Preparation method of high-conductivity graphene copper composite material

Abstract

The application discloses a preparation method of high-conductivity graphene copper composite material, and relates to the technical field of composite material preparation. The application aims to solve the problem of weak adhesion of the interface of graphene copper and to improve the interface adhesion of graphene copper. The application comprises the following steps: S1: placing graphene-coated copper foil into a magnetron sputtering chamber; S2: using a pure copper target as a copper source to perform magnetron sputtering treatment on the graphene-coated copper foil, sputtering a layer of copper on the surface of the graphene-coated copper foil to prepare graphene-coated copper foil treated by copper plating; and S3: placing the graphene-coated copper foil treated by copper plating prepared in step S2 into a hot-pressing chamber, setting appropriate hot-pressing temperature and pressure, and performing hot-pressing forming on the graphene-coated copper foil treated by copper plating by using a laminated hot-pressing method to obtain the high-conductivity graphene copper composite material.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of composite material preparation, and particularly relates to a preparation method of high-conductivity graphene copper composite material. BACKGROUND

[0002] Pure metals have 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 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 is better than that of copper (about 108% IACS), but the cost is too high, so copper-based materials have been serving 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 more and more stringent; and adding other alloy materials (such as tin, rare earth elements, etc.) also has the phenomenon of electrical conductivity decline due to unstable process or copper-based lattice distortion, and has certain limitations. The use of copper and new materials for composite preparation of ultra-high conductivity copper-based composite materials has attracted extensive research.

[0004] Graphene is a carbon isomer 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 awakens its high strength and good electrical conductivity, and the 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 surface 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 conductivity and thermal conductivity of copper, and becomes an excellent reinforcing material for copper-based composite materials. Graphene-reinforced copper-based materials have been widely used in the automobile and aerospace industries.

[0005] However, the wettability between graphene and copper is poor, resulting in poor interface bonding and reduced material strength. During the preparation of the composite material, the structure of graphene is often damaged, and the excellent performance of graphene is strongly dependent on the complete structure. Therefore, the performance of the obtained graphene composite material is often far from the theoretical value. In addition, the interface between graphene and copper lacks adhesion, and the uniform dispersion of graphene in the entire metal matrix is a key problem in the preparation of the composite material. Therefore, the interface structure of graphene and copper needs to be regulated to improve the weak adhesion between graphene and copper, which is a key problem in improving the performance of graphene and copper composite material, and is of great significance to the research of composite materials. SUMMARY

[0006] The application provides a preparation method of a high-conductivity graphene and copper composite material, which comprises the following steps:

[0007] S1: placing a graphene-coated copper foil into a magnetron sputtering chamber;

[0008] S2: using a pure copper target as a copper source to perform magnetron sputtering treatment on the graphene-coated copper foil, sputtering a layer of copper on the surface of the graphene-coated copper foil to obtain a graphene-coated copper foil treated by copper plating;

[0009] S3: placing the graphene-coated copper foil treated by copper plating prepared in step S2 into a hot pressing chamber, setting appropriate hot pressing temperature and pressure, and performing hot pressing forming on the graphene-coated copper foil treated by copper plating by using a laminated hot pressing method to obtain a high-conductivity graphene and copper composite material.

[0010] In the application, the thickness of the graphene-coated copper foil in step S1 is 10-100 μm.

[0011] In the application, the thickness of the copper sputtered in step S2 is 1-1000 nm, the magnetron sputtering time is 0.5-60 min, the magnetron sputtering chamber is subjected to vacuum treatment, the vacuum degree is 2.0×10 -3 Pa-1.0×10 -4 Pa; and the graphene-coated copper foil treated by copper plating obtained in step S2 is vacuum sealed after being taken out.

[0012] The application further provides that the temperature in the hot-pressing chamber in step S3 is heated to 600-1100 DEG C, the heating time is 20-100 min, then the temperature is kept constant for 20-100 min, and then the temperature is cooled to room temperature, the cooling time is 20-100 min; the pressure in the hot-pressing chamber is increased to 20-120 MPa, the pressure increasing time is 20-100 min, then the pressure is kept constant for 20-100 min, and then the pressure is decreased to 0 Pa, the pressure decreasing time is 20-100 min; the hot-pressing chamber is kept in vacuum or filled with argon for protection.

[0013] The application further provides a preparation scheme of the high-conductivity graphene copper composite material, which is characterized by comprising the following steps:

[0014] S1: the graphene-coated copper foil is placed into an electroplating tank, and an electroplating solution is added;

[0015] S2: an electroplating process is adopted to electroplate and treat the graphene-coated copper foil in step S1, so as to electroplate and deposit a layer of copper on the surface of the graphene-coated copper foil, thereby obtaining a copper-plated graphene-coated copper foil;

[0016] S3: the copper-plated graphene-coated copper foils prepared in step S2 are placed into a hot-pressing chamber, appropriate hot-pressing temperature and pressure are set, and the copper-plated graphene-coated copper foils are hot-pressed by using a laminated hot-pressing method, so as to obtain the high-conductivity graphene copper composite material.

[0017] The application further provides that the thickness of the graphene-coated copper foil in step S1 is 10-100 μm.

[0018] The application further provides that the anode of the electroplating process in step S2 is a pure copper plate, the cathode is a titanium plate, the current density of the electroplating process in step S2 is 1-50 A / dm 2 , the electroplating time is 0.5-30 min, the thickness of the copper plating is 1-1000 nm, the electroplating temperature in step S2 is 25-70 DEG C, and the copper-plated graphene-coated copper foils prepared in step S2 are vacuum-sealed after being taken out.

[0019] The application further provides that the temperature in the hot-pressing chamber in step S3 is heated to 600-1100 DEG C, the heating time is 20-100 min, then the temperature is kept constant for 20-100 min, and then the temperature is cooled to room temperature, the cooling time is 20-100 min; the pressure in the hot-pressing chamber is increased to 20-120 MPa, the pressure increasing time is 20-100 min, then the pressure is kept constant for 20-100 min, and then the pressure is decreased to 0 Pa, the pressure decreasing time is 20-100 min; the hot-pressing chamber is kept in vacuum or filled with argon for protection.

