High-elasticity low-thermal-resistance graphene thermal interface material and preparation method thereof

Abstract

This invention provides a highly elastic, low-thermal-resistance graphene thermal interface material and its preparation method. Its main characteristics are high elasticity, low thermal resistance, and an extremely wide operating temperature range, making it suitable for thermal management in 3C products, high-power electronic chips, new energy vehicles, and extreme high and low temperature environments. By selecting a graphitized graphene aerogel film as a high-thermal-conductivity framework, and in-situ composited with incompletely graphitized graphene treated with high-temperature annealing as an elastic component, and introducing a micro-buckling structure to further enhance vertical surface thermal conductivity, a flexible graphene thermal interface material with both high elasticity and low thermal resistance is prepared. The elastic thermal interface material is composed only of graphene with different structures and treated at different temperatures, and can be used in a temperature range of -200℃ to 1000℃. Compared with metal-based thermal interface materials, it is more resistant to chemical corrosion, and simultaneously improves the problem of traditional graphene aerogels struggling to balance high thermal conductivity and high elasticity.

Description

Technical Field

[0001] This invention belongs to the field of thermal management materials technology, and specifically relates to a highly elastic, low thermal resistance graphene thermal interface material and its preparation method. Background Technology

[0002] With the rapid development of information technology and the high miniaturization and integration of electronic components, heat dissipation has gradually become a bottleneck restricting the development of many fields. Localized overheating caused by the inability to transfer heat in a timely manner can lead to chip frequency reduction, increased battery side reactions, and decreased lifespan / reliability of electronic products. Thermal interface materials are flexible materials with high thermal conductivity and low modulus. Filling the space between heat-generating elements and heat sinks can improve the interface environment between them and enhance heat transfer. Developing high-performance thermal interface materials is crucial for promoting the rapid development of technologies such as smartphones, new energy vehicles, and 5G, and has extremely high market value.

[0003] Existing thermal interface materials are mainly composed of elastic polymer matrices and composites of metal fillers, inorganic fillers, or carbon materials, and have relatively low thermal conductivity (5-10 W / m). -1 K -1 Furthermore, graphene has a narrow applicable temperature range (-40 to 200℃), making it difficult to meet the heat dissipation requirements of high-power chips, high-energy-density battery cells, and extreme high and low temperature environments. Although graphene has been used to prepare high-performance thermal interface materials, it is mainly used as a thermally conductive filler. A few thermal interface materials composed entirely of graphene cannot simultaneously achieve both thermal conductivity and physical-mechanical properties. Whether it is possible to prepare pure graphene thermal interface materials with both high elasticity and low thermal resistance, enhance thermal conductivity and physical-mechanical properties, broaden the operating temperature range, and provide new solutions to thermal management problems is an urgent problem and a significant challenge. Summary of the Invention

[0004] The purpose of this invention is to provide a highly elastic, low-thermal-resistance graphene thermal interface material, comprising at least a graphitized graphene aerogel film as a high-thermal-conductivity framework and high-temperature annealed but incompletely graphitized graphene as an elastic component, forming a thermal interface material with high and low temperature resistance, high elasticity, and low thermal resistance. By filling a high-thermal-conductivity graphene foam film with an elastic graphene component, the problem of achieving both high thermal conductivity and elasticity in a single graphene aerogel can be effectively improved, thereby realizing the preparation of a low-thermal-resistance, high-elasticity graphene thermal interface material.

[0005] The technical solution adopted in this invention is: a highly elastic, low thermal resistance graphene thermal interface material, comprising at least a graphitized graphene aerogel film as a highly thermally conductive framework, with a density of 23–87 mg / cm³. -3The elastic component is graphene that has been annealed at high temperature but not fully graphitized. The elastic component is filled on the inner surface of the high thermal conductivity framework in a non-close-packed form, resulting in an overall material density of 32–139 mg / cm³. -3 This forms the thermal interface material of the present invention, which is resistant to high and low temperatures, highly elastic, and has low thermal resistance.

