Capacitor and method for producing a capacitor

• US 6,842,328 B2
• Filed: 05/30/2003
• Issued: 01/11/2005
• Est. Priority Date: 05/30/2003
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Anthony Rorvick, Brian Melody, Christian Nielsen, Joachim Hossick Schott, John Norton, John Tony Kinard, Mark Viste
• Inventors: Nielsen, Christian, Viste, Mark, Norton, John, Rorvick, Anthony, Kinard, John Tony, Schott, Joachim Hossick, Melody, Brian
• Primary Examiner(s): Dinkins, Anthony
• Assistant Examiner(s): Ha, Nguyen T.
• Application Number:
  US10/449,879
• Publication Number:
  US 20040240144A1
• Time in Patent Office: 592 Days
• Field of Search: 361/302, 361/303, 361/305, 361/502, 361/503, 361/504, 361508-509, 361/512, 361/516, 361/520, 361/523, 361/528, 361530-532, 361/525
• US Class Current: 361/302
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: H01G 9/042 characterised by the material H01G11/22 takes precedence
• CPC Class Codes: H01G 9/0425 specially adapted for cathode
• CPC Class Codes: H01G 9/045 based on aluminium
• CPC Class Codes: Y10S 977/932 for electronic or optoelectronic application

Abstract

An electrode for a capacitor includes a substrate comprising at least one of glassy carbon and a metal. According to various embodiments, the substrate may be provided as glassy carbon or any of a variety of metals for use in capacitors. The capacitor also includes an activated carbon material adjacent the substrate. The activated carbon layer includes oxygen-containing functional groups. A material is provided in contact with the activated carbon layer for providing enhanced capacitance for the electrode. Various types of capacitance-enhancing materials may be utilized, including carbon nanotubes and conductive metal oxides.

Claims

1. An electrode for a capacitor comprising:

a substrate comprising at least one of glassy carbon and a metal;

an activated carbon material adjacent the substrate, the activated carbon layer comprising oxygen-containing functional groups; and

a material provided in contact with the activated carbon material for providing enhanced capacitance for the electrode.

2. The electrode of claim 1, wherein the substrate comprises at least one of titanium, aluminum, tantalum, niobium, and zirconium.

3. The electrode of claim 2, wherein the substrate comprises titanium.

4. The electrode of claim 1, wherein the activated carbon material includes a plurality of pores and at least a portion of the material provided in contact with the activated carbon material is provided within the plurality of pores.

5. The electrode of claim 1, wherein at least a portion of the material provided in contact with the activated carbon material is embedded within the activated carbon material.

6. The electrode of claim 1, wherein the material provided in contact with the activated carbon material comprises carbon nanotubes.

7. The electrode of claim 1, wherein the material provided in contact with the activated carbon material comprises a conductive metal oxide.

8. The electrode of claim 7, wherein the conductive metal oxide is provided in suspension with a graphite material.

9. The electrode of claim 7, wherein the conductive metal oxide is provided as micrometer-sized particles.

10. The electrode of claim 7, wherein the material provided in contact with the activated carbon material comprises an oxide of at least one metal from at least one of Group VII and Group VIII of the periodic table.

11. The electrode of claim 10, wherein the oxide is selected from the group consisting of ruthenium dioxide, iridium dioxide, manganese dioxide, silver vanadium oxide, vanadium pentoxide, titanium dioxide, rhenium dioxide, osmium dioxide, molybdenum dioxide, rhodium dioxide, vanadium dioxide, and tungsten dioxide.

12. The electrode of claim 1, further comprising a carbide layer intermediate the activated carbon material and the substrate.

13. The electrode of claim 12, wherein the carbide layer comprises titanium carbide.

14. The electrode of claim 12, wherein the carbide layer is chemisorbed on a surface of the substrate.

15. The electrode of claim 1, wherein the electrode is a cathode for an electrolytic capacitor.

16. The electrode of claim 1, wherein the electrode has a capacitance of greater than approximately 20 milliFarads per square centimeter.

17. An electrode for an electrolytic capacitor comprising:

a substrate comprising at least one of titanium and glassy carbon; and

a carbonaceous layer adjacent the substrate;

wherein the carbonaceous layer includes an activated carbon region and a capacitance-enhancing material provided adjacent the activated carbon region.

18. The electrode of claim 17, further comprising a carbide material provided intermediate the substrate and the carbonaceous layer.

