Nano carbon-based electrode material and preparation method thereof

Abstract

The invention belongs to the field of electrode materials, and provides a nano carbon-based electrode material which comprises the following raw materials in parts by mass: 5-9 parts of graphene, 1-5 parts of vanadium nitride, 1.5-4 parts of a gas-phase carbon source, 0.5-2.5 parts of a modifier and 0.5-2 parts of a metal catalyst, the graphene is multilayer, the gas-phase carbon source is methane, the modifier is a silane coupling agent, and the metal catalyst is a combination of copper and nickel; the invention also provides a preparation method of the nano carbon-based electrode material. Vanadium nitride and graphene are combined, so that the prepared nano carbon-based electrode material has high specific capacity, and multilayer graphene has a large number of micropores and mesopores, which is beneficial to rapid transmission and adsorption of electrolyte ions and improves energy storage efficiency.

Description

Technical Field

[0001] This invention belongs to the field of electrode materials, specifically a nano-carbon-based electrode material and its preparation method. Background Technology

[0002] To address the energy challenges facing humanity, developing renewable energy sources such as solar, hydro, and wind power has become a major trend in replacing fossil fuels. However, renewable energy sources are characterized by intermittency and instability, making them unsuitable for direct grid integration and continuous power supply. Therefore, the development of energy storage devices for collecting renewable energy is particularly important. Among various energy storage devices, electrochemical energy storage, with its high conversion efficiency and environmental friendliness, has become the preferred choice for storing electrical energy.

[0003] With the rapid development of renewable energy technologies, the performance requirements for energy storage devices such as batteries and supercapacitors are increasing. Nano-carbon-based electrode materials have attracted widespread attention due to their excellent conductivity, good mechanical strength, and large specific surface area.

[0004] However, traditional carbon nanomaterials, such as carbon nanotubes and activated carbon, while possessing good electrical conductivity, may exhibit insufficient conductivity during high-rate charge-discharge processes, leading to energy loss and reduced efficiency. Carbon nanomaterials are also prone to structural changes during charge-discharge cycles, resulting in a decrease in the mechanical strength of electrode materials and consequently affecting the cycle life of the battery. For example, carbon nanotubes may aggregate or break under high temperature or high pressure conditions. Furthermore, in composite materials, poor interfacial contact between carbon nanomaterials and active materials may lead to an increase in charge transfer resistance.

[0005] To this end, those skilled in the art have proposed a nano-carbon-based electrode material and its preparation method, aiming to improve the conductivity, structural stability and environmental adaptability of the electrode material. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a nano-carbon-based electrode material and its preparation method, thereby resolving the issues mentioned in the background art.

[0007] According to a first aspect of this disclosure, a nano-carbon-based electrode material is proposed, comprising the following raw materials in parts by mass: 5-9 parts graphene, 1-5 parts vanadium nitride, 1.5-4 parts gaseous carbon source, 0.5-2.5 parts modifier, and 0.5-2 parts metal catalyst.

[0008] Preferably, the graphene is a single layer or multiple layers.

[0009] Preferably, the gaseous carbon source is one of methane, ethylene, and acetylene.

[0010] Preferably, the modifier is a silane coupling agent.

[0011] Preferably, the metal catalyst is one or a combination of copper and nickel.

[0012] According to a second aspect of this disclosure, a method for preparing a nano-carbon-based electrode material is proposed, comprising the following preparation steps:

[0013] S1. Prepare single-layer or multi-layer graphene by chemical vapor deposition;

[0014] S2. Vanadium nitride precursor was synthesized by solvothermal method and calcined at high temperature in ammonia atmosphere to obtain vanadium nitride nanoparticles.

[0015] S3. Mix graphene and vanadium nitride nanoparticles in a certain proportion using ultrasonic stirring;

[0016] S4. Vanadium nitride nanoparticles are sputtered onto the graphene surface by magnetron sputtering to form a composite material;

[0017] S5. The composite material is sintered at a high temperature of 1000℃-2800℃ under an argon protective atmosphere;

[0018] S6. Nitrogen and oxygen heteroatoms are introduced into the graphene surface through chemical vapor deposition to increase active sites, and the surface of the composite material is modified using silane coupling agents.

[0019] S7. The composite material is coated onto a conductive substrate of copper or nickel foil and then compacted and formed by calendering or cold isostatic pressing.