[0006] In some embodiments of the present invention, the high thermal conductivity framework mainly refers to graphene aerogel film that has undergone graphitization treatment at 2300-3150℃, and the graphitization treatment time is generally 1 hour.

[0007] This invention also provides a method for preparing a highly elastic, low thermal resistance graphene thermal interface material, comprising the following steps:

[0008] (1) The graphene oxide solution is coated into a film, dried, and then placed in a 5-85% hydrazine hydrate solution for foaming for 15-300 min. The foamed graphene aerogel film is then graphitized. The foaming temperature is 20-90℃.

[0009] (2) Impregnate the graphene aerogel membrane with a concentration of 0.2–5 mg g. -1 Vacuum infusion of graphene oxide solution for 1–2 hours, followed by drying at 40–60°C and high-temperature annealing for 1–3 hours at 1000–2000°C, yields a highly elastic, low-thermal-resistance graphene thermal interface material.

[0010] This invention also provides a method for preparing a highly elastic, low thermal resistance graphene thermal interface material, comprising the following steps:

[0011] (1) The graphene oxide solution is coated into a film, dried, and then placed in a 5-85% hydrazine hydrate solution for foaming for 15-300 min. The foamed graphene aerogel film is then graphitized. The foaming temperature is 20-90℃.

[0012] (2) Impregnate the graphene aerogel membrane with a concentration of 0.2–5 mg g. -1 Vacuum infusion of graphene oxide solution for 1–2 h, followed by immersion in hydrazine hydrate solution for 1–5 h to introduce micro-bent structures on the surface of graphene oxide sheets, replacement of hydrazine hydrate solution with ethanol, drying in an environment of 40–60 °C, and then high-temperature annealing treatment for 1–3 h at an annealing temperature of 1000–2000 °C.

[0013] Furthermore, the strong reducing agent is a 60-85% hydrazine hydrate solution.

[0014] Furthermore, the graphene oxide is a single layer or multiple layers.

[0015] The obtained thermal interface material exhibits a springback rate of 50–99% when the compression ratio does not exceed 98%; and a vertical surface thermal conductivity ranging from 8 to 20 W / m. -1 K -1 When the applied pressure is 10–1200 kPa, the thermal resistance range is 0.02–2 K cm. 2 W -1 .

[0016] Unless otherwise specified, all concentrations mentioned above are volume percentages.

[0017] The beneficial effects of this invention are as follows:

[0018] (1) The graphene / graphene composite foam film of this invention possesses properties not found in graphene foam films of any single component. It exhibits the high thermal conductivity of highly graphitized graphene aerogels while possessing the compressibility-resilience of incompletely graphitized graphene aerogels. Since heat transfer in graphene primarily occurs through graphite lattice vibrations, highly graphitized graphene with a large atomic mean free path constitutes a continuous thermally conductive network with high thermal conductivity. Incompletely graphitized graphene, due to the presence of oxygen-containing functional groups and out-of-plane carbon atoms on its surface, has a larger coefficient of friction and cross-linking structure between sheets compared to highly graphitized graphene, macroscopically manifesting as the compressibility-resilience of an aerogel. By combining highly graphitized / incompletely graphitized graphene aerogels at the microscopic level, the high thermal conductivity of the former is maintained while the latter is endowed with excellent elasticity, improving the problem of the difficulty in simultaneously achieving high thermal conductivity and high elasticity in traditional graphene aerogels. When the compression ratio does not exceed 98%, the resilience is 50-99%. The thermal conductivity of the vertical plane ranges from 8 to 20 W / m. -1 K -1 When the applied pressure is 10–1200 kPa, the thermal resistance range is 0.02–2 K cm. 2 W -1 .

