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CN-117342546-B - Graphene material, preparation method thereof, graphene composite material and electronic equipment

CN117342546BCN 117342546 BCN117342546 BCN 117342546BCN-117342546-B

Abstract

The application relates to a graphene material, a preparation method thereof, a graphene composite material and electronic equipment, wherein the graphene material has a pore structure, and the tearing strength of the graphene material is more than or equal to 30gf/25mm along the thickness direction of the graphene material. The graphene material provided by the application has a macroscopic structure, mechanical strength and excellent thermal property.

Inventors

  • ZHANG YAN
  • WANG QIANLONG
  • ZHANG DENGKE
  • CUI JIAMING
  • Yi Keqi

Assignees

  • 深圳市深瑞墨烯科技有限公司

Dates

Publication Date
20260505
Application Date
20230922

Claims (10)

  1. 1. A graphene material is characterized by having a pore structure, wherein the thickness of the graphene material is more than or equal to 1mm, the tearing strength of the graphene material is 30 gf/25-40 gf/25mm along the thickness direction of the graphene material, the graphene material has at least one chemical bond of hydrogen bond, covalent bond and pi-pi non-covalent bond, the mass content of carbon element in the graphene material is more than or equal to 99.9%, the horizontal thermal conductivity of the graphene material is 30W/m.K-40W/m.K, the vertical thermal conductivity of the graphene material is 1.2W/m.K-2.5W/m.K, and the compression rebound rate of the graphene material is 90% -95%.
  2. 2. The graphene material according to claim 1, wherein the compressive strength of the graphene material is not less than 5MPa.
  3. 3. The graphene material of claim 1 or 2, wherein the graphene material comprises at least one of the following features: (1) The density of the graphene material is 0.1 g/cm 3 ~0.3 g/cm 3 ; (2) The pore structure of the graphene material is distributed in a three-dimensional net shape; (3) The average pore diameter of the pores in the graphene material is 1-200 mu m.
  4. 4. A method for preparing a graphene material according to any one of claims 1 to 3, comprising the following preparation steps: Placing graphene oxide original films in an interface enhancement solution for infiltration treatment, wherein N pieces of graphene oxide original films after infiltration are laminated, and obtaining N layers of graphene oxide pre-expansion films, N is more than or equal to 2, the solute of the interface enhancement solution comprises an additive, the additive comprises at least one of polyamic acid, graphene oxide quantum dots, graphene quantum dots, polymer quantum dots, polyvinyl alcohol and polyacrylic acid, the solvent of the interface enhancement solution comprises at least one of water, methanol and ethanol, the thickness of the graphene oxide original films is 50-1000 mu m, the mass ratio of carbon atoms to oxygen atoms in the graphene oxide original films is (1-3): 1, the graphene oxide original films are provided with three-dimensional net-shaped distributed holes, and the average pore diameter range of the holes is 1-150 mu m; And drying and graphitizing the N-layer graphene oxide pre-expansion film to obtain a graphene material, wherein the tearing strength of the graphene material is more than or equal to 30gf/25mm, the graphitizing is performed under a hot-pressing condition, and the hot-pressing pressure of the graphitizing is less than or equal to 100 KPa.
  5. 5. The method of manufacturing according to claim 4, characterized in that the method comprises at least one of the following features: (1) The graphene oxide precursor film includes an oxygen-containing functional group; (2) The graphene oxide precursor film comprises an oxygen-containing functional group, wherein the oxygen-containing functional group comprises at least one of an epoxy group, a hydroxyl group and a carboxyl group; (3) At least part of graphene oxide in the graphene oxide raw film is arranged in a directional manner along the horizontal direction or the vertical direction; (4) The adjacent two layers of graphene oxide pre-expansion films are connected through at least one of hydrogen bonds, covalent bonds and pi-pi non-covalent bonds; (5) The solid content of the interface reinforcing solution is 0.1% -1%.
  6. 6. The method of manufacturing according to claim 4, characterized in that the method comprises at least one of the following features: (1) The time of the infiltration treatment is 5 s-60 s; (2) The temperature of the drying treatment is 60-400 ℃; (3) The heating rate of the drying treatment is less than or equal to 10 ℃ per minute; (4) And the drying treatment time is 5-20 hours.
  7. 7. The method of manufacturing according to claim 4, characterized in that the method comprises at least one of the following features: (1) The graphitization treatment temperature is 2700-3100 ℃; (2) The graphitization treatment time is 14-50 h; (3) The temperature rising rate of the graphitization treatment is less than or equal to 5 ℃ per minute.
  8. 8. A graphene composite material, characterized in that it comprises a graphene material according to any one of claims 1 to 3 or a graphene material prepared by a preparation method of a graphene material according to any one of claims 4 to 7, and a phase change material, at least part of which is located within the pore structure.
  9. 9. The graphene composite of claim 8, wherein the graphene composite comprises at least one of the following features: (1) The phase change material comprises at least one of an organic phase change material and an inorganic phase change material; (2) The phase change material comprises an organic phase change material, and the organic phase change material comprises at least one of paraffin, n-hexadecane, n-octadecane, n-eicosane, stearic acid and palmitic acid; (3) The thickness of the graphene composite material is more than or equal to 1mm; (4) The density of the graphene composite material is 1.0 g/cm 3 ~1.5 g/cm 3 ; (5) The horizontal heat conductivity coefficient of the graphene composite material is more than or equal to 35W/m.K, and the vertical heat conductivity coefficient of the graphene composite material is more than or equal to 2W/m.K; (6) The phase transition enthalpy of the graphene composite material is more than or equal to 150J/g.
  10. 10. An electronic device comprising an electronic device and the graphene composite material of any one of claims 8 or 9.

