Carbonaceous nanoparticles, methods of making same and uses thereof

1. A supercapacitor, comprising:

a first electrode comprising a first substrate and carbonaceous nanoparticles;

a second electrode comprising a second substrate and carbonaceous nanoparticles;

a separator positioned between the first electrode and the second electrode; and

an electrolyte,

wherein the carbonaceous nanoparticles are made by

reacting a first carbon source with a second carbon source in the presence of a nitrogen source in a DC arc furnace to form a composite nanoparticle, wherein the second carbon source comprises a dopant, wherein the composite nanoparticle comprises a crystalline carbon phase having an amorphous phase comprising dopant or carbide; and

removing the amorphous phase from the composite nanoparticle by heating at 450° C. in air to form the carbonaceous nanoparticle, wherein the carbonaceous nanoparticle comprises a nano-porous particle having a framework consisting of inter-nested carbon nano-horns and twisted nano-graphite sheets.

2. The supercapacitor of claim 1 , wherein the first substrate comprises a first metal.

3. The supercapacitor of claim 2 , wherein the first metal comprises stainless steel.

4. The supercapacitor of claim 1 , wherein the second substrate comprises a second metal.

5. The supercapacitor of claim 4 , wherein the second metal comprises stainless steel.

6. The supercapacitor of claim 1 , wherein the separator comprises plastic.

7. The supercapacitor of claim 6 , wherein the plastic comprises polypropylene.

8. The supercapacitor of claim 6 , wherein the plastic comprises a composition resistant to attack by acids and bases.

9. The supercapacitor of claim 1 , wherein the electrolyte comprises potassium hydroxide.

10. The supercapacitor of claim 1 , wherein the supercapacitor has an energy density greater than or equal to about 2 mWh/cm 3 .

11. The supercapacitor of claim 1 having a power density, wherein the power density comprises greater than or equal to about 4 kW/cm 3 .

12. A method of making an electrode for a supercapacitor, comprising:

applying to a substrate a suspension of a liquid dispersant comprising carbonaceous nanoparticles formed according to a method, said method comprising:

reacting a first carbon source with a second carbon source in the presence of a nitrogen source in a DC arc furnace to form a composite nanoparticle, wherein the second carbon source comprises a dopant, wherein the composite nanoparticle comprises a crystalline carbon phase having an amorphous phase comprising dopant or carbide; and

removing the amorphous phase from the composite nanoparticle by heating at 450° C. in air to form the carbonaceous nanoparticle, wherein the carbonaceous nanoparticle comprises a nano-porous particle having a framework consisting of inter-nested carbon nano-horns and twisted nano-graphite sheets;

drying the suspension of carbonaceous nanoparticles on the substrate; and

compacting the dried suspension of carbonaceous nanoparticles on the substrate with a uniaxial pressure less than or equal to 1000 MPa to create an electrode.

13. The method of claim 12 , wherein the liquid dispersant comprises an alcohol.

14. The supercapacitor of claim 1 , wherein the first carbon source is selected from graphite and carbon black.

15. The supercapacitor of claim 1 , wherein the dopant comprises boron.

16. The supercapacitor of claim 1 , wherein the dopant comprises boron carbide (B 4 C).

17. The supercapacitor of claim 1 , wherein the ratio of the weight percent of the first carbon source to the second carbon source comprises from about 2:1 to about 20:1.

18. The supercapacitor of claim 5 , wherein the ratio of the weight percent of the first carbon source to the second carbon source comprises about 9:1.