Preparation method of graphene copper composite material and graphene copper composite material

Abstract

The invention provides a preparation method of a graphene-copper composite material and the graphene-copper composite material, and the preparation method comprises the following steps: controlling a copper foil to only grow graphene on part of the surface so as to obtain a graphene-copper sheet material; the at least two graphene copper sheets are stacked in sequence; in every two adjacent graphene copper sheets, part of the copper foil of one graphene copper sheet is in contact with part of the copper foil of the other graphene copper sheet; and the graphene copper sheets are subjected to hot pressing, so that every two adjacent graphene copper sheets are metallurgically bonded.

Description

Technical Field

[0001] This invention relates to the field of graphene copper preparation process, and in particular to a method for preparing a graphene copper composite material and the graphene copper composite material. Background Technology

[0002] Copper, as a metallic material with excellent electrical conductivity, is widely used in various industries. To further improve the conductivity of copper, the common methods are to increase its purity and reduce grain boundaries and defects. However, these methods have gradually reached their physical limits, significantly increasing the technical requirements and cost demands.

[0003] Based on the aforementioned industry development status, researchers in this field have gradually changed their research approach, combining copper and graphene to create graphene-copper composite materials. These composite materials consist of numerous interlaced copper substrate layers and graphene layers. Due to graphene's extremely high carrier mobility, graphene-copper composite materials exhibit superior electrical conductivity compared to pure copper, and the higher the graphene content, the higher the conductivity of the composite material.

[0004] The traditional preparation process of graphene copper composite material is as follows: First, graphene is grown on the surface of a large number of copper foils using chemical vapor deposition to obtain graphene copper sheets. Then, a large number of graphene copper sheets are stacked together, and finally, the large number of graphene copper sheets are hot-pressed together to obtain graphene copper composite material.

[0005] However, in actual manufacturing, it was found that to achieve a tight bond between different graphene copper sheets, significant pressure needs to be applied during hot pressing, making the hot pressing conditions quite demanding. Insufficient hot pressing pressure will lead to poor contact between the different graphene copper sheets, ultimately reducing the conductivity of the graphene copper composite material. Summary of the Invention

[0006] Therefore, it is necessary to address the problem that existing graphene-copper composite materials cannot simultaneously achieve high conductivity and low hot-pressing pressure during preparation, and to provide a preparation method for graphene-copper composite materials and a graphene-copper composite material.

[0007] The technical solution provided by this invention is as follows:

[0008] A method for preparing a graphene-copper composite material, comprising:

[0009] Graphene is grown on only a portion of the surface of copper foil to obtain graphene copper sheets.

[0010] At least two of the graphene copper sheets are stacked sequentially;

[0011] In two adjacent graphene copper sheets, a portion of the copper foil of one graphene copper sheet is in contact with a portion of the copper foil of the other graphene copper sheet.

[0012] The graphene copper sheet is hot-pressed to connect adjacent graphene copper sheets.

[0013] In some embodiments, the graphene is grown on both sides of the copper foil.

[0014] In some embodiments, the graphene is grown on the surface of the copper foil by chemical vapor deposition;

[0015] During the growth process, both growth gas and dilution gas are introduced to ensure that the graphene grows only on a portion of the surface of the copper foil.

[0016] In some embodiments, the growth gas includes methane and hydrogen, and the dilution gas includes argon and / or nitrogen.

[0017] In some embodiments, the flow rate of methane in the growth gas is 10 sccm-2000 sccm, the flow rate of hydrogen is 10 sccm-2000 sccm, and the flow rate of the dilution gas is no greater than 2000 sccm.

[0018] In some embodiments, the flow rate of methane in the growth gas is 20 sccm-120 sccm, the flow rate of hydrogen is 30 sccm-150 sccm, and the flow rate of the dilution gas is 100 sccm-500 sccm.

[0019] In some embodiments, the flow ratio of methane to hydrogen in the growth gas is 1:2-4:5, and the flow ratio of the growth gas to the dilution gas is 1:10-27:20.

[0020] In some embodiments, the thickness of the copper foil is 4.5μm-150μm, the number of graphene crystal layers is 1-6, and the number of stacked graphene copper sheets is 2-200.

