Synthesis of three-dimensional graphene foam: use as supercapacitors

• US 9,691,916 B2
• Filed: 05/31/2016
• Issued: 06/27/2017
• Est. Priority Date: 06/01/2012
• Status: Active Grant

• Current Assignee: National University of Singapore
• Original Assignee: National University of Singapore
• Inventors: Lee, Jonghak, Kahya, Orhan, Ozyilmaz, Barbaros
• Primary Examiner(s): YI, STELLA KIM
• Application Number:
  US15/169,076
• Publication Number:
  US 20160271843A1
• Time in Patent Office: 392 Days
• Field of Search: None
• CPC Class Codes: B29C 43/003 characterised by the choice of material
• CPC Class Codes: B29K 2105/04 cellular or porous
• CPC Class Codes: B29L 2031/00 Other particular articles
• CPC Class Codes: C01B 32/182 Graphene
• CPC Class Codes: C01B 32/198 Graphene oxide
• CPC Class Codes: C23F 4/04 by physical dissolution
• CPC Class Codes: H01G 11/28 arranged or disposed on a current collector; Layers or phases between electrodes and current collectors, e.g. adhesives
• CPC Class Codes: H01G 11/36 Nanostructures, e.g. nanofibres, nanotubes or fullerenes
• CPC Class Codes: H01G 11/38 Carbon pastes or blends; Binders or additives therein
• CPC Class Codes: H01G 11/48 Conductive polymers
• CPC Class Codes: H01G 11/68 characterised by their material
• CPC Class Codes: H01G 11/70 characterised by their structure
• CPC Class Codes: H01G 11/86 specially adapted for electrodes carbonisation or activation of carbon for the manufacture of electrodes H01G11/34
• CPC Class Codes: H01L 31/0224 Electrodes
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors
• CPC Class Codes: Y10T 29/43 Electric condenser making
• CPC Class Codes: Y10T 428/24997 Of metal-containing material

Abstract

The invention relates to three-dimensional crystalline foams with high surface areas, high lithium capacity, and high conductivity for use as electrode materials and methods for their fabrication. In additional embodiments, the invention also relates to the use of three-dimensional crystalline foams as supercapacitors for improved charge and energy storage.

Claims

1. A three-dimensional crystalline graphene foam, comprising a core that includes a group IV-B element and a graphene layer surrounding the core, wherein the three-dimensional crystalline graphene foam is produced by the steps of:

a) mixing a carbon source coated on a group IV-B element and a skelet powder together to obtain a uniform mixture, the skelet powder having a particle size of 1 nm to 10 μ

m;

b) applying pressure to the uniform mixture obtained in step (a) to obtain a closed packed structure;

c) applying temperature and pressure to the closed packed structure to form a graphene sheet layered around the skelet powder and the group IV-B element; and

d) removing the skelet powder from the closed packed structure using a chemical bath to dissolve the skelet powder away from the closed packed structure leaving voids,

thereby forming the three-dimensional crystalline graphene foam.

2. The three-dimensional crystalline graphene foam of claim 1, wherein the pressure applied in step (b) is between 0.1 MPa and 50 MPa.

3. The three-dimensional crystalline graphene foam of claim 2, wherein the pressure applied in step (c) is between 0.1 MPa and 50 MPa.

4. The three-dimensional crystalline graphene foam of claim 3, wherein the temperature applied in step (c) is between 800°

C. and 3400°

C.

5. The three-dimensional crystalline graphene foam of claim 4, wherein the group IV-B element is silicon, germanium, tin, lead, or a combination thereof.

6. The three-dimensional crystalline graphene foam of claim 5, wherein the group IV-B element is a silicon nanoparticle.

7. The three-dimensional crystalline graphene foam of claim 1, wherein the skelet powder has a particle size of 1 nm to 1 μ

m.

8. The three-dimensional crystalline graphene foam of claim 7, wherein the pressure applied in step (b) is between 0.1 MPa and 50 MPa.

9. The three-dimensional crystalline graphene foam of claim 8, wherein the pressure applied in step (c) is between 0.1 MPa and 50 MPa.

10. The three-dimensional crystalline graphene foam of claim 9, wherein the temperature applied in step (c) is between 800°

C. and 3400°

C.

11. The three-dimensional crystalline graphene foam of claim 10, wherein the group IV-B element is silicon, germanium, tin, lead, or a combination thereof.

12. The three-dimensional crystalline graphene foam of claim 11, wherein the group IV-B element is a silicon nanoparticle.

13. The three-dimensional crystalline graphene foam of claim 1, wherein the skelet powder has a particle size of 5 nm to 100 nm.

14. The three-dimensional crystalline graphene foam of claim 13, wherein the pressure applied in step (b) is between 0.1 MPa and 50 MPa.

15. The three-dimensional crystalline graphene foam of claim 14, wherein the pressure applied in step (c) is between 0.1 MPa and 50 MPa.

16. The three-dimensional crystalline graphene foam of claim 15, wherein the temperature applied in step (c) is between 800°

C. and 3400°

C.

17. The three-dimensional crystalline graphene foam of claim 16, wherein the group IV-B element is silicon, germanium, tin, lead, or a combination thereof.

18. The three-dimensional crystalline graphene foam of claim 17, wherein the group IV-B element is a silicon nanoparticle.

19. A three-dimensional crystalline graphene foam, comprising a core that includes a group IV-B element and 1 to 20 layers of graphene surrounding the core, wherein the 1 to 20 layers of graphene are arranged as an intercalated network of continuously connected graphene sheets forming a porous network.

20. The three-dimensional crystalline graphene foam of claim 19, wherein 1 to 5 layers of graphene surround the core.

21. The three-dimensional crystalline graphene foam of claim 20, wherein the group IV-B element is silicon, germanium, tin, lead, or a combination thereof.