Rechargeable power source for mobile devices which includes an ultracapacitor
Provided herein is a rechargeable power source that can be quickly charged and used for charging mobile and cordless devices. The power source includes an ultracapacitor which comprises a composite structure including, for example open graphene structures or graphene nanoribbons attached to an oxide layer. The oxide layer is on a metal foil surface. The oxide layer includes more than one metal atom.
1. A portable rechargeable power source for charging mobile devices, wherein the power source is fully charged in less than 10 minutes, the power source comprising an AC-DC power converter and an energy storage unit comprised of a battery and an ultracapacitor wherein the ultracapacitor has a composite structure comprising:
a metal foil current collector with thickness of less than 500 μm and a root mean square roughness in the range 2 to 200 nm;
a metal oxide layer less than 100 nm thick disposed on a surface of the metal foil and including one or more atoms of iron, nickel, aluminium, cobalt, copper, chromium and gold metal atoms or alloys thereof;
carbon nanotubes disposed on at least part of the metal oxide layer and which have been plasma treated to increase surface wettability, and wherein the carbon nanotubes comprise mesopores in the diameter range of from 2 nm to 50 nm, wherein the carbon nanotubes have been unzipped to create open graphene structures or carbon nanoribbons, and wherein the carbon nanotubes are coated with an electrically conducting polymer; and
an electrolyte comprising an ionic liquid comprising pyridinium salts, imidazolium salts, or a combination thereof.
2. The power source of claim 1 wherein the carbon nanotubes have also been water treated to remove impurities.
3. The power source of claim 1 wherein the carbon nanotubes are free from amorphous carbon impurities.
4. The power source of claim 1 wherein those parts of the metal oxide layer free from carbon nanotubes are coated with a metal or organic polymer film which prevents direct growth of the carbon nanotubes thereon.
5. The power source of claim 1 wherein the carbon nanotubes are coated with particles of one or more oxides of ruthenium, manganese, iron, nickel and magnesium.
6. The power source of claim 1 , wherein the power source is fully charged in less than 5 minutes.
7. The power source of claim 1 , wherein the power source is fully charged in less than 1 minute.
8. The power source of claim 1 , wherein the total capacity of the power source is at least 5 mAh or 0.025 Wh.
9. The power source of claim 1 , wherein the mobile device is a Universal Serial Device and is charged by a Universal Serial Bus.
10. The power source of claim 1 , wherein the input for the power source is an AC plug.
11. The power source of claim 10 , wherein the AC plug is connected to a wall mounted electricity outlet.
12. The power source of claim 1 , wherein the power source is charged at greater than 20_W.
13. The power source of claim 1 , wherein the power source is charged at greater than 50_W.
14. The power source of claim 1 , wherein the power source is used to charge mobile phones.
15. The power source of claim 1 , wherein the power source is used to charge laptop computers.
16. The power source of claim 1 , wherein the power source is used to power a light source.
17. The power source of claim 1 , wherein the power source is used to charge cordless power tools.
18. The power source of claim 1 , wherein the ultracapacitor energy storage unit comprises multiple pairs of stacked electrodes.
19. The power source of claim 1 , wherein the electrolyte is in the form of a liquid or a gel.
20. The power source of claim 1 , wherein the electrolyte is selected from the group consisting of N-alkyl-pyridinium salts, 1, 3-bisalkyl-imidazolium salts, and a combination thereof.
21. The power source of claim 1 , wherein the ultracapacitor further comprises an electrolytic membrane.
22. The power source of claim 1 , wherein the ultracapacitor is an asymmetrical capacitor.