[0020] The application further provides a preparation scheme of the high-conductivity graphene copper composite material.

[0021] S1: placing the graphene-coated copper foil into a thermal evaporation chamber;

[0022] S2: performing evaporation treatment on the graphene-coated copper foil by taking copper particles or copper wires as the copper source, evaporating a copper layer on the surface of the graphene-coated copper foil, and preparing a graphene-coated copper foil treated by copper plating;

[0023] S3: placing the graphene-coated copper foil treated by copper plating prepared in the step S2 into a hot-pressing chamber, setting appropriate hot-pressing temperature and pressure, and performing hot-pressing forming on the graphene-coated copper foil treated by copper plating by using a laminated hot-pressing method, so as to obtain the high-conductivity graphene copper composite material.

[0024] In the step S1, the graphene-coated copper foil has a thickness of 10-100 μm.

[0025] In the step S2, the thickness of the evaporated copper layer is 1-1000 nm, and the evaporation time is 0.5-50 min; the thermal evaporation chamber is subjected to vacuum treatment, and the vacuum degree is 1.0x10 -3 Pa-1.0x10 -4 Pa; and the graphene-coated copper foil treated by copper plating prepared in the step S2 is taken out and vacuum-sealed for storage.

[0026] In the step S3, the temperature in the hot-pressing chamber is heated to 600-1100℃, the heating time is 20-100 min, then the temperature is kept constant for 20-100 min, after the constant-temperature keeping is finished, the temperature is cooled to room temperature, and the cooling time is 20-100 min; the pressure in the hot-pressing chamber is increased to 20-120 MPa, the increasing time is 20-100 min, then the pressure is kept constant for 20-100 min, after the constant-pressure keeping is finished, the pressure is decreased to 0 Pa, and the decreasing time is 20-100 min; the hot-pressing chamber is kept in vacuum or filled with argon for protection.

[0027] The application has the following beneficial effects:

[0028] 1. The graphene copper composite material close to full density, good interface combination and super high conductivity can be prepared by the steps of magnetron sputtering, heat treatment and laminated hot-pressing, and the method is controllable and easy for large-scale production.

[0029] 2. The graphene copper composite material close to full density, good interface combination and super high conductivity can be prepared by the steps of electroplating, heat treatment and laminated hot-pressing, and the method is controllable and easy for large-scale production.

[0030] 3. By the steps of thermal evaporation, heat treatment, and laminated hot pressing, a graphene copper composite material with near full density, good interface bonding between graphene and copper, and ultra-high electrical conductivity can be prepared, and the method has good controllability and is easy to scale up. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 A process flow diagram of Example 1 is shown.

[0032] Figure 2 A process flow diagram of Example 5 is shown.

[0033] Figure 3 A process flow diagram of Example 9 is shown.

[0034] Figure 4 A schematic diagram of the thermal evaporation process of Example 9 is shown. DETAILED DESCRIPTION

[0035] Those skilled in the art can improve the process parameters as appropriate based on the content herein. In particular, it should be noted that all similar substitutions and modifications will be apparent to those skilled in the art, and are considered to be included in the present application. The method and application of the present application have been described by preferred embodiments, and relevant personnel can modify or appropriately change and combine the methods and applications described herein without departing from the content, spirit and scope of the present application, to realize and apply the present application technology.

[0036] Example 1

[0037] The present embodiment proposes a method for preparing a high-conductivity graphene copper composite material, comprising the following steps:

[0038] S1: Place the graphene-coated copper foil into a magnetron sputtering chamber.

[0039] S2: Use a pure copper target as the copper source to perform magnetron sputtering treatment on the graphene-coated copper foil, and sputter a layer of copper on the surface of the graphene-coated copper foil to prepare a copper-plated graphene-coated copper foil.

[0040] S3: Place the plurality of layers of the copper-plated graphene-coated copper foil prepared in step S2 into a hot pressing chamber, set appropriate hot pressing temperature and pressure, and use laminated hot pressing to hot press the copper-plated graphene-coated copper foil to obtain a high-conductivity graphene copper composite material.

[0041] In step S1, the thickness of the graphene-coated copper foil is 10-100 μm.

[0042] The thickness of the copper magnetron sputtered in step S2 is 1-1000 nm, and the magnetron sputtering time is 0.5-60 min; the vacuum degree in the magnetron sputtering chamber is 2.0x10 -3 Pa; the copper-plated graphene-coated copper foil prepared in step S2 is taken out and vacuum-sealed for storage. It should be noted that the magnetron sputtering time is determined according to the copper plating thickness, that is, the thicker the copper plating, the longer the magnetron sputtering time. -4 Pa; the copper-plated graphene-coated copper foil prepared in step S2 is taken out and vacuum-sealed for storage. It should be noted that the magnetron sputtering time is determined according to the copper plating thickness, that is, the thicker the copper plating, the longer the magnetron sputtering time.

[0043] The temperature in the hot-pressing chamber is first raised to 600-1100℃, the heating time is 20-100 min, then the temperature is kept constant for 20-100 min, and then the temperature is cooled to room temperature, the cooling time is 20-100 min.

[0044] The pressure in the hot-pressing chamber is first raised to 20-120 MPa, the pressure time is 20-100 min, then the pressure is kept constant for 20-100 min, and then the pressure is reduced to 0 Pa, the pressure reduction time is 20-100 min; the hot-pressing chamber is maintained in a vacuum or filled with argon for protection.

[0045] Example 2

[0046] The high-conductivity graphene copper composite material is prepared by the method of Example 1, the graphene-coated copper foil and the magnetron sputtering copper target are purchased, and the preparation process is as follows:

[0047] S1: The graphene-coated copper foil with a thickness of 50 μm is placed in the magnetron sputtering chamber.

[0048] S2: The graphene-coated copper foil surface is coated with copper by constant-speed magnetron sputtering; the purity of the copper target is 99.9999%, the vacuum degree of the magnetron sputtering chamber is 5.0x10 -4 Pa, and the magnetron sputtering time is 25 min, so that a layer of copper is sputtered on the surface of the graphene-coated copper foil, the copper plating thickness is 40 nm, and the copper-plated graphene-coated copper foil is obtained.

