Graphene composite copper material and preparation method thereof

Abstract

This application relates to the field of advanced copper-based materials technology, mainly to a graphene composite copper material and its preparation method. The graphene composite copper material is prepared by an electroplating solution comprising the following raw materials: copper sulfate: 220-240 g / L; sulfuric acid: 8%-12% (volume ratio); chloride ions: 30-90 ppm; disodium ethylenediaminetetraacetate: 3-5 g / L; graphene colloidal particles: 0.1-2 g / L; polyoxyethylene ether: 0.01-0.2 g / L; ascorbic acid: 0.01-0.1 g / L; electroplating additive: 1-20 ml / L; and the balance being pure water. The graphene composite copper material prepared by the electroplating solution provided in this application exhibits good electrical conductivity, thermal conductivity, mechanical properties, and ductility.

Description

Technical Field

[0001] This application relates to the field of advanced copper-based materials technology, and mainly to a graphene composite copper material and its preparation method. Background Technology

[0002] Graphene is widely used in composite materials due to its excellent electrical conductivity, thermal conductivity, and mechanical strength. Introducing graphene into a copper matrix can significantly improve the various properties of copper materials, making it promising for applications in electronic devices such as electrical conductivity, heat dissipation, and high-strength wires. However, in the preparation of graphene composite materials, the agglomeration of nanomaterials and the dispersion and uniformity of graphene are key factors affecting the performance of the composite materials.

[0003] The preparation of graphene-copper composite materials typically involves using CVD to generate graphene on the surface of pre-prepared copper nanoparticles, or laminating graphene films with copper and then rolling them under high temperature and pressure. This method is costly, inefficient, and energy-intensive, making it difficult to scale up for industrial production. Furthermore, due to the nano-agglomeration properties and strong van der Waals forces of graphene, it is prone to agglomeration during production, resulting in uneven dispersion within the copper matrix. This agglomeration not only reduces the electrical and thermal conductivity, mechanical strength, and ductility of the composite material but also creates defects in the copper matrix, reducing the material's corrosion resistance.

[0004] Therefore, existing technologies still need improvement and development. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this application is to provide a graphene composite copper material and its preparation method.

[0006] The technical solution of this application is as follows: A graphene-copper composite material is prepared by electroplating, the electroplating solution comprising the following raw materials: Copper sulfate: 220-240 g / L; Sulfuric acid: 8%–12%, by volume; Chloride ions: 30-90 ppm; (preferably 37% analytical grade hydrochloric acid) Disodium ethylenediaminetetraacetate: 3-5 g / L; Graphene colloidal particles: 0.1–2 g / L; Polyoxyethylene ether: 0.01–0.2 g / L; Ascorbic acid: 0.01–0.1 g / L; Electroplating additives: 1-20 ml / L; The remainder is pure water.

[0007] Furthermore, the graphene colloidal particle solution includes the following steps: Graphene nanosheets and a dispersant are dissolved in pure water or an alcohol solvent to obtain a graphene slurry. Sodium dodecylbenzenesulfonate and silane coupling agent were dissolved in an aqueous graphene slurry to obtain a graphene colloidal particle solution.

[0008] Surfactants and dispersants in graphene colloidal particle solutions exhibit competitive adsorption and space-filling effects, synergistically improving the stability and uniformity of graphene colloidal particles in electroplating solutions.

[0009] Graphene in the graphene colloidal particles acts as a conductive carrier, and together with copper ions, they serve as electron transport channels. By incorporating the electrodeposition kinetics, the two work together to ensure the stability of the electrolyte and the uniformity of the deposited layer.

[0010] Graphene and copper ions in graphene colloidal particles are co-deposited during electrodeposition, forming a graphene-copper co-deposited structure. Graphene nanosheets alter the nanoscale deposition conditions and surface deposition rate of the coating, refining the copper atom crystals, improving crystallinity, reducing crystal defects, and decreasing lattice interface stress. After deposition, graphene nanosheets change the microscale deposition potential, refine the coating grains, and improve the uniformity of the deposition layer. Simultaneously, electrochemistry enhances the interfacial bonding strength between graphene nanosheets and copper atoms, forming a triple synergistic effect of chemical bonding, solid solution strengthening, and molecular forces.

[0011] Furthermore, the amount of silane coupling agent used is 1%–5% of the weight of the graphene nanosheets; The amount of sodium dodecylbenzenesulfonate used is 8%–12% of the weight of the graphene nanosheets.