Description

Graphene material, preparation method thereof, graphene composite material and electronic equipment Technical Field The invention relates to the technical field of heat dissipation materials, in particular to a graphene material, a preparation method thereof, a graphene composite material and electronic equipment. Background The ultrahigh thermal conductivity of graphene at present makes the graphene have unique advantages in the field of thermal management materials. The graphene film is a mutually communicated porous material prepared by chemical vapor deposition, solution mixing, porous template, solvent plasticizing foaming or combination of the methods. The graphene film is beneficial to effectively reducing contact thermal resistance between sheets and improving thermal performance of the composite material. The graphene heat conduction material is limited in application due to low structural mechanical strength and poor structural stability of the graphene heat conduction material when the graphene heat conduction material exceeds a certain thickness in the existing preparation process due to factors of a graphene slurry formulation process, a coating process and a foaming pore-forming process. At present, a mode of preparing a graphene thick film by foaming a reducing agent is simple and easy to implement, but is influenced by the original film thickness, and the thick film is often prepared by improving the solubility of the reducing agent or prolonging the foaming time, so that the strength of a hole wall structure is weakened or even collapses due to excessive expansion of the film. Therefore, how to make the graphene material have both macroscopic structure and mechanical strength and excellent thermal properties is a problem to be solved at present. Disclosure of Invention The application aims to provide a graphene material, a preparation method thereof, a graphene composite material and electronic equipment, wherein the graphene material has a macroscopic structure, mechanical strength and excellent thermal property, and can be used as graphene foam/aerogel in the fields of fire resistance, heat insulation, rebound, heat conduction, heat dissipation and the like. In a first aspect, the application provides a graphene material, which has a pore structure, wherein the thickness of the graphene material is more than or equal to 1mm, and the tearing strength of the graphene material is more than or equal to 30gf/25mm along the thickness direction of the graphene material. In some embodiments, the compressive strength of the graphene material is greater than or equal to 5Mpa. In some embodiments, the graphene material has a density of 0.1g/cm 3～0.3g/cm3. In some embodiments, the pore structure of the graphene material is in a three-dimensional network distribution. In some embodiments, the graphene material has a compression spring rate of 90% -95%. In some embodiments, the graphene material has a horizontal thermal conductivity of > 30W/m-K and the graphene material has a vertical thermal conductivity of > 1W/m-K. In some embodiments, the graphene material has a mass content of carbon element of greater than or equal to 99.9%. In some embodiments, the average pore size of the pores in the graphene material is 1 μm to 200 μm. In a second aspect, the present application provides a method for preparing a graphene material, including the following preparation steps: placing the graphene oxide original film in an interface enhancement solution for infiltration treatment, and laminating the infiltrated N graphene oxide original films to obtain an N-layer graphene oxide pre-expansion film, wherein N is more than or equal to 2; And drying and graphitizing the N-layer graphene oxide pre-expansion film to obtain a graphene material, wherein the tearing strength of the graphene material is more than or equal to 30gf/25mm. In some embodiments, the thickness of the single-layer graphene oxide porous raw film is 50-1000 μm. In some embodiments, the mass ratio of carbon atoms to oxygen atoms in the graphene oxide precursor film is (1-3): 1. In some embodiments, the graphene oxide precursor film includes oxygen-containing functional groups. In some embodiments, the graphene oxide precursor film includes an oxygen-containing functional group including at least one of an epoxy group, a hydroxyl group, and a carboxyl group. In some embodiments, the graphene oxide primary membrane has three-dimensional network distribution of pores with an average pore diameter ranging from 1 μm to 200 μm. In some embodiments, at least a portion of graphene oxide in the graphene oxide precursor film is aligned in a horizontal direction or a vertical direction. In some embodiments, two adjacent layers of the graphene oxide pre-expanded film are connected by at least one of hydrogen bond, covalent bond, pi-pi non-covalent bond. In some embodiments, the interface enhancing solution includes an additive comprising at least one of a hydro