[0020] Preferably, the preparation of the graphene includes the following steps:

[0021] S101. Hydrogen is introduced and methane is used as a carbon source. Its adsorption and catalytic decomposition on the copper surface form active C fragments. These active fragments migrate on the substrate surface and form stable graphene cores.

[0022] S102 and active C fragments continue to aggregate, forming graphene cores, and gradually form a continuous film through crystal domain splicing, growing multilayer graphene.

[0023] S103. After graphene growth is completed, the temperature is slowly lowered and the graphene is transferred from the substrate to the silicon wafer substrate.

[0024] Preferably, the preparation of the vanadium nitride nanoparticles includes the following steps:

[0025] S201. Dissolve the vanadium source in deionized water to form a homogeneous solution, and gradually add the nitrogen source urea, stirring until homogeneous and fully mixed.

[0026] S202. Transfer the mixed solution to a high-pressure reactor and seal it. React at a temperature of 180℃-220℃ for 6-12 hours to promote precursor formation.

[0027] S203. After the reaction is complete, the mixture is allowed to cool naturally to room temperature. The precipitate is then collected by centrifugation or filtration and washed with deionized water to remove unreacted substances.

[0028] S204. The washed precipitate is dried in a vacuum drying oven to obtain vanadium nitride precursor;

[0029] S205. The dried vanadium nitride precursor is placed in a high-temperature furnace and ammonia is introduced as a nitrogen source during the calcination process.

[0030] S206, temperature is raised to 600℃-900℃ and maintained for 2-4 hours. After calcination, it is gradually cooled to room temperature while maintaining ammonia flow. The sample is taken out of the furnace and pulverized by grinding to obtain vanadium nitride nanoparticles.

[0031] Preferably, the S4 composite process includes:

[0032] S401. Fix the graphene sheets onto the substrate of the magnetron sputtering equipment to make its surface flat;

[0033] S402. In the magnetron sputtering equipment, evacuate to 10... -6 Torr's pressure;

[0034] S403. Introduce inert argon gas, set the power to 50-200W, and start the sputtering process. The sputtering time is 5-15 minutes.

[0035] S404. After sputtering is completed, the gas inflow is shut off, and the pressure is gradually restored to normal. The graphene sheets are then removed to obtain the composite material.

[0036] Preferably, in the chemical vapor deposition process for preparing graphene, the temperature is controlled at 600℃-1000℃, the pressure is maintained in a low-pressure environment of 5mTorr-40Torr, and the hydrogen flow rate is 10-100sccm.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] 1. This invention combines vanadium nitride with graphene to produce nano-carbon-based electrode materials with high specific capacity. The multilayer graphene has a large number of micropores and mesopores, which helps the rapid transport and adsorption of electrolyte ions and improves energy storage efficiency.

[0039] 2. This invention enhances the structural stability of the composite material through high-temperature sintering, enabling it to remain stable during long-term charge-discharge cycles; graphene, as a physical barrier layer, effectively inhibits the aggregation and dissolution of vanadium nitride nanoparticles, extending the service life of the electrode material.

[0040] 3. The high electrical conductivity and porous structure of the composite material of this invention promote rapid charge transfer and ion transport, thereby achieving efficient charge and discharge performance; and the preparation process of this composite material can use environmentally friendly materials and processes, reducing the emission of harmful substances and meeting green environmental protection requirements. Attached Figure Description

[0041] Figure 1 This is a flowchart illustrating the preparation process of the nano-carbon-based electrode material of the present invention.

[0042] Figure 2 This is a flowchart of the graphene preparation steps of the present invention;

[0043] Figure 3 This is a flowchart of the vanadium nitride nanoparticle preparation steps of the present invention;

[0044] Figure 4 This is a flowchart of the steps for preparing composite materials by magnetron sputtering according to the present invention. Detailed Implementation

[0045] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0046] Example 1: The present invention provides a nano-carbon-based electrode material comprising the following raw materials in parts by weight: 5 parts graphene, 1 part vanadium nitride, 1.5 parts gaseous carbon source, 0.5 parts modifier, and 0.5 parts metal catalyst.

[0047] The graphene is multilayered, the gaseous carbon source is methane, the modifier is a silane coupling agent, and the metal catalyst is a combination of copper and nickel.

