Current collector for a double electric layer capacitor

• US 7,446,998 B2
• Filed: 02/22/2006
• Issued: 11/04/2008
• Est. Priority Date: 06/24/2005
• Status: Expired due to Fees

• Current Assignee: Universal Supercapacitors, LLC
• Original Assignee: Universal Supercapacitors, LLC
• Inventors: Litvinenko, Sergey Vitalievich, Kharisov, Gamir Galievich, Razumov, Sergey Nikolaevich, Kazaryan, Samvel Avakovich, Nedoshivin, Valery Pavlovich, Kazarov, Vladimir Alexandrovich
• Primary Examiner(s): THOMAS, ERIC W
• Application Number:
  US11/358,981
• Publication Number:
  US 20060292384A1
• Time in Patent Office: 986 Days
• Field of Search: 361502-503
• US Class Current: 361/502
• 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 current collector for use in a capacitor having an aqueous or non-aqueous electrolyte, such as an aqueous sulfuric acid electrolyte. The conductive basis of the current collector may be manufactured from a number of conductive metals but, preferably, is 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. The resulting protective layer is also substantially devoid of pores through which the electrolyte can permeate.

Claims

1. A capacitor current collector comprising:

a conductive basis; and

a protective coating covering at least part of said conductive basis, said protective coating comprising a conductive composite that includes a conductive carbon powder and a polymer binder, said protective coating for substantially preventing an electrolyte of sulfuric acid aqueous solution from contacting a portion of said conductive basis covered by said protective coating.

2. The current collector of claim 1, wherein said conductive basis comprises lead.

3. The current collector of claim 1, wherein said conductive basis comprises a lead alloy.

4. The current collector of claim 3, wherein said lead alloy comprises lead and tin.

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

6. The current collector of claim 1, wherein said protective coating exhibits p-type conductivity.

7. The current collector of claim 1, wherein said polymer binder is resistant to an aqueous sulfuric acid electrolyte.

8. The current collector of claim 7, wherein said polymer binder comprises perchlorovinyl.

9. The current collector of claim 1, wherein said conductive composite material is applied to said conductive basis as a paste.

10. The current collector of claim 1, wherein said conductive composite material also 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.

11. The current collector of claim 1, wherein said capacitor is a double electric layer electrochemical capacitor.

12. The current collector of claim 11, wherein said capacitor is a heterogeneous electrochemical supercapacitor.

13. The current collector of claim 11, wherein said capacitor is a symmetric electrochemical supercapacitor.

14. A current collector for use in an electrochemical capacitor having an aqueous sulfuric acid electrolyte, comprising:

a conductive basis of lead or a lead alloy; and

a protective layer residing on said conductive basis, said protective layer constructed from one or more layers of one or more protective coating materials, each protective coating material comprising a conductive composite that includes a conductive carbon powder and a polymer binder;

wherein each layer of protective coating material is subjected to a solvent evaporation process and a thermal treatment process prior to deposition of a subsequent layer of protective coating material; and

wherein said resulting protective layer is substantially non-porous and prevents said aqueous sulfuric acid electrolyte from contacting said conductive basis, thereby avoiding oxidation of said conductive basis by said aqueous sulfuric acid electrolyte.

15. The current collector of claim 14, wherein said protective layer exhibits p-type conductivity.

16. The current collector of claim 14, wherein said polymer binder is resistant to said aqueous sulfuric acid electrolyte.

17. The current collector of claim 16, wherein said polymer binder comprises perchlorovinyl.

18. The current collector of claim 14, wherein said conductive composite material is applied to said conductive basis as a paste.

19. The current collector of claim 14, wherein said conductive composite material also 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.

20. The current collector of claim 14, wherein said capacitor is a double electric layer electrochemical capacitor.

21. The current collector of claim 20, wherein said capacitor is a heterogeneous electrochemical supercapacitor.

22. The current collector of claim 20, wherein said capacitor is a symmetric electrochemical supercapacitor.

23. The current collector of claim 14, wherein said protective coating is formed from multiple layers, the first layer of which is comprised of a conductive composite that exhibits good adhesion to a lead-based conductive basis.

24. The current collector of claim 23, wherein said first layer of said protective coating material has a thickness of about 0.5-1.0 μ

m.

25. The current collector of claim 14, wherein said protective coating is formed from multiple layers, each of which is of substantially equal thickness.

26. The current collector of claim 14, wherein each layer of conductive composite material is subjected to a solvent evaporation process and a thermal treatment process prior to deposition of a subsequent layer of conductive composite material.

27. The current collector of claim 14, wherein said conductive carbon powder has a particle size of between about 300-500 Å

prior to said conductive composite being applied to said conductive basis.

28. A capacitor current collector comprising:

a conductive basis; and

a protective coating covering at least part of said conductive basis, said protective coating comprising a conductive composite that includes a conductive carbon powder and a perchlorovinyl polymer binder that is resistant to an aqueous sulfuric acid electrolyte, said protective coating for substantially preventing said aqueous sulfuric acid electrolyte from contacting a portion of said conductive basis covered by said protective coating.

29. The current collector of claim 28, wherein said conductive basis comprises lead.

30. The current collector of claim 28, wherein said conductive basis comprises a lead alloy.

31. The current collector of claim 30, wherein said lead alloy comprises lead and tin.

32. The current collector of claim 28, wherein said conductive basis is selected from the group consisting of nickel, copper, iron and aluminum.

33. The current collector of claim 28, wherein said protective coating exhibits p-type conductivity.

34. The current collector of claim 28, wherein said conductive composite material is applied to said conductive basis as a paste.

35. The current collector of claim 28, wherein said capacitor is a double electric layer electrochemical capacitor.

36. The current collector of claim 35, wherein said capacitor is a heterogeneous electrochemical supercapacitor.

37. The current collector of claim 35, wherein said capacitor is a symmetric electrochemical supercapacitor.