Preparation method of graphene porous carbon material
Graphene-based porous carbon materials are prepared through carbonization-alkali activation-boron catalysis treatment, which solves the problems of low conductivity and ion transfer efficiency of porous carbon materials, and realizes lithium-ion battery negative electrode materials with high specific capacity and excellent conductivity, which is suitable for CVD silicon-carbon negative electrode substrates.
Patent Information
- Application Number
- CN202510859563.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-25
- Publication Date
- 2025-09-19
AI Technical Summary
The conductivity and ion transmission efficiency of existing lithium-ion battery negative electrode materials are relatively low, especially porous carbon materials as the base material of CVD silicon-carbon negative electrodes, which are difficult to meet the needs of high-efficiency energy storage systems.
Using coconut shell as a precursor, graphene-based porous carbon materials are prepared through a three-step process of carbonization-alkali activation-atomic crystal boron catalysis. Potassium hydroxide etching and metallic potassium vapor insertion are used to create pores, and a few-layer graphene structure is generated using a boron catalyst to improve the conductive properties of the material.
Graphene-based porous carbon materials significantly improve specific capacity, initial efficiency and electrical conductivity, have low cost and short process routes, are suitable as the substrate for CVD silicon-carbon negative electrode materials, and enhance the energy storage performance of lithium-ion batteries.
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Figure CN120664537A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of lithium ion battery negative electrode materials, and specifically relates to a preparation method and application of a graphene porous carbon material. Background Art
[0002] As humanity's demand for energy continues to grow, the search for renewable and green energy sources has received widespread attention, and large-scale, efficient energy storage systems require further development. As efficient energy storage devices, the performance of lithium-ion batteries is highly dependent on their anode materials. Silicon / carbon anodes have evolved from first-generation nano-silicon / carbon, second-generation silicon oxide (or pre-lithiated silicon oxide), to today's third-generation vapor-deposited silicon / carbon (CVD silicon-carbon). Currently, most vapor-deposited silicon / carbon anodes use carbon as a substrate for silicon deposition, which is then coated with a layer of carbon material. The substrate material has evolved from early graphite materials to today's porous carbon materials.
[0003] Porous carbon is a hard carbon. Its high specific surface area and tunable pore structure make it an optimal substrate for CVD silicon-carbon anode deposition. However, because hard carbon's electrical conductivity is weaker than graphite and silicon's conductivity is extremely poor, the ion transport efficiency of CVD silicon-carbon materials is low. Graphene, on the other hand, has a unique single-atomic-layer two-dimensional structure. Its continuous sp² hybridized carbon network provides a long-range electron conduction path, significantly reducing the electrode's internal resistance. Furthermore, few-layer graphene has a high specific surface area, which increases the exposure of active sites and improves lithium storage capacity. Graphene's flexible two-dimensional structure also mitigates volume changes during lithium insertion and extraction, inhibiting electrode pulverization.
[0004] Therefore, the generation of graphene in porous carbon can significantly reduce its resistance as a CVD silicon-carbon negative electrode material and improve its conductive properties. Summary of the Invention
[0005] The purpose of the present invention is to solve the problems existing in the above-mentioned prior art and to provide a method for preparing a graphene porous carbon material.
[0006] The present invention is achieved through the following technical solutions: According to one aspect of the present invention, there is provided a method for preparing a graphene porous carbon material, comprising the following steps: 1) The coconut shell is washed, dried, crushed and ground into powder. After drying, it is placed in a tube furnace and carbonized by introducing protective gas. The obtained carbonized material is taken out and ground in a mortar, and finally placed in a drying oven for drying.
[0007] 2) The dried carbonized material is mixed with potassium hydroxide and boron catalyst and ground. After drying, it is placed in a tubular furnace and activated by introducing protective gas.
[0008] 3) The activated material is sequentially washed with deionized water, neutralized with a weak acid, washed with deionized water multiple times, filtered, and dried. The final product is the graphene porous carbon material.