[0012] Furthermore, graphene nanosheets and dispersants are dissolved in pure water or ethanol solvent and ultrasonically treated for 20-60 minutes with an ultrasonic power of 150-250W and a frequency of 35-45kHz to obtain graphene slurry.

[0013] Furthermore, the silane coupling agent is KH-550.

[0014] The Si-OH bonds generated by the hydrolysis of KH-550 silane coupling agent undergo condensation reactions with the hydroxyl and carboxyl groups on the surface of graphene colloidal particles to form C-Si covalent bonds, thus constructing chemical anchors. The dual effect of chemical bonding and physical dispersion ensures that the graphene nanosheets are uniformly suspended in the electrolyte, guaranteeing that the graphene nanosheets can be continuously transported to the cathode surface by the electric field during electrodeposition, reducing deposition defects caused by agglomeration.

[0015] Graphene nanosheets can reduce interfacial stress, refine grains, improve the uniformity of the deposited layer, and effectively enhance the interfacial bonding strength between graphene and the copper substrate.

[0016] Surfactants and dispersants work synergistically to ensure uniform distribution of graphene nanosheets, enabling them to form strong interfacial bonds with copper atoms during deposition. Solid solution reinforcement and gradient interfaces work synergistically to improve the mechanical and electrical properties of the coating. Through mechanistic interactions, these systems form a chain-like synergistic effect of chemical bonding, physical dispersion, electrochemical stabilization, and structural reinforcement, ultimately achieving comprehensive performance optimization of graphene-copper composite materials in terms of electrical conductivity, thermal conductivity, mechanical strength, ductility, corrosion resistance, and service life.

[0017] This application also provides a method for preparing a graphene-copper composite material, comprising the following steps: Copper sulfate, sulfuric acid, chloride ions, disodium ethylenediaminetetraacetate, ascorbic acid, electroplating additives, and water are mixed and stirred evenly to obtain an electroplating solution. Graphene slurry, polyoxyethylene ether, and water are mixed and stirred until homogeneous to obtain a graphene colloidal particle solution. A graphene colloidal particle solution was added to the electroplating solution and stirred until homogeneous to obtain a composite electrolyte. Electrochemical deposition is performed by submerging both the cathode and anode in an electrolyte solution; a copper sheet is used as the cathode. After deposition, the material is washed and dried to obtain graphene-copper composite material.

[0018] Furthermore, the parameters for electrochemical deposition are: constant current deposition, with a current density of 1–5 A / dm³. 2 The deposition time is 30-120 minutes.

[0019] Furthermore, the parameters for electrochemical deposition are: constant current deposition, with a current density of 1–3 A / dm³. 2 The deposition time is 45-75 minutes.

[0020] Furthermore, a phosphor bronze anode is used as the anode.

[0021] Compared with the prior art, this application has the following beneficial effects: 1. After hydrolysis, the silane coupling agent generates Si-OH bonds, which condense with the hydroxyl and carboxyl groups on the graphene surface to form C-Si covalent bonds, constructing chemical anchors. The dispersant, through its surface hydroxyl groups, works in conjunction with the surfactant to generate a steric hindrance effect. The synergistic effect of these two factors ensures that the graphene nanosheets are uniformly suspended in the electrolyte, guaranteeing continuous transport of graphene to the cathode surface during electrodeposition and reducing uneven deposition caused by graphene nanosheet aggregation. This dual mechanism of chemical bonding and physical dispersion significantly improves the dispersion stability and uniformity of graphene nanosheets in the electroplating solution, laying the foundation for the preparation of composite materials.

[0022] 2. Ascorbic acid forms a reducing + buffering synergistic system with sulfuric acid in the plating bath, acting as a reducing agent to enhance Cu plating performance. 2+ Reduction efficiency. Detailed Implementation

[0023] To facilitate understanding of this application, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of this application.

[0024] This application provides a graphene-copper composite material, prepared by an electroplating solution comprising the following raw materials: Copper sulfate: 220-240 g / L, preferably copper sulfate pentahydrate; preferably electroplating grade, high purity copper sulfate; Sulfuric acid: 8%-12% by volume, sulfuric acid with a purity of 98% or higher, preferably CP.AR grade; Chloride ions: 30-90 ppm, preferably analytical grade AR hydrochloric acid with a content of 37% or higher.

[0025] Disodium EDTA: 3-5 g / L; CP grade preferred; Graphene colloidal particles: 0.1–2.0 g / L; Polyoxyethylene ether: 0.01-0.2 g / L, preferably AEO-9; Ascorbic acid: 0.01-0.1 g / L; preferably chemically pure.