[0021] In some embodiments, the hot pressing pressure is 30MPa-50MPa, the hot pressing temperature is 600℃-1050℃, the hot pressing vacuum degree is 0.1Pa-0.001Pa, and the hot pressing time is 10min-240min.

[0022] A graphene-copper composite material is prepared using the aforementioned method for preparing graphene-copper composite materials.

[0023] The inventors discovered that, due to their inherent material properties, graphene and copper foil require significant hot-pressing pressure to achieve bonding, whether between graphene sheets or between graphene and copper foil. Therefore, in the existing preparation process of graphene-copper composite materials, the bonding of adjacent graphene-copper sheets already requires substantial hot-pressing pressure. Furthermore, to improve the conductivity of the final graphene-copper composite material, existing technologies typically maximize the graphene content in the graphene-copper sheets. This further increases the hot-pressing pressure required for bonding the graphene-copper sheets. Insufficient hot-pressing pressure leads to poor contact between the graphene-copper sheets, negatively impacting the overall conductivity of the graphene-copper composite material.

[0024] However, further research by the inventors revealed that excessive hot-pressing pressure would damage the integrity and continuity of graphene, causing irregular cracks and additional defects in the graphene, which would also adversely affect the electrical conductivity of the graphene-copper composite material.

[0025] This invention overcomes the existing technological bias that higher graphene content equates to better electrical conductivity in graphene-copper composites. Instead, it reduces the graphene content in the graphene-copper sheet by controlling the localized growth of graphene on the copper foil surface. Based on the foregoing analysis, reducing the graphene content directly lowers the pressure requirements during the hot-pressing process. Secondly, the localized growth of graphene on the copper foil surface leaves a portion of the copper foil exposed after the graphene growth is complete. Consequently, adjacent graphene-copper sheets can form direct contact, leading to adhesion and grain transformation at high temperatures. This allows the copper foils to connect directly and maintain connection strength, reducing the required hot-pressing connection strength between the copper foil and graphene, thus also reducing the pressure requirements during the hot-pressing process.

[0026] By simultaneously reducing the pressure requirements during the hot-pressing process through the two methods mentioned above, graphene breakage can be effectively reduced while maintaining its integrity. Thus, by lowering the hot-pressing pressure requirements, the electrical conductivity of the final graphene-copper composite material is actually ensured. Attached Figure Description

[0027] Figure 1 This is a process diagram illustrating the preparation method of the graphene-copper composite material in an embodiment of the present invention;

[0028] Figure 2 This is a scanning electron microscope image of graphene in Example 1 of the present invention;

[0029] Figure 3 This is a scanning electron microscope image of graphene in Example 2 of the present invention;

[0030] Figure 4 This is a scanning electron microscope image of graphene in Example 3 of the present invention;

[0031] Figure 5 This is a scanning electron microscope image of graphene in Example 4 of the present invention;

[0032] Figure 6 This is a scanning electron microscope image of the graphene in Comparative Example 1 of the present invention.

[0033] 1. Copper foil; 2. Graphene copper sheet; 3. Graphene copper composite material. Detailed Implementation

[0034] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described in detail below. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0035] Comparative example:

[0036] This comparative example provides a method for preparing graphene-copper composite material 3, including the following steps:

[0037] Step 101: Graphene is grown on the surface of copper foil 1 by chemical vapor deposition to obtain graphene copper sheet 2. During the graphene growth process, only growth gas is introduced into the quartz tube, and no dilution gas (such as argon or nitrogen) is introduced. The growth gas may include, for example, methane and hydrogen.

[0038] When graphene is grown on one side of copper foil 1, the above preparation method results in graphene covering the entire upper surface of copper foil 1.

[0039] When graphene is grown on both sides of copper foil 1, the above preparation method results in graphene covering both the upper and lower surfaces of copper foil 1.

[0040] Step 102: Prepare at least two of the above-mentioned graphene copper sheets 2, and stack all the graphene copper sheets 2 to form a material to be hot-pressed.

[0041] When graphene is grown on one side of copper foil 1, for two adjacent graphene copper sheets 2, the copper foil of one graphene copper sheet 2 will directly contact the graphene of the other graphene copper sheet 2, but will not contact the copper foil of the other graphene copper sheet 2.

