Preparation method of three-dimensional architecture carbon composite powder

Abstract

The application relates to a preparation method of a three-dimensional architecture alkene-carbon composite powder, which comprises the following steps: S1. mixing a catalyst and a carbon sphere precursor in hydrochloric acid to complete the configuration of a reaction solution; S2. stirring and mixing the reaction solution and graphene powder to obtain a mixed solution, and placing the mixed solution into an oven to react, so as to obtain a carbon sphere-graphene combination; S3. performing suction filtration cleaning on the combination after the reaction by using deionized water, and performing drying until the pH value is 7-7.5; S4. taking the carbon sphere-graphene combination after the drying and adding an additive into a solution to stir into a flocculent state, and then loading the flocculent state into a crucible; S5. pushing the crucible into a tube furnace to pass through reducing gas, carbon source gas and inert gas according to a set growth program to grow carbon nanotubes, and taking out the target three-dimensional architecture alkene-carbon composite powder material after the program is ended and the temperature is reduced to room temperature. The preparation process is simple, the effect is obvious, and a certain scale production can be realized, so that the application is a new preparation method of an alkene-carbon architecture composite material.

Description

Technical Field

[0001] This invention relates to the field of graphene modification and composite material technology, and in particular to a method for preparing a three-dimensional graphene-carbon composite powder. Background Technology

[0002] Graphene, carbon atoms arranged in sp... 2 Two-dimensional carbon atom monolayers bonded by hybridization have been a hot topic in new material preparation, processing, and application research since their successful fabrication in 2004, due to their excellent electrical, thermal, and mechanical properties. With continuous exploration and application of this material, single or even pure graphene materials are gradually failing to meet the needs of practical applications, leading to the emergence of two new research and development fields: modified graphene and graphene composites. Graphene modification involves elemental doping, surface functionalization, and defect construction, aiming to suppress or enhance existing properties or create new ones by modifying the two-dimensional planar framework of graphene, such as insulation, superconductivity, and opening band gaps. Compared to graphene modification that starts from adjusting and "destroying" its own structure, graphene composites / composite frameworks utilize the synergistic effects between materials, complementing each other's strengths and weaknesses. This allows them to retain their own advantages while synergistically combining the unique properties of other materials to achieve superior performance.

[0003] Carbon spheres, as carbon members of the olefin family, are simple to synthesize, readily available, and diverse in their materials. They possess a large specific surface area, good flowability, high mechanical strength, good thermal stability, and biocompatibility. Carbon nanotubes, on the other hand, can be viewed as one-dimensional tubular structures formed by graphene rolled up along a specific angle. Their one-dimensional confined structure allows electrons to move within them with ballistic transport characteristics, thus giving them superior electrical conductivity compared to graphene.

[0004] Combining graphene, carbon spheres, carbon nanotubes, and other carbon-based materials into a cohesive framework for the synergistic development of new materials and the attribution of new properties is a promising research direction. The SCI paper "Self-supporting activated carbon / carbon nanotube / reduced graphene oxide flexible electrode for high performance supercapacitor" uses a vacuum filtration method to deposit activated carbon particles, carbon nanotubes, and reduced graphene oxide into a film to prepare electrodes for supercapacitors. However, this vacuum filtration method physically mixes various substrates, and the materials are combined through weak forces such as van der Waals forces, electrostatic interactions, and π-π interactions. Therefore, the interfacial bonding strength is weak, and the interfacial resistance and thermal resistance are high, leading to problems such as electrode delamination, peeling, and uneven charge density distribution during later applications. Chinese invention patent CN 116470060... Chinese invention patent A, "A Composite Material of Carbon Nanotubes, Graphene, and Carbon Black and Its Preparation Method," uses common mechanical stirring and mixing, with water as a solvent and polyvinylpyrrolidone as a dispersant, to prepare an aqueous conductive slurry by adding carbon nanotubes, graphene, and carbon black. This is clearly a purely physical mechanical mixing process; the three materials can still be considered independent entities, without forming a composite structure. Furthermore, there is no chemical interaction between the three materials, and issues of agglomeration, sedimentation, and stacking exist. Chinese invention patent CN116332168 A, "A Preparation Method and Application of Graphene-Carbon Nanotube Composite Material," prepares a graphene-carbon nanotube composite material, mentioning that the complementary combination of graphene and carbon nanotubes effectively avoids the stacking of graphene and the agglomeration of carbon nanotubes in solution. However, it still uses traditional simple mechanical mixing and is not a composite structure material. Chinese invention patent CN114068927... A. Graphene / Carbon Nanotube Composite Materials and Their Preparation Method This paper describes a chemical vapor deposition method for growing carbon nanotubes on the surface of graphene using a catalyst, resulting in a sea urchin-like graphene / carbon nanotube composite material. Graphene microspheres act as the substrate for carbon nanotube growth, preventing entanglement and providing stable mechanical support. The two components work synergistically, showing promising application prospects. However, this method has a relatively complex process, requiring specialized fluidized bed equipment, and the sample morphology and size are not uniform. Summary of the Invention

