Asymmetric hybrid supercapacitors based on nanotube nanowire composites

1. An asymmetric supercapacitor, comprising:

a first structure; and

a second structure spaced apart from said second structure;

wherein one of the first and second structures comprises an anode, and one of the first and second structures comprises a cathode;

wherein the first structure comprises an activated carbon electrode;

wherein the second structure comprises a nanocomposite electrode;

wherein the nanocomposite electrode comprises a first network of nanowires that are interpenetrating with a second network of nanowires; and

wherein the interpenetrating first and second networks of nanowires form a mesh structure.

2. An asymmetric supercapacitor as recited in claim 1 , wherein the first network of nanowires and second network of nanowires form a composite mesh of nanowires that form hierarchical porous channels, such that substantially all pores in the supercapacitor electrode have diameters less than 20 nm or greater than 100 nm.

3. An asymmetric supercapacitor as recited in claim 1 , wherein the first network of nanowires comprises metal oxide nanowires.

4. An asymmetric supercapacitor as recited in claim 3 , wherein the second network of nanowires comprise carbon nanotubes (CNTs).

5. An asymmetric supercapacitor as recited in claim 4 , wherein the first network of nanowires comprises V 2 O 5 nanowires.

6. An asymmetric supercapacitor as recited in claim 4 , wherein the CNT's provide conductive pathways for electron transport and current collection.

7. An asymmetric supercapacitor as recited in claim 4 , wherein the first structure comprises the anode and the second structure comprises the cathode.

8. An asymmetric supercapacitor as recited in claim 4 , wherein the first structure comprises the cathode and the second structure comprises the anode.

9. An asymmetric supercapacitor as recited in claim 4 , wherein the nanocomposite electrode has a thickness greater than 100 μm.

10. An asymmetric supercapacitor as recited in claim 4 , wherein the first and second structures each comprise a substrate supporting the active carbon and nanocomposite electrodes; and

wherein the supercapacitor further comprises an electrically insulating separator between the first structure and the second structure.

11. An asymmetric supercapacitor as recited in claim 1 , wherein the mesh structure forms hierarchical porous channels, such that substantially all pores in the supercapacitor electrode have diameters less than 20 nm or greater than 100 nm.

12. An asymmetric supercapacitor as recited in claim 1 , wherein the first network of nanowires comprises metal oxide nanowires.

13. An asymmetric supercapacitor as recited in claim 12 , wherein the second network of nanowires comprise carbon nanotubes (CNTs).

14. An asymmetric supercapacitor as recited in claim 13 , wherein the first network of nanowires comprises V 2 O 5 nanowires.

15. An asymmetric supercapacitor as recited in claim 14 , further comprising:

an electrolyte;

wherein the mesh structure forms hierarchical porous channels;

wherein the V 2 O 5 nanowires are configured to react with said electrolyte; and

wherein the porous channels promote electrolyte transport.

16. An asymmetric supercapacitor as recited in claim 13 , wherein the CNTs provide conductive pathways for electron transport and current collection.

17. An asymmetric supercapacitor as recited in claim 13 , wherein the nanocomposite electrode has a thickness greater than 100 μm.

18. An asymmetric supercapacitor as recited in claim 1 , wherein the interpenetrating first and second networks of nanowires form a mesh structure having hierarchical porous channels.

19. An asymmetric supercapacitor as recited in claim 18 , wherein the first network of nanowires comprises metal oxide nanowires.

20. An asymmetric supercapacitor as recited in claim 19 , wherein the second network of nanowires comprise carbon nanotubes (CNTs).

21. An asymmetric supercapacitor as recited in claim 20 , wherein the first network of nanowires comprises V 2 O 5 nanowires.

22. An asymmetric supercapacitor as recited in claim 20 , wherein the nanocomposite electrode has a thickness greater than 100 μm.