[0042] When graphene is grown on both sides of copper foil 1, for two adjacent graphene copper sheets 2, the graphene on one graphene copper sheet 2 will be in direct contact with the graphene on the other graphene copper sheet 2.

[0043] Step 103: Hot-press the material to be hot-pressed to connect two adjacent graphene copper sheets 2, forming a graphene copper composite material 3.

[0044] The inventors discovered that, regardless of whether copper foil 1 is joined to graphene via hot pressing, or whether graphene is joined to graphene via hot pressing, the required hot pressing pressure is relatively high due to the material properties. Furthermore, increasing the graphene thickness increases the difficulty of joining copper foil 1 to graphene or between graphene layers, further increasing the required hot pressing pressure. Excessive hot pressing pressure, however, damages the integrity and continuity of the graphene, causing irregular fractures and additional defects, ultimately negatively impacting the conductivity of the final graphene-copper composite material 3.

[0045] Example:

[0046] like Figure 1 As shown, this embodiment provides a method for preparing graphene-copper composite material 3, including the following steps:

[0047] Step 201: Graphene is grown on the surface of copper foil 1 by chemical vapor deposition to obtain graphene copper sheet 2. During the graphene growth process, a growth gas and a dilution gas (such as argon or nitrogen) are simultaneously introduced into the quartz tube. The growth gas may include, for example, methane and hydrogen.

[0048] When graphene is grown on only one side of copper foil 1, the above preparation method results in graphene being grown only in a portion of the upper surface of copper foil 1, leaving a portion of the upper surface of copper foil 1 exposed. Therefore, the graphene has a certain duty cycle. In the case of graphene growth on only one side of copper foil 1, the duty cycle of graphene is the ratio of the area of ​​the graphene-grown portion of the upper surface of copper foil 1 to the area of ​​the ungrown portion of the upper surface of copper foil 1.

[0049] When graphene is grown on both sides of copper foil 1, the above preparation method results in graphene being grown only in partial locations on the upper surface and lower surface of copper foil 1. A portion of both the upper and lower surfaces of copper foil 1 is exposed, thus giving the graphene a certain duty cycle. In the case of graphene growth on both sides of copper foil 1, the duty cycle is the ratio of the total area of ​​the graphene-grown portions to the total area of ​​the ungrown portions.

[0050] Step 202: Prepare at least two of the above-mentioned graphene copper sheets 2, and stack all the graphene copper sheets 2 to form a material to be hot-pressed.

[0051] Since part of the surface of the copper foil 1 is exposed, and the thickness of the graphene is very thin, only nanometer-sized, after the graphene copper sheet 2 is stacked, for two adjacent graphene copper sheets 2, part of the copper foil 1 of one graphene copper sheet 2 can contact part of the copper foil 1 of the other graphene copper sheet 2, that is, copper foil-copper foil contact.

[0052] Step 203: Hot-press the material to be hot-pressed to connect two adjacent graphene copper sheets 2, forming a graphene copper composite material 3.

[0053] This embodiment achieves localized graphene growth on the surface of copper foil 1 by incorporating diluent gas during the graphene growth process. Compared to the previous approach of first growing graphene completely on the surface of copper foil 1 and then cutting the graphene to achieve localized graphene growth, this embodiment omits the graphene cutting step, achieving the following effects: First, it simplifies the process flow; second, it avoids damage to the surface of copper foil 1 caused by cutting, thus preventing the creation of new defects on the surface of copper foil 1 that could reduce the conductivity of the graphene-copper composite material 3; third, cutting can easily damage the graphene at the cut surface, which is detrimental to maintaining the integrity of the graphene during subsequent hot pressing. By avoiding the cutting process, it is beneficial to maintain the integrity of the graphene during subsequent hot pressing.

[0054] Due to its inherent material properties, copper foil requires only a small amount of hot-pressing pressure to achieve a metallurgical bond between copper foils at high temperatures, forming a copper foil-to-copper foil connection. This ensures the connection strength between adjacent graphene copper sheets 2, thereby reducing the requirements for the connection strength between graphene and copper foil, or between graphene sheets themselves. Consequently, the pressure required for the hot-pressing process is also reduced.