[0019] (2) By utilizing the self-shrinking mechanism of graphene oxide solution in a strong reducing agent, graphene oxide solution is further injected into the graphene foam and treated with a strong reducing agent solution to achieve self-folding assembly inside the graphene oxide sheets. This introduces a micro-buckling structure to the surface of the incompletely graphitized graphene, providing more rapid transmission channels for thermal phonons in the vertical direction. This further improves the out-of-plane thermal conductivity of the graphene / graphene composite foam film and reduces the overall thermal resistance, which helps to further improve the material performance.

[0020] (3) Thanks to the pure graphene structure, the prepared high-elasticity, low-thermal-resistance graphene thermal interface material has an extremely wide operating temperature range. Compared with polymer-based thermal interface materials, it has better environmental tolerance and anti-aging properties and can be used in the temperature range of -200℃ to 1000℃. It is also more resistant to chemical corrosion than metal-based thermal interface materials. Attached Figure Description

[0021] Figure 1 The image shows a compression-rebound photograph of the graphene composite aerogel in Example 1. As can be seen from the image, the 1.5cm high composite aerogel was compressed to 0.75cm and then completely returned to its initial state.

[0022] Figure 2 The image shows a scanning electron microscope image of the graphene composite aerogel in Example 2. Comparing Figure a and Figure b, it can be seen that the incompletely graphitized graphene serves as an elastic scaffold filling the highly graphitized, thermally conductive graphene aerogel network.

[0023] Figure 3 The figure shows the stress-strain curves of the graphene composite aerogel under different compression rates in Example 2. It can be seen from the figure that it has excellent elasticity when compressed to 10% to 80%.

[0024] Figure 4 The images show scanning electron microscope (SEM) images of the surfaces of elastic graphene treated with 80% hydrazine hydrate and ordinary graphene in Example 3. As can be seen from the images, the surfaces of the graphene treated with 80% hydrazine hydrate have a micro-buckling structure.

[0025] Figure 5 The figure shows the stress-strain curves of the graphene composite aerogel in Example 4 after being frozen with liquid nitrogen. As can be seen from the figure, it still has excellent elasticity when compressed to 10-80% after experiencing extreme low temperature environment.

[0026] Figure 6 The figure shows the stress-strain curves of the graphene composite aerogel after vacuum treatment at 1000℃ in Example 5, which show that it still has excellent elasticity after experiencing extreme high temperature environment. Detailed Implementation

[0027] The present invention will be specifically described below through embodiments. These embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-essential changes and adjustments made by those skilled in the art based on the above-described invention shall fall within the scope of protection of the present invention.

[0028] Example 1:

[0029] (1) 200g 15mg g -1A graphene oxide aqueous solution was used as a slurry, and a clean glass plate was used as a substrate. An automatic doctor blade coater was used to coat the graphene oxide aqueous solution into a film. The graphene oxide film was then peeled off the glass plate and placed in a 20% hydrazine hydrate solution at 60°C for 240 minutes to foam. Subsequently, it was placed in a graphitization furnace and heated at 10°C for 1 minute under an argon atmosphere. -1 The temperature was increased to 2800℃ and held for 1 hour to obtain a highly graphitized graphene foam film with a density of 23 mg / cm³. -3 .

[0030] (2) Immerse the above graphene foam film in 0.2 mg g solution. -1 The graphene oxide was vacuum-infused in an aqueous solution for 2 hours, dried in an oven at 60°C for 6 hours, and then placed in a tube furnace and heated at 10°C for 1 minute under an argon atmosphere. -1 The temperature was increased to 1600℃ and held for 1 hour to obtain a highly graphitized / incompletely graphitized graphene composite foam film.

[0031] The graphene / graphene composite foam film obtained through the above steps has a mass ratio of highly graphitized to incompletely graphitized graphene of approximately 7:3, an overall thickness of 1.5 cm, and a density of 32 mg / cm³. -3 The out-of-plane thermal conductivity was measured to be 8.1 W / m using the transient laser scintillation method. -1 K -1 The thermal resistance at 100 kPa was measured to be 0.21 K cm using the steady-state heat flow meter method. 2 W -1 It can be fully restored after being compressed by 50%. Figure 1 ).

