Capacitor

• US 7,667,954 B2
• Filed: 08/09/2007
• Issued: 02/23/2010
• Est. Priority Date: 05/30/2003
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc), Kemet Electronics Corporation (Yageo Corporation)
• Original Assignee: Medtronic Incorporated (Medtronic Plc), Kemet Electronics Corporation (Yageo Corporation)
• Inventors: Schott, Joachim Hossick, Melody, Brian, Lessner, Philip Michael, Kinard, John Tony
• Primary Examiner(s): THOMAS, ERIC W
• Application Number:
  US11/891,084
• Publication Number:
  US 20070274025A1
• Time in Patent Office: 929 Days
• Field of Search: 361502-517, 607/5
• US Class Current: 361/516
• CPC Class Codes: A61N 1/3956 Implantable devices for applying electric shocks to the heart, e.g. for cardioversion
• CPC Class Codes: H01G 11/48 Conductive polymers
• CPC Class Codes: H01G 11/56 Solid electrolytes, e.g. gels; Additives therein
• CPC Class Codes: H01G 9/042 characterised by the material H01G11/22 takes precedence
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors

Abstract

A capacitor includes a container, a positive electrode, a negative electrode, and a fluid electrolyte. The positive electrode includes a metal substrate and an active material provided in contact with the metal substrate. The active material includes at least one of poly(ethylene 3,4-dioxythiophene) and a titanate.

Claims

1. A capacitor comprising a container, a positive electrode, a negative electrode, and a fluid electrolyte, wherein the positive electrode comprises a metal substrate that is integrally formed with the container and an active material provided in contact with the metal substrate, the active material comprising at least one of poly(ethylene 3,4-dioxythiophene) and a titanate.

2. The capacitor of claim 1, wherein the active material comprises poly(ethylene 3,4-dioxythiophene).

3. The capacitor of claim 1, wherein the active material comprises at least one material selected from the group consisting of beryllium titanate, magnesium titanate, calcium titanate, strontium titanate, barium titanate, lead titanate, cadmium titanate, niobium titanate, strontium titanate, and organic titanates.

4. The capacitor of claim 1, wherein the metal substrate is a wall of the container.

5. The capacitor of claim 1, wherein the metal substrate comprises stainless steel.

6. The capacitor of claim 1, wherein the metal substrate comprises titanium.

7. The capacitor of claim 1, wherein the metal substrate comprises at least one material selected from the group consisting of silver, tantalum, niobium, zirconium, aluminum, and alloys thereof.

8. The capacitor of claim 1, wherein the negative electrode comprises at least one material selected from the group consisting of tantalum, aluminum, titanium, niobium, zirconium, and alloys thereof.

9. The capacitor of claim 1, wherein the active material has a specific capacitance of greater than approximately 10 milliFarads per square centimeter.

10. The capacitor of claim 1, wherein the active material is provided as a layer having a thickness of between approximately 0.0001 and 0.025 inches.

11. A capacitor comprising:

a housing;

a positive electrode comprising a substrate and a layer of poly(ethylene 3,4-dioxythiophene) provided on the substrate, the substrate forming a wall of the housing and comprising a metal selected from the group consisting of titanium, tantalum, stainless steel, aluminum, niobium, zirconium, and alloys thereof;

a negative electrode; and

a liquid electrolyte.

12. The capacitor of claim 11, wherein the substrate comprises stainless steel.

13. The capacitor of claim 11, wherein the metal comprises titanium.

14. The capacitor of claim 11, wherein the layer of poly(ethylene 3,4-dioxythiophene) has a thickness of between approximately 0.0001 and 0.025 inches.

15. The capacitor of claim 11, wherein the layer of poly(ethylene 3,4-dioxythiophene) has a specific capacitance of at least approximately 10 milliFarads per square centimeter.

16. The capacitor of claim 15, wherein the layer of poly(ethylene 3,4-dioxythiophene) has a specific capacitance of at least approximately 20 milliFarads per square centimeter.

17. The capacitor of claim 11, wherein the negative electrode comprises tantalum.

18. A capacitor comprising:

a housing;

a positive electrode comprising a substrate and a layer of poly(ethylene 3,4-dioxythiophene) provided on the substrate, the substrate comprising a metal selected from the group consisting of titanium, tantalum, stainless steel, aluminum, niobium, zirconium, and alloys thereof;

a negative electrode; and

a liquid electrolyte;

wherein the negative electrode comprises a porous sintered tantalum slug.

19. A capacitor comprising:

a housing;

a positive electrode comprising a substrate that is a wall of the housing and a titanate material provided on the substrate, the substrate comprising a metal selected from the group consisting of titanium, tantalum, stainless steel, aluminum, niobium, zirconium, and alloys thereof;

a negative electrode; and

a liquid electrolyte.

20. The capacitor of claim 19, wherein the substrate comprises tantalum.

21. The capacitor of claim 19, wherein the metal comprises titanium.

22. The capacitor of claim 19, wherein the titanate material is selected from the group consisting of beryllium titanate, magnesium titanate, calcium titanate, strontium titanate, barium titanate, lead titanate, cadmium titanate, niobium titanate, strontium titanate, and organic titanates.

23. The capacitor of claim 19, wherein the titanate material has a dielectric constant that is greater than approximately 50.

24. The capacitor of claim 19, wherein the negative electrode comprises tantalum.

25. A medical device comprising:

an electrolytic capacitor including a container, a positive electrode, a negative electrode, and a fluid electrolyte;

wherein the positive electrode comprises a metal substrate formed as part of the container and an active provided in contact with the metal substrate, the active material comprising poly(ethylene 3,4-dioxythiophene); and

wherein the medical device is configured for implantation into a human to provide a therapeutic high voltage treatment.

26. The medical device of claim 25, wherein the medical device is selected from the group consisting of a pacemaker, a cardioverter, a defibrillator, a neural stimulator, and a drug administering device.

27. The medical device of claim 25, wherein the metal substrate comprises titanium.

28. The medical device of claim 25, wherein the metal substrate comprises at least one material selected from the group consisting of stainless steel, silver, tantalum, niobium, zirconium, aluminum, and alloys thereof.

29. The medical device of claim 25, wherein the metal substrate comprises aluminum.

30. The medical device of claim 25, wherein the negative electrode comprises at least one material selected from the group consisting of tantalum, aluminum, titanium, niobium, zirconium, and alloys thereof.

31. A medical device comprising:

an electrolytic capacitor including a positive electrode, a negative electrode, and a fluid electrolyte;

wherein the positive electrode comprises a titanate selected from the group consisting of beryllium titanate, magnesium titanate, lead titanate, cadmium titanate, niobium titanate, organic titanates, and combinations thereof;

wherein the medical device is configured for implantation into a human to provide a therapeutic high voltage treatment.

32. The medical device of claim 31, wherein the titanate has a dielectric constant of at least approximately 50.

33. The medical device of claim 31, wherein the titanate has a dielectric constant of at least approximately 100.

34. The medical device of claim 31, wherein the positive electrode has a specific capacitance of greater than approximately 10 milliFarads per square centimeter.

35. The medical device of claim 31, wherein the positive electrode is provided as a layer having a thickness of between approximately 0.0001 and 0.025 inches.

36. The medical device of claim 31, wherein the medical device is selected from the group consisting of a pacemaker, a cardioverter, a defibrillator, a neural stimulator, and a drug administering device.