Method for preparing high-conductivity graphene copper composite by electroless plating

Abstract

The application discloses a method for preparing high-conductivity graphene copper composite material through electroless plating and relates to the technical field of composite materials. The application aims to solve the problem of weak adhesion of graphene interface and to improve the adhesion of graphene interface by regulating the interface structure of graphene / copper. The application comprises the following steps: S1, placing graphene-coated copper foil into an electroless plating tank and adding electroless plating solution into the electroless plating tank; S2, performing electroless plating treatment on the graphene-coated copper foil through the electroless plating solution in step S1 by using an electroless plating process, so that a layer of copper is deposited on the surface of the graphene-coated copper foil to generate copper-plated graphene-coated copper foil; and S3, placing the copper-plated graphene-coated copper foil generated in step S2 into a hot-pressing chamber, stacking multiple layers of the copper-plated graphene-coated copper foil, and hot-pressing the multiple layers of the copper-plated graphene-coated copper foil by using a hot-pressing process to obtain high-conductivity graphene copper composite material.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of composite materials, and particularly relates to a method for preparing high-conductivity graphene copper composite material by electroless plating. BACKGROUND

[0002] Pure metals have always been considered to have the lowest electrical conductivity at room temperature, since the first formal record of the electrical conductivity of copper about 100 years ago, a large number of studies on highly refined copper metal have only improved the electrical conductivity by about 3%, and the current widely implemented international annealed copper standard (IACS) records the electrical conductivity of pure copper at room temperature as 5.8 x 10 7 S / M, only the electrical conductivity of silver in the metal is better than that of copper (about 108% IACS) but the cost is too high, so copper-based materials have always been used as the main conductive material.

[0003] In order to improve the electrical conductivity of copper-based materials, the method for preparing high-purity copper by improving purity, reducing grain boundaries and reducing defects has gradually approached the physical limit, the cost is significantly increased, and the technical requirements are also more and more demanding; and adding other alloy materials (such as tin, rare earth elements, etc.), there are also phenomena of electrical conductivity decline due to unstable process or copper matrix lattice distortion, which has certain limitations; using copper and new materials to prepare ultra-high-conductivity copper-based composite materials has attracted extensive research.

[0004] Graphene is a carbon atom allotrope and two-dimensional crystal material, which is a basic single-layer SP 2 Hybrid (two-dimensional honeycomb structure) carbon atom. In 2004, British scientists successfully prepared graphene sheets for the first time, and the internal carbon atoms are combined with high σ bond strength, and each carbon atom can provide an unbound free electron. This unique structure determines its high strength and good electrical conductivity, its strength is as high as 130 GPa, and the carrier mobility is 15000 cm 2 / (Vs), both of which are the highest among the known materials. Not only that, graphene also has high specific area and thermal conductivity, as well as unique properties such as molecules, quantum, and tunneling effect. Due to its special two-dimensional structure and excellent performance, graphene has good advantages in improving the mechanical properties of materials and maintaining the high electrical conductivity and thermal conductivity of copper, and becomes an excellent reinforcing material for copper-based composite materials, and graphene reinforced copper-based materials have been applied to the automobile and aerospace industries.

[0005] However, the wettability between graphene and copper is poor, the interfacial bonding between them is poor, which leads to the decrease of material strength. In the preparation process of the composite material, the structure of graphene is often damaged, and the excellent performance of graphene is strongly dependent on the complete and large structure. Therefore, the performance of the obtained graphene composite material is often far from the theoretical value. In addition, the interface between graphene / copper lacks adhesion and other problems, which leads to weak interfacial adhesion and reduces the basic mechanics and electricity of the metal due to the elastic incompatibility. The uniform dispersion of graphene in the whole metal matrix is a key problem in the preparation of composite materials. SUMMARY

[0006] In order to solve the above problems, that is, to regulate the interface structure of graphene / copper to improve the problem of weak adhesion of graphene / copper interface, the present application provides a method for preparing high-conductive graphene / copper composite material by electroless plating, which has the following steps:

[0007] S1: Put the graphene-coated copper foil into the electroless plating tank, and then add electroless plating solution into the electroless plating tank;

[0008] S2: Using electroless plating process, the graphene-coated copper foil is treated by electroless plating with the electroless plating solution in step S1, so that a layer of copper is deposited on the surface of the graphene-coated copper foil, to generate a copper-plated graphene-coated copper foil;

[0009] S3: Put the copper-plated graphene-coated copper foil generated in step S2 into a hot pressing chamber, and stack multiple layers of the copper-plated graphene-coated copper foil, and use hot pressing process to hot press the multiple layers of the copper-plated graphene-coated copper foil to obtain high-conductive graphene / copper composite material.