[0005] In summary, this invention employs a two-step method of hydrothermal and chemical vapor deposition, using large-diameter wrinkled graphene, carbon spheres, and carbon nanotubes as structural building blocks, nickel and cobalt compounds as catalysts, and urea, melamine, and dicyandiamide as additives and dopants. Under certain reaction conditions, a three-dimensional graphene-carbon composite powder is prepared by introducing carbon-containing gas.

[0006] To address the aforementioned problems, the primary objective of this invention is to provide a method for preparing three-dimensional olefin-carbon composite powder, comprising the following steps:

[0007] S1. The catalyst and carbon sphere precursor are mixed in hydrochloric acid to prepare the reaction solution, wherein the catalyst is an oxide or salt of nickel or cobalt;

[0008] S2. The reaction solution and graphene powder are stirred and mixed to obtain a mixture. The mixture is then placed in an oven for reaction to obtain a carbon sphere-graphene composite.

[0009] S3. The reacted carbon sphere-graphene composite was filtered and washed with deionized water until the pH value was 7-7.5, and then dried.

[0010] S4. Take the dried carbon ball-graphene composite and the additive, add them to an ethanol or methanol solution, mix and stir until they form flocculent material, and then place them in a crucible. The additive is any one or more of urea, melamine, and dicyandiamide.

[0011] S5. Push the crucible into the tube furnace and introduce reducing gas, carbon source gas and inert gas according to the set growth program to grow carbon nanotubes. After the program ends, cool to room temperature and take out the material to obtain the target three-dimensional structured olefin-carbon composite powder material.

[0012] In some preferred embodiments, the carbon sphere precursor is one or more of sucrose, glucose, cyclodextrin, fructose, cellulose, and starch.

[0013] Furthermore, the growth process described in step S5 includes low-temperature heating-holding, medium-temperature heating-holding, high-temperature heating-holding growth, and natural cooling processes. The low-temperature heating-holding temperature is 200-250℃ and the time is 15-45 minutes; the medium-temperature heating-holding temperature is 500-650℃ and the time is 15-45 minutes; the high-temperature heating-holding temperature is 800-850℃ and the time is 15-60 minutes.

[0014] Furthermore, the growth process requires the continuous introduction of reducing gas and inert gas, with a volume ratio of reducing gas to inert gas of 1:1 to 1:4. On one hand, although the carbon spheres and graphene mixed powder prepared by the hydrothermal method has been dried, it still retains a significant amount of oxygen-containing functional groups and chemically bound water. The oxygen-containing substances released during the heating process can oxidize the catalyst, leading to catalyst deactivation. Therefore, a reducing atmosphere can effectively maintain the catalyst's activity to provide for carbon nanotube growth. On the other hand, the reducing gas is also a raw material for carbon nanotube growth, facilitating the decomposition of the carbon source and obtaining a considerable amount of carbon active species to provide for the catalyst's carbon nanotube growth. In some preferred embodiments, the reducing gas is hydrogen, and the inert gas is any one or a combination of nitrogen, argon, and helium.