[0032] Example 2:

[0033] (1) 200g 4mg g -1 A graphene oxide aqueous solution was used as a slurry, and a clean glass plate was used as a substrate. An automatic doctor blade coater was used to coat the graphene oxide aqueous solution into a film, with a 1 mm gap between the doctor blade and the substrate. The graphene oxide film was then peeled off the substrate and placed in a 5% concentration hydrazine hydrate solution at 60°C for 15 minutes at room temperature. Subsequently, it was placed in a graphitization furnace and heated at 10°C for 1 minute under an argon atmosphere. -1 The temperature was increased to 2800℃ at a certain heating rate and held for 1 hour to obtain a highly graphitized graphene foam film with a density of 87 mg / cm³. -3 Microscopic morphology such as Figure 2 As shown in a.

[0034] (2) Immerse the above graphene foam film in 5 mg g -1The graphene oxide was vacuum-infused in an aqueous solution for 2 hours, dried in an oven at 40°C for 6 hours, and then placed in a tube furnace and heated at 10°C / min under an argon atmosphere. -1 Heating to 1000℃ at a certain heating rate and holding for 3 hours yielded a highly graphitized / incompletely graphitized graphene composite foam film with a microstructure as shown in the figure. Figure 2 As shown in b, it can be seen that the graphene component injected in step 2 is filled in the graphene aerogel network.

[0035] The graphene / graphene composite foam film obtained through the above steps has a mass ratio of highly graphitized to incompletely graphitized graphene of approximately 2:1, an overall thickness of approximately 220 μm, and a density of 135 mg / cm³. -3 Microscopic morphology such as Figure 2 As shown in b, the out-of-plane thermal conductivity using the transient laser flare method is 13.8 W / m. -1 K -1 The thermal resistance at 100 kPa was measured to be 0.1 Kcm using the steady-state heat flow meter method. 2 W -1 It exhibits excellent elasticity as the compression ratio increases sequentially from 10% to 80%. Figure 3 ).

[0036] Example 3:

[0037] (1) 200g 4mg g -1 A graphene oxide aqueous solution was used as a slurry, and a clean glass plate was used as a substrate. An automatic doctor blade coater was used to coat the graphene oxide aqueous solution into a film, with a 1 mm gap between the doctor blade and the substrate. The graphene oxide film was then peeled off the substrate and placed in a 5% concentration hydrazine hydrate solution at 60°C for 15 minutes at room temperature. Subsequently, it was placed in a graphitization furnace and heated at 10°C for 1 minute under an argon atmosphere. -1 The temperature was increased to 2800℃ and held for 1 hour to obtain a highly graphitized graphene foam film with a density of 85 mg / cm³. -3 .

[0038] (2) Immerse the above graphene foam film in 5 mg g -1 The graphene / graphene oxide composite foam was vacuum-infused in an aqueous solution for 2 hours, then transferred to an 80% hydrazine hydrate solution for another 2 hours. The remaining hydrazine hydrate solution in the graphene / graphene oxide composite foam was replaced with anhydrous ethanol and dried in an oven at 60°C for 6 hours. The foam was then placed in a tube furnace and heated at 10°C for 1 minute under an argon atmosphere. -1 The temperature was increased to 1600℃ and held for 1 hour to obtain a highly graphitized / microscopically buckled incomplete graphitized graphene composite foam film.

[0039] The graphene / graphene composite foam film obtained through the above steps has a mass ratio of highly graphitized to incompletely graphitized graphene of approximately 2:1, an overall thickness of 210 μm, and a density of 139 mg / cm³. -3 Incomplete graphene treated with 80% hydrazine hydrate exhibited more micro-wrinkled structures compared to graphene films treated with direct heat treatment. Figure 4 This effectively improved the overall thermal conductivity of the graphene composite foam film in the vertical direction, with an out-of-plane thermal conductivity of 17.2 W / m measured using the transient laser scintillation method. -1 K -1 The thermal resistance at 100 kPa was measured to be 0.05 K cm using the steady-state heat flow meter method. 2 W -1 .