[0049] S3: 16 pieces of graphene-coated copper foil prepared in step S2 are placed in the vacuum hot-pressing chamber for laminated hot-pressing; the material is heated to 950℃ before hot-pressing, the heating time is 40 min, the constant temperature time is 40 min, and the hot-pressing is performed during the constant temperature time, and the formed high-conductivity graphene copper composite material is cooled to room temperature after cooling for 40 min.

[0050] The pressure intensity during hot-pressing 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, so that the high-conductivity graphene copper composite material is obtained.

[0051] The graphene-coated copper foil selected in this embodiment has a length of 20 mm and a width of 20 mm. The copper source has a diameter of 50.8 mm and a thickness of 4 mm.

[0052] The vacuum degree of the hot-pressing chamber in this embodiment is 8.0 x 10 -4 Pa.

[0053] The high-conductivity graphene copper composite material prepared in step S3 is subjected to electrical performance testing according to the Van der Pauw method, and the electrical conductivity thereof is 110.2% IACS.

[0054] Embodiment 3

[0055] The high-conductivity graphene copper composite material is prepared by the method of embodiment 1. The graphene-coated copper foil and the magnetron sputtering copper target are commercially available, and the preparation process is as follows:

[0056] S1: The graphene-coated copper foil with a thickness of 25 μm is placed into the magnetron sputtering chamber.

[0057] S2: The graphene-coated copper foil surface is subjected to constant-speed magnetron sputtering copper plating by using the magnetron sputtering process. The purity of the pure copper target used as the copper source is 99.9999%, the vacuum degree of the magnetron sputtering chamber is 5.0 x 10 -4 Pa, and the magnetron sputtering time is 15 min, so that a layer of copper is sputtered on the surface of the graphene-coated copper foil, the copper plating thickness is 25 nm, and the graphene-coated copper foil after copper plating treatment is obtained.

[0058] S3: Sixteen pieces of the graphene-coated copper foil prepared in step S2 are placed into the vacuum hot-pressing chamber for laminated hot-pressing. Before hot-pressing, the material is heated to 950°C, the heating time is 40 min, the constant-temperature time is 40 min, and hot-pressing is performed during the constant-temperature time. After cooling for 40 min, the formed high-conductivity graphene copper composite material is cooled to room temperature.

[0059] The pressing intensity during hot-pressing is 50 MPa, the pressing 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.

[0060] The graphene-coated copper foil selected in this embodiment has a length of 20 mm and a width of 20 mm. The copper source has a diameter of 50.8 mm and a thickness of 4 mm.

[0061] The vacuum degree of the hot-pressing chamber in this embodiment is 8.0 x 10 -4 Pa.

[0062] The high-conductivity graphene copper composite material prepared in step S3 is subjected to electrical performance testing according to the Van der Pauw method, and the electrical conductivity thereof is 111.9% IACS.

[0063] Example 4

[0064] A high-conductivity graphene copper composite was prepared by the method of Example 1. The graphene-coated copper foil and the magnetron sputtering copper target were purchased. The preparation process was as follows:

[0065] S1: The graphene-coated copper foil with a thickness of 25 pm was placed in the magnetron sputtering chamber.

[0066] S2: The graphene-coated copper foil surface was plated with copper at a constant speed by magnetron sputtering process. The purity of the pure copper target as the copper source was 99.9999%. The vacuum degree of the magnetron sputtering chamber was 5.0 x 10 -4 Pa, and the magnetron sputtering time was 35 min, so that a layer of copper was sputtered on the surface of the graphene-coated copper foil, and the copper plating thickness was 50 nm, obtaining the graphene-coated copper foil treated by copper plating.

[0067] S3: 16 pieces of graphene-coated copper foil prepared in step S2 were placed in the vacuum hot pressing chamber for laminated hot pressing. The material was heated to 900 °C before hot pressing, and the heating time was 40 min, and the constant temperature time was 40 min. During the hot pressing, the formed high-conductivity graphene copper composite was cooled to room temperature after cooling for 40 min.

[0068] The pressing strength during hot pressing was 50 MPa, the pressing time was 40 min, the constant pressure time was 40 min, and finally the pressure was reduced to 0 Pa for 40 min, so that the high-conductivity graphene copper composite was obtained.

[0069] In this embodiment, the length of the graphene-coated copper foil was 20 mm, and the width was 20 mm. The diameter of the copper source was 50.8 mm, and the thickness was 4 mm.

[0070] In this embodiment, the vacuum degree of the hot pressing chamber was 8.0 x 10 -4 Pa.

[0071] The high-conductivity graphene copper composite prepared in step S3 was tested for electrical properties according to the Van der Pauw method, and the electrical conductivity was 108.9% IACS.

[0072] Example 5

[0073] A high-conductivity graphene copper composite was prepared by the method of Example 1. The graphene-coated copper foil and the magnetron sputtering copper target were purchased. The preparation process was as follows:

[0074] S1: The graphene-coated copper foil with a thickness of 25 pm was placed in the magnetron sputtering chamber.

[0075] S2: The surface area of the graphene-coated copper foil is plated with copper by using a magnetron sputtering process at a constant speed. The purity of the pure copper target used as the copper source is 99.9999%, and the vacuum degree of the magnetron sputtering chamber is 5.0 x 10 -4 Pa. The magnetron sputtering time is 60 min, so that a layer of copper is sputtered on the surface of the graphene-coated copper foil, and the copper plating thickness is 1000 nm. Thus, a graphene-coated copper foil treated by copper plating is obtained.

[0076] S3: The 16 graphene-coated copper foils prepared in step S2 are placed in a vacuum hot pressing chamber for laminated hot pressing. The materials are heated to 950°C before hot pressing, and the heating time is 40 min. The hot pressing forming is performed during the constant temperature time of 40 min. After cooling for 40 min, the formed high-conductive graphene copper composite material is cooled to room temperature.

[0077] The pressure intensity during the hot pressing process is 50 MPa, the pressure time is 40 min, and the constant pressure time is 40 min. Finally, the pressure is reduced to 0 Pa for 40 min, so that the high-conductive graphene copper composite material is obtained.