[0010] The further setting of the present application is that the thickness of the graphene-coated copper foil in step S1 is 10-100 μm.

[0011] The further setting of the present application is that the electroless plating solution in step S1 includes main salt component A, pretreatment agent B and reducing agent C; the main salt component A is one or more combinations of copper sulfate pentahydrate, disodium ethylenediaminetetraacetate, polyvinylpyrrolidone, gelatin and potassium sodium tartrate; the pretreatment agent B is one or more combinations of stannous chloride, palladium chloride and HCL solution; the reducing agent C is one or more combinations of formaldehyde aqueous solution, ammonia water and hydrazine hydrate.

[0012] The further setting of the present application is that the concentration of copper sulfate pentahydrate is selected as 0.02-0.08 m; the concentration of disodium ethylenediaminetetraacetate is selected as 0.01-0.04 m; the concentration of polyvinylpyrrolidone is selected as 0.005-0.01 m; the density of gelatin is selected as 0.5-1 g / L; the concentration of sodium tartrate is selected as 0.03-0.08 m.

[0013] The further setting of the application is that the concentration of stannous chloride is selected as 0.1-0.2 m; the concentration of palladium chloride is 0.001-0.004 m; and the concentration of HCL solution is selected as 1-12 m.

[0014] The further setting of the application is that the concentration of formaldehyde aqueous solution is selected as 0.03-0.13 m; the concentration of ammonia water is selected as 0.02-0.08 m; and the concentration of hydrazine hydrate is selected as 0.01-0.06 m.

[0015] The further setting of the application is that the copper-plated graphene-coated copper foil generated in step S2 is vacuum sealed.

[0016] The further setting of the application is that the heating in the hot-pressing chamber is to 600-1100 DEG C, the heating time is 20-100 min, then constant temperature is kept for 20-100 min, after the constant temperature keeping is finished, cooling to room temperature is performed, and the cooling time is 20-100 min.

[0017] The further setting of the application is that the pressure in the hot-pressing chamber is first increased to 20-120 MPa, the pressure increasing time is 20-100 min, then constant pressure is kept for 20-100 min, after the constant pressure keeping is finished, the pressure is reduced to 0 Pa, and the pressure reducing time is 20-100 min.

[0018] The further setting of the application is that the vacuum or argon filling is maintained in the hot-pressing chamber for protection.

[0019] The beneficial effect of the application is that the graphene-coated copper foil is used as the basic material, the high-conductive graphene copper composite material prepared through the process steps of chemical plating, heat treatment and laminated hot pressing is more compact, the organization is uniform, the interface combination is good, the conductive performance is higher, and the process controllability of the method is good, and the method is easy to scale production. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 The flow chart of the process of the method is shown. DETAILED DESCRIPTION

[0021] The person skilled in the art can refer to the content herein, and appropriately improve the process parameters. It is particularly pointed out that all similar replacements and changes are obvious to the person skilled in the art, and they are all regarded as included in the application. The method and application of the application have been described through the preferred embodiments, and the related personnel can modify or appropriately change and combine the method and application described herein without departing from the content, spirit and scope of the application, to realize and apply the technical content of the application.

[0022] The application provides a method for preparing high-conductivity graphene copper composite material by electroless plating.

[0023] S1: placing graphene-coated copper foil into an electroless plating tank, and adding an electroless plating solution into the electroless plating tank;

[0024] S2: performing electroless plating treatment on the graphene-coated copper foil in the electroless plating solution in step S1 by using an electroless plating process, so that a layer of copper is deposited on the surface of the graphene-coated copper foil, thereby producing copper-plated graphene-coated copper foil;

[0025] S3: placing the copper-plated graphene-coated copper foil produced in step S2 into a hot-pressing chamber, stacking a plurality of pieces of the copper-plated graphene-coated copper foil in multiple layers, and hot-pressing the multiple layers of the copper-plated graphene-coated copper foil by using a hot-pressing process, so as to obtain high-conductivity graphene copper composite material.

