Graphene aerogels
Graphene aerogels with high conductivity and surface areas including a method for making a graphene aerogel, including the following steps: (1) preparing a reaction mixture comprising a graphene oxide suspension and at least one catalyst; (2) curing the reaction mixture to produce a wet gel; (3) drying the wet gel to produce a dry gel; and (4) pyrolyzing the dry gel to produce a graphene aerogel. Applications include electrical energy storage including batteries and supercapacitors.
1. A composition comprising at least one graphene aerogel comprising a three-dimensional structure of graphene sheets, wherein the graphene sheets are directly chemically crosslinked with each other by covalent carbon bonds.
2. The composition of claim 1 , wherein the atomic oxygen content is 5% or less.
3. The composition of claim 1 , wherein the graphene sheets are randomly oriented.
4. The composition of claim 1 , wherein the sheets have lateral dimensions of at least 200 nm.
5. The composition of claim 1 , wherein the graphene sheet surfaces are substantially free of carbon nanoparticles.
6. The composition of claim 1 , wherein the composition is mesoporous.
7. The composition of claim 1 , wherein the composition has a peak pore diameter of about 2 nm to about 50 nm.
8. The composition of claim 1 , wherein the composition comprises a monolith.
9. The composition of claim 1 , wherein the composition has a surface area of 500 m 2 /g or more and has an electrical conductivity of 20 S/m or more.
10. A composition comprising at least one graphene aerogel monolith, wherein the monolith has an electrical conductivity of at least about 25 S/m, and wherein the graphene aerogel monolith comprises a network of graphene sheets directly chemically crosslinked with each other by sp 2 carbon bonds.
11. The composition of claim 10 , wherein the conductivity is at least 55 S/m.
12. The composition of claim 10 , wherein the conductivity is at least 87 S/m.
13. The composition of claim 10 , wherein the BET surface area is at least 584 m 2 /g.
14. The composition of claim 10 , wherein the BET surface area is at least 762 m 2 /g.
15. The composition of claim 10 , wherein the mesopore volume is at least 2.9 cm 3 /g.
16. The composition of claim 10 , wherein the mesopore volume is at least 3.3 cm 3 /g.
17. The composition of claim 10 , wherein the mesopore volume is at least 2.9 cm 3 /g, the BET surface area is at least 584 m 2 /g, and the conductivity is at least 25 S/m.
18. The composition of claim 10 , wherein the composition shows in x-ray diffraction a broad peak from about 12° to about 20° and a sharper feature at about 28°.
19. The composition of claim 10 , wherein the composition shows in x-ray diffraction no significant peaks for an amorphous structure.
20. The composition of claim 10 , wherein the atomic oxygen content is 5% or less.
21. The composition of claim 10 , wherein the aerogel comprises graphene sheets which are randomly oriented, and wherein the graphene sheets comprises single-layered and few-layered graphene.
22. The composition of claim 10 , wherein the aerogel comprises graphene sheets which have lateral dimensions of at least 200 nm.
23. The composition of claim 10 , wherein the aerogel comprises graphene sheet for which the surfaces are substantially free of carbon nanoparticles.
24. The composition of claim 10 , wherein the aerogel is mesoporous.
25. The composition of claim 10 , wherein the aerogel has a peak pore diameter of about 2 nm to about 50 nm.
26. The composition of claim 1 , wherein the graphene aerogel has a elastic modulus of 10 MPa or more.
27. A device comprising a composition according to claim 1 .
28. A device according to claim 27 , wherein the device is a capacitor, a battery, an electrode, a sensor, an actuator, a membrane, a catalyst support, or a hydrogen storage device.
29. The composition of claim 1 , wherein less than 10% of the graphene sheets in the graphene aerogel are interconnected only by physical crosslinks.
30. The composition of claim 1 , wherein less than 5% of the graphene sheets in the graphene aerogel are interconnected only by physical crosslinks.
31. The composition of claim 1 , wherein less than 1% of the graphene sheets in the graphene aerogel are interconnected only by physical crosslinks.
32. The composition of claim 1 , wherein at least 70% of the covalent carbon bonds crosslinking the graphene sheets are sp 2 bonds.
33. The composition of claim 1 , wherein at least 90% of the covalent carbon bonds crosslinking the graphene sheets are sp 2 bonds.