[0078] In this embodiment, the length of the graphene-coated copper foil is 20 mm, and the width is 20 mm. The diameter of the copper source is 50.8 mm, and the thickness is 4 mm.

[0079] In this embodiment, the vacuum degree of the hot pressing chamber is 8.0 x 10 -4 Pa.

[0080] According to the Van der Pauw method, the electrical performance test of the high-conductive graphene copper composite material prepared in step S3 is performed, and the electrical conductivity is 108.4% IACS.

[0081] Example 6

[0082] The high-conductive graphene copper composite material is prepared by using the method of Example 1. The graphene-coated copper foil and the magnetron sputtering copper target are purchased products, and the preparation process is as follows:

[0083] S1: The graphene-coated copper foil with a thickness of 25 μm is placed in a magnetron sputtering chamber.

[0084] S2: The surface area of the graphene-coated copper foil is plated with copper by using a magnetron sputtering process at a constant speed. The purity of the pure copper target used as the copper source is 99.9999%, and the vacuum degree of the magnetron sputtering chamber is 5.0 x 10 -4 Pa. The magnetron sputtering time is 60 min, so that a layer of copper is sputtered on the surface of the graphene-coated copper foil, and the copper plating thickness is 1000 nm. Thus, a graphene-coated copper foil treated by copper plating is obtained.

[0085] S3: Put 16 pieces of graphene-coated copper foil prepared in step S2 into a vacuum hot pressing chamber for laminated hot pressing. Before hot pressing, heat the material to 950℃, heat for 40 min, constant temperature for 40 min, and hot pressing during the period. After cooling for 40 min, cool the formed high-conductive graphene copper composite material to room temperature.

[0086] The pressure strength during hot pressing 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, thereby obtaining the high-conductive graphene copper composite material.

[0087] In this embodiment, the length of the graphene-coated copper foil is 20 mm, and the width is 20 mm. The diameter of the copper source is 50.8 mm, and the thickness is 4 mm.

[0088] In this embodiment, the vacuum degree of the hot pressing chamber is 8.0 x 10 -4 Pa.

[0089] According to the Van der Pauw method, the electrical performance test of the high-conductive graphene copper composite material prepared in step S3 is performed, and the electrical conductivity is 106.7% IACS.

[0090] Embodiment 7

[0091] This embodiment proposes a preparation method of a high-conductive graphene copper composite material, which comprises the following steps:

[0092] S1: Put the graphene-coated copper foil into an electroplating tank and add an electroplating solution.

[0093] S2: Adopt electroplating process to electroplate and treat the graphene-coated copper foil in step S1, and deposit a layer of copper on the surface of the graphene-coated copper foil to prepare a copper-plated graphene-coated copper foil.

[0094] S3: Put multiple layers of the copper-plated graphene-coated copper foil prepared in step S2 into a hot pressing chamber, set appropriate hot pressing temperature and pressure, and use laminated hot pressing method to hot press and form the copper-plated graphene-coated copper foil to obtain a high-conductive graphene copper composite material.

[0095] In step S1, the thickness of the graphene-coated copper foil is 10-100 μm.

[0096] In step S2, the anode of the electroplating process adopts a pure copper plate, the cathode adopts a titanium plate, and the current density of the electroplating process is 1-50 A / dm 2The plating time is 0.5-30 min, the plating temperature is 25-70 °C, and the thickness of the copper plating is 1-1000 nm; the copper-plated graphene-coated copper foil prepared in step S2 is taken out and stored in a vacuum after sealing.

[0097] In step S3, the temperature in the hot-pressing chamber is first increased to 600-1100 °C, the heating time is 20-100 min, then the temperature is kept constant for 20-100 min, and after the constant temperature is kept, the temperature is cooled to room temperature, and the cooling time is 20-100 min.

[0098] In the hot-pressing chamber, the pressure is first increased to 20-120 MPa, the pressure increasing time is 20-100 min, then the pressure is kept constant for 20-100 min, and after the constant pressure is kept, the pressure is reduced to 0 Pa, and the pressure reducing time is 20-100 min; the hot-pressing chamber is maintained in a vacuum or filled with argon for protection.

[0099] Example 8

[0100] The high-conductivity graphene copper composite material is prepared by the method of Example 7, and the graphene-coated copper foil is purchased. The preparation process is as follows:

[0101] S1: Place the graphene-coated copper foil with a thickness of 50 μm into the plating tank and add the plating solution. In this example, the length of the graphene-coated copper foil is 100 mm, and the width is 80 mm.

[0102] S2: The graphene-coated copper foil is subjected to plating treatment, and a layer of copper is deposited on the surface of the graphene-coated copper foil to form a copper-plated graphene-coated copper foil.

[0103] The temperature of the plating solution is controlled at 30 °C, the current density is 15 A / dm 2 , the plating time is 20 min, the thickness of the copper plating is 1 μm, and a copper-plated graphene-coated copper foil is obtained.

[0104] S3: Place 16 pieces of 20 mm x 20 mm graphene-coated copper foil prepared in step S2 into the vacuum hot-pressing chamber for laminated hot-pressing. Before hot-pressing, the material is heated to 950 °C, the heating time is 40 min, the constant temperature time is 40 min, and during the hot-pressing, the material is formed. After cooling for 40 min, the formed high-conductivity graphene copper composite material is cooled to room temperature.

[0105] During the hot-pressing, the pressure intensity 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, thereby obtaining a high-conductivity graphene copper composite material.

[0106] The vacuum degree of the hot pressing chamber in this embodiment is 8.0 x 10 -4 Pa.

[0107] The high-conductivity graphene copper composite prepared in step S3 is subjected to electrical performance testing according to the Van der Pauw method, and the electrical conductivity thereof is 108.2% IACS.

[0108] Example 9

[0109] The high-conductivity graphene copper composite is prepared by the method of Example 7, and the graphene-coated copper foil is a commercially available product. The preparation process is as follows:

[0110] S1: The graphene-coated copper foil with a thickness of 50 pm is placed in an electroplating tank, and an electroplating solution is added. In this embodiment, the graphene-coated copper foil has a length of 100 mm and a width of 80 mm.