[0015] Furthermore, the carbon source gas is introduced during the high-temperature heating-holding process, and the volume ratio of the carbon source gas to the reducing gas is 1:10 to 5:10. In some preferred embodiments, the carbon source gas is a gaseous carbon source such as methane, ethylene, or acetylene; in other preferred embodiments, the carbon source gas can be vapor generated from a liquid carbon source, such as ethanol, methanol, acetone, or toluene, which contains carbon sources. The vapor is generated using a common bubbling device, and if necessary, it can be appropriately heated at a constant temperature to promote the evaporation of the liquid carbon source.

[0016] Furthermore, the catalyst is one or more of cobalt trioxide, nickel trioxide, cobalt chloride, nickel chloride, cobalt nitrate, and nickel nitrate.

[0017] Furthermore, before placing the mixture into the oven for reaction in step S2, a hydrochloric acid solution needs to be added. The molar concentration of the hydrochloric acid solution in steps S1 and S2 is 6-10 mol / L. The amount of hydrochloric acid solution used in step S2 is determined according to the volume of the reaction vessel, that is, the total volume of the hydrochloric acid solution, catalyst, graphene, and carbon sphere precursor should account for 80% of the inner volume of the reaction vessel. In the reaction, hydrochloric acid acts as a mineralizing agent, changing the pH of the reaction system, accelerating the decomposition and polymerization process of the carbon sphere precursor, controlling the catalytic synthesis of carbon spheres, and enhancing the functionalization of the carbon sphere surface, which is beneficial for further modification and alteration of the carbon spheres, i.e., facilitating nitrogen doping and the attachment and growth of carbon nanotubes on them. On the other hand, it also acts as a solvent. When the catalyst used in the reaction is nickel or cobalt oxide, the high concentration of hydrochloric acid provides a dissolving effect, allowing it to be better dispersed on the carbon spheres and graphene sheets in the form of an ionized catalyst, which is conducive to the uniform precipitation and catalytic growth of carbon nanotubes during the subsequent high-temperature growth process.

[0018] Furthermore, the reaction conditions and time in the oven in step S2 are 150°C for 12 hours.

[0019] Furthermore, the mass of the carbon sphere precursor added is 5-20 times the mass of the graphene added.

[0020] Furthermore, the catalyst is added at a mass of 1-20% of the graphene, preferably 5-10%. Carbon nanotubes grow under metal catalysts following a gas-liquid-solid (VLS) growth mechanism. A key characteristic of this mechanism is the presence of visible catalyst nanoparticles at the bottom or top of the carbon nanotubes or nanowires. The diameter of the carbon nanotubes or nanowires is closely related to the size of the catalyst particles. Currently, in the application of carbon nanotubes, it is generally believed that uniform growth morphology and size lead to better results—such as improving the specific capacity of new energy batteries and enhancing hydrogen adsorption and storage in hydrogen storage. Correspondingly, the catalyst needs to be of uniform size and distribution, avoiding disorderly aggregation and fusion. Too low a catalyst concentration cannot effectively capture active carbon substances in the gas phase for carbon nanotube growth, while too high a catalyst concentration will lead to aggregation and fusion of catalyst particles at high temperatures, which is detrimental to catalyst dispersion. Furthermore, excessive catalyst introduces cumbersome impurity removal steps in later stages. In battery and related applications, the presence of excessive metallic impurities can cause electrolyte decomposition, generating bubbles, which can lead to electrode material breakage and detachment from the current collector, resulting in battery safety issues. In some preferred embodiments, typically but not limitingly, the catalyst is added at a mass ratio of 5%, 6%, 7%, 8%, 9%, or 10% of the graphene.

[0021] Furthermore, the mass of the additive mentioned in step S4 is 1-5 times that of the dried carbon sphere-graphene composite.

[0022] Furthermore, the ethanol or methanol solution mentioned in step S4 is an aqueous solution containing different volume fractions of it, such as anhydrous ethanol solution, 50% wt ethanol aqueous solution, 75% wt aqueous solution, etc.