[0048] Example 2: This example is basically the same as the previous example, except that it includes the following raw materials in parts by weight: 7 parts graphene, 3 parts vanadium nitride, 2.5 parts gaseous carbon source, 1.5 parts modifier, and 1 part metal catalyst.

[0049] The graphene is multilayered, the gaseous carbon source is methane, the modifier is a silane coupling agent, and the metal catalyst is a combination of copper and nickel.

[0050] Example 3: This example is basically the same as the previous example, except that it includes the following raw materials in parts by mass: 9 parts graphene, 5 parts vanadium nitride, 4 parts gaseous carbon source, 2.5 parts modifier, and 2 parts metal catalyst.

[0051] The graphene is multilayered, the gaseous carbon source is methane, the modifier is a silane coupling agent, and the metal catalyst is a combination of copper and nickel.

[0052] Results: As shown in the table below, the nano-carbon-based electrode materials at different mass fractions are as follows:

[0053]

[0054] As shown in the table above, the excellent conductivity of graphene combined with the conductivity of vanadium nitride forms a good conductive network. With increasing mass fractions of graphene and vanadium nitride, the conductivity of the electrode material significantly improves, reaching its highest value in Example 3. Specific capacity also increases with increasing graphene and vanadium nitride content, reaching a maximum of 270 mAh / g in Example 3, indicating enhanced energy storage capability and more efficient energy storage. Cycle stability also improves with increasing component content, reaching a maximum of 93%, indicating that the electrode material maintains good performance during multiple charge-discharge cycles and is suitable for long-term use. However, with further increases in components, conductivity and specific capacity decrease, except for cycle stability. Therefore, the optimal mass fraction of this nano-carbon-based electrode material is found in Example 3.

[0055] Example 4: As shown in the attached document Figure 1 To be continued Figure 4 As shown, the present invention also provides a method for preparing a nano-carbon-based electrode material, comprising the following preparation steps:

[0056] S1. Prepare single-layer or multi-layer graphene by chemical vapor deposition;

[0057] S2. Vanadium nitride precursor was synthesized by solvothermal method and calcined at high temperature in ammonia atmosphere to obtain vanadium nitride nanoparticles.

[0058] S3. Mix graphene and vanadium nitride nanoparticles in a certain proportion using ultrasonic stirring to ensure uniform dispersion of the two materials.

[0059] S4. Vanadium nitride nanoparticles are sputtered onto the surface of graphene using magnetron sputtering technology, and uniformly deposited on the graphene sheets to form a tightly contacted interface, thus constituting a composite material.

[0060] S5. The composite material is sintered at a high temperature of 1000℃-2800℃ under an argon protective atmosphere to improve the electrical conductivity and structural stability of the composite material.

[0061] S6. Nitrogen and oxygen heteroatoms are introduced into the graphene surface by chemical vapor deposition to increase active sites, and the surface of the composite material is modified by silane coupling agent to improve its performance in a specific electrolyte.

[0062] S7. The composite material is coated onto a conductive substrate of copper or nickel foil and then compacted and formed by calendering or cold isostatic pressing.

[0063] By adjusting the mass fraction of graphene and VN nanoparticles, the performance of the composite material can be optimized, enabling it to exhibit excellent electrochemical performance in energy storage devices such as supercapacitors and lithium-ion batteries.

[0064] The preparation of graphene includes the following steps:

[0065] S101. Hydrogen is introduced and methane is used as a carbon source. Its adsorption and catalytic decomposition on the copper surface form active C fragments (CHx, x=0-3). These active fragments migrate on the substrate surface and form stable graphene cores.

[0066] S102 and active C fragments continue to aggregate, forming graphene cores, and gradually form a continuous film through crystal domain splicing, growing multilayer graphene.

[0067] S103. After graphene growth is completed, the temperature is slowly lowered and the graphene is transferred from the substrate to the silicon wafer substrate.

[0068] In the chemical vapor deposition process for graphene preparation, the temperature is controlled at 600℃-1000℃ to promote the decomposition of the carbon source and the growth of graphene, while the pressure is maintained at a low pressure environment of 5 mTorr-40 Torr, and the hydrogen flow rate is 10-100 sccm. Simultaneously, introducing hydrogen into the reaction system can promote carbon source decomposition and improve the uniformity and quality of graphene; furthermore, hydrogen also has the effect of etching the graphene boundaries and internal defects.

