Ultracapacitor with a novel carbon
Disclosed is a carbon material that can be useful, for example, in ultracapacitors. Also disclosed are applications and devices containing the carbon material.
1. An activated expanded graphite oxide prepared by:
exposing a graphite oxide to microwave energy from about 300 MHz to about 300 GHz to provide an expanded graphite oxide; and
contacting the expanded graphite oxide with a basic or reducing activator to form an activated expanded graphite oxide, wherein the activated expanded graphite oxide has a three-dimensional distribution of mesopores, wherein at least a portion of the mesopores have a width of from about 0.5 nm to about 10 nm.
2. The activated expanded graphite oxide of claim 1 , wherein the activated expanded graphite oxide has a specific surface area of at least about 1,280 m 2 /g.
3. The activated expanded graphite oxide product of claim 1 , wherein the activated expanded graphite oxide has an electrical conductivity of at least about 500 S/m.
4. The activated expanded graphite oxide of claim 1 , wherein the activated expanded graphite oxide has a pore volume of up to about 2.14 cm 3 /g.
5. The activated expanded graphite oxide of claim 1 , wherein the activated expanded graphite oxide has a specific capacitance of at least about 160 F/g.
6. The activated expanded graphite oxide of claim 1 , wherein the activated expanded graphite oxide has a volumetric capacitance of at least about 60 F/cm 3 .
7. The activated expanded graphite oxide of claim 1 , wherein the activated expanded graphite oxide has an energy density of at least about 70 Wh/kg.
8. The activated expanded graphite oxide of claim 1 , wherein the activated expanded graphite oxide has a power density of at least about 250 kW/kg.
9. The activated expanded graphite of claim 1 , wherein at least a portion of the pore walls comprise curved surfaces.
10. The activated expanded graphite oxide of claim 1 , wherein the activated expanded graphite oxide comprises a plurality of n-membered rings, wherein each of the n-membered rings are positioned in the same plane, and wherein n is from about 5 to about 8.
11. The activated expanded graphite oxide of claim 1 , wherein the activator at least partially digests the expanded graphite oxide to form the activated expanded graphite oxide.
12. The activated expanded graphite oxide of claim 1 , wherein the activator restructures at least a portion of the expanded graphite oxide to form the activated expanded graphite oxide.
13. The activated expanded graphite oxide of claim 1 , wherein the activator comprises potassium hydroxide (KOH).
14. The activated expanded graphite oxide of claim 1 , wherein the microwave energy is between about 100 W and about 2,500 W.
15. The activated expanded graphite oxide of claim 1 , wherein the activated the activated expanded graphite oxide has a specific surface area of up to about 3,100 m 2 /g.
16. An electrode comprising an activated expanded graphite oxide prepared by:
exposing a graphite oxide to microwave energy from about 300 MHz to about 300 GHz to provide an expanded graphite oxide; and
contacting the expanded graphite oxide with a basic or reducing activator to form an activated expanded graphite oxide, wherein the activated expanded graphite oxide has a three-dimensional distribution of Mesopores, wherein at least a portion of the mesopores have a width of from about 0.5 nm to about 10 nm.
17. The electrode of claim 16 , wherein the activated expanded graphite oxide has a specific surface area of at least about 1,280 m 2 /g.
18. The electrode of claim 16 , wherein the activated expanded graphite oxide has an electrical conductivity of at least about 500 S/m.
19. The electrode of claim 16 , the activated expanded graphite oxide has a pore volume of up to about 2.14 cm 3 /g.
20. The electrode of claim 16 , wherein the activated expanded graphite oxide has a specific capacitance of at least about 160 F/g.
21. The electrode of claim 16 , wherein the activated expanded graphite oxide has a volumetric capacitance of at least about 60 F/cm 3 .
22. The electrode of claim 16 , wherein the activated expanded graphite oxide has an energy density of at least about 70 Wh/kg.
23. The electrode of claim 16 , wherein the activated expanded graphite oxide has a power density of at least about 250 kW/kg.
24. The electrode of claim 16 , wherein at least a portion of the pore walls of the activated expanded graphite comprise curved surfaces.
25. The electrode of claim 16 , wherein the activated expanded graphite oxide comprises a plurality of n-membered rings, wherein each of the n-membered rings are positioned in the same plane, and wherein n is from about 5 to about 8.
26. The electrode of claim 16 , wherein the activator at least partially digests the expanded graphite oxide to form the activated expanded graphite oxide.
27. The electrode of claim 16 , wherein the activator restructures at least a portion of the expanded graphite oxide to form the activated expanded graphite oxide.
28. The electrode of claim 16 , wherein the activator comprises potassium hydroxide (KOH).
29. The electrode of claim 16 , wherein the microwave energy is between about 100 W and about 2,500 W.
30. The electrode of claim 16 , wherein the activated the activated expanded graphite oxide has a specific surface area of up to about 3,100 m 2 /g.