[0040] Example 4:

[0041] (1) 200g 12mg g -1 A graphene oxide aqueous solution was used as a slurry, and a clean glass plate was used as a substrate. An automatic doctor blade coater was used to coat the graphene oxide aqueous solution into a film, with a 1mm gap between the doctor blade and the substrate. The graphene oxide film was then peeled off the substrate and placed in an 85% hydrazine hydrate solution at 90°C for 60 minutes to foam. Subsequently, it was placed in a graphitization furnace and heated at 10°C for 1 minute under an argon atmosphere. -1 The temperature was increased to 3150℃ and held for 1 hour to obtain a highly graphitized graphene foam film with a density of 24 mg / cm³. -3 .

[0042] (2) Immerse the above graphene foam film in 2 mg g -1 The graphene oxide was vacuum-infused in an aqueous solution for 1 hour, dried in an oven at 60°C for 6 hours, and then placed in a tube furnace and heated at 10°C / min under an argon atmosphere. -1 The temperature was increased to 2000℃ and held for 1 hour to obtain a highly graphitized / incompletely graphitized graphene composite foam film.

[0043] The graphene / graphene composite foam film obtained through the above steps has a mass ratio of highly graphitized to incompletely graphitized graphene of approximately 3:2, an overall thickness of approximately 2.1 mm, and a density of 42 mg / cm³. -3 The out-of-plane thermal conductivity using the transient laser scintillation method is 8.9 W / m. -1 K -1 The thermal resistance at 100 kPa was measured to be 0.17 K cm using the steady-state heat flow meter method. 2 W -1 After being frozen in liquid nitrogen for 30 minutes, it was immediately removed and subjected to stress-strain testing. The results showed that it still exhibited excellent compressibility-resilience. Figure 5 Furthermore, the rate of change of thermal conductivity and thermal resistance is less than 2%.

[0044] Comparative Example 1:

[0045] (1) 200g 15mg g -1 A graphene oxide aqueous solution was used as a slurry, and a clean glass plate was used as a substrate. An automatic doctor blade coater was used to coat the graphene oxide aqueous solution into a film. The graphene oxide film was then peeled off the glass plate and placed in a 20% hydrazine hydrate solution at 60°C for 240 minutes to foam. Subsequently, it was placed in a graphitization furnace and heated at 10°C for 1 minute under an argon atmosphere. -1 The temperature was increased to 2800℃ and held for 1 hour to obtain a highly graphitized graphene foam film.

[0046] The graphene foam film obtained through the above steps has an overall thickness of 1.6 cm and a density of 23 mg / cm³. -3 The out-of-plane thermal conductivity was measured to be 5.2 W / m using the transient laser scintillation method. -1 K -1 The thermal resistance at 100 kPa was measured to be 0.38 K cm using the steady-state heat flow meter method. 2 W -1 It cannot spring back after compression.

[0047] Comparative Example 2:

[0048] (1) 200g 15mg g -1 A graphene oxide aqueous solution was used as a slurry, and a clean glass plate was used as a substrate. An automatic doctor blade coater was used to coat the graphene oxide aqueous solution into a film. The graphene oxide film was peeled off the glass plate and placed in a 20% hydrazine hydrate solution at 60°C for 240 minutes to foam. Subsequently, it was placed in a graphitization furnace and heated at 10°C for 1 minute under an argon atmosphere. -1 The temperature was increased to 2800℃ and held for 1 hour to obtain a highly graphitized graphene foam film with a density of 23 mg / cm³. -3 .

[0049] (2) Immerse the above graphene foam film in 0.2 mg g solution. -1 Graphene oxide was vacuum-infused in an aqueous solution for 10 min, dried in an oven at 60 °C for 6 h, and then placed in a tube furnace and heated at 10 °C / min under an argon atmosphere. -1 The temperature was increased to 1600℃ and held for 1 hour to obtain a highly graphitized / incompletely graphitized graphene composite foam film.