[0111] S2: The graphene-coated copper foil is subjected to electroplating treatment to deposit a layer of copper on the surface of the graphene-coated copper foil, thereby preparing a copper-plated graphene-coated copper foil.

[0112] The temperature of the electroplating solution is controlled at 25°C, the current density is 10 A / dm 2 , the electroplating time is 15 min, the copper plating thickness is 800 nm, and a copper-plated graphene-coated copper foil is obtained.

[0113] S3: Sixteen pieces of the graphene-coated copper foil prepared in step S2, each with a size of 20 mm x 20 mm, are placed in a vacuum hot pressing chamber for lamination and hot pressing. Before hot pressing, the materials are heated to 950°C, and the heating time is 40 min. The hot pressing is performed during the constant temperature time of 40 min. After cooling for 40 min, the formed high-conductivity graphene copper composite is cooled to room temperature.

[0114] The pressing strength during hot pressing is 50 MPa, the pressing time is 40 min, the constant pressure time is 40 min, and finally the pressure is reduced for 40 min to 0 Pa, thereby obtaining a high-conductivity graphene copper composite.

[0115] The vacuum degree of the hot pressing chamber in this embodiment is 8.0 x 10 -4 Pa.

[0116] The high-conductivity graphene copper composite prepared in step S3 is subjected to electrical performance testing according to the Van der Pauw method, and the electrical conductivity thereof is 107.4% IACS.

[0117] Example 10

[0118] The high-conductivity graphene copper composite is prepared by the method of Example 7, and the graphene-coated copper foil is a commercially available product. The preparation process is as follows:

[0119] S1: A graphene-coated copper foil with a thickness of 50 μm was placed in an electroplating tank, and an electroplating solution was added. In this embodiment, the graphene-coated copper foil selected has a length of 100 mm and a width of 80 mm.

[0120] S2: The graphene-coated copper foil was subjected to electroplating treatment to deposit a layer of copper on the surface of the graphene-coated copper foil to produce a copper-plated graphene-coated copper foil.

[0121] The temperature of the electroplating solution was controlled at 25°C, the current density was 10 A / dm 2 , the electroplating time was 1 min, the copper plating thickness was 50 nm, and a copper-plated graphene-coated copper foil was obtained.

[0122] S3: Sixteen pieces of the graphene-coated copper foil produced in step S2, each with a size of 20 mm x 20 mm, were placed in a vacuum hot-pressing chamber for lamination and hot pressing. Before hot pressing, the materials were heated to 900°C, and the heating time was 40 min. The temperature was kept constant for 40 min, during which hot pressing was performed. After cooling for 40 min, the formed high-conductivity graphene copper composite material was cooled to room temperature.

[0123] During the hot pressing process, the pressure intensity was 50 MPa, the pressure time was 40 min, the constant pressure time was 40 min, and finally the pressure was reduced to 0 Pa for 40 min, thereby obtaining a high-conductivity graphene copper composite material.

[0124] In this embodiment, the vacuum degree of the hot-pressing chamber was 8.0 x 10 -4 Pa.

[0125] The high-conductivity graphene copper composite material produced in step S3 was subjected to electrical performance testing according to the Van der Pauw method, and the electrical conductivity was 108.5% IACS.

[0126] Example 11

[0127] A high-conductivity graphene copper composite material was prepared using the method of Example 7. The graphene-coated copper foil was a commercially available product, and the preparation process was as follows:

[0128] S1: A graphene-coated copper foil with a thickness of 50 μm was placed in an electroplating tank, and an electroplating solution was added. In this embodiment, the graphene-coated copper foil selected has a length of 100 mm and a width of 80 mm.

[0129] S2: The graphene-coated copper foil was subjected to electroplating treatment to deposit a layer of copper on the surface of the graphene-coated copper foil to produce a copper-plated graphene-coated copper foil.

[0130] The temperature of the electroplating solution was controlled at 25°C, the current density was 5 A / dm 2 , the electroplating time was 0.5 min, the copper plating thickness was 1 nm, and a copper-plated graphene-coated copper foil was obtained.

[0131] S3: 16 pieces of 20 mm x 20 mm graphene-coated copper foils prepared in step S2 were placed into a vacuum hot pressing chamber for laminated hot pressing. The material was heated to 900°C before hot pressing, with a heating time of 40 min, a constant temperature time of 40 min, and hot pressing forming during the period. After cooling for 40 min, the formed high-conductive graphene copper composite material was cooled to room temperature.

[0132] The pressure intensity during hot pressing was 50 MPa, the pressure time was 40 min, the constant pressure time was 40 min, and finally the pressure was reduced for 40 min to reduce the pressure to 0 Pa, thereby obtaining the high-conductive graphene copper composite material.

[0133] The vacuum degree of the hot pressing chamber in this embodiment was 8.0 x 10 -4 Pa.

[0134] The high-conductive graphene copper composite material prepared in step S3 was tested for electrical performance according to the Van der Pauw method, and the electrical conductivity was 104.1% IACS.

[0135] Example 12

[0136] A high-conductive graphene copper composite material was prepared using the method of Example 7, and the graphene-coated copper foil was a commercially available product. The preparation process was as follows:

[0137] S1: A graphene-coated copper foil with a thickness of 50 pm was placed into an electroplating tank and electroplating solution was added. The graphene-coated copper foil selected in this embodiment had a length of 100 mm and a width of 80 mm.

[0138] S2: The graphene-coated copper foil was subjected to electroplating treatment to deposit a layer of copper on the surface of the graphene-coated copper foil to prepare a copper-plated graphene-coated copper foil.

[0139] The temperature of the electroplating solution was controlled at 50°C, the current density was 40 A / dm 2 , the electroplating time was 25 min, the copper plating thickness was 1000 nm, and a copper-plated graphene-coated copper foil was obtained.

[0140] S3: 16 pieces of 20 mm x 20 mm graphene-coated copper foils prepared in step S2 were placed into a vacuum hot pressing chamber for laminated hot pressing. The material was heated to 900°C before hot pressing, with a heating time of 40 min, a constant temperature time of 40 min, and hot pressing forming during the period. After cooling for 40 min, the formed high-conductive graphene copper composite material was cooled to room temperature.