[0009] Furthermore, in step 1), during the carbonization treatment, the carbonization holding temperature is 450-600° C., the carbonization holding time is 120-240 min, and the protective gas is high-purity argon or nitrogen.
[0010] Furthermore, in step 2), the mass ratio of the carbonized material, potassium hydroxide and boron catalyst is 1:(3-4):(0.2-0.6).
[0011] Furthermore, in step 2), the boron catalyst is one of boric acid, boron oxide, and metaboric acid.
[0012] Furthermore, in step 2), during the activation treatment, the activation holding temperature is 700-900° C., the activation holding time is 120-240 min, and the protective gas is high-purity argon or nitrogen.
[0013] Furthermore, in step 3), the weak acid is one of dilute hydrochloric acid, dilute sulfuric acid, and dilute chloric acid.
[0014] Furthermore, in step 1), during the carbonization treatment, the carbonization heating rate is 2 to 10°C / min.
[0015] Furthermore, in step 2), during the activation treatment, the activation heating rate is 2 to 10°C / min.
[0016] Furthermore, in step 3), the concentration of the weak acid is 0.1 to 0.5 mol / L.
[0017] The method of the present invention uses coconut shell as a precursor and obtains a graphene porous carbon material through a three-step treatment of carbonization-alkali activation-atomic crystal boron catalysis. The graphene porous carbon material presents a graphene porous structure including an amorphous carbon structure, graphitized dendrites and a few-layer graphene structure.
[0018] According to another aspect of the present invention, there is provided the use of the graphene porous carbon material prepared by the above preparation method as a CVD silicon-carbon negative electrode material for lithium-ion batteries.
[0019] Compared with the prior art, the present invention has the following beneficial effects: 1) The method of the present invention provides a graphene-based porous carbon material, which can also be referred to as a porous carbon substrate for a CVD silicon-carbon negative electrode material. The material exhibits an amorphous carbon matrix, graphitized dendrites, and a few-layer graphene structure. The activation method is chemical alkali activation, wherein potassium hydroxide etching and metallic potassium vapor insertion between carbon layers cause expansion to produce a large number of pores. A boron catalyst such as boric acid is added during the activation step. The boric acid first reacts with part of the potassium hydroxide to form potassium tetraborate. In a subsequent high-temperature reaction, potassium tetraborate produces boron-catalyzed graphitization of the carbon material, thereby forming a few-layer graphene structure in the amorphous carbon matrix.
[0020] 2) The graphene-based porous carbon material provided by the method of the present invention, i.e., the porous carbon substrate of the CVD silicon-carbon negative electrode material, has the advantages of a short preparation process, low graphitization temperature, short graphitization time, and good crystal morphology. In addition, the generation of the graphene structure improves its specific capacity, initial efficiency, and conductive properties in the negative electrode material.
[0021] In summary, the graphene-based porous carbon material prepared by the method of the present invention has lower cost and shorter process route than the production of graphene alone. Compared with traditional porous carbon substrate materials, it has higher specific capacity and better conductivity, and can be applied on a large scale to the substrate preparation of CVD silicon-carbon negative electrode materials. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The drawings herein are used to provide further illustration of the present invention and constitute a part of this application. The illustrative embodiments of the present invention and their description are used to explain the present invention and do not constitute improper limitations on the present invention.
[0023] Figure 1 TEM images of graphene porous carbon materials prepared by adding boric acid in different proportions according to Examples 1 and 2 of the present invention.
[0024] Figure 2 This is the charge and discharge curve of a battery made with the graphene porous carbon material prepared in Example 2.
[0025] Figure 3 This is a long cycle diagram of a battery made with the graphene porous carbon material prepared in Example 2.