[0050] The graphene / graphene composite foam film obtained through the above steps has a mass ratio of highly graphitized to incompletely graphitized graphene of approximately 15:1, an overall thickness of 1.5 cm, and a density of 25 mg / cm³. -3 The out-of-plane thermal conductivity was measured to be 5.7 W / m using the transient laser scintillation method. -1 K -1 The thermal resistance at 100 kPa was measured to be 0.35 K cm using the steady-state heat flow meter method. 2 W -1 It cannot spring back after compression.

[0051] Comparative Example 3:

[0052] (1) 200g 15mg g -1 A graphene oxide aqueous solution was used as a slurry, and a clean glass plate was used as a substrate. An automatic doctor blade coater was used to coat the graphene oxide aqueous solution into a film. The graphene oxide film was peeled off the glass plate and placed in a 20% hydrazine hydrate solution at 60°C for 240 minutes to foam. Subsequently, it was placed in a graphitization furnace and heated at 10°C for 1 minute under an argon atmosphere. -1 The temperature was increased to 2800℃ and held for 1 hour to obtain a highly graphitized graphene foam film with a density of 23 mg / cm³. -3 .

[0053] (2) Immerse the above graphene foam film in 0.2 mg g solution. -1 The graphene oxide was vacuum-infused in an aqueous solution for 2 hours, dried in an oven at 60°C for 6 hours, and then placed in a tube furnace and heated at 10°C for 1 minute under an argon atmosphere. -1 The temperature was increased to 500℃ and held for 1 hour to obtain a highly graphitized / incompletely graphitized graphene composite foam film.

[0054] The graphene / graphene composite foam film obtained through the above steps has a mass ratio of highly graphitized to incompletely graphitized graphene of approximately 2:1, an overall thickness of 1.5 cm, and a density of 35 mg / cm³. -3 The out-of-plane thermal conductivity was measured to be 4.5 W / m using the transient laser scintillation method. -1 K -1 The thermal resistance at 100 kPa was measured to be 0.31 K cm using the steady-state heat flow meter method. 2 W -1 Furthermore, after 1000 compressions at 85%, the rebound rate is only 47%.

[0055] Comparative Example 4:

[0056] (1) 200g 15mg g -1A graphene oxide aqueous solution was used as a slurry, and a clean glass plate was used as a substrate. An automatic doctor blade coater was used to coat the graphene oxide aqueous solution into a film. The graphene oxide film was peeled off the glass plate and placed in a 20% hydrazine hydrate solution at 60°C for 240 minutes to foam. Subsequently, it was placed in a graphitization furnace and heated at 10°C for 1 minute under an argon atmosphere. -1 The temperature was increased to 2800℃ and held for 1 hour to obtain a highly graphitized graphene foam film with a density of 23 mg / cm³. -3 .

[0057] (2) Immerse the above graphene foam film in 0.2 mg g solution. -1 The graphene oxide was vacuum-infused in an aqueous solution for 2 hours, dried in an oven at 60°C for 6 hours, and then placed in a tube furnace and heated at 10°C / min under an argon atmosphere. -1 The temperature was increased to 2300℃ and held for 1 hour to obtain a highly graphitized / graphitized graphene composite foam film.

[0058] The graphene / graphene composite foam film obtained through the above steps has a high graphitization to graphite mass ratio of approximately 3:1, an overall thickness of 1.3 cm, and a density of 30 mg / cm³. -3 The out-of-plane thermal conductivity was measured to be 8.2 W / m² using the transient laser scintillation method. -1 K -1 The thermal resistance at 100 kPa was measured to be 0.19 K cm using the steady-state heat flow meter method. 2 W -1 Furthermore, after 1000 cycles of 85% compression, the rebound rate is only 13%.