19. The electrode of claim 18, wherein the substrate comprises titanium.

20. The electrode of claim 17, wherein the capacitance-enhancing material comprises at least one of carbon nanotubes and a conductive metal oxide.

21. The electrode of claim 20, wherein the capacitance-enhancing material comprises carbon nanotubes.

22. The electrode of claim 20, wherein the capacitance-enhancing material comprises a conductive metal oxide selected from the group consisting of ruthenium dioxide, iridium dioxide, manganese dioxide, silver vanadium oxide, vanadium pentoxide, titanium dioxide, rhenium dioxide, osmium dioxide, molybdenum dioxide, rhodium dioxide, vanadium dioxide, and tungsten dioxide.

23. The electrode of claim 17, wherein the carbonaceous layer further comprises non-activated carbon-containing material.

24. The electrode of claim 17, wherein the electrode has a capacitance of greater than approximately 20 milliFarads per square centimeter.

25. An electrode for a capacitor comprising:

a substrate comprising at least one of glassy carbon and a metal;

an activated carbon material adjacent the substrate; and

carbon nanotubes provided adjacent the activated carbon material;

whereby the activated carbon material and the carbon nanotubes provide enhanced capacitance for the electrode.

26. The electrode of claim 25, wherein the carbon nanotubes are single-walled carbon nanotubes.

27. The electrode of claim 25, wherein the carbon nanotubes are multi-walled carbon nanotubes.

28. The electrode of claim 25, wherein the substrate comprises at least one of titanium, aluminum, tantalum, niobium, and zirconium.

29. The electrode of claim 28, wherein the substrate comprises titanium.

30. The electrode of claim 25, further comprising a conductive metal oxide adjacent the activated carbon material.

31. The electrode of claim 30, wherein the conductive metal oxide comprises at least one of ruthenium dioxide, iridium dioxide, manganese dioxide, silver vanadium oxide, vanadium pentoxide, titanium dioxide, rhenium dioxide, osmium dioxide, molybdenum dioxide, rhodium dioxide, vanadium dioxide, and tungsten dioxide.

32. The electrode of claim 25, further comprising a carbide layer intermediate the activated carbon material and the substrate.

33. The electrode of claim 25, wherein the electrode is a cathode for an electrolytic capacitor.

34. The electrode of claim 25, wherein the electrode has a capacitance of greater than approximately 20 milliFarads per square centimeter.

35. An electrode for a capacitor comprising:

a substrate comprising at least one of glassy carbon and a metal;

an activated carbon material adjacent the substrate; and

an electronically conductive metal oxide provided adjacent the activated carbon material;

whereby the activated carbon material and the electronically conductive metal oxide provide enhanced capacitance for the electrode.

36. The electrode of claim 35, wherein the conductive metal oxide is an oxide of one or more metals included in at least one of Group VII and Group VIII of the periodic table.

37. The electrode of claim 35, wherein the conductive metal oxide comprises at least one of ruthenium dioxide, iridium dioxide, manganese dioxide, silver vanadium oxide, vanadium pentoxide, titanium dioxide, rhenium dioxide, osmium dioxide, molybdenum dioxide, rhodium dioxide, vanadium dioxide, and tungsten dioxide.

38. The electrode of claim 35, wherein the conductive metal oxide is provided as a sol-gel material.

39. The electrode of claim 35, wherein the conductive metal oxide is provided in a suspension with a graphite material.

40. The electrode of claim 35, wherein the conductive metal oxide has a particle size between approximately 0.1 and 2.0 micrometers.

41. The electrode of claim 35, wherein the substrate comprises at least one of titanium, aluminum, tantalum, niobium, and zirconium.

42. The electrode of claim 41, wherein the substrate comprises titanium.

43. The electrode of claim 35, wherein the activated carbon material includes a plurality of pores and at least a portion of the electronically conductive metal oxide is provided within the plurality of pores.

44. The electrode of claim 35, further comprising carbon nanotubes adjacent the activated carbon material.

45. The electrode of claim 35, further comprising a carbide layer intermediate the activated carbon material and the substrate.

46. The electrode of claim 35, wherein the electrode is a cathode for an electrolytic capacitor.

47. The electrode of claim 35, wherein the electrode has a capacitance of greater than approximately 20 milliFarads per square centimeter.