[0026] Figure 4 This is the impedance spectrum of a battery made from the graphene porous carbon material prepared in Example 2. DETAILED DESCRIPTION
[0027] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further clearly and completely described below with reference to the accompanying drawings and in conjunction with specific embodiments. It should be noted that, unless there is a conflict, the features in the embodiments and examples of this application can be combined with each other. Example 1
[0028] This embodiment provides a method for preparing a graphene porous carbon material, comprising the following steps: 1) The coconut shell was cleaned, dried, crushed, and ground into powder. After drying, the coconut shell was placed in a tubular furnace and carbonized by introducing high-purity argon gas. The carbonization heating rate was 5°C / min, the carbonization holding temperature was 600°C, and the carbonization holding time was 120 min. The carbonized material was taken out and placed in a mortar, ground for half an hour, and then dried in a drying oven.
[0029] 2) The carbonized material and potassium hydroxide were mixed and ground in a mass ratio of 1:4, dried, and placed in a tubular furnace to introduce high-purity argon gas for activation treatment; the activation heating rate was 5°C / min, the activation holding temperature was 900°C, and the activation holding time was 120 min.
[0030] 3) The activated material is sequentially washed with deionized water, neutralized with 0.2 mol / L dilute hydrochloric acid, washed with deionized water multiple times, filtered, and dried to obtain a graphene porous carbon material. Example 2
[0031] This embodiment provides a method for preparing a graphene porous carbon material, comprising the following steps: 1) The coconut shell was cleaned, dried, crushed and ground into powder. After drying, it was placed in a tube furnace and introduced with high-purity argon gas for carbonization treatment. The carbonization heating rate was 5°C / min, the carbonization holding temperature was 600°C, and the carbonization holding time was 120 min. The obtained carbonized material was taken out and placed in a mortar for half an hour, and then placed in a drying oven for drying.
[0032] 2) The carbonized material was mixed with potassium hydroxide and boric acid in a mass ratio of 1:4:0.4, ground, dried, and placed in a tube furnace to introduce high-purity argon gas for activation treatment; the activation heating rate was 5°C / min, the activation holding temperature was 900°C, and the activation holding time was 120 min.
[0033] 3) The activated material is sequentially washed with deionized water, neutralized with 0.2 mol / L dilute hydrochloric acid, washed with deionized water multiple times, filtered, and dried to obtain a graphene porous carbon material. Example 3
[0034] This embodiment provides a method for preparing a graphene porous carbon material, comprising the following steps: 1) The coconut shell was cleaned, dried, crushed and ground into powder. After drying, it was placed in a tube furnace and introduced with high-purity argon gas for carbonization treatment. The carbonization heating rate was 5°C / min, the carbonization holding temperature was 600°C, and the carbonization holding time was 120 min. The obtained carbonized material was taken out and placed in a mortar for half an hour, and then placed in a drying oven for drying.
[0035] 2) The carbonized material and potassium hydroxide were mixed and ground in a mass ratio of 1:4, dried, and placed in a tubular furnace to introduce high-purity argon gas for activation treatment; the activation heating rate was 5°C / min, the activation holding temperature was 800°C, and the activation holding time was 120 min.
[0036] 3) The activated material was sequentially washed with deionized water, neutralized with 0.2 mol / L dilute hydrochloric acid, washed with deionized water multiple times, filtered, and dried to obtain a graphene porous carbon material. Example 4
[0037] This embodiment provides a method for preparing a graphene porous carbon material, comprising the following steps: 1) The coconut shell was cleaned, dried, crushed and ground into powder. After drying, it was placed in a tube furnace and introduced with high-purity argon gas for carbonization treatment. The carbonization heating rate was 5°C / min, the carbonization holding temperature was 600°C, and the carbonization holding time was 120 min. The obtained carbonized material was taken out and placed in a mortar for half an hour, and then placed in a drying oven for drying.