[0141] The pressure intensity during hot pressing was 50 MPa, the pressure time was 40 min, the constant pressure time was 40 min, and finally the pressure was reduced for 40 min to reduce the pressure to 0 Pa, thereby obtaining the high-conductive graphene copper composite material.

[0142] The vacuum degree of the hot-pressing chamber in this embodiment is 8.0x10 -4 Pa.

[0143] The electrical conductivity of the high-conductivity graphene copper composite material prepared in step S3 is tested according to the Van der Pauw method, and the electrical conductivity is 109.2% IACS.

[0144] Embodiment 13

[0145] This embodiment provides a preparation method of a high-conductivity graphene copper composite material, comprising the following steps:

[0146] S1: The graphene-coated copper foil is placed into a hot evaporation chamber.

[0147] S2: The graphene-coated copper foil is subjected to evaporation treatment using copper particles or copper wires as the copper source to evaporate a layer of copper on the surface of the graphene-coated copper foil, thereby preparing a graphene-coated copper foil subjected to copper plating treatment.

[0148] S3: The graphene-coated copper foil subjected to copper plating treatment prepared in step S2 is placed into a hot-pressing chamber, appropriate hot-pressing temperature and pressure are set, and the graphene-coated copper foil subjected to copper plating treatment is subjected to hot-pressing forming by using the lamination hot-pressing method, so as to obtain a high-conductivity graphene copper composite material.

[0149] In step S1, the thickness of the graphene-coated copper foil is 10-100 μm.

[0150] In step S2, the thickness of the evaporated copper layer is 1-1000 nm, and the evaporation time is 0.5-50 min; the hot evaporation chamber is subjected to vacuum treatment, and the vacuum degree thereof is 1.0x10 -3 Pa-1,0x10 -4 Pa; and the graphene-coated copper foil subjected to copper plating treatment prepared in step S2 is taken out and vacuum-sealed for storage. It should be noted that the evaporation time is determined according to the thickness of the copper plating, that is, the thicker the copper plating, the longer the evaporation time.

[0151] In step S3, the hot-pressing chamber is first heated to 600-1100°C, the heating time is 20-100 min, then the temperature is kept constant for 20-100 min, after the constant-temperature holding is completed, the temperature is cooled to room temperature, and the cooling time is 20-100 min.

[0152] In the hot-pressing chamber, the pressure is first increased to 20-120 MPa, the pressure increasing time is 20-100 min, then the pressure is kept constant for 20-100 min, after the constant-pressure holding is completed, the pressure is reduced to 0 Pa, and the pressure reducing time is 20-100 min; the hot-pressing chamber is maintained in vacuum or filled with argon for protection.

[0153] Embodiment 14

[0154] A high-conductivity graphene copper composite was prepared by the method of Example 13, and the graphene-coated copper foil was a commercially available product. The preparation process was as follows:

[0155] S1: The graphene-coated copper foil with a thickness of 50 pm was placed into a thermal evaporation chamber.

[0156] S2: The surface of the graphene-coated copper foil was subjected to constant-speed thermal copper evaporation by an evaporation process; a copper wire target with a purity of 99.9999% was used as the copper source, the vacuum degree of the evaporation chamber was 5.0 x 10 -4 Pa, the evaporation heating current was 50 A, and the evaporation time was 25 min, so that a layer of copper was evaporated on the surface of the graphene-coated copper foil, the copper plating thickness was 60 nm, and a copper-plated graphene-coated copper foil was obtained.

[0157] S3: Sixteen graphene-coated copper foils prepared in step S2 were placed into a vacuum hot-pressing chamber for lamination and hot pressing. Before hot pressing, the materials were heated to 950°C, the heating time was 40 min, the constant-temperature time was 40 min, and hot pressing was performed during the constant-temperature time. After cooling for 40 min, the formed high-conductivity graphene copper composite was cooled to room temperature.

[0158] The pressure intensity during hot pressing was 50 MPa, the pressure time was 40 min, the constant-pressure time was 40 min, and finally the pressure was reduced to 0 Pa for 40 min, so that the high-conductivity graphene copper composite was obtained.

[0159] In this embodiment, the length of the graphene-coated copper foil was 20 mm, and the width was 20 mm. The length of the copper source was 15 mm, and the diameter was 1 mm.

[0160] In this embodiment, the vacuum degree of the hot-pressing chamber was 1.0 x 10 -3 Pa.

[0161] The high-conductivity graphene copper composite prepared in step S3 was subjected to electrical property testing according to the Van der Pauw method, and the electrical conductivity was 112.1% IACS.

[0162] Example 15

[0163] A high-conductivity graphene copper composite was prepared by the method of Example 13, and the graphene-coated copper foil was a commercially available product. The preparation process was as follows:

[0164] S1: The graphene-coated copper foil with a thickness of 25 pm was placed into a thermal evaporation chamber.

[0165] S2: The surface of the graphene-coated copper foil was subjected to constant-speed thermal copper evaporation by an evaporation process; a copper wire target with a purity of 99.9999% was used as the copper source, the vacuum degree of the evaporation chamber was 5.0 x 10-4 Pa, the vacuum degree of the evaporation chamber was 5.0 x 10 -3 Pa, and the evaporation heating current was 50 A. The evaporation lasted for 15 min, so that a layer of copper was evaporated on the surface of the graphene-coated copper foil, and the copper plating thickness was 30 nm. Thus, the graphene-coated copper foil treated by copper plating was obtained.

[0166] S3: 16 pieces of the graphene-coated copper foil prepared in step S2 were placed into a vacuum hot-pressing chamber for laminated hot-pressing. Before hot-pressing, the materials were heated to 950 ℃, the heating time was 40 min, the constant temperature time was 40 min, and hot-pressing was performed during the constant temperature time. After cooling for 40 min, the formed high-conductive graphene copper composite material was cooled to room temperature.

