated porous carbon material, characterized in that: The invention is prepared by the preparation method described in any one of claims 1 to 7.

9. A use of the resin-based self-activated porous carbon material as claimed in claim 8, characterized in that: It is used to prepare negative electrode materials for lithium batteries.

10. The use according to claim 9, characterized in that: The preparation of the negative electrode material for a lithium battery comprises the following steps: Under a protective atmosphere, silicon is first deposited on the resin-based self-activated porous carbon material by chemical vapor deposition using a silicon source gas; then the resin-based self-activated porous carbon material is carbon-coated by chemical vapor deposition using a carbon source gas to obtain a lithium battery negative electrode material; the silicon source gas is at least one of monosilane, disilane, dichlorosilane, silicon tetrachloride, dichlorodihydrosilane, and trichlorosilane, and the temperature of the silicon deposition is 450-480°C and the time is 2-4h; the carbon source gas is at least one of acetylene, methane, propane, and cyclohexane, and the temperature of the carbon coating is 560-580°C and the time is 2-4h.

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