[0038] 2) The carbonized material, potassium hydroxide, and boric acid were mixed and ground in a mass ratio of 1:4:0.4, dried, and placed in a tubular furnace and activated by introducing high-purity argon gas; the activation heating rate was 5°C / min, the activation holding temperature was 800°C, and the activation holding time was 120 min.
[0039] 3) The activated material is sequentially washed with deionized water, neutralized with 0.2 mol / L dilute hydrochloric acid, washed with deionized water multiple times, filtered, and dried to obtain a graphene porous carbon material. Example 5
[0040] This embodiment provides a method for preparing a graphene porous carbon material, comprising the following steps: 1) The coconut shell was cleaned, dried, crushed and ground into powder. After drying, it was placed in a tube furnace and introduced with high-purity argon gas for carbonization treatment. The carbonization heating rate was 5°C / min, the carbonization holding temperature was 600°C, and the carbonization holding time was 120 min. The obtained carbonized material was taken out and placed in a mortar for half an hour, and then placed in a drying oven for drying.
[0041] 2) The carbonized material and potassium hydroxide were mixed and ground in a mass ratio of 1:4, dried, and placed in a tube furnace to introduce high-purity argon gas for activation treatment; the activation heating rate was 5°C / min, the activation holding temperature was 700°C, and the activation holding time was 120 min.
[0042] 3) The activated material is sequentially washed with deionized water, neutralized with 0.2 mol / L dilute hydrochloric acid, washed with deionized water multiple times, filtered, and dried to obtain a graphene porous carbon material. Example 6
[0043] This embodiment provides a method for preparing a graphene porous carbon material, comprising the following steps: 1) The coconut shell was cleaned, dried, crushed and ground into powder. After drying, it was placed in a tube furnace and introduced with high-purity argon gas for carbonization treatment. The carbonization heating rate was 5°C / min, the carbonization holding temperature was 600°C, and the carbonization holding time was 120 min. The obtained carbonized material was taken out and placed in a mortar for half an hour, and then placed in a drying oven for drying.
[0044] 2) The carbonized material, potassium hydroxide, and boric acid were mixed and ground in a mass ratio of 1:4:0.4, dried, and placed in a tubular furnace to introduce high-purity argon gas for activation treatment; the activation heating rate was 5°C / min, the activation holding temperature was 700°C, and the activation holding time was 120 min.
[0045] 3) The activated material is sequentially washed with deionized water, neutralized with 0.2 mol / L dilute hydrochloric acid, washed with deionized water multiple times, filtered, and dried to obtain a graphene porous carbon material. Example 7
[0046] This embodiment provides a method for preparing a graphene porous carbon material, comprising the following steps: 1) The coconut shell was cleaned, dried, crushed and ground into powder. After drying, it was placed in a tube furnace and introduced with high-purity argon gas for carbonization treatment. The carbonization heating rate was 5°C / min, the carbonization holding temperature was 600°C, and the carbonization holding time was 120 min. The obtained carbonized material was taken out and placed in a mortar for half an hour, and then placed in a drying oven for drying.
[0047] 2) The carbonized material, potassium hydroxide, and boric acid were mixed and ground in a mass ratio of 1:4:0.6, dried, and placed in a tubular furnace to introduce high-purity argon gas for activation treatment; the activation heating rate was 5°C / min, the activation holding temperature was 900°C, and the activation holding time was 120 min.
[0048] 3) The activated material is sequentially washed with deionized water, neutralized with 0.2 mol / L dilute hydrochloric acid, washed with deionized water multiple times, filtered, and dried to obtain a graphene porous carbon material. Example 8
[0049] This embodiment provides a method for preparing a graphene porous carbon material, comprising the following steps: 1) The coconut shell was cleaned, dried, crushed and ground into powder. After drying, it was placed in a tube furnace and introduced with high-purity argon gas for carbonization treatment. The carbonization heating rate was 5°C / min, the carbonization holding temperature was 600°C, and the carbonization holding time was 120 min. The obtained carbonized material was taken out and placed in a mortar for half an hour, and then placed in a drying oven for drying.