[0023] The second objective of this invention is to provide an application of the three-dimensional olefin-carbon composite powder prepared by the above-mentioned preparation method in lithium-ion battery electrode materials, lithium-sulfur battery electrode materials, supercapacitor electrode materials, shielding materials, and electro / chemical catalytic materials.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] (1) Introduction of large-diameter wrinkled graphene: Large-diameter wrinkled graphene is nested with each other to provide strength guarantee, flexible support and anchor carbon spheres;

[0026] (2) Introduction of carbon spheres: The amorphous shell of carbon spheres, as a defect structure, provides more active growth sites. The carbon source is cracked and sprouted in situ under the catalysis of the metal catalyst to grow carbon nanotubes. The presence of the amorphous shell of carbon spheres and the generation of carbon nanotubes enable carbon nanotubes and carbon spheres to be bonded by C-C covalent bonds, and the interface strength is significantly improved.

[0027] (3) The nitrogen-containing additives such as urea and melamine used in the preparation process have a promoting effect on the growth of carbon nanotubes, which can be attributed to the additives maintaining the activity of the catalyst. In addition, the addition of additives can effectively introduce nitrogen doping, thereby further regulating the conductivity of the entire carbon material structure.

[0028] (4) The blocking effect of carbon spheres can effectively prevent the re-stacking of graphene sheets, while the introduction of carbon nanotubes can also effectively prevent the stacking of graphene and the aggregation of carbon spheres.

[0029] (5) is a simple process with obvious effect, which can realize the preparation of three-dimensional structured olefin-carbon composite materials on a certain scale.

[0030] In summary, by designing the physical architecture and chemical doping growth, a composite powder material is ultimately formed with graphene anchoring and encapsulating carbon spheres, carbon nanotubes growing in situ from the carbon spheres, and the three working together. This is a new method for preparing three-dimensional composite materials to improve the shortcomings and deficiencies of existing technologies or to provide a new method for preparing composite materials. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 The image shows a scanning electron microscope image of the graphene powder used in the present invention.

[0033] Figure 2 This is a scanning electron microscope image of the graphene / carbon sphere / carbon nanotube three-dimensional composite powder prepared in Example 1 of this invention;

[0034] Figure 3 This is the EDX spectrum of the graphene / carbon sphere / carbon nanotube three-dimensional composite powder prepared in Example 1 of this invention;

[0035] Figure 4 This is a scanning electron microscope image of the graphene / carbon sphere / carbon nanotube three-dimensional composite powder prepared in Example 2 of this invention;

[0036] Figure 5 This is a scanning electron microscope image of the graphene / carbon sphere / carbon nanotube three-dimensional composite powder prepared in Example 3 of this invention;

[0037] Figure 6 This is a scanning electron microscope image of the graphene / carbon sphere / carbon nanotube three-dimensional composite powder prepared in Example 4 of this invention;

[0038] Figure 7 This is a scanning electron microscope image of the composite powder obtained in Comparative Example 1 of this invention;

[0039] Figure 8 This is a scanning electron microscope image of the composite powder obtained in Comparative Example 2 of this invention;

[0040] Figure 9 This is a scanning electron microscope image of the composite powder obtained in Comparative Example 3 of this invention;

[0041] Figure 10 This is a scanning electron microscope image of the composite powder obtained in Comparative Example 4 of this invention;

[0042] Figure 11 This is a scanning electron microscope image of the composite powder obtained in Comparative Example 5 of this invention;

[0043] Figure 12 This is a scanning electron microscope image of the composite powder obtained in Comparative Example 6 of this invention;

[0044] Figure 13 This is a scanning electron microscope image of the composite powder obtained in Comparative Example 7 of this invention. Implementation

[0045] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. Example 1

[0046] A method for preparing a three-dimensional olefin-carbon composite material includes the following steps:

[0047] S1. Weigh 0.021g of nickel trioxide. The mass percentage of nickel in this reagent is 70.98%, so the actual mass of nickel is 0.015g. Weigh 2.1g of sucrose. Put both into a beaker and add 50ml of 8mol / L hydrochloric acid solution. Stir and mix well.