[0055] Furthermore, since the amount of graphene between two adjacent copper foils 1 is reduced compared to the comparative ratio, the amount of graphene that the copper foils 1 need to connect during the hot pressing process is also reduced accordingly, which also reduces the pressure required for the hot pressing process.

[0056] Due to the combined effect of the above two aspects, the pressure required during the hot pressing process is significantly reduced.

[0057] The significant reduction in pressure during hot pressing reduces the fragmentation of graphene within the graphene-copper composite material 3, further preserving the integrity of the graphene. This, in turn, compensates for the adverse effect of reduced graphene content on conductivity, ultimately ensuring the conductivity of the graphene-copper composite material 3.

[0058] Example 1:

[0059] This embodiment provides a method for preparing graphene-copper composite material 3, including the following steps:

[0060] Step 201: Graphene is grown on both sides of a 25μm thick copper foil 1 by chemical vapor deposition to obtain a graphene copper sheet 2.

[0061] During the graphene growth process, growth gases (methane and hydrogen) and dilution gases (argon) were simultaneously introduced into the quartz tube. The methane flow rate was 20 sccm, the hydrogen flow rate was 30 sccm, the argon flow rate was 100 sccm, the graphene growth temperature was 1030℃, and the growth time was 10 min.

[0062] like Figure 2 As shown, the graphene obtained in this embodiment has 1-2 crystal layers, the crystal shape is petal-shaped, and the duty cycle is about 91%.

[0063] Step 202: Prepare seven graphene copper sheets 2 as described above, and stack all the graphene copper sheets 2 to form a material to be hot-pressed.

[0064] Step 203: Hot-press the material to be hot-pressed in a vacuum hot press furnace to connect two adjacent graphene copper sheets 2 to form a graphene copper composite material 3.

[0065] The vacuum degree of the hot pressing environment is 0.1 Pa, the temperature during the hot pressing process is 950℃, the hot pressing pressure is 30 MPa, and the hot pressing time is 60 min.

[0066] According to the van der Berg method test, with reference standard T / CSTM 00591 2022, the conductivity of the graphene copper composite material 3 in this embodiment is 110% IASC.

[0067] Example 2:

[0068] This embodiment provides a method for preparing graphene-copper composite material 3, including the following steps:

[0069] Step 201: Graphene is grown on both sides of a 4.5 μm thick copper foil 1 by chemical vapor deposition to obtain a graphene copper sheet 2.

[0070] During the graphene growth process, growth gases (methane and hydrogen) and dilution gases (nitrogen) were simultaneously introduced into the quartz tube. The methane flow rate was 20 sccm, the hydrogen flow rate was 30 sccm, and the nitrogen flow rate was 500 sccm. The graphene growth temperature was 1030℃, and the growth time was 15 min.

[0071] like Figure 3 As shown, the graphene obtained in this embodiment has 1-2 crystal layers, hexagonal crystal shape, and a duty cycle of approximately 60%.

[0072] Step 202: Prepare 160 graphene copper sheets 2 as described above, and stack all the graphene copper sheets 2 to form a material to be hot-pressed.

[0073] Step 203: Hot-press the material to be hot-pressed in a vacuum hot press furnace to connect two adjacent graphene copper sheets 2 to form a graphene copper composite material 3.

[0074] The vacuum degree of the hot pressing environment is 0.1 Pa, the temperature during the hot pressing process is 650℃, the hot pressing pressure is 50 MPa, and the hot pressing time is 180 min.

[0075] According to the van der Berg method test, with reference standard T / CSTM 00591 2022, the conductivity of the graphene copper composite material 3 in this embodiment is 107% IASC.

[0076] Example 3:

[0077] This embodiment provides a method for preparing graphene-copper composite material 3, including the following steps:

[0078] Step 201: Graphene is grown on both sides of a 100μm thick copper foil 1 by chemical vapor deposition to obtain a graphene copper sheet 2.

[0079] During the graphene growth process, growth gases (methane and hydrogen) and dilution gases (argon) were simultaneously introduced into the quartz tube. The methane flow rate was 20 sccm, the hydrogen flow rate was 40 sccm, the argon flow rate was 100 sccm, the graphene growth temperature was 1030℃, and the growth time was 10 min.

