METHOD OF PRODUCING A CAPACITOR

• US 20080229565A1
• Filed: 05/29/2008
• Published: 09/25/2008
• Est. Priority Date: 09/30/2002
• Status: Active Grant

• Current Assignee: Kemet Electronics Corporation (Yageo Corporation)
• Original Assignee: Medtronic Incorporated (Medtronic Plc), Kemet Electronics Corporation (Yageo Corporation)
• Inventors: Kinard, John Tony, Schott, Joachim Hossick, Melody, Brian
• Granted Patent: US 8,339,769 B2
• Time in Patent Office: Days
• US Class Current: 29/25.03
• CPC Class Codes: A61N 1/3975 Power supply A61N1/378 takes precedence
• CPC Class Codes: H01G 11/30 characterised by their material
• CPC Class Codes: H01G 11/32 Carbon-based
• CPC Class Codes: H01G 9/008 Terminals
• 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 9/06 Mounting in containers
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors

Abstract

A method of making an electrolytic capacitor includes providing a first electrode that includes a metal substrate, a carbide layer, and a carbonaceous material. The metal substrate includes a metal selected from the group consisting of titanium, aluminum, tantalum, niobium, zirconium, silver, steel, and alloys and combinations thereof. The method further includes providing a second electrode and an electrolyte.

Claims

1. A method of making an electrolytic capacitor comprising:

providing a first electrode comprising a metal substrate, a carbide layer, and a carbonaceous material, the metal substrate comprising a metal selected from the group consisting of titanium, aluminum, tantalum, niobium, zirconium, silver, steel, and alloys and combinations thereof;

providing a second electrode; and

providing an electrolyte.

2. The method of claim 1, further comprising roughening a surface of the substrate.

3. The method of claim 2, wherein the roughening step utilizes at least one process selected from the group consisting of grit blasting and etching.

4. The method of claim 2, wherein the roughness of the surface as measured by the distance between peaks and valleys at the surface is between approximately 2 and 5 micrometers.

5. The method of claim 1, further comprising providing a material comprising carbon adjacent the substrate and subjecting the material comprising carbon to a temperature of between approximately 800 and 1000 degrees Celsius to form the carbide layer.

6. The method of claim 5, wherein the step of providing a material comprising carbon adjacent the substrate comprises depositing the material comprising carbon on the substrate.

7. The method of claim 5, wherein the material comprising carbon comprises graphite.

8. The method of claim 1, wherein the step of providing a first electrode comprises providing the carbonaceous material adjacent the carbide layer and heating the carbonaceous material in an oxygen-containing atmosphere to activate at least a portion of the carbonaceous material.

9. The method of claim 8, further comprising introducing an oxide of manganese into the carbonaceous material.

10. The method of claim 9, wherein the step of introducing an oxide of manganese into the carbonaceous material comprises providing a solution comprising manganese nitrate and heating the solution and the carbonaceous material to form the oxide of manganese.

11. The method of claim 8, wherein the step of heating the carbonaceous material in an oxygen-containing atmosphere to activate at least a portion of the carbonaceous material comprising heating the carbonaceous material to a temperature of between approximately 300 and 500 degrees Celsius for a period of between approximately 30 and 90 minutes.

12. The method of claim 8, wherein the step of heating the carbonaceous material in an oxygen-containing atmosphere produces a carbonaceous layer having a layer of activated carbon and a layer of non-activated carbon.

13. The method of claim 1, wherein the substrate comprises titanium.

14. The method of claim 1, wherein the substrate comprises aluminum.

15. The method of claim 1, further comprising forming a native oxide layer on the substrate.

16. The method of claim 1, wherein the carbide layer comprises a metal carbide.

17. A method of making an electrolytic capacitor comprising:

preparing a first electrode by providing a carbide layer and a carbonaceous layer on a metal substrate, the carbonaceous layer comprising activated carbon and the metal substrate comprising a metal selected from the group consisting of titanium, aluminum, tantalum, niobium, zirconium, silver, and steel, and alloys and combinations thereof; and

providing the first electrode in a housing along with a second electrode and an electrolyte.

18. The method of claim 17, further comprising roughening a surface of the substrate such that the roughness of the surface as measured by the distance between peaks and valleys at the surface is between approximately 2 and 5 micrometers.

19. The method of claim 17, further comprising providing a carbon-containing material adjacent the substrate and subjecting the carbon-containing material to a temperature of between approximately 800 and 1000 degrees Celsius to form the carbide layer.

20. The method of claim 17, wherein the carbonaceous layer includes both activated and non-activated carbon.

21. The method of claim 17, further comprising introducing an oxide of manganese into the carbonaceous layer.

22. The method of claim 21, wherein the step of introducing an oxide of manganese into the carbonaceous layer comprises providing a solution comprising manganese nitrate and heating the solution and the carbonaceous layer to form the oxide of manganese.

23. The method of claim 17, wherein the substrate comprises a metal selected from the group consisting of titanium and aluminum.

24. The method of claim 17, wherein the carbide layer comprises a metal carbide.

25. A method of making an electrolytic capacitor comprising:

providing a first layer of material and a second layer of material on a substrate to form a first electrode, the first layer of material comprising a carbide and the second layer of material comprising a carbonaceous material, the substrate formed from a metal selected from the group consisting of titanium, aluminum, tantalum, niobium, zirconium, silver, and steel, and alloys and combinations thereof;

providing the first electrode in a housing;

providing a second electrode in the housing; and

providing an electrolyte in the housing.

26. The method of claim 25, further comprising roughening a surface of the substrate using a process selected from the group consisting of grit blasting and etching.

27. The method of claim 26, wherein the roughness of the surface is between approximately 2 and 5 micrometers.

28. The method of claim 25, further comprising providing graphite adjacent the substrate and subjecting the graphite to a temperature of between approximately 800 and 1000 degrees Celsius to form the first layer.

29. The method of claim 28, wherein the graphite is provided as a suspension of graphite powder in alcohol.

30. The method of claim 25, wherein the step of providing the second layer of material comprises heating the carbonaceous material in an oxygen-containing atmosphere to activate at least a portion of the carbonaceous material.

31. The method of claim 30, further comprising introducing an oxide of manganese into the carbonaceous material.

32. The method of claim 31, wherein the step of introducing an oxide of manganese into the carbonaceous material comprises providing a solution comprising manganese nitrate and heating the solution and the carbonaceous material to form the oxide of manganese.

33. The method of claim 25, wherein the substrate comprises titanium or aluminum.

34. The method of claim 25, wherein the carbide comprises a metal carbide.