[0026] Electroplating additives are available in 1-20 ml / L. Commercially available electroplating additives must be compatible with the type of rectifier, whether it is DC or pulse.

[0027] Deionized water: Add to a total of 1000 parts by weight.

[0028] A method for preparing graphene colloidal particles includes the following steps: Step a: Dissolve graphene nanosheets and dispersant in pure water or ethanol solvent (anhydrous ethanol), and sonicate for 20-60 minutes. The ultrasonic power is 150-250W and the frequency is 35-45kHz to obtain a graphene slurry with a concentration of 1-50mg / mL.

[0029] Step b: Under magnetic stirring (250-350 rpm), slowly add the silane coupling agent (preferably KH-550) and sodium dodecylbenzenesulfonate simultaneously. Then, continue stirring the reaction at room temperature for 1-3 hours.

[0030] The amount of silane coupling agent used is 1%–5% of the weight of graphene nanosheets.

[0031] The amount of sodium dodecylbenzenesulfonate used is 8%–12% of the weight of the graphene nanosheets.

[0032] Step c: Wash and centrifuge repeatedly with anhydrous ethanol to remove unreacted silane coupling agent. Centrifuge at 4500-5500 rpm for 5-20 minutes, repeat washing multiple times to obtain graphene colloidal particles.

[0033] Graphene colloidal particles subsequently exhibit colloidal suspension properties in solution. Through the synergistic effect of KH-550 silane coupling agent and SDBS surfactant, graphene forms a bistable system of chemical bonding and electrostatic repulsion. The solvation effect of ethanol solvent further promotes the hydrolytic diffusion of the silane coupling agent, ensuring that graphene nanosheets are uniformly suspended in the electroplating solution in a monolayer or few-layer state, preventing aggregation. This uniform dispersion ensures the continuous and stable delivery of graphene to the cathode surface during electrodeposition, forming a dense and uniform composite coating.

[0034] If graphene nanosheets are used in subsequent steps in powder form, they are prone to re-aggregation through π-π stacking or van der Waals forces due to the loss of dispersants, solvation protection, and the dynamic stabilizing effect of surfactants. Redispersion requires additional energy input (such as ultrasound or high-speed stirring), which may introduce new defects or damage the surface modification layer, resulting in uneven dispersion and affecting the quality of the deposited layer.

[0035] This application also provides a method for preparing a graphene-copper composite material, comprising the following steps: Step 1: Mix copper sulfate, sulfuric acid, chloride ions, disodium ethylenediaminetetraacetate, ascorbic acid, electroplating additives, and deionized water, and stir well to obtain the electroplating preparation solution.

[0036] Step 2: Disperse graphene slurry, polyoxyethylene ether and nano-silica in deionized water and sonicate for 20-60 minutes to form a uniformly dispersed graphene colloidal particle solution.

[0037] Step 3: Slowly add the graphene colloidal particle solution to the electroplating preparation solution and stir until homogeneous to obtain the electroplating solution.

[0038] Step 4: Polish the copper sheet with sandpaper until it is shiny, and then clean it with deionized water using ultrasonic cleaning.

[0039] Step 5: Polish the phosphor bronze anode with sandpaper until it is shiny, and then ultrasonically clean it with deionized water to remove the oil and oxide layer on the surface.

[0040] Step 6: Fix the cleaned copper sheet as the cathode and the phosphor bronze anode as the anode in the electrolytic cell, with a distance of 10-15 cm between the two electrodes.

[0041] Step 7: Pour the prepared electrolyte into the electrolytic cell, ensuring the liquid level covers the electrodes.

[0042] Step 8: Turn on the electrochemical workstation and set the deposition parameters: constant current deposition, current density of 1-5 A / dm³. 2 The deposition time is 30-120 minutes.

[0043] Step 9: Begin electrochemical deposition and record voltage changes during the deposition process.

[0044] Step 10: After deposition, remove the deposited copper sheet, rinse it with deionized water, and obtain graphene composite copper material.

[0045] The present application will be further described below through specific embodiments.

[0046] Example 1 This embodiment provides a graphene-copper composite material, prepared by an electroplating solution comprising the following raw materials: Copper sulfate: 230 kg, in this example, copper sulfate pentahydrate; Sulfuric acid: 10 kg; Hydrochloric acid: 60 ppm; Disodium ethylenediaminetetraacetate: 4 kg; Graphene colloidal particles: 1.0 kg.

[0047] Polyoxyethylene ether: 0.12 kg, in this example it is AEO-9; Ascorbic acid: 0.02 kg; 20L of electroplating additives; Deionized water: Add to 1000kg.