[0080] like Figure 4 As shown, the graphene obtained in this embodiment has 1 to 3 crystal layers, the crystal shape is petal-shaped, and the duty cycle is about 80%.

[0081] Step 202: Prepare forty graphene copper sheets 2 as described above, and stack all the graphene copper sheets 2 to form a material to be hot-pressed.

[0082] Step 203: Hot-press the material to be hot-pressed in a vacuum hot press furnace to connect two adjacent graphene copper sheets 2 to form a graphene copper composite material 3.

[0083] The vacuum degree of the hot pressing environment is 0.1 Pa, the temperature during the hot pressing process is 850℃, the hot pressing pressure is 50 MPa, and the hot pressing time is 30 min.

[0084] According to the van der Berg method test, with reference standard T / CSTM 00591 2022, the conductivity of the graphene copper composite material 3 in this embodiment is 109% IASC.

[0085] Example 4:

[0086] This embodiment provides a method for preparing graphene-copper composite material 3, including the following steps:

[0087] Step 201: Graphene is grown on both sides of a 7μm thick copper foil 1 by chemical vapor deposition to obtain a graphene copper sheet 2.

[0088] During the graphene growth process, growth gases (methane and hydrogen) and dilution gases (nitrogen) were simultaneously introduced into the quartz tube. The methane flow rate was 120 sccm, the hydrogen flow rate was 150 sccm, and the nitrogen flow rate was 200 sccm. The graphene growth temperature was 1030℃, and the growth time was 15 min.

[0089] like Figure 5 As shown, the graphene obtained in this embodiment has 1 to 2 crystal layers, the crystals are island-shaped, and the duty cycle is about 95%.

[0090] Step 202: Prepare forty graphene copper sheets 2 as described above, and stack all the graphene copper sheets 2 to form a material to be hot-pressed.

[0091] Step 203: Hot-press the material to be hot-pressed in a vacuum hot press furnace to connect two adjacent graphene copper sheets 2 to form a graphene copper composite material 3.

[0092] The vacuum degree of the hot pressing environment is 0.1 Pa, the temperature during the hot pressing process is 1000℃, the hot pressing pressure is 50 MPa, and the hot pressing time is 120 min.

[0093] According to the van der Berg method test, with reference standard T / CSTM 00591 2022, the conductivity of the graphene copper composite material 3 in this embodiment is 112% IASC.

[0094] Comparative Example 1:

[0095] This comparative example provides a method for preparing graphene-copper composite material 3, including the following steps:

[0096] Step 101: Graphene is grown on both sides of a 7μm thick copper foil 1 by chemical vapor deposition to obtain a graphene copper sheet 2.

[0097] In the graphene growth process described above, only growth gases (methane and hydrogen) were introduced into the quartz tube. The methane flow rate was 100 sccm, and the hydrogen flow rate was 100 sccm. The growth temperature was 1030℃, and the growth time was 30 minutes.

[0098] like Figure 6 As shown, in this comparative example, the final graphene completely covers the upper and lower surfaces of copper foil 1, and the number of graphene crystal layers is 1-2 layers.

[0099] Step 102: Prepare forty graphene copper sheets 2 as described above, and stack all the graphene copper sheets 2 to form a material to be hot-pressed.

[0100] Step 103: Hot-press the material to be hot-pressed in a vacuum hot press furnace to connect two adjacent graphene copper sheets 2 to form a graphene copper composite material 3.

[0101] The vacuum degree of the hot pressing environment is 0.1 Pa, the temperature during the hot pressing process is 1000℃, the hot pressing pressure is 120 MPa, and the hot pressing time is 120 minutes.

[0102] According to the van der Berg method test, with reference standard T / CSTM 00591 2022, the conductivity of the comparative graphene copper composite material 3 is 108% IASC.

[0103] Comparative Example 2:

[0104] This comparative example provides a method for preparing graphene-copper composite material 3, including the following steps:

[0105] Step 101: Graphene is grown on both sides of a 7μm thick copper foil 1 by chemical vapor deposition to obtain a graphene copper sheet 2.

[0106] In the graphene growth process described above, only growth gases (methane and hydrogen) were introduced into the quartz tube. The methane flow rate was 100 sccm, and the hydrogen flow rate was 100 sccm. The growth temperature was 1030℃, and the growth time was 30 minutes.