[0050] 2) The carbonized material, potassium hydroxide, and boric acid were mixed and ground in a mass ratio of 1:4:0.6, dried, and placed in a tubular furnace to introduce high-purity argon gas for activation treatment; the activation heating rate was 5°C / min, the activation holding temperature was 800°C, and the activation holding time was 120 min.
[0051] 3) The activated material is sequentially washed with deionized water, neutralized with 0.2 mol / L dilute hydrochloric acid, washed with deionized water multiple times, filtered, and dried to obtain a graphene porous carbon material. Example 9
[0052] This embodiment provides a method for preparing a graphene porous carbon material, comprising the following steps: 1) The coconut shell was cleaned, dried, crushed and ground into powder. After drying, it was placed in a tube furnace and introduced with high-purity argon gas for carbonization treatment. The carbonization heating rate was 5°C / min, the carbonization holding temperature was 600°C, and the carbonization holding time was 120 min. The obtained carbonized material was taken out and placed in a mortar for half an hour, and then placed in a drying oven for drying.
[0053] 2) The carbonized material, potassium hydroxide, and boric acid were mixed and ground in a mass ratio of 1:4:0.6, dried, and placed in a tubular furnace to introduce high-purity argon gas for activation treatment; the activation heating rate was 5°C / min, the activation holding temperature was 700°C, and the activation holding time was 120 min.
[0054] 3) The activated material is sequentially washed with deionized water, neutralized with 0.2 mol / L dilute hydrochloric acid, washed with deionized water multiple times, filtered, and dried to obtain a graphene porous carbon material. Example 10
[0055] This embodiment provides a method for preparing a graphene porous carbon material, comprising the following steps: 1) The coconut shell was cleaned, dried, crushed and ground into powder. After drying, it was placed in a tube furnace and introduced with high-purity argon gas for carbonization treatment. The carbonization heating rate was 5°C / min, the carbonization holding temperature was 600°C, and the carbonization holding time was 120 min. The obtained carbonized material was taken out and placed in a mortar for half an hour, and then placed in a drying oven for drying.
[0056] 2) The carbonized material, potassium hydroxide, and boric acid were mixed and ground in a mass ratio of 1:4:0.2, dried, and placed in a tubular furnace to introduce high-purity argon gas for activation treatment; the activation heating rate was 5°C / min, the activation holding temperature was 900°C, and the activation holding time was 120 min.
[0057] 3) The activated material is sequentially washed with deionized water, neutralized with 0.2 mol / L dilute hydrochloric acid, washed with deionized water multiple times, filtered, and dried to obtain a graphene porous carbon material. Example 11
[0058] This embodiment provides a method for preparing a graphene porous carbon material, comprising the following steps: 1) The coconut shell was cleaned, dried, crushed and ground into powder. After drying, it was placed in a tube furnace and introduced with high-purity nitrogen for carbonization treatment. The carbonization heating rate was 2°C / min, the carbonization holding temperature was 450°C, and the carbonization holding time was 240 min. The obtained carbonized material was taken out and placed in a mortar for half an hour and then dried in a drying oven.
[0059] 2) The carbonized material was mixed with potassium hydroxide and boron oxide in a mass ratio of 1:3:0.6, ground, dried, and placed in a tube furnace to introduce high-purity nitrogen for activation treatment; the activation heating rate was 2°C / min, the activation holding temperature was 900°C, and the activation holding time was 180 min.
[0060] 3) The activated material is sequentially washed with deionized water, neutralized with 0.1 mol / L dilute sulfuric acid, washed with deionized water multiple times, filtered, and dried to obtain a graphene porous carbon material. Example 12
[0061] This embodiment provides a method for preparing a graphene porous carbon material, comprising the following steps: 1) The coconut shell was cleaned, dried, crushed and ground into powder. After drying, it was placed in a tubular furnace and introduced with high-purity nitrogen for carbonization treatment. The carbonization heating rate was 10°C / min, the carbonization holding temperature was 500°C, and the carbonization holding time was 180 min. The obtained carbonized material was taken out and placed in a mortar for half an hour, and then placed in a drying oven for drying.