[0048] Preparation method of graphene colloidal particle solution: Step a: Dissolve commercially available graphene nanosheets (xGnP M-5, XG Sciences in this example) and dispersant in pure water or anhydrous ethanol, and sonicate for 30 minutes at an ultrasonic power of 200W and a frequency of 40kHz to obtain a graphene slurry with a concentration of 1mg / mL.

[0049] Step b: Under magnetic stirring (300 rpm), slowly add γ-aminopropyltriethoxysilane and sodium dodecylbenzenesulfonate simultaneously. Continue stirring at room temperature for 2 hours.

[0050] The amount of γ-aminopropyltriethoxysilane used is 2% of the weight of the graphene nanosheets.

[0051] The amount of sodium dodecylbenzenesulfonate used is 10% of the weight of the graphene nanosheets.

[0052] Step c: Wash and centrifuge repeatedly with anhydrous ethanol to remove unreacted silane coupling agent. Centrifuge at 5000 rpm for 15 minutes, repeat washing multiple times to obtain graphene colloidal particles.

[0053] In this embodiment, a method for preparing a composite electroplating solution for preparing graphene-copper composite materials is also provided. The method includes the following steps: Step 1: Dissolve copper sulfate, sulfuric acid, hydrochloric acid, ascorbic acid, and disodium ethylenediaminetetraacetate in deionized water and stir well to obtain the electroplating solution.

[0054] Step 2: Disperse graphene slurry, polyoxyethylene ether and nano silica (0.01 g / L) in deionized water and sonicate for 30 minutes to form a uniformly dispersed graphene colloidal particle solution.

[0055] Step 3: Slowly add the graphene colloidal particle solution to the electroplating preparation solution and stir until homogeneous to obtain the electroplating solution.

[0056] Step 4: Polish the copper sheet (99.99% purity, size: 50mm×20mm×0.5mm) with sandpaper until it is shiny, and then clean it with deionized water to remove the oil and oxide layer on the surface.

[0057] Step 5: Polish the phosphor bronze anode (purity 99.99%, size: 20mm×20mm×0.1mm) with sandpaper until it is shiny, and then clean it with deionized water to remove the oil and oxide layer on the surface.

[0058] Step 6: Fix the cleaned copper sheet as the cathode and the phosphor bronze anode as the anode in the electrolytic cell, with a distance of 10-15 cm between the two electrodes.

[0059] Step 7: Pour the prepared electrolyte into the electrolytic cell, ensuring the liquid level covers the electrodes.

[0060] Step 8: Turn on the electrochemical workstation and set the deposition parameters: constant current deposition, current density of 2A / dm³. 2 The deposition time was 60 minutes.

[0061] Step 9: Begin electrochemical deposition and record voltage changes during the deposition process.

[0062] Step 10: After deposition, remove the deposited copper sheet, rinse it with deionized water, dry it, and then remove it to obtain graphene composite copper material.

[0063] Performance testing: 1. Conductivity Test: The resistivity of the composite material was tested using the four-probe method, according to standard GB / T 3048.4-2025 "Electrical Performance Test Methods for Wires and Cables - Part 4: DC Resistance Test of Conductors". Testing instrument: RTS-9 four-probe tester. Five points were evenly selected on the copper sheet surface for testing, and the average value was taken.

[0064] 2. Tensile Strength Test: The tensile strength of the composite material was tested using a universal testing machine, according to the standard GB / T228.1-2021 "Metallic materials, tensile testing—Part 1: Tests at room temperature". The composite material was cut into standard tensile specimens, and the tensile rate was 2 mm / min. Testing instrument: Instron 5967 universal testing machine.

[0065] 3. Thermal Conductivity Test: The thermal conductivity of the composite material is tested using the laser flash method. According to standard GB / T 22588-2008 "Measurement of Thermal Diffusivity or Thermal Conductivity by Flash Method", a laser emits a thermal pulse of energy Q onto the surface of a thin sample of thickness L, while simultaneously measuring and recording the temperature response T(L, t) on the back side of the sample. Based on the mathematical model of the unsteady-state heat conduction process, the thermal diffusivity of the sample can be determined. The formula for calculating the thermal diffusivity is as follows: t0.5 is the time required for the back surface temperature to reach half of its maximum temperature. The thermal conductivity can be obtained by combining the relationship between thermal diffusivity and thermal conductivity.

[0066] In the formula, ρ is density and c is specific heat capacity.

