Thermal management system containing a graphene oxide-coated graphitic foil laminate for electronic device application

• US 20140124176A1
• Filed: 11/02/2012
• Published: 05/08/2014
• Est. Priority Date: 11/02/2012
• Status: Active Grant

• Current Assignee: Global Graphene Group, Inc.
• Original Assignee: Global Graphene Group, Inc.
• Inventors: Zhamu, Aruna, Wang, Mingchao, Xiong, Wei, Jang, Bor Z.
• Granted Patent: US 10,229,862 B2
• Time in Patent Office: Days
• US Class Current: 165/133
• CPC Class Codes: F28F 21/02 of carbon, e.g. graphite
• CPC Class Codes: F28F 3/00 Plate-like or laminated elements; Assemblies of plate-like or laminated elements specially adapted for movement F28F5/00
• CPC Class Codes: H01L 23/373 Cooling facilitated by selection of materials for the device or materials for thermal expansion adaptation, e.g. carbon
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

A heat dissipation system, comprising: (a) an electronic device comprising a heat source, wherein the heat source transmits heat to a second component or an external surface of the device; (b) a heat-conducting layer being positioned such that one of its major surfaces is in operative contact with the heat source such that it is interposed between the heat source and the second component or the external surface. The heat-conducting layer comprises at least one graphene oxide-coated graphitic foil laminate which thermally shields the second component or the external surface from heat generated by the heat source, and wherein the laminate is composed of a graphitic substrate/core layer with at least one primary surface coated with a graphene oxide coating layer. This graphene oxide-coated laminate exhibits a combination of exceptional thermal conductivity, electrical conductivity, mechanical strength, surface hardness, and scratch resistance, making this the most effective heat dissipation system.

Claims

1. A heat dissipation system, comprising:

(a) an electronic device comprising a heat source, wherein the heat source transmits heat to a second component or an external surface of the electronic device;

(b) a heat-conducting layer comprising two major surfaces, wherein one of said major surfaces is in operative contact with the heat source such that the heat-conducting layer is interposed between the heat source and the second component or the external surface of the electronic device;

wherein the heat-conducting layer comprises at least one graphene oxide-coated graphitic foil laminate which thermally shields the second component or the external surface of the electronic device from heat generated by the heat source, and wherein the laminate is composed of a graphitic substrate or core layer having two opposed primary surfaces and at least a graphene oxide coating layer deposited on at least one of said two primary surfaces, wherein said graphitic substrate or core layer has a thickness greater than 1 nm, and said graphene oxide coating layer has a thickness greater than 1 nm and an oxygen content of 0.01%-40% by weight based on the total graphene oxide coating weight.

2. The heat dissipation system as defined in claim 1, wherein said graphene oxide coating layer is produced from thermal conversion of a graphene oxide gel.

3. The heat dissipation system of claim 1, wherein the electronic device further comprises a heat dissipation device positioned in a location not directly adjacent to the heat source and wherein one of the major surfaces of the heat-conducting layer is in operative contact with the heat dissipation device.

4. The heat dissipation system of claim 3, wherein the heat dissipation device comprises a heat sink, a heat pipe, a heat plate, or a combination thereof.

5. The heat dissipation system of claim 1, wherein a thermal transfer material is positioned between the heat-conducting layer and the heat source.

6. The heat dissipation system of claim 5, wherein the thermal transfer material comprises a metal or a thermal interface material.

7. The heat dissipation system of claim 1, wherein the electronic device is a portable computing device containing a central processing unit (CPU), a battery, or a supercapacitor as a heat source.

8. The heat dissipation system of claim 1, wherein the electronic device is a digital camera, a mobile phone, a laptop computer, a tablet, and electronic book or e-book, a power tool, or a hand-held video recording device.

9. The heat dissipation system as defined in claim 1, wherein the graphitic substrate layer or graphene oxide coating layer has a thickness less than 200 μ

m

10. The heat dissipation system as defined in claim 1, wherein said graphene oxide coating comprises a unitary graphene layer or a single crystal of graphene planes obtained from a heat treatment of a graphene oxide gel.