[0069] Furthermore, controlling the growth temperature to 600-800℃ helps reduce defects and grain boundaries in graphene; controlling it to 800-1000℃ helps increase the growth rate, but excessively high temperatures can easily lead to graphene inhomogeneity and coarse grains. Simultaneously, setting a low-pressure environment increases the mean free path of gas molecules, thereby reducing collisions between gas molecules and allowing the carbon source gas to be more uniformly distributed on the substrate surface. This is beneficial for uniform nucleation and growth of graphene, resulting in high-quality graphene with larger domain sizes and fewer defects. However, as the pressure increases, collisions between gas molecules increase, which can affect the uniformity of graphene. Moreover, both normal and high-pressure environments increase the interaction between gas molecules, affecting the uniformity and quality of graphene.

[0070] The preparation of vanadium nitride nanoparticles includes the following steps: S201, dissolving a vanadium source in deionized water or ethanol to form a homogeneous solution, and gradually adding a nitrogen source, urea or ammonia, stirring until homogeneous and fully mixed; the vanadium source is vanadium oxide or vanadium chloride.

[0071] S202. Transfer the mixed solution to a high-pressure reactor and seal it. React at a temperature of 180℃-220℃ for 6-12 hours to promote precursor formation.

[0072] S203. After the reaction is complete, the mixture is allowed to cool naturally to room temperature. The precipitate is then collected by centrifugation or filtration and washed with deionized water to remove unreacted substances.

[0073] S204. The washed precipitate is dried in a vacuum drying oven to obtain vanadium nitride precursor;

[0074] S205. Place the dried vanadium nitride precursor into a high-temperature furnace. Ensure that the furnace environment is clean. During the calcination process, introduce ammonia gas as a nitrogen source to prevent oxidation.

[0075] S206, temperature is raised to 600℃-900℃ and maintained for 2-4 hours to promote the formation of vanadium nitride. After calcination, it is gradually cooled to room temperature while maintaining ammonia flow to prevent oxidation. The sample is taken out of the furnace and pulverized by grinding to obtain vanadium nitride nanoparticles.

[0076] The S4 composite process includes:

[0077] S401. Fix the graphene sheets onto the substrate of the magnetron sputtering equipment to make its surface flat;

[0078] S402. In the magnetron sputtering equipment, evacuate to 10... -6 Torr's pressure;

[0079] S403. Introduce inert argon gas, set the power to 50-200W, and start the sputtering process. The sputtering time is 5-15 minutes.

[0080] S404. After sputtering is complete, the gas inflow is shut off, and the pressure is gradually restored to normal. The graphene sheets are then carefully removed to obtain the composite material.

[0081] It is important to note that the constructions and arrangements of this application shown in several different exemplary embodiments are merely illustrative. Although only a few embodiments are described in detail in this disclosure, those who consult this disclosure will readily understand that many modifications are possible (e.g., changes in the size, dimensions, structure, shape, and proportions of various elements, as well as parameter values ​​(e.g., temperature, pressure, etc.), mounting arrangements, use of materials, color, orientation, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in this application). For example, an element shown as integrally formed may be composed of multiple parts or elements, the position of elements may be inverted or otherwise altered, and the nature or number or position of discrete elements may be changed or altered. Therefore, all such modifications are intended to be included within the scope of the invention. The order or sequence of any process or method steps may be changed or rearranged according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure described herein that performs the function, and not only structurally equivalent but also equivalent in structure. Other substitutions, modifications, changes, and omissions may be made in the design, operation, and arrangement of the exemplary embodiments without departing from the scope of the invention. Therefore, the present invention is not limited to the specific embodiments, but extends to various modifications that still fall within the scope of the appended claims.

[0082] Furthermore, in order to provide a concise description of exemplary embodiments, not all features of actual embodiments (i.e., those features that are not relevant to the best mode of carrying out the invention as currently considered, or those features that are not relevant to implementing the invention) may be omitted.

[0083] It should be understood that numerous specific implementation decisions can be made during the development of any actual implementation method, and in any engineering or design project. Such development efforts may be complex and time-consuming, but for those of ordinary skill in the art who benefit from this disclosure, the development effort will be a routine work of design, manufacturing, and production without requiring much experimentation.