[0062] 2) The carbonized material was mixed with potassium hydroxide and metaboric acid in a mass ratio of 1:3:0.2, ground, dried, and placed in a tube furnace to introduce high-purity nitrogen for activation treatment; the activation heating rate was 10°C / min, the activation holding temperature was 900°C, and the activation holding time was 240 min.
[0063] 3) The activated material is sequentially washed with deionized water, neutralized with 0.5 mol / L dilute chloric acid, washed with deionized water multiple times, filtered, and dried to obtain a graphene porous carbon material.
[0064] Furthermore, the technical solution of the present invention is further analyzed and explained in detail below in combination with the specific contents of the above embodiments.
[0065] In the above-mentioned embodiments, Example 1 and Example 2, Example 3 and Example 4, and Example 6 and Example 6 are three groups of comparative examples. The two examples in each group have basically the same technical solutions, except that boric acid is not added in the former examples of each group, while boric acid is added in the latter examples of each group. That is, boric acid is not added in Examples 1, 3, and 5, while boric acid is added in Examples 2, 4, and 6. Taking Examples 1 and 2 as examples, they are analyzed as follows: The structural characterization and analysis of the graphene porous carbon materials prepared in the two examples are as follows: Figure 1 TEM images of graphene porous carbon materials prepared by adding different proportions of boric acid in Examples 1 and 2 of the present invention. Figure 1 It can be seen that the graphene porous carbon material prepared in Example 1 without adding boric acid presents an amorphous matrix, while the graphene porous carbon material prepared in Example 2 with the addition of boric acid can be observed to have a few-layer graphene structure on the amorphous matrix.
[0066] Table 1 shows the data obtained by BET testing of the graphene porous carbon materials prepared in Examples 1 and 2 with the addition of different proportions of boric acid. As can be seen from Table 1, the graphene porous carbon material prepared in Example 1 without the addition of boric acid has a slightly larger specific surface area than the graphene porous carbon material prepared in Example 2 with the addition of boric acid. This is because part of the potassium hydroxide is consumed by the reaction with the boric acid first, resulting in a reduction in the proportion of potassium hydroxide used for activation and pore formation. The specific surface area of the prepared material is slightly reduced, but still as high as 1366 m 2 g -1 ; However, both the pore volume and pore size have increased. The increase in pore volume can provide a larger volume space for silicon deposition, and the increase in pore size can increase the transmission rate of lithium ions.
[0067] Table 1
[0068] The performance characterization analysis of the graphene porous carbon material prepared in Example 2 is carried out. Specifically, the graphene porous carbon material prepared in Example 2 is used to prepare the energy storage battery electrode, which specifically includes: first, the graphene porous carbon material prepared in Example 2, the conductive agent (acetylene black) and the binder (CMC+SBR) are selected and poured into a clean agate mortar in a mass ratio of 8:1:1, and ground until the viscous liquid has a metallic reflective color and is relatively uniform; then the ground slurry is dripped or applied to the surface of the copper foil, the coated copper foil is placed in a clean vacuum drying oven for drying, the unused part of the dried copper foil is cut off, the mass is weighed, and the battery is assembled in a glove box; finally, the battery capacity and performance at different current densities are tested, and the test results are as follows: Figure 2 、 Figure 3 and Figure 4 shown.