11. The heat dissipation system as defined in claim 10, wherein said unitary graphene layer or single crystal has a lateral dimension greater than 100 μ

m.

12. The heat dissipation system as defined in claim 10, wherein said unitary graphene layer or single crystal has a lateral dimension greater than 10 mm.

13. The heat dissipation system as defined in claim 1, wherein the graphitic substrate or core layer is selected from flexible graphite foil, graphene film, graphene paper, graphite particle paper, carbon-carbon composite film, carbon nano-fiber paper, or carbon nano-tube paper.

14. The heat dissipation system as defined in claim 1, wherein the graphitic substrate or core layer is selected from flexible graphite foil produced by re-compression of exfoliated graphite worms or exfoliated graphite flakes of natural graphite and/or artificial graphite.

15. The heat dissipation system as defined in claim 1, wherein the graphitic substrate or core layer is a graphene film comprising pristine graphene, graphene oxide, reduced graphene oxide, graphene fluoride, hydrogenated graphene, doped graphene, functionalized graphene, or a combination thereof.

16. The heat dissipation system as defined in claim 1, wherein the graphitic substrate layer is a graphene film comprising a single-layer graphene sheet or a multiple-layer graphene platelet having less than 100 graphene planes.

17. The heat dissipation system as defined in claim 1, wherein the graphitic substrate layer is a graphene film comprising multi-layer graphene sheets having a thickness of 6.7 nm to 20 nm.

18. The heat dissipation system as defined in claim 1, wherein the graphitic substrate layer is a graphene film comprising pristine graphene that contains no oxygen.

19. The heat dissipation system as defined in claim 1, wherein said graphene oxide is a reduced graphene oxide having an oxygen content less than 5% by weight.

20. The heat dissipation system as defined in claim 1, wherein said graphene oxide contains a reduced graphene oxide obtained from a graphene oxide gel.

21. The heat dissipation system as defined in claim 1, wherein said graphene oxide has an oxygen weight fraction of 23% to 35% and is thermally conductive but not electrically conductive.

22. The heat dissipation system as defined in claim 1, wherein said graphene oxide is obtained from a graphene oxide gel, which gel is composed of graphene oxide molecules dispersed in an acidic medium having a pH value of no higher than 5 and said graphene oxide molecules have an oxygen content no less than 20% by weight while in a gel state.

23. The heat dissipation system as defined in claim 1, wherein said graphene oxide is obtained from a graphene oxide gel, which gel is obtained by immersing a graphitic material in a powder or fibrous form in an oxidizing liquid medium in a reaction vessel at a reaction temperature for a length of time sufficient to obtain a graphene oxide gel composed of graphene oxide molecules dispersed in the liquid medium and said graphene oxide molecules have an oxygen content no less than 20% by weight and a molecular weight less than 43,000 g/mole while in a gel state.

24. The heat dissipation system as defined in claim 22, wherein said graphene oxide molecules have a molecular weight less than 4,000 g/mole while in a gel state.

25. The heat dissipation system as defined in claim 22, wherein said graphene oxide molecules have a molecular weight between 200 g/mole and 4,000 g/mole while in a gel state.

26. The heat dissipation system as defined in claim 22, wherein said graphene oxide coating is obtained by depositing said graphene oxide gel to form a graphene oxide gel coating on a primary surface of said graphitic core or substrate and removing a residual liquid from said coating.

27. The heat dissipation system as defined in claim 23, wherein said graphene oxide coating is obtained by depositing said graphene oxide gel to form a graphene oxide gel coating, removing a residual liquid from said coating, subjecting said graphene-oxide to a heat treatment temperature of at least 150°

C. for thermal reduction and/or re-graphitization.

28. The heat dissipation system as defined in claim 23, wherein said graphene oxide coating is obtained by depositing said graphene oxide gel to form a graphene oxide gel coating, removing a residual liquid from said coating, subjecting said graphene-oxide to a heat treatment temperature of at least 1,500°

C. for re-graphitization.

29. The heat dissipation system as defined in claim 23, wherein said graphene oxide coating is obtained by depositing said graphene oxide gel to form a graphene oxide gel coating, removing a residual liquid from said coating, subjecting said graphene-oxide to a heat treatment temperature from 300°

C. to 1,500°

C. for re-graphitization.

30. The heat dissipation system as defined in claim 23, wherein said graphene oxide coating is obtained by depositing said graphene oxide gel to form a graphene oxide gel coating, removing a residual liquid from said coating, subjecting said graphene-oxide to a heat treatment temperature from 1,500°

C. to 2,500°

C. for re-graphitization.

31. The heat dissipation system as defined in claim 23, wherein said graphene oxide coating forms into a unitary structure after a re-graphitization treatment.