[0084] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A nano-carbon-based electrode material, characterized in that, The raw materials include the following parts by weight: 5-9 parts graphene, 1-5 parts vanadium nitride, 1.5-4 parts gaseous carbon source, 0.5-2.5 parts modifier, and 0.5-2 parts metal catalyst.

2. The nano-carbon-based electrode material as described in claim 1, characterized in that: The graphene is either a single layer or multiple layers.

3. The nano-carbon-based electrode material as described in claim 1, characterized in that: The gaseous carbon source is one of methane, ethylene, and acetylene.

4. The nano-carbon-based electrode material as described in claim 1, characterized in that: The modifier is a silane coupling agent.

5. The nano-carbon-based electrode material as described in claim 1, characterized in that: The metal catalyst is one or a combination of copper and nickel.

6. A method for preparing a nano-carbon-based electrode material, used to prepare the nano-carbon-based electrode material according to any one of claims 1-5, characterized in that, The preparation steps include the following: S1. Prepare single-layer or multi-layer graphene by chemical vapor deposition; S2. Vanadium nitride precursor was synthesized by solvothermal method and calcined at high temperature in ammonia atmosphere to obtain vanadium nitride nanoparticles. S3. Mix graphene and vanadium nitride nanoparticles in a certain proportion using ultrasonic stirring; S4. Vanadium nitride nanoparticles are sputtered onto the graphene surface by magnetron sputtering to form a composite material. S5. The composite material is sintered at a high temperature of 1000℃-2800℃ under an argon protective atmosphere; S6. Nitrogen and oxygen heteroatoms are introduced into the graphene surface through chemical vapor deposition to increase active sites, and the surface of the composite material is modified using silane coupling agents. S7. The composite material is coated onto a conductive substrate of copper or nickel foil and then compacted and formed by calendering or cold isostatic pressing.

7. The method for preparing a nano-carbon-based electrode material as described in claim 6, characterized in that: The preparation of the graphene includes the following steps: S101. Hydrogen is introduced and methane is used as a carbon source. Its adsorption and catalytic decomposition on the copper surface form active C fragments. These active fragments migrate on the substrate surface and form stable graphene cores. S102 and active C fragments continue to aggregate, forming graphene cores, and gradually form a continuous film through crystal domain splicing, growing multilayer graphene. S103. After graphene growth is completed, the temperature is slowly lowered and the graphene is transferred from the substrate to the silicon wafer substrate.

8. The method for preparing a nano-carbon-based electrode material as described in claim 6, characterized in that: The preparation of the vanadium nitride nanoparticles includes the following steps: S201. Dissolve the vanadium source in deionized water to form a homogeneous solution, and gradually add the nitrogen source urea, stirring until homogeneous and fully mixed. S202. Transfer the mixed solution to a high-pressure reactor and seal it. React at a temperature of 180℃-220℃ for 6-12 hours to promote precursor formation. S203. After the reaction is complete, the mixture is allowed to cool naturally to room temperature. The precipitate is then collected by centrifugation or filtration and washed with deionized water to remove unreacted substances. S204. The washed precipitate is dried in a vacuum drying oven to obtain vanadium nitride precursor; S205. The dried vanadium nitride precursor is placed in a high-temperature furnace and ammonia is introduced as a nitrogen source during the calcination process. S206, temperature is raised to 600℃-900℃ and maintained for 2-4 hours. After calcination, it is gradually cooled to room temperature while maintaining ammonia flow. The sample is taken out of the furnace and pulverized by grinding to obtain vanadium nitride nanoparticles.

9. The method for preparing a nano-carbon-based electrode material as described in claim 6, characterized in that: The S4 composite process includes: S401. Fix the graphene sheets onto the substrate of the magnetron sputtering equipment to make its surface flat; S402. In the magnetron sputtering equipment, evacuate to 10... -6 Torr's pressure; S403. Introduce inert argon gas, set the power to 50-200W, and start the sputtering process. The sputtering time is 5-15 minutes. S404. After sputtering is completed, the gas inflow is shut off, and the pressure is gradually restored to normal. The graphene sheets are then removed to obtain the composite material.

10. The method for preparing a nano-carbon-based electrode material as described in claim 7, characterized in that: In the chemical vapor deposition process for preparing graphene, the temperature is controlled at 600℃-1000℃, the pressure is maintained in a low-pressure environment of 5mTorr-40Torr, and the hydrogen flow rate is 10-100sccm.

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