[0167] During the hot-pressing, the pressure intensity was 50 MPa, the pressure time was 40 min, the constant pressure time was 40 min, and finally the pressure was reduced to 0 Pa for 40 min. Thus, the high-conductive graphene copper composite material was obtained.

[0168] In this embodiment, the length of the graphene-coated copper foil was 20 mm, and the width was 20 mm. The length of the copper source was 15 mm, and the diameter was 1 mm.

[0169] In this embodiment, the vacuum degree of the hot-pressing chamber was 1.0 x 10 -3 Pa.

[0170] According to the Van der Pauw method, the electrical performance test was performed on the high-conductive graphene copper composite material prepared in step S3, and the electrical conductivity was 108.2% IACS.

[0171] Example 16

[0172] The high-conductive graphene copper composite material was prepared by the method of Example 13. The graphene-coated copper foil was a commercially available product, and the preparation process was as follows:

[0173] S1: The graphene-coated copper foil with a thickness of 25 μm was placed into a hot evaporation chamber.

[0174] S2: The graphene-coated copper foil was subjected to constant-speed hot copper evaporation on the surface by using an evaporation process. The copper source was a copper wire target with a purity of 99.9999%. The vacuum degree of the evaporation chamber was 5.0 x 10 -4 Pa, and the evaporation heating current was 50 A. The evaporation lasted for 15 min, so that a layer of copper was evaporated on the surface of the graphene-coated copper foil, and the copper plating thickness was 30 nm. Thus, the graphene-coated copper foil treated by copper plating was obtained.

[0175] S3: 16 pieces of the graphene-coated copper foil prepared in step S2 were placed into a vacuum hot-pressing chamber for laminated hot-pressing. Before hot-pressing, the materials were heated to 950 ℃, the heating time was 40 min, the constant temperature time was 40 min, and hot-pressing was performed during the constant temperature time. After cooling for 40 min, the formed high-conductive graphene copper composite material was cooled to room temperature.

[0176] The high-conductivity graphene copper composite material is obtained by hot pressing at a pressure of 50 MPa for 40 min, constant pressure for 40 min, and finally decompression for 40 min to reduce the pressure to 0 Pa.

[0177] In this embodiment, the graphene-coated copper foil has a length of 20 mm and a width of 20 mm. The copper source has a length of 15 mm and a diameter of 1 mm.

[0178] In this embodiment, the vacuum degree of the hot pressing chamber is 1.0 x 10 -3 Pa.

[0179] The high-conductivity graphene copper composite material prepared in step S3 is tested for electrical properties according to the Van der Pauw method, and the electrical conductivity is 107.9% IACS.

[0180] Embodiment 17

[0181] The high-conductivity graphene copper composite material is prepared by the method of embodiment 13. The graphene-coated copper foil is a commercially available product, and the preparation process is as follows:

[0182] S1: Place the graphene-coated copper foil with a thickness of 50 μm into the hot evaporation chamber.

[0183] S2: Use the evaporation process to perform constant-speed hot copper evaporation on the surface area of the graphene-coated copper foil. Use a copper wire target with a purity of 99.9999% as the copper source, and the vacuum degree of the evaporation chamber is 5.0 x 10 -4 Pa. The evaporation heating current is 50 A, and the evaporation time is 0.5 min. Thus, a layer of copper with a thickness of 1 nm is evaporated on the surface of the graphene-coated copper foil, obtaining the copper-plated graphene-coated copper foil.

[0184] S3: Place 16 pieces of the graphene-coated copper foil prepared in step S2 into the vacuum hot pressing chamber for laminated hot pressing. Heat the material to 950°C before hot pressing for 40 min, and maintain the temperature for 40 min. Perform hot pressing during this period, and cool the formed high-conductivity graphene copper composite material to room temperature after cooling for 40 min.

[0185] The high-conductivity graphene copper composite material is obtained by hot pressing at a pressure of 50 MPa for 40 min, constant pressure for 40 min, and finally decompression for 40 min to reduce the pressure to 0 Pa.

[0186] In this embodiment, the graphene-coated copper foil has a length of 20 mm and a width of 20 mm. The copper source has a length of 15 mm and a diameter of 1 mm.

[0187] In this embodiment, the vacuum degree of the hot pressing chamber is 1.0 x 10-3 Pa.

[0188] The high-conductivity graphene copper composite prepared in step S3 was tested for electrical properties according to the Van der Pauw method, and the electrical conductivity was 105.2% IACS.

[0189] Example 18

[0190] A high-conductivity graphene copper composite was prepared using the method of Example 13, and the graphene-coated copper foil was a commercially available product. The preparation process was as follows:

[0191] S1: The graphene-coated copper foil with a thickness of 50 pm was placed in a thermal evaporation chamber.

[0192] S2: The surface area of the graphene-coated copper foil was subjected to constant-speed thermal copper evaporation using an evaporation process. A copper wire target with a purity of 99.9999% was used as the copper source, the vacuum degree of the evaporation chamber was 5.0 x 10 -4 Pa, the evaporation heating current was 50 A, and the evaporation time was 50 min, thereby evaporating a layer of copper on the surface of the graphene-coated copper foil, with a copper plating thickness of 1000 nm, to obtain a copper-plated graphene-coated copper foil.

[0193] S3: Sixteen pieces of the graphene-coated copper foil prepared in step S2 were placed in a vacuum hot-pressing chamber for lamination and hot pressing. The material was heated to 950°C before hot pressing, with a heating time of 40 min and a constant temperature time of 40 min, during which hot pressing was performed. After cooling for 40 min, the formed high-conductivity graphene copper composite was cooled to room temperature.

[0194] The pressing intensity during hot pressing was 50 MPa, the pressing time was 40 min, the constant pressure time was 40 min, and finally the pressure was reduced for 40 min to 0 Pa, thereby obtaining the high-conductivity graphene copper composite.

[0195] In this example, the length of the graphene-coated copper foil was 20 mm, and the width was 20 mm. The length of the copper source was 15 mm, and the diameter was 1 mm.

[0196] In this example, the vacuum degree of the hot-pressing chamber was 1.0 x 10 -3 Pa.

[0197] The high-conductivity graphene copper composite prepared in step S3 was tested for electrical properties according to the Van der Pauw method, and the electrical conductivity was 110.3% IACS.