[0026] In step S1, the thickness of the graphene-coated copper foil is selected to be 10-100 μm.

[0027] The electroless plating solution in step S1 comprises a main salt component A, a treatment agent B and a reducing agent C. The main salt component A is one or a combination of copper sulfate pentahydrate, disodium ethylenediaminetetraacetate, polyvinylpyrrolidone, gelatin and potassium sodium tartrate. The treatment agent B is one or a combination of stannous chloride, palladium chloride and HCL solution. The reducing agent C is one or a combination of formaldehyde aqueous solution, ammonia water and hydrazine hydrate.

[0028] The concentration of copper sulfate pentahydrate in the main salt component A is selected to be 0.02-0.08 m; the concentration of disodium ethylenediaminetetraacetate is selected to be 0.01-0.04 m; the concentration of polyvinylpyrrolidone is selected to be 0.005-0.01 m; the density of gelatin is selected to be 0.5-1 g / L; and the concentration of sodium tartrate is selected to be 0.03-0.08 m.

[0029] The concentration of stannous chloride in the treatment agent B is selected to be 0.1-0.2 m; the concentration of palladium chloride is selected to be 0.001-0.004; and the concentration of HCL solution is selected to be 1-12 m.

[0030] The concentration of formaldehyde aqueous solution in the reducing agent C is selected to be 0.03-0.13 m; the concentration of ammonia water is selected to be 0.02-0.08 m; and the concentration of hydrazine hydrate is selected to be 0.01-0.06 m.

[0031] The copper-plated graphene-coated copper foil produced in step S2 is vacuum-sealed.

[0032] Heating in the hot-pressing chamber to 600-1100℃, heating time is 20-100min, then constant temperature for 20-100min, after the end of the constant temperature cooling to room temperature, cooling time is 20-100min.

[0033] First pressurized to 20-120MPa in the hot-pressing chamber, pressure time is 20-100min, then constant pressure for 20-100min, after the end of constant pressure to reduce pressure to 0Pa, pressure time is 20-100min.

[0034] Maintain vacuum or fill in argon protection in the hot-pressing chamber.

[0035] Example 1

[0036] The graphene-coated copper foil is prepared by the above method, and the chemical plating solution used in the chemical plating is purchased. The preparation process is as follows:

[0037] First, the graphene-coated copper foil with a thickness of 50μm is selected in step S1 and placed in the chemical plating tank. The surface is chemically plated with copper by using the chemical plating solution. The graphene-coated copper foil selected in this embodiment is 100mm long and 80mm wide.

[0038] Second, the main salt component A of the chemical plating solution in step S2 is selected as follows: copper sulfate pentahydrate concentration is 0.035m; ethylenediaminetetraacetic acid disodium concentration is 0.02m; polyvinylpyrrolidone concentration is 0.007m; gelatin density is 0.6g / L; potassium sodium tartrate concentration is 0.067m, and each component is mixed into the main salt component A.

[0039] The pretreatment agent B is selected as follows: stannous chloride concentration is 0.12m, then 60m HCL solution is added, sensitized for 15min, then 0.0014m palladium chloride is added, and then 1m HCL solution is added, activated for 15min.

[0040] The temperature of the above-activated chemical plating solution is controlled at 45℃, and the reducing agent C is added. The reducing agent C is selected as follows: formaldehyde aqueous solution concentration is 0.11m; ammonia water concentration is 0.04m, mixed and adjusted to PH 13, and kept for 15min.

[0041] Finally, a layer of copper is deposited on the surface of the graphene-coated copper foil to obtain the copper-plated graphene-coated copper foil, which is vacuum sealed.

[0042] Step S3: Take 16 pieces of the above-prepared copper-plated graphene-coated copper foil and stack them into the vacuum hot-pressing chamber. The multi-layer copper-plated graphene-coated copper foil is hot-pressed to obtain a high-conductivity graphene copper composite material.