[0059] Table 1 Test results for different embodiments

[0060]

[0061]

[0062] Comparative Example 1 is a graphene film without graphene oxide infusion. It lacks compressive resilience and has low thermal conductivity due to the absence of vertical thermal conduction pathways. Comparative Example 2 is a graphene film infused with graphene oxide for a short period. Because the graphene oxide did not fully overlap and form pathways within the graphene bubble film, the resulting material still has low thermal conductivity and lacks compressive resilience.

[0063] Although both Comparative Examples 3 and 4 underwent sufficient graphene oxide infusion, the heat treatment time did not meet the requirements. The heat treatment temperature of Comparative Example 3 was too low, resulting in insufficient reduction of the infused graphene oxide, which hindered heat transfer and led to a significant decrease in the overall thermal conductivity and compressive resilience of the material. The heat treatment temperature of Comparative Example 4 was too high, causing the infused graphene oxide to be graphitized, forming a highly graphitized / graphitized graphene composite foam film. Although the thermal conductivity increased significantly, it lost its compressive resilience.

[0064] Similarly, comparing Examples 2 and 3, it can be found that chemically reducing the infused membrane further significantly improves the thermal conductivity. This is because the self-shrinking mechanism of graphene oxide folds in the strong reducing agent provides more rapid transmission channels for thermal phonons in the vertical direction, further improving the out-of-plane thermal conductivity of the graphene / graphene composite foam membrane.

Claims

1. A highly elastic, low thermal resistance graphene thermal interface material, characterized in that, Density ranges from 32 to 139 mg / cm³ -3 It comprises at least a thermally conductive framework and an elastic component filled within the thermally conductive framework, wherein the thermally conductive framework is a graphene aerogel film after graphitization treatment, with a density of 23–87 mg / cm³. -3 The elastic component is graphene annealed at 1000–2000℃.

2. The thermal interface material according to claim 1, characterized in that, The graphitization treatment of the thermally conductive skeleton refers to heat treatment at 2300-3150℃ for 1 hour.

3. The thermal interface material according to claim 1, characterized in that, When the compression rate does not exceed 98%, the rebound rate is 50-99%.

4. The thermal interface material according to claim 1, characterized in that, The thermal conductivity of the vertical plane ranges from 8 to 20 W / m. -1 K -1 When the applied pressure is 10–1200 kPa, the thermal resistance range is 0.02–2 K cm. 2 W -1 .

5. A method for preparing a highly elastic, low thermal resistance graphene thermal interface material, characterized in that, Includes the following steps: (1) The graphene oxide solution is coated into a film, dried, and then placed in a hydrazine hydrate solution with a volume fraction of 5-85% for 15-300 min to foam the foamed graphene aerogel film; the foaming temperature is 20-90℃. (2) Impregnate the graphene aerogel membrane with a concentration of 0.2–5 mg g. -1 Vacuum infusion of graphene oxide solution for 1–2 hours, followed by drying at 40–60°C and high-temperature annealing for 1–3 hours at 1000–2000°C, yields a highly elastic, low-thermal-resistance graphene thermal interface material.

6. A method for preparing a highly elastic, low thermal resistance graphene thermal interface material, characterized in that, Includes the following steps: (1) The graphene oxide solution is coated into a film, dried, and then placed in a hydrazine hydrate solution with a volume fraction of 5-85% for 15-300 min to foam. The foamed graphene aerogel film is then graphitized, with the foaming temperature being 20-90℃. (2) Impregnate the graphene aerogel membrane with a concentration of 0.2–5 mg g. -1 Vacuum infusion of graphene oxide solution for 1-2 hours, followed by immersion in hydrazine hydrate solution for 1-5 hours to introduce micro-bent structures on the surface of graphene oxide sheets. After replacing the hydrazine hydrate solution with ethanol and drying in an environment of 40-60℃, high-temperature annealing treatment is performed for 1-3 hours at an annealing temperature of 1000-2000℃.

7. The method according to claim 6, characterized in that, The volume fraction of the hydrazine hydrate solution is 60–85%.

8. The method according to claim 5 or 6, characterized in that, The graphene oxide in the graphene oxide solution is a single layer or multiple layers.

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