[0198] In summary, the application can prepare graphene copper composite material close to full density, good interface bonding of graphene copper, and super high conductivity of graphene copper through the steps of magnetron sputtering, heat treatment, and laminated hot pressing, and the method is good in controllability and easy for large-scale production. Through the steps of electroplating, heat treatment, and laminated hot pressing, graphene copper composite material close to full density, good interface bonding of graphene copper, and super high conductivity of graphene copper can be prepared, and the method is good in controllability and easy for large-scale production. Through the steps of thermal evaporation, heat treatment, and laminated hot pressing, graphene copper composite material close to full density, good interface bonding of graphene copper, and super high conductivity of graphene copper can be prepared, and the method is good in controllability and easy for large-scale production.

[0199] The above is only the preferred embodiment of the application, and it should be pointed out that, for those skilled in the art, several improvements and refinements can be made without departing from the principles of the application, and these improvements and refinements should also be within the protection scope of the application.

Claims

1. A method for preparing a highly conductive graphene-copper composite material, characterized in that: The steps include the following: S1: Place the graphene-coated copper foil into the magnetron sputtering chamber; S2: Using a pure copper target as the copper source, magnetron sputtering is performed on graphene-coated copper foil to sputter a layer of copper onto the surface of the graphene-coated copper foil, thus producing copper-plated graphene-coated copper foil. S3: The copper-plated graphene-coated copper foil prepared in the multi-layer step S2 is placed into the hot pressing chamber, and an appropriate hot pressing temperature and pressure are set. The copper-plated graphene-coated copper foil is hot-pressed using the stacked hot pressing method to obtain a highly conductive graphene-copper composite material. In step S1, the thickness of the graphene-coated copper foil is 10-100 μm; In step S3, the temperature inside the hot pressing chamber is raised to 600-1100℃ for 20-100 minutes, then kept at a constant temperature for 20-100 minutes, and finally cooled to room temperature for 20-100 minutes. The pressure inside the hot pressing chamber is increased to 20-120 MPa for 20-100 minutes, then kept at a constant pressure for 20-100 minutes, and finally reduced to 0 Pa for 20-100 minutes. The hot pressing chamber is maintained under vacuum or filled with argon for protection.

2. The method for preparing the highly conductive graphene-copper composite material according to claim 1, characterized in that: In step S2, the thickness of the copper sputtered by magnetron sputtering is 1-1000 nm, and the magnetron sputtering time is 0.5-60 min; the magnetron sputtering chamber is subjected to vacuum treatment with a vacuum degree of 2.0 × 10⁻⁶. -3 Pa-1.0×10 -4 Pa; After the copper-plated graphene-coated copper foil prepared in step S2 is removed, it is vacuum-sealed and stored.

3. A method for preparing a highly conductive graphene-copper composite material, characterized in that: The steps include the following: S1: Place the graphene-coated copper foil into the electroplating tank and add the electroplating solution; S2: Using an electroplating process, the graphene-coated copper foil described in step S1 is electroplated to deposit a layer of copper on the surface of the graphene-coated copper foil, so as to produce copper-plated graphene-coated copper foil. S3: Place the copper-plated graphene-coated copper foil prepared in the multi-layer step S2 into the hot pressing chamber, set an appropriate hot pressing temperature and pressure, and use the stacked hot pressing method to hot press the copper-plated graphene-coated copper foil to obtain a highly conductive graphene copper composite material. In step S1, the thickness of the graphene-coated copper foil is 10-100 μm; In step S3, the temperature inside the hot pressing chamber is raised to 600-1100℃ for 20-100 minutes, then kept at a constant temperature for 20-100 minutes, and finally cooled to room temperature for 20-100 minutes. The pressure inside the hot pressing chamber is increased to 20-120 MPa for 20-100 minutes, then kept at a constant pressure for 20-100 minutes, and finally reduced to 0 Pa for 20-100 minutes. The hot pressing chamber is maintained under vacuum or filled with argon for protection.

4. The method for preparing the highly conductive graphene-copper composite material according to claim 3, characterized in that: In step S2 of the electroplating process, the anode is a pure copper plate, and the cathode is a titanium plate; the current density in step S2 is 1-50 A / dm². 2 The electroplating time is 0.5-30 min; the electroplating temperature in step S2 is 25-70℃, and the copper plating thickness is 1-1000 nm; after the copper-plated graphene-coated copper foil is taken out in step S2, it is vacuum sealed and stored.

5. A method for preparing a highly conductive graphene-copper composite material, characterized in that: The steps include the following: S1: Place the graphene-coated copper foil into the thermal evaporation chamber; S2: Using copper particles or copper wires as the copper source, the graphene-coated copper foil is vapor-deposited to form a copper-plated graphene-coated copper foil. S3: Place the copper-plated graphene-coated copper foil prepared in the multi-layer step S2 into the hot pressing chamber, set an appropriate hot pressing temperature and pressure, and use the stacked hot pressing method to hot press the copper-plated graphene-coated copper foil to obtain a highly conductive graphene copper composite material. In step S1, the thickness of the graphene-coated copper foil is 10-100 μm; In step S3, the temperature inside the hot pressing chamber is raised to 600-1100℃ for 20-100 minutes, then kept at a constant temperature for 20-100 minutes, and finally cooled to room temperature for 20-100 minutes. The pressure inside the hot pressing chamber is increased to 20-120 MPa for 20-100 minutes, then kept at a constant pressure for 20-100 minutes, and finally reduced to 0 Pa for 20-100 minutes. The hot pressing chamber is maintained under vacuum or filled with argon for protection.

6. The method for preparing the highly conductive graphene-copper composite material according to claim 5, characterized in that: In step S2, the thickness of the copper layer deposited is 1-1000 nm, and the deposition time is 0.5-50 min; the thermal deposition chamber is subjected to vacuum treatment with a vacuum degree of 1.0 × 10⁻⁶. -3 Pa-1.0×10 -4 Pa; After the copper-plated graphene-coated copper foil prepared in step S2 is removed, it is vacuum-sealed and stored.

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