[0043] The material is heated to 950℃ before hot pressing, the heating time is 40 min, and the constant temperature is kept for 40 min. During this period, hot pressing is performed. After cooling for 40 min, the formed high-conductivity graphene copper composite material is cooled to room temperature.

[0044] During the hot pressing process, the pressure strength is 50 MPa, the pressure time is 40 min, the constant pressure time is 40 min, and finally the pressure is reduced to 0 Pa for 40 min, so that the high-conductivity graphene copper composite material is obtained.

[0045] In this embodiment, the vacuum degree in the hot pressing chamber is maintained at 8.0*10 -4 Pa.

[0046] The high-conductivity graphene copper composite material prepared in Example 1 is tested for electrical performance by the Van der Pauw method, and the conductivity is measured to be 109.5% IACS.

[0047] Example 2

[0048] All conditions of step S1 of this embodiment are set the same as all conditions of step S1 of Example 1.

[0049] The main salt component A of the chemical plating solution in step S2 is selected as follows: the concentration of copper sulfate pentahydrate is 0.03 m; the concentration of disodium ethylenediaminetetraacetate is 0.03 m; the concentration of polyvinylpyrrolidone is 0.006 m; the density of gelatin is 0.6 g / L; the concentration of potassium sodium tartrate is 0.067 m, and the components are mixed into the main salt component A.

[0050] The pretreatment agent B is selected as follows: the concentration of stannous chloride is 0.13 m, and then 50 m of HCl solution is added, sensitized for 15 min, then 0.0012 m of palladium chloride is added, and then 2 m of HCl solution is added, and activated for 15 min.

[0051] The temperature of the above-mentioned activated chemical plating solution is controlled at 45℃, and the reducing agent C is added. The reducing agent C is selected as follows: the concentration of ammonia is 0.04 m; the concentration of hydrazine hydrate is 0.03 m, and after mixing, the PH is adjusted to 13 and kept for 15 min.

[0052] Finally, a layer of copper is deposited on the surface of the graphene-coated copper foil to obtain a copper-plated graphene-coated copper foil, which is vacuum sealed.

[0053] All conditions of step S3 of this embodiment are set the same as all conditions of step S3 of Example 1.

[0054] The high-conductivity graphene copper composite material prepared in Example 2 is tested for electrical performance by the Van der Pauw method, and the conductivity is measured to be 107.1% IACS.

[0055] Example 3

[0056] The conditions of step S1 of this embodiment are set the same as all the conditions of step S1 in Embodiment 1.

[0057] The main salt component A of the electroless plating solution in step S2 is selected to have a copper sulfate pentahydrate concentration of 0.035 m; a polyvinylpyrrolidone concentration of 0.006 m; and a gelatin density of 0.6 g / L.

[0058] The pretreatment agent B is selected to have a stannous chloride concentration of 0.12 m, and then a 70 m HCl solution is added thereto, and after sensitization for 15 min, a 0.0012 m palladium chloride solution is added, and then a 1 m HCl solution is added, and activation is performed for 15 min.

[0059] The temperature of the electroless plating solution after the above activation is controlled to be 45°C, and the reducing agent C is added, and the reducing agent C is selected to have a formaldehyde solution concentration of 0.11 m; and the PH is adjusted to be 13, and maintained for 15 min.

[0060] Finally, a layer of copper is deposited on the surface of the graphene-coated copper foil to obtain a copper-plated graphene-coated copper foil, and the copper-plated graphene-coated copper foil is vacuum-sealed.

[0061] The heating temperature of step S3 of this embodiment is 1000°C, and the pressure intensity is 75 MPa, and the rest of the conditions are set the same as all the conditions of step S3 in Embodiment 1.

[0062] The high-conductivity graphene copper composite material prepared in Embodiment 3 is tested for electrical performance by the Van der Pauw method, and the conductivity is measured to be 113.5% IACS.

[0063] Embodiment 4

[0064] The conditions of step S1 of this embodiment are set the same as all the conditions of step S1 in Embodiment 1.

