Method of manufacturing a current collector for a double electric layer capacitor

• US 7,799,099 B2
• Filed: 10/27/2008
• Issued: 09/21/2010
• Est. Priority Date: 06/24/2005
• Status: Expired due to Fees

• Current Assignee: Universal Supercapacitors, LLC
• Original Assignee: Universal Supercapacitors, LLC
• Inventors: Nedoshivin, Valery Pavlovich, Kazarov, Vladimir Alexandrovich, Litvinenko, Sergey Vitalievich, Kharisov, Gamir Galievich, Razumov, Sergey Nikolaevich, Kazaryan, Samvel Avakovich
• Primary Examiner(s): Ghyka; Alexander G
• Assistant Examiner(s): Nikmanesh; Seahvosh J
• Application Number:
  US12/258,875
• Publication Number:
  US 20090044389A1
• Time in Patent Office: 694 Days
• Field of Search: 29/250.3
• US Class Current: 29/25.03
• CPC Class Codes: H01G 11/22 Electrodes
• CPC Class Codes: H01G 11/58 Liquid electrolytes
• CPC Class Codes: H01G 11/68 characterised by their material
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors
• CPC Class Codes: Y10T 428/31678 Of metal

Abstract

A method of manufacturing a current collector for use in a capacitor (e.g., a DEL capacitor) having an aqueous or non-aqueous electrolyte, such as an aqueous sulfuric acid electrolyte. The conductive basis of the current collector is preferably, but not necessarily, comprised of lead or a lead alloy. The portion of the conductive basis that will be in contact with the electrolyte is provided with a protective layer that is created by deposition of one or more layers of one or more protective coating materials thereto. Each protective coating material is comprised of at least a conductive carbon powder and a polymer binder that is resistant to the electrolyte. Preferably, but not essentially, the protective coating material(s) are applied to the conductive basis in the form of a paste, which is subsequently subjected to a solvent evaporation step and a thermal treatment step.

Claims

1. A method of manufacturing a capacitor current collector that is resistant to acidic electrolytes, comprising:

providing a conductive basis formed from an electrically conductive metal;

coating at least certain surfaces of said conductive basis with a protective coating material comprising a conductive composite that includes a conductive carbon powder and a polymer binder, wherein the protective coating material is resistant to a sulfuric acid electrolyte;

subjecting said protective coating material to a solvent evaporation step; and

subjecting said protective coating material to a thermal treatment step.

2. The method of claim 1, wherein said conductive basis is comprised of lead or a lead alloy.

3. The method of claim 1, wherein said conductive basis is selected from the group consisting of nickel, copper, iron and aluminum.

4. The method of claim 1, wherein said protective coating material exhibits p-type conductivity.

5. The method of claim 1, wherein said polymer binder is resistant to an aqueous sulfuric acid electrolyte.

6. The method of claim 5, wherein said polymer binder comprises perchlorovinyl.

7. The method of claim 1, wherein said protective coating material is applied to said conductive basis as a paste.

8. The method of claim 7, wherein said paste further includes one or more components selected from the group consisting of a plasticizer, a solvent, a dispersant, a wetting agent, and an anti-foaming agent.

9. The method of claim 7, wherein said conductive carbon powder has a particle size of less than about 500 Å

.

10. The method of claim 7, wherein said paste is homogenized after mixing.

11. The method of claim 7, wherein said paste is filtered prior to application to said conductive basis.

12. The method of claim 1, wherein said protective coating material is subjected to a solvent evaporation step after deposition to said conductive basis.

13. The method of claim 12, wherein said solvent evaporation step comprises air drying.

14. The method of claim 13, wherein said protective coating material is air dried for approximately two hours.

15. The method of claim 12, further comprising subjecting said protective coating material to a thermal treatment step subsequent to said solvent evaporation step.

16. The method of claim 1, wherein more than one layer of one or more protective coating materials is applied to said conductive basis.