[0107] Step 102: Prepare forty graphene copper sheets 2 as described above, and stack all the graphene copper sheets 2 to form a material to be hot-pressed.

[0108] Step 103: Hot-press the material to be hot-pressed in a vacuum hot press furnace to connect two adjacent graphene copper sheets 2 to form a graphene copper composite material 3.

[0109] The vacuum degree of the hot pressing environment is 0.1 Pa, the temperature during the hot pressing process is 1000℃, the hot pressing pressure is 30 MPa, and the hot pressing time is 120 minutes.

[0110] According to the van der Berg method test, with reference standard T / CSTM 00591 2022, the conductivity of the comparative graphene copper composite material 3 is 104% IASC.

[0111] First, the hot-pressing pressure in Examples 1-4 was only 30MPa-50MPa, far lower than the 120MPa in Comparative Example 1. Second, the electrical conductivity of the graphene-copper composite material 3 in Examples 1-4 was similar to that in Comparative Example 1.

[0112] This confirms that the preparation method of the graphene copper composite material provided in this application can simultaneously take into account the electrical conductivity of the final graphene copper composite material and the low hot-pressing pressure during its preparation process.

[0113] Further comparison of Comparative Example 1 and Comparative Example 2 reveals that when graphene completely covers both the upper and lower surfaces of copper foil 1, a decrease in hot-pressing pressure from 120 MPa to 30 MPa leads to a significant decrease in the electrical conductivity of the graphene-copper composite material 3. This is because lower hot-pressing pressure makes it difficult to break down the graphene, thus hindering the achievement of better bonding between copper particles.

[0114] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0115] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for preparing a graphene-copper composite material, characterized in that, include: Graphene is grown on only a portion of the surface of copper foil to obtain graphene copper sheets. At least two of the graphene copper sheets are stacked sequentially; In two adjacent graphene copper sheets, a portion of the copper foil of one graphene copper sheet is in contact with a portion of the copper foil of the other graphene copper sheet. The graphene copper sheet is hot-pressed to connect adjacent graphene copper sheets.

2. The method for preparing the graphene-copper composite material according to claim 1, characterized in that, The graphene is grown on both sides of the copper foil.

3. The method for preparing the graphene-copper composite material according to claim 1, characterized in that, The graphene is grown on the surface of the copper foil by chemical vapor deposition; During the growth process, both growth gas and dilution gas are introduced to ensure that the graphene grows only on a portion of the surface of the copper foil.

4. The method for preparing the graphene-copper composite material according to claim 3, characterized in that, The growth gas includes methane and hydrogen, and the dilution gas includes argon and / or nitrogen.

5. The method for preparing the graphene-copper composite material according to claim 4, characterized in that, The flow rate of methane in the growth gas is 10 sccm-2000 sccm, the flow rate of hydrogen is 10 sccm-2000 sccm, and the flow rate of the dilution gas is no greater than 2000 sccm.

6. The method for preparing the graphene-copper composite material according to claim 5, characterized in that, The flow rate of methane in the growth gas is 20 sccm-120 sccm, the flow rate of hydrogen is 30 sccm-150 sccm, and the flow rate of the dilution gas is 100 sccm-500 sccm.

7. The method for preparing the graphene-copper composite material according to claim 6, characterized in that, The flow ratio of methane to hydrogen in the growth gas is 1:2-4:5, and the flow ratio of the growth gas to the dilution gas is 1:10-27:

20.

8. The method for preparing the graphene-copper composite material according to claim 1, characterized in that, The thickness of the copper foil is 4.5μm-150μm, the number of graphene crystal layers is 1-6, and the number of stacked graphene copper sheets is 2-200.

9. The method for preparing the graphene-copper composite material according to claim 1, characterized in that, The hot pressing pressure is 30MPa-50MPa, the hot pressing temperature is 600℃-1050℃, the hot pressing vacuum degree is 0.1Pa-0.001Pa, and the hot pressing time is 10min-240min.

10. A graphene-copper composite material, characterized in that, The graphene-copper composite material was prepared using the preparation method described in any one of claims 1-9.

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