[0067] 4. Ductility Test: Samples were tested according to GB / T 228.1-2021 "Metallic Materials - Tensile Testing - Part 1: Tests at Room Temperature". Sample surfaces were smooth and flat, avoiding scratches, cracks, and other defects. Appropriate grinding and polishing were performed, followed by ultrasonic testing. A universal testing machine was used as the core equipment for the tensile testing of metallic materials. The sample was held in clamps, and the tensile strength was recorded using a tensile tester.

[0068] Test results: 1. The resistivity is 1.40 × 10⁻⁶ -8 Ω·m.

[0069] 2. The tensile strength is 400 MPa.

[0070] 3. Thermal conductivity: 560 W / (m·K) 4. Elongation: 35%.

[0071] Comparative Example 1 The difference from Example 1 is that the graphene colloidal particles are replaced with commercially available graphene nanosheets.

[0072] Test results: 1. The resistivity is 1.57 × 10⁻⁶ -8 Ω·m.

[0073] 2. The tensile strength is 355 MPa.

[0074] 3. Thermal conductivity: 520 W / (m·K) 4. Elongation: 32% Comparative Example 2 The difference from Example 1 is that nano-silica and polyoxyethylene ether are omitted.

[0075] Test results: 1. The resistivity is 1.62 × 10⁻⁶ -8 Ω·m.

[0076] 2. The tensile strength is 300 MPa.

[0077] 3. Thermal conductivity: 445 W / (m·K) 4. Elongation: 27%.

[0078] Comparative Example 3 Commercially available pure copper sheets (99.99% purity, size: 50mm×20mm×0.5mm) were used as a control group.

[0079] Test results: 1. The resistivity is 1.72 × 10⁻⁶ -8 Ω·m.

[0080] 2. The tensile strength is 280 MPa.

[0081] 3. Thermal conductivity 440 W / (m·K).

[0082] 4. Elongation: 25%.

[0083] According to the test data, Example 1 shows a significant improvement in electrical conductivity, thermal conductivity, mechanical properties, and ductility compared to Comparative Examples 1-3.

[0084] It should be understood that the application of this application is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of this application.

Claims

1. A graphene-copper composite material, characterized in that, It is prepared by an electroplating solution, which includes the following raw materials: Copper sulfate: 220-240 g / L; Sulfuric acid: 8%–12%, by volume; Chloride ions: 30-90 ppm; Disodium ethylenediaminetetraacetate: 3-5 g / L; Graphene colloidal particles: 0.1–2 g / L; Polyoxyethylene ether: 0.01–0.2 g / L; Ascorbic acid: 0.01–0.1 g / L; Electroplating additives: 1-20 ml / L; The remainder is pure water.

2. The graphene-copper composite material according to claim 1, characterized in that, A graphene colloidal particle solution, comprising the following steps: Graphene nanosheets and a dispersant are dissolved in pure water or ethanol solvent to obtain a graphene slurry. Sodium dodecylbenzenesulfonate and silane coupling agent were dissolved in graphene slurry, and after washing and centrifugation, graphene colloidal particles were obtained.

3. The graphene-copper composite material according to claim 2, characterized in that, The amount of silane coupling agent used is 1%–5% of the weight of the graphene nanosheets; The amount of sodium dodecylbenzenesulfonate used is 8%–12% of the weight of the graphene nanosheets.

4. The graphene-copper composite material according to claim 2, characterized in that, Graphene nanosheets and a dispersant are dissolved in pure water or ethanol solvent and ultrasonically treated for 20-60 minutes at an ultrasonic power of 150-250W and a frequency of 35-45kHz to obtain a graphene slurry.

5. The graphene-copper composite material according to claim 2, characterized in that, The silane coupling agent is KH-550.

6. A method for preparing a graphene-copper composite material based on any one of claims 1-5, characterized in that, Includes the following steps: Copper sulfate, sulfuric acid, chloride ions, disodium ethylenediaminetetraacetate, ascorbic acid, electroplating additives, and water are mixed and stirred evenly to obtain an electroplating solution for later use. Graphene slurry, polyoxyethylene ether, and water are mixed and stirred until homogeneous to obtain a graphene colloidal particle solution. Electroplating solution and graphene colloidal particle solution are mixed to obtain electroplating solution; A phosphorus copper anode or an inert anode is inserted into the electroplating solution, and a copper sheet is used as the cathode for electrochemical deposition. After deposition, the material is washed and dried to obtain graphene-copper composite material.

7. The method for preparing the graphene-copper composite material according to claim 6, characterized in that, The parameters for electrochemical deposition are: constant current deposition, with a current density of 1–5 A / dm³. 2 The deposition time is 30-120 minutes.

Images