17. The method of claim 16, wherein each layer of said protective coating material is subjected to a solvent evaporation step and a thermal treatment step prior to deposition of a subsequent layer of protective coating material.

18. The method of claim 17, wherein the temperature associated with said thermal treatment step for each layer of said protective coating material is substantially the same.

19. The method of claim 17, wherein the temperature associated with said thermal treatment step for a first layer of said protective coating material is different than the temperature associated with said thermal treatment step for additional layers of said protective coating material.

20. The method of claim 16, wherein a first layer of said protective coating material is selected based on its adhesive properties with respect to the particular conductive basis material to which it will be applied.

21. A method of manufacturing a capacitor current collector that is resistant to acidic electrolytes, comprising:

providing a conductive basis formed from lead or a lead alloy;

forming a protective layer on said conductive basis by coating at least certain surfaces of said conductive basis with one or more layers of one or more protective coating materials, each of which comprises a conductive composite that includes a conductive carbon powder and a polymer binder, wherein the one or more protective coating materials is resistant to a sulfuric acid electrolyte; and

subjecting each layer of said protective coating material to a solvent evaporation step and a thermal treatment step, said solvent evaporation step and said thermal treatment step occurring prior to the deposition of any additional layers of protective coating material;

wherein said resulting protective layer is substantially non-porous and capable of preventing an aqueous acid electrolyte from contacting and oxidizing said conductive basis.

22. The method of claim 21, wherein said protective coating material exhibits p-type conductivity.

23. The method of claim 21, wherein said polymer binder is resistant to an aqueous sulfuric acid electrolyte.

24. The method of claim 23, wherein said polymer binder comprises perchlorovinyl.

25. The method of claim 21, wherein said protective coating material is applied to said conductive basis as a paste.

26. The method of claim 25, wherein said paste further includes one or more components selected from the group consisting of a plasticizer, a solvent, a dispersant, a wetting agent, and an anti-foaming agent.

27. The method of claim 25, wherein said conductive carbon powder has a particle size of less than about 500 Å

.

28. The method of claim 25, wherein said paste is homogenized after mixing.

29. The method of claim 25, wherein said paste is filtered prior to application to said conductive basis.

30. The method of claim 21, wherein said solvent evaporation step comprises air drying.

31. The method of claim 30, wherein said protective coating material is air dried for approximately two hours.

32. The method of claim 21, wherein the temperature associated with said thermal treatment step for each layer of said protective coating material is substantially the same.

33. The method of claim 21, wherein the temperature associated with said thermal treatment step for a first layer of said protective coating material is different than the temperature associated with said thermal treatment step for additional layers of said protective coating material.

34. The method of claim 21, wherein a first layer of said protective coating material is selected based on its adhesive properties with respect to the lead-based conductive basis material to which it will be applied.

35. A method of manufacturing a current collector for a double electric layer capacitor, said current collector resistant to acidic electrolytes, and comprising:

providing a conductive basis formed from lead or a lead alloy;

preparing at least one protective coating material comprising a conductive composite that includes a conductive carbon powder and a polymer binder that is resistant to at least a sulfuric acid electrolyte, said at least one protective coating material exhibiting p-type conductivity;

forming a protective layer on said conductive basis by coating at least certain surfaces of said conductive basis with at least one layer of said at least one protective coating material in the form of a paste; and

subjecting each layer of said protective coating material to a solvent evaporation step and a thermal treatment step, said solvent evaporation step and said thermal treatment step occurring prior to the deposition of any additional layers of protective coating material;

wherein said resulting protective layer is substantially non-porous and capable of preventing an aqueous sulfuric acid electrolyte from contacting and oxidizing said conductive basis.

36. The method of claim 35, wherein said polymer binder comprises perchlorovinyl.

37. The method of claim 35, wherein said protective coating material paste further includes one or more components selected from the group consisting of a plasticizer, a solvent, a dispersant, a wetting agent, and an anti-foaming agent.

38. The method of claim 35, wherein said solvent evaporation step comprises air drying.