[0065] The main salt component A of the electroless plating solution in step S2 is selected to have a copper sulfate pentahydrate concentration of 0.035 m; a polyvinylpyrrolidone concentration of 0.0067 m; and a gelatin density of 0.6 g / L.

[0066] The pretreatment agent B is selected to have a stannous chloride concentration of 0.12 m, and then a 70 m HCl solution is added thereto, and after sensitization for 15 min, a 0.0012 m palladium chloride solution is added, and then a 1 m HCl solution is added, and activation is performed for 15 min.

[0067] The temperature of the electroless plating solution after the above activation is controlled to be 45°C, and the reducing agent C is added, and the reducing agent C is selected to have a formaldehyde solution concentration of 0.11 m; and the PH is adjusted to be 13, and maintained for 15 min.

[0068] Finally, a layer of copper is deposited on the surface of the graphene-coated copper foil to obtain a graphene-coated copper foil with copper plating, and the graphene-coated copper foil with copper plating is vacuum sealed.

[0069] All conditions of step S3 of this embodiment are set the same as all conditions of step S3 of embodiment 3.

[0070] The high-conductivity graphene copper composite prepared in embodiment 4 is subjected to electrical performance testing by using the Van der Pauw method, and the conductivity is measured to be 114.3% IACS.

[0071] Embodiment 5

[0072] First, the graphene-coated copper foil with a thickness of 10 μm is placed in a chemical plating tank, and the surface thereof is subjected to chemical copper plating by using a chemical plating solution. The graphene-coated copper foil selected in this embodiment is 100 mm long and 80 mm wide.

[0073] Second, all conditions of step S2 of this embodiment are set the same as all conditions of step S2 of embodiment 4.

[0074] The heating temperature of step S3 of this embodiment is 1000 ℃, and the pressure intensity is 20 MPa, and all other conditions are set the same as all conditions of step S3 of embodiment 1.

[0075] The high-conductivity graphene copper composite prepared in embodiment 5 is subjected to electrical performance testing by using the Van der Pauw method, and the conductivity is measured to be 103.4% IACS.

[0076] Embodiment 6

[0077] First, the graphene-coated copper foil with a thickness of 100 μm is placed in a chemical plating tank, and the surface thereof is subjected to chemical copper plating by using a chemical plating solution. The graphene-coated copper foil selected in this embodiment is 100 mm long and 80 mm wide.

[0078] Second, all conditions of step S2 of this embodiment are set the same as all conditions of step S2 of embodiment 4.

[0079] The heating temperature of step S3 of this embodiment is 1000 ℃, and the pressure intensity is 20 MPa, and all other conditions are set the same as all conditions of step S3 of embodiment 1.

[0080] The high-conductivity graphene copper composite prepared in embodiment 6 is subjected to electrical performance testing by using the Van der Pauw method, and the conductivity is measured to be 104.5% IACS.

[0081] Embodiment 7

[0082] Firstly, the graphene-coated copper foil with a thickness of 100 μm is placed in a chemical plating tank, and the surface thereof is subjected to chemical copper plating by using a chemical plating solution. The graphene-coated copper foil selected in the present embodiment has a length of 100 mm and a width of 80 mm.

[0083] Secondly, all conditions of step S2 of the present embodiment are set in the same manner as all conditions of step S2 of embodiment 4.

[0084] The heating temperature of step S3 of the present embodiment is 600 DEG C, and the pressure strength is 20 MPa, and all other conditions are set in the same manner as all conditions of step S3 of embodiment 1.

[0085] The high-conductivity graphene copper composite material prepared in embodiment 7 is subjected to electrical property testing by using the Van der Pauw method, and the conductivity is measured to be 100.8% IACS.

[0086] Embodiment 8

[0087] Firstly, the graphene-coated copper foil with a thickness of 100 μm is placed in a chemical plating tank, and the surface thereof is subjected to chemical copper plating by using a chemical plating solution. The graphene-coated copper foil selected in the present embodiment has a length of 100 mm and a width of 80 mm.

[0088] Secondly, all conditions of step S2 of the present embodiment are set in the same manner as all conditions of step S2 of embodiment 4.