[0048] S2. Add 0.3g of graphene powder to the mixture prepared in step S1 and stir to mix. Then add an appropriate amount of hydrochloric acid solution of the same concentration as in step S1 until the volume of the mixture is 80% of the volume of the inner liner of the high-pressure reactor. Here, a 100ml reaction liner is used, so the total volume of the mixture is 80ml. Then tighten the high-pressure reactor and put it into an oven at 150℃ for 12h.

[0049] S3. After cooling to room temperature, remove the reactor, pour off the clear liquid on top, and then filter and wash it with deionized water until the pH value is 7-7.5, and then dry it.

[0050] S4. Weigh 0.1g of the dried powder and 0.3g of urea, add 3ml of 50% ethanol aqueous solution and stir to mix. After mixing into flocculent form, place it in a crucible.

[0051] S5. Push the crucible into the tube furnace, heat it to 250℃ and hold it for 30 minutes, during which 100 sccm of hydrogen and 300 sccm of argon are introduced. Then heat it to 600℃ and hold it for 30 minutes, during which 100 sccm of hydrogen and 300 sccm of argon are introduced. Finally, heat it to 800℃ and hold it for 30 minutes, during which 100 sccm of hydrogen, 400 sccm of argon and 30 sccm of ethylene are introduced. After the process ends, cool it to room temperature and remove it to obtain the graphene / carbon sphere / carbon nanotube three-dimensional composite powder material.

[0052] Scanning electron microscope image of the graphene powder, the reaction raw material in Example 1, is shown below. Figure 1 As shown, the surface of the graphene powder exhibits an accordion-like multi-fold morphology, with the lateral dimensions of the sheets exceeding 100 μm. The large sheet diameter and folded features ensure that the graphene sheets are nested together, providing strength and flexible support, while also allowing carbon spheres to anchor and adhere to them, thus facilitating the efficient construction of this graphene-carbon composite architecture.

[0053] The graphene / carbon sphere / carbon nanotube three-dimensional composite powder material prepared in Example 1 is as follows: Figure 2 As shown, from Figure 2 The SEM characterization results clearly show smooth, uniformly sized carbon spheres anchored and distributed on the surface wrinkles of large-sheet graphene and in the unfilled mesoporous regions of the graphene framework, while uniformly and densely grown coiled carbon nanotubes are visible on the surface of the carbon spheres. Through the growth of carbon nanotubes on the amorphous shell of carbon spheres, a highly efficient and robust chemical interface with C / C covalent bonds was successfully constructed. The carbon spheres and carbon nanotubes are uniformly anchored and filled in the graphene framework and voids, thus achieving the efficient and sophisticated construction of a graphene / carbon sphere / carbon nanotube three-dimensional structure material. Furthermore, from... Figure 3 The EDX spectrum shows that the introduction of nitrogen-containing additive urea successfully introduced nitrogen doping into the architecture system. The nitrogen doping amount is about 10%. The introduction of nitrogen doping can effectively improve the electrochemical performance and surface wettability of the architecture material. Example 2

[0054] Compared with Example 1, the amount of urea added in step S4 was changed to 0.1g, while the other steps remained the same.

[0055] Example 2 prepared a three-dimensional composite powder material of graphene / carbon spheres / carbon nanotubes, as shown in the example. Figure 4 As shown, from Figure 4 The SEM characterization results clearly show that, compared with Example 1, the growth density of carbon nanotubes on the carbon sphere surface in Example 2 is significantly reduced. This indicates that reducing the amount of additives significantly affects the growth density of carbon nanotubes. When no additives are added, as in Comparative Examples 2 and 3, ... Figure 8-9 It was found that no carbon nanotubes were generated on the surface of the carbon spheres, which shows the important role of additives in regulating the growth of carbon nanotubes. Example 3

[0056] Compared with Example 1, the urea in step S4 is replaced with melamine, while the other steps are the same.