[0069] Electrochemical tests show that the battery made of the graphene porous carbon material prepared in Example 2 has excellent battery performance. Figure 2 The charge and discharge curves of ordinary commercial porous carbon and graphene porous carbon respectively. It can be seen that the discharge / charge capacity of the first cycle is 1544 and 3521 mAhg respectively. -1 , indicating that the initial discharge specific capacity of graphene-based porous carbon is higher and it has better lithium storage performance; the initial coulombic efficiencies are 42.1% and 47.9% respectively, indicating that the graphene-based porous carbon material can embed more lithium ions and effectively utilize them, reducing irreversible capacity loss. In subsequent cycles, the capacity gradually stabilized, and the coulombic efficiency gradually approached 100%. In the 2nd to 17th cycles, the coulombic efficiency was maintained at 90-95%, and the subsequent coulombic efficiency was maintained above 95%, indicating that the embedding process of lithium ions in this material is highly reversible (deintercalation). And in Figure 3 In the long cycle diagram, after about 45 cycles, the battery capacity stabilizes at 479 mAhg -1 , which is 241 mAhg higher than the capacity of ordinary porous carbon as CVD silicon-carbon negative electrode material -1 , indicating that it has excellent cycle stability. It also shows that the prepared graphene porous carbon material has better lithium storage performance than ordinary porous carbon and is more suitable for application in CVD silicon-carbon negative electrode materials. Figure 4 It can be seen from the impedance spectrum that after graphene is formed in the graphene-formed porous carbon material, the impedance is significantly reduced and the electron transfer rate is significantly increased. This is because the ordered structure of graphene is more suitable for ion transmission, indicating that the porous carbon material with graphene has a better ion transmission rate.
[0070] The above is a clear and complete description of the technical solutions in the embodiments of the present invention. The embodiments described are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts are within the scope of protection of the present invention.
Claims
1. A method for preparing a graphene porous carbon material, characterized in that: The steps include: 1) Wash and dry the coconut shell, crush it and grind it into powder. After drying, place it in a tube furnace and introduce protective gas for carbonization. Take out the carbonized material and grind it in a mortar. Finally, dry it in a drying oven. 2) The dried carbonized material is mixed with potassium hydroxide and boron catalyst and ground, and after drying, placed in a tube furnace and activated by introducing protective gas; 3) The activated material is sequentially washed with deionized water, neutralized with a weak acid, washed with deionized water multiple times, filtered, and dried. The final product is the graphene porous carbon material.
2. The method for preparing a graphene porous carbon material according to claim 1, wherein: In step 1), during the carbonization treatment, the carbonization holding temperature is 450-600° C., the carbonization holding time is 120-240 minutes, and the protective gas is high-purity argon or nitrogen.
3. The method for preparing a graphene porous carbon material according to claim 1, wherein: In step 2), the mass ratio of the carbonized material, potassium hydroxide and boron catalyst is 1:(3-4):(0.2-0.6).
4. The method for preparing a graphene porous carbon material according to claim 1, wherein: In step 2), the boron catalyst is one of boric acid, boron oxide, and metaboric acid.
5. The method for preparing a graphene porous carbon material according to claim 1, wherein: In step 2), during the activation treatment, the activation holding temperature is 700-900° C., the activation holding time is 120-240 min, and the protective gas is high-purity argon or nitrogen.
6. The method for preparing a graphene porous carbon material according to claim 1, wherein: In step 3), the weak acid is one of dilute hydrochloric acid, dilute sulfuric acid, and dilute chloric acid.
7. The method for preparing a graphene porous carbon material according to claim 2, wherein: In step 1), during the carbonization treatment, the carbonization heating rate is 2 to 10°C / min.
8. The method for preparing a graphene porous carbon material according to claim 5, wherein: In step 2), during the activation treatment, the activation heating rate is 2 to 10°C / min.
9. The method for preparing a graphene porous carbon material according to claim 6, wherein: In step 3), the concentration of the weak acid is 0.1 to 0.5 mol / L.
10. Use of the graphene porous carbon material prepared by the method according to any one of claims 1 to 9 as a CVD silicon-carbon negative electrode material for lithium-ion batteries.