[0089] The heating temperature of step S3 of the present embodiment is 1000 DEG C, and the pressure strength is 120 MPa, and all other conditions are set in the same manner as all conditions of step S3 of embodiment 1.

[0090] The high-conductivity graphene copper composite material prepared in embodiment 8 is subjected to electrical property testing by using the Van der Pauw method, and the conductivity is measured to be 111.8% IACS

[0091] In summary, the graphene-coated copper foil is used as a basic material, and the high-conductivity graphene copper composite material prepared by the process steps of chemical plating, heat treatment and lamination heat pressing is more compact, has a uniform structure, a good interface combination and a higher conductivity, and the process is controllable and easy to scale up.

[0092] The above only describes the preferred embodiments of the present application, and it should be noted that those skilled in the art can make several improvements and refinements without departing from the principles of the present application, and these improvements and refinements should also be within the protection scope of the present application.

Claims

1. A method for preparing highly conductive graphene-copper composite materials by chemical plating, characterized in that, It includes the following steps: S1: Place the graphene-coated copper foil into the electroless plating tank, and then add the electroless plating solution into the electroless plating tank; S2: Using a chemical plating process, the graphene-coated copper foil is chemically plated with the chemical plating solution described in step S1, so that a layer of copper is deposited on the surface of the graphene-coated copper foil to generate copper-plated graphene-coated copper foil. S3: Place the copper-plated graphene-coated copper foil generated in step S2 into a hot pressing chamber, and stack multiple copper-plated graphene-coated copper foils in multiple layers. Use a hot pressing process to hot press the multiple layers of copper-plated graphene-coated copper foils into shape to obtain a highly conductive graphene-copper composite material. The thickness of the graphene-coated copper foil in step S1 is 10-100 μm; The hot pressing chamber is heated to 600-1100℃ for 20-100 minutes, then kept at a constant temperature for 20-100 minutes, and then cooled to room temperature for 20-100 minutes after the holding period. The thermocompression chamber is first pressurized to 20-120 MPa for 20-100 min, then kept at constant pressure for 20-100 min, and finally depressurized to 0 Pa for 20-100 min.

2. The method for preparing highly conductive graphene-copper composite material by chemical plating according to claim 1, characterized in that: The electroless plating solution in step S1 includes a main salt component A, a treatment agent B, and a reducing agent C; the main salt component A is one or more of copper sulfate pentahydrate, disodium ethylenediaminetetraacetate, polyvinylpyrrolidone, gelatin, and potassium sodium tartrate; the treatment agent B is one or more of stannous chloride, palladium chloride, and HCl solution; and the reducing agent C is one or more of formaldehyde aqueous solution, ammonia, and hydrazine hydrate.

3. The method for preparing highly conductive graphene-copper composite materials by chemical plating according to claim 2, characterized in that: The concentration of copper sulfate pentahydrate is selected as 0.02-0.08 mg; the concentration of disodium ethylenediaminetetraacetate is selected as 0.01-0.04 mg; the concentration of polyvinylpyrrolidone is selected as 0.005-0.01 mg; the density of gelatin is selected as 0.5-1 g / L; and the concentration of sodium tartrate is selected as 0.03-0.08 mg.

4. The method for preparing highly conductive graphene-copper composite materials by chemical plating according to claim 2, characterized in that: The concentration of stannous chloride is selected to be 0.1-0.2 mg; the concentration of palladium chloride is selected to be 0.001-0.004 mg; and the concentration of HCl solution is selected to be 1-12 mg.

5. The method for preparing highly conductive graphene-copper composite materials by chemical plating according to claim 2, characterized in that: The concentration of the formaldehyde aqueous solution is selected as 0.03-0.13 mg; the concentration of the ammonia solution is selected as 0.02-0.08 mg; and the concentration of the hydrazine hydrate is selected as 0.01-0.06 mg.

6. The method for preparing highly conductive graphene-copper composite material by chemical plating according to claim 1, characterized in that: The copper-plated graphene-coated copper foil generated in step S2 is vacuum sealed.

7. The method for preparing highly conductive graphene-copper composite material by chemical plating according to claim 1, characterized in that: The thermocompression chamber is maintained under vacuum or filled with argon gas for protection.

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