High energy density capacitors and method of manufacturing

• US 7,474,521 B2
• Filed: 02/28/2006
• Issued: 01/06/2009
• Est. Priority Date: 02/28/2006
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Hossick-Schott, Joachim
• Primary Examiner(s): THOMAS, ERIC W
• Application Number:
  US11/364,673
• Publication Number:
  US 20070188980A1
• Time in Patent Office: 1,043 Days
• Field of Search: 361/508, 361511-512, 361/516, 361517-521, 29/250.3
• US Class Current: 361/518
• CPC Class Codes: H01G 9/042 characterised by the material H01G11/22 takes precedence
• CPC Class Codes: H01G 9/10 Sealing, e.g. of lead-in wires

Abstract

A capacitor including a flexible case and method for manufacturing the same are provided. The capacitor includes an electrode assembly encased in a sealed flexible case. The electrode assembly includes an anode formed from a high surface area valve metal and a cathode operatively positioned relative to the anode. The flexible case may conform to an exterior contour of the electrode assembly.

Claims

1. A capacitor, comprising:

an electrode assembly having an exterior contour;

the electrode assembly comprising an anode formed from a high surface area valve metal and a cathode operatively positioned relative to the anode; and

a flexible case for encasing the electrode assembly, the flexible case being hermetically sealed,

the anode being a porous slug of a pressed and sintered valve metal powder.

2. The capacitor of claim 1 wherein the flexible case conforms to the exterior contour of the electrode assembly.

3. The capacitor of claim 1 wherein the flexible case includes one of an elastic material and a heat-shrinkable material.

4. The capacitor of claim 1 wherein the flexible case includes any of polypropylene, polyethylene, latex and a fluoropolymer.

5. The capacitor of claim 1 wherein the cathode includes a solid polymer.

6. The capacitor of claim 5, wherein the solid polymer being impregnated in the formed anode.

7. The capacitor of claim 5 further including a conductive contact operatively positioned relative to the solid polymer and a cathode lead electrically coupled to the conductive contact and extending therefrom.

8. The capacitor of claim 1 wherein the cathode includes a cathode material deposited on a conductive substrate.

9. The capacitor of claim 8 wherein the conductive substrate includes any of a foil, a woven mesh, and a non-woven mesh.

10. The capacitor of claim 8 wherein the cathode substrate includes any of titanium, aluminum, tantalum, niobium, nickel and a conductive polymer.

11. The capacitor of claim 10 wherein the sealing member includes any of a tie wrap, a wire, a band, and a heat-shrinkable member.

12. The capacitor of claim 8 wherein the cathode substrate includes a cathode lead extending there from.

13. The capacitor of claim 8 wherein the flexible case includes a laminated material including a flexible outer layer and a metallic inner layer and wherein the metallic inner layer forms the cathode substrate.

14. The capacitor of claim 1 wherein the flexible case includes an anode lead sleeve and a cathode lead sleeve extending there from.

15. The capacitor of claim 1 wherein the flexible case being sealed using any of heat, pressure, an adhesive, and a sealing member.

16. The capacitor of claim 1 wherein the anode is formed as a slug-type anode.

17. A method for fabricating a capacitor, comprising:

forming an anode, the anode being formed from a valve metal powder sintered and pressed into a porous slug;

forming a cathode in operative relation to the anode, the anode and cathode forming an electrode assembly;

positioning the electrode assembly in a flexible case; and

sealing the flexible case.

18. The method of claim 17 wherein forming the cathode comprises depositing a cathode material on a cathode substrate.

19. The method of claim 18 further including filling the flexible case with a liquid electrolyte.

20. The method of claim 17 wherein forming the cathode includes impregnating the anode with a liquid conductive polymer.

21. The method of claim 17 wherein the flexible case includes one of an elastic material and a heat-shrinkable material.

22. The method of claim 17 further including inserting an anode lead through an anode lead sleeve and inserting a cathode lead through a cathode lead sleeve, the anode and cathode lead sleeves being included on the flexible case, and sealing the anode and cathode lead sleeves.

23. The method of claim 17 further including applying heat to shrink the flexible case to conform to an exterior contour of the electrode assembly.

24. The method of claim 17 wherein sealing the case includes any of applying heat, applying pressure, applying an adhesive, applying a sealing member.

25. The method of claim 17 wherein the flexible case being formed from a laminate including an outer flexible layer and an inner metallic layer, the inner metallic layer forming a substrate for one of a cathode and a cathode contact.

26. The method of claim 17 further including removing excess case material after sealing the flexible case.

27. The method of claim 17 wherein forming the anode includes forming a slug-type pellet of valve metal material.

28. A capacitor, comprising:

an electrode assembly having an exterior contour;

the electrode assembly comprising an anode formed from a high surface area valve metal and a cathode operatively positioned relative to the anode and at least one lead extending from one of the anode and the cathode; and

a flexible case for encasing the electrode assembly, the flexible case being hermetically sealed,

the flexible case comprising a lead sleeve extending therefrom for receiving the at least one lead.

29. A capacitor, comprising:

an electrode assembly having an exterior contour;

the electrode assembly comprising an anode formed from a high surface area valve metal and a cathode operatively positioned relative to the anode; and

a flexible case for encasing the electrode assembly, the flexible case being hermetically sealed and being tightly-fitting to snugly conform to the exterior contour of the electrode assembly.