[0057] Example 3 shows the preparation of a three-dimensional composite powder material of graphene / carbon spheres / carbon nanotubes. Figure 5 As shown, from Figure 5 The SEM characterization results show that its growth is similar to that of Example 1. The carbon nanotubes grow uniformly on the surface of the carbon spheres, and the combination of carbon spheres and carbon nanotubes is uniformly distributed and anchored on the graphene framework sheets, thus constructing a three-dimensional composite powder material of graphene / carbon spheres / carbon nanotubes. Example 4

[0058] Compared to Example 1, nickel trioxide in step S1 is replaced with cobalt trioxide. The mass percentage of cobalt trioxide is 71.02%, which is similar to that of nickel trioxide. Calculations show that the amount used is almost the same as that of nickel trioxide, so 0.021g is still weighed. The remaining steps are the same.

[0059] Example 4 shows the preparation of a three-dimensional composite powder material of graphene / carbon spheres / carbon nanotubes. Figure 6 As shown, from Figure 6 The SEM characterization results show that its growth is similar to that of Example 1. The carbon nanotubes grow uniformly on the surface of the carbon spheres, and the combination of carbon spheres and carbon nanotubes is uniformly distributed and anchored on the graphene framework sheets, thus constructing a three-dimensional composite powder material of graphene / carbon spheres / carbon nanotubes. Comparative Example 1

[0060] Compared to Example 1, the ethylene flow rate in step S5 is changed to 0 sccm, i.e., no carbon source is used. The remaining steps are the same. Comparative Example 2

[0061] Compared to Example 1, urea is not added in step S4. The remaining steps are the same. Comparative Example 3

[0062] Compared to Example 1, melamine is not added in step S4. The remaining steps are the same. Comparative Example 4

[0063] Compared to Example 1, no nickel trioxide catalyst was added in step S1. The remaining steps were the same. Comparative Example 5

[0064] Compared to Example 1, the amount of nickel trioxide catalyst added in step S1 was changed to 0.1056g, and the actual mass of nickel was 0.075g. The remaining steps were the same.

[0065] The SEM results of Comparative Example 5 are as follows Figure 11 As shown, when the amount of catalyst added exceeds 20% and reaches 25%, only a few traces of nanotubes can be found in local areas. The nanotubes become short and thick, and larger catalyst particles that have aggregated and fused on the plane of the graphene sheets can be seen. At this time, the critical nucleation work of active carbon on the catalyst surface becomes larger, making nucleation difficult, the catalyst efficiency decreases, and the carbon nanotube growth density also decreases. Comparative Example 6

[0066] Compared to Example 1, the amount of nickel trioxide catalyst added in step S1 was changed to 0.0038g, and the actual mass of nickel was 0.0027g. The remaining steps were the same.

[0067] The SEM results for Comparative Example 6 are as follows Figure 12 As shown, when the amount of catalyst added is less than 1%, only a few nanotubes can be found in local areas, and the coverage of carbon nanotubes is low and they are scattered. Comparative Example 7

[0068] Compared to Example 1, the temperature of the high-temperature process in step S5 was adjusted from 800°C to 750°C. The remaining steps are the same.

[0069] The SEM results for Comparative Example 7 are as follows: Figure 13 As shown, however, after the temperature in the high-temperature stage was lowered from 800℃ to 750℃, no carbon nanotubes were generated under the same growth conditions. Therefore, the realization of catalyst activity and the cracking of carbon source require the participation of appropriate temperature.

[0070] The SEM results of comparative examples 1-4 are as follows Figure 7-10 As shown, it can be clearly seen that there is no trace of carbon nanotube formation on the carbon spheres. Combined with the results of Examples 1-4, it can be concluded that the catalyst, additives, and carbon source are all indispensable and complement each other to ensure the formation of carbon nanotubes on the surface of the carbon spheres. In addition, the addition of additives can successfully introduce nitrogen doping into this composite material. Since the radius of nitrogen atoms is not much different from that of carbon atoms, the incorporation of nitrogen atoms will not cause serious distortion of the olefin carbon material's own framework. At the same time, since the electronegativity of nitrogen atoms is greater than that of carbon atoms, it will significantly improve the electrochemical performance of the olefin carbon material and enhance its application performance.

