Dry particle based capacitor and methods of making same

• US 7,352,558 B2
• Filed: 04/02/2004
• Issued: 04/01/2008
• Est. Priority Date: 07/09/2003
• Status: Active Grant

• Current Assignee: Tesla Inc.
• Original Assignee: Maxwell Technologies Incorporated (Tesla Inc.)
• Inventors: Mitchell, Porter, Xi, Xiaomei, Zhong, Linda, Zou, Bin
• Primary Examiner(s): Ha; Nguyen T.
• Application Number:
  US10/817,590
• Publication Number:
  US 20060133012A1
• Time in Patent Office: 1,460 Days
• Field of Search: 361502-504, 361508-512, 361/516, 361/528, 361/532
• US Class Current: 361/502
• CPC Class Codes: H01G 11/22 Electrodes
• CPC Class Codes: H01G 11/38 Carbon pastes or blends; Binders or additives therein
• CPC Class Codes: H01G 11/42 Powders or particles, e.g. composition thereof
• CPC Class Codes: H01G 11/86 specially adapted for electrodes carbonisation or activation of carbon for the manufacture of electrodes H01G11/34
• CPC Class Codes: H01G 9/00 Electrolytic capacitors, rectifiers, detectors, switching devices, light-sensitive or temperature-sensitive devices; Processes of their manufacture
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors

Abstract

An inexpensive and reliable dry process based capacitor and method for making a self-supporting dry electrode film for use therein is disclosed. Also disclosed is an exemplary process for manufacturing an electrode for use in an energy storage device product, the process comprising: supplying dry carbon particles; supplying dry binder; dry mixing the dry carbon particles and dry binder; and dry fibrillizing the dry binder to create a matrix within which to support the dry carbon particles as dry material.

Claims

1. A process for manufacturing an electrode for use in an energy storage device product, the process comprising the steps of:

supplying dry carbon particles;

supplying dry binder;

dry mixing the dry carbon particles and dry binder; and

dry fibrillizing the dry binder to create a matrix within which to support the dry carbon particles as a dry material.

2. The process of claim 1, wherein the step of dry fibrillizing comprises application of sufficiently high-shear.

3. The process of claim 2, wherein the high-shear is applied in a jet-mill.

4. The process of claim 2, wherein the application of sufficiently high-shear is effectuated by application of a high pressure.

5. The process of claim 4, wherein the high pressure is applied as a high pressure gas.

6. The process of claim 5, wherein the gas comprises oxygen.

7. The process of claim 5, wherein the pressure is greater than or equal to about 60 PSI.

8. The process of claim 6, wherein the gas is applied at with a water content of less than 20 ppm.

9. The process of claim 1, further comprising a step of compacting the dry material.

10. The process of claim 9, wherein the step of compacting is performed after one pass through a compacting apparatus.

11. The process of claim 10, wherein the compacting apparatus is a roll-mill.

12. The process of claim 10, wherein after the one pass through the compacting apparatus the dry material comprises a self supporting dry film.

13. The process of claim 12, wherein the self supporting dry film comprises a thickness of less than about 250 microns.

14. The process of claim 12, wherein the self supporting dry film is formed as a continuous sheet.

15. The process of claim 14, wherein the sheet is at least one meter long.

16. The process of claim 1, wherein the dry material is manufactured without the substantial use of any processing additives.

17. The process of claim 16, wherein the processing additives include:

hydrocarbons, high boiling point solvents, antifoaming agents, surfactants, dispersion aids, water, pyrrolidone mineral spirits, ketones, naphtha, acetates, alcohols, glycols, toluene, xylene, and isoparaffinic fluids.

18. The process of claim 1, further comprising a step of calendering the dry material onto a substrate.

19. The process of claim 18, wherein the substrate comprises a collector.

20. The process of claim 19, wherein the collector comprises an aluminum foil.

21. The process of claim 18, wherein the dry material is calendered directly onto the substrate without use of an intermediate layer.

22. The process of claim 18, wherein the dry material is calendered onto a treated substrate.

23. The process of claim 1, wherein the dry binder comprises a fibrillizable fluoropolymer.

24. The process of claim 1, wherein the dry material consists of the dry carbon particles and the dry binder.

25. The process of claim 1, wherein the dry material comprises between about 50% to 99% activated carbon.

26. The process of claim 1, wherein the dry material comprises between about 0% to 25% conductive carbon.

27. The process of claim 1, wherein the dry material comprises between about 0.5% to 20% fluoropolymer particles.

28. The process of claim 1, wherein the dry material comprises between about 80% to 95% activated carbon and between about 0% to 15% conductive carbon, and wherein the dry binder comprises between about 3% to 15% fluoropolymer.

29. A method of manufacturing an electrode, comprising the steps of:

mixing dry carbon and dry binder particles; and

forming a self-supporting film from the dry particles without the use of any processing additives.

30. The method of claim 29, wherein the processing additives include:

hydrocarbons, high boiling point solvents, antifoaming agents, surfactants, dispersion aids, water, pyrrolidone mineral spirits, ketones, naphtha, acetates, alcohols, glycols, toluene, xylene, and isoparaffinic fluids.