32. The heat dissipation system as defined in claim 1, wherein said graphitic foil contains a material selected from natural graphite, artificial graphite, meso-phase carbon, meso-phase pitch, meso-carbon micro-bead, soft carbon, hard carbon, coke, carbon fiber, carbon nano-fiber, carbon nano-tube, or a combination thereof.

33. The heat dissipation system as defined in claim 1, wherein said graphene oxide is produced from oxidation of a graphitic material selected from natural graphite, artificial graphite, meso-phase carbon, meso-phase pitch, meso-carbon micro-bead, soft carbon, hard carbon, coke, carbon fiber, carbon nano-fiber, carbon nano-tube, or a combination thereof.

34. The heat dissipation system as defined in claim 1, wherein said graphene oxide-coated graphitic foil laminate has a Rockwell hardness value greater than 60.

35. The heat dissipation system as defined in claim 1, wherein said graphene oxide-coated graphitic foil laminate has an in-plane thermal conductivity greater than 1,700 W/mK or through-plane thermal conductivity less than 5 W/mK.

36. The heat dissipation system as defined in claim 1, wherein said graphene oxide-coated graphitic foil laminate has an in-plane electrical conductivity greater than 5,000 S/cm.

37. The heat dissipation system as defined in claim 1, wherein said graphene oxide-coated graphitic foil laminate has an in-plane electrical conductivity greater than 3,000 S/cm and an in-plane thermal conductivity greater than 1,000 W/mK or a through-plane thermal conductivity lower than 10 W/mK.

38. The heat dissipation system as defined in claim 1, wherein said graphene oxide-coated graphitic foil laminate has an electrical conductivity greater than 1,500 S/cm, an in-plane thermal conductivity greater than 600 W/mK, a physical density greater than 1.4 g/cm³, and a tensile strength greater than 10 MPa.

39. The heat dissipation system as defined in claim 1, wherein said graphene oxide-coated graphitic foil laminate has an in-plane electrical conductivity greater than 2,000 S/cm, an in-plane thermal conductivity greater than 800 W/mK, a physical density greater than 1.8 g/cm³, and a tensile strength greater than 40 MPa.

40. The heat dissipation system as defined in claim 1, wherein said graphene oxide-coated graphitic foil laminate has an in-plane electrical conductivity greater than 5,000 S/cm, an in-plane thermal conductivity greater than 1,500 W/mK, a physical density greater than 2.0 g/cm³, and a tensile strength greater than 60 MPa.

41. The heat dissipation system of claim 1, wherein a graphene oxide coating layer is deposited on each of said two primary surfaces of said graphitic core layer.

42. The heat dissipation system of claim 1, wherein at least one of said graphene oxide coating layer is further deposited with a layer of electrically insulating material.

43. A heat dissipation system, comprising:

(A) an electronic device comprising a heat source, wherein the heat source transmits heat to a second component or an external surface of the electronic device;

(B) a heat-conducting layer comprising two major surfaces, the heat-conducting layer being positioned such that one of its major surfaces is in operative contact with the heat source such that it is interposed between the heat source and the second component or the external surface of the electronic device;

wherein the heat-conducting layer comprises at least one graphene oxide-coated graphitic foil laminate which thermally shields the second component or the external surface of the electronic device from heat generated by the heat source, and wherein the laminate is composed of a graphitic substrate or core layer having two opposed primary surfaces and at least a graphene oxide coating layer deposited on at least one of said two primary surfaces, wherein said graphene oxide coating layer contains a unitary graphene layer or graphene single crystal obtained from a heat treatment of a graphene oxide gel and has an oxygen content of less than 5% by weight based on the total graphene oxide weight.