[0071] In summary, by designing the physical architecture and chemical doping growth, a composite powder material is ultimately formed with graphene anchoring and encapsulating carbon spheres, carbon nanotubes growing in situ from the carbon spheres, and the three working together. This is a new method for preparing three-dimensional composite materials to improve the shortcomings and deficiencies of existing technologies or to provide a new method for preparing composite materials.

[0072] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0073] The above description describes specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preparing a three-dimensional olefin-carbon composite powder, characterized in that, The method comprises the following steps: S1. Mixing a catalyst, a carbon sphere precursor and hydrochloric acid to prepare a reaction solution, wherein the catalyst is an oxide or a salt of nickel or cobalt; S2. Stirring and mixing the reaction solution with graphene powder to obtain a mixed solution, and placing the mixed solution in an oven to react, thereby obtaining a carbon sphere-graphene combination; S3. Washing the carbon sphere-graphene combination after reaction by using deionized water until the pH value is 7-7.5, and then drying; S4. Adding an additive to an ethanol or methanol solution, wherein the additive is any one or more of urea, melamine and dicyandiamide, and stirring to obtain a flocculent mixture, and then placing the flocculent mixture in a crucible; S5. Pushing the crucible into a tube furnace, and introducing a reducing gas, a carbon source gas and an inert gas according to a set growth program to grow carbon nanotubes, and then taking out the carbon nanotubes after the program ends and the temperature decreases to room temperature, thereby obtaining a target three-dimensional architecture carbon composite powder material, wherein the growth program comprises a low-temperature heating-keeping process, a medium-temperature heating-keeping process, a high-temperature heating-keeping process and a natural cooling process, the temperature of the low-temperature heating-keeping process is 200-250℃, and the time is 15-45 min; the temperature of the medium-temperature heating-keeping process is 500-650℃, and the time is 15-45 min; the temperature of the high-temperature heating-keeping process is 800-850℃, and the time is 15-60 min. In steps S1 and S2, the added amount of the catalyst accounts for 1-20% of the added amount of graphene.

2. A method for preparing the three-dimensional olefin-carbon composite powder as described in claim 1, characterized in that, In the growth program, the reducing gas and the inert gas are introduced throughout the process, and the volume ratio of the reducing gas to the inert gas is 1:1-1:

4.

3. A method for preparing the three-dimensional olefin-carbon composite powder as described in claim 2, characterized in that, The carbon source gas is introduced in the high-temperature heating-keeping process, and the volume ratio of the carbon source gas to the reducing gas is 1:10-5:

10.

4. A method for preparing the three-dimensional olefin-carbon composite powder as described in claim 1, characterized in that, The catalyst is one or more of cobalt trioxide, nickel trioxide, cobalt chloride, nickel chloride, cobalt nitrate and nickel nitrate.

5. A method for preparing the three-dimensional olefin-carbon composite powder as described in claim 1, characterized in that, Before the mixed solution is placed in the oven to react in step S2, a hydrochloric acid solution also needs to be added, and the concentration of the hydrochloric acid solution in steps S1 and S2 is 6-10 mol / L.

6. A method for preparing the three-dimensional olefin-carbon composite powder as described in claim 1, characterized in that, The added amount of the carbon sphere precursor is 5-20 times of the added amount of graphene.

7. A method for preparing the three-dimensional olefin-carbon composite powder as described in claim 1, characterized in that, The added amount of the catalyst accounts for 5-10% of the added amount of graphene.

8. A method for preparing the three-dimensional olefin-carbon composite powder as described in claim 1, characterized in that, In step S4, the added amount of the additive is 1-5 times of the amount of the carbon sphere-graphene combination after drying.

9. The three-dimensional architecture carbon composite powder prepared by the method of any one of claims 1-8 is applied to lithium ion battery electrode materials, lithium-sulfur battery electrode materials, supercapacitor electrode materials, shielding materials and electro / chemical catalytic materials.

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