Heterogeneous electrochemical supercapacitor and method of manufacture

• US 20060291140A1
• Filed: 02/22/2006
• Published: 12/28/2006
• Est. Priority Date: 06/24/2005
• Status: Active Grant

• Current Assignee: Universal Supercapacitors, LLC
• Original Assignee: Universal Supercapacitors, LLC
• Inventors: Litvinenko, Sergey Vitalievich, Kharisov, Gamir Galievich, Razumov, Sergey Nikolaevich, Kazaryan, Samvel Avakovich, Kazarov, Vladimir Alexandrovich
• Granted Patent: US 7,312,976 B2
• Time in Patent Office: Days
• US Class Current: 361/502
• CPC Class Codes: H01G 11/30 characterised by their material
• CPC Class Codes: H01G 11/46 Metal oxides
• CPC Class Codes: H01G 11/58 Liquid electrolytes
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors

Abstract

The present invention relates to a double electric layer heterogeneous electrochemical supercapacitor (HES) and a method of manufacture. Single-cell or multi-cell versions of the HES can be produced. Output characteristics of the HES are optimized by carefully controlling particular parameters of the HES'"'"' design and construction. For example, the ratio between the charging capacities of the positive electrode and negative electrode of the HES is carefully selected and controlled, an active material of higher efficiency than the active material used by typical electrochemical capacitors is preferably utilized in the construction of both the positive and negative electrodes, a separator with improved operating parameters is used, and the negative electrode current collector is preferably manufactured from a material having a matching layer—which ensures high conductivity, high hydrogen gassing overpotential, and high stability within a range of negative electrode operating potentials within the electrolyte environment of the HES.

Claims

1. A double electric layer heterogeneous electrochemical capacitor, comprising:

a sealable case for housing the components of said capacitor;

at least one positive electrode comprised of a porous, conductive lead-based material containing a dopant;

at least one negative electrode having a porous active mass portion affixed to a current collector portion;

a porous separator separating said at least one positive and negative electrode; and

an aqueous sulfuric acid electrolyte which penetrates into pores in each of said electrodes and said separator;

wherein approximately 60% to approximately 90% of a developed surface area of said active mass of said at least one negative electrode contains pores of between about 5 Å and

about 50 Å

in diameter; and

wherein said current collector portion of said negative electrode is made of a lead-tin alloy.

2. The heterogeneous electrochemical capacitor of claim 1, wherein said at least one positive electrode is non-polarizable.

3. The heterogeneous electrochemical capacitor of claim 1, wherein said at least one negative electrode is polarizable.

4. The heterogeneous electrochemical capacitor of claim 1, wherein said lead-based material consists essentially of a mixture of Pb, Pb₃O₄ and PbO powders.

5. The heterogeneous electrochemical capacitor of claim 4, wherein approximately 5-20 weight percent of Pb, approximately 40-70 weight percent of Pb₃O₄, and approximately 10-40 weight percent of PbO is used.

6. The heterogeneous electrochemical capacitor of claim 4, wherein the particle size of said Pb, Pb₃O₄ and PbO powders is between about 0.5 μ

m and about 3.0 μ

m.

7. The heterogeneous electrochemical capacitor of claim 1, wherein, after being subjected to a forming process, said lead-based material is comprised at least substantially of β

-phase acicular crystals.

8. The heterogeneous electrochemical capacitor of claim 7, wherein said β

-phase acicular crystals are between about 10.0 μ

m and about 12.0 μ

m in length.

9. The heterogeneous electrochemical capacitor of claim 1, wherein said dopant is an admixture of titanium oxide.

10. The heterogeneous electrochemical capacitor of claim 1, wherein approximately 0.8-15 atomic percent of titanium oxide is present.

11. The heterogeneous electrochemical capacitor of claim 9, wherein said titanium oxide is of a composition that comports with the chemical formula Ti_nO_2n-1.

12. The heterogeneous electrochemical capacitor of claim 11, wherein said titanium oxide is Ti₇O₁₃, Ti₈O₁₅, or a combination of both.

13. The heterogeneous electrochemical capacitor of claim 1, wherein said dopant is an admixture of bismuth.

14. The heterogeneous electrochemical capacitor of claim 13, wherein said admixture of bismuth is Bi₂O₃ or Bi(NO₃)₃.5H₂O.

15. The heterogeneous electrochemical capacitor of claim 13, wherein approximately 2.0-8.0 atomic percent of bismuth is present.

16. The heterogeneous electrochemical capacitor of claim 1, wherein said active mass of said negative electrode consists essentially of an activated carbon material.

17. The heterogeneous electrochemical capacitor of claim 1, wherein said active mass of said negative electrode consists essentially of an activated carbon black.

18. The heterogeneous electrochemical capacitor of claim 1, wherein said active mass of said negative electrode consists essentially of mixture of an activated carbon material and of an activated carbon black.

19. The heterogeneous electrochemical capacitor of claims 16, 17 or 18, wherein said active mass has a specific surface area of between about 1,200 m²/g and about 1,700 m²/g.

20. The heterogeneous electrochemical capacitor of claim 19, further comprising a polymer binder.

21. The heterogeneous electrochemical capacitor of claim 1, wherein said current collector of said negative electrode is thermally treated.

22. The heterogeneous electrochemical capacitor of claim 1, wherein said current collector of said negative electrode contains approximately 1.5-4.0 weight percent of tin.

23. The heterogeneous electrochemical capacitor of claim 1, further comprising a matching layer coated to at least a portion of said current collector of said negative electrode.

24. The heterogeneous electrochemical capacitor of claim 23, wherein said matching layer consists essentially of a polymer that is chemically stable in a sulfuric acid electrolyte and an amount of a conductive titanium oxide compound.

25. The heterogeneous electrochemical capacitor of claim 23, wherein said matching layer consists essentially of a polymer that is chemically stable in a sulfuric acid electrolyte and an amount of a conductive material selected from the group consisting of SiTi₂N₄, TiCN, TiC, TiN and carbon.

26. The heterogeneous electrochemical capacitor of claim 1, wherein said electrodes have an asymmetric absolute capacitance.

27. The heterogeneous electrochemical capacitor of claim 26, wherein the absolute capacitance of one of said electrodes is at least three times greater than the absolute capacitance of the other electrode.

28. A method of constructing a double electric layer heterogeneous electrochemical capacitor, comprising:

providing a sealable case for housing the components of said capacitor;

locating at least one positive electrode comprised of a porous, conductive lead-based material containing a dopant within said case;

locating at least one negative electrode having a porous active mass portion affixed to a current collector portion within said case;

placing a porous separator between said at least one positive and negative electrode;

substantially filling said case with an aqueous sulfuric acid electrolyte which penetrates into pores in each of said electrodes and said separator;

subjecting said at least one positive electrode to a forming process; and

sealing said case;

wherein approximately 60% to approximately 90% of a developed surface area of said active mass of said at least one negative electrode contains pores of between about 5 Å and

about 50 Å

in diameter; and

wherein said current collector portion of said negative electrode is made of a lead-tin alloy.

29. The method of claim 28, wherein said at least one positive electrode is non-polarizable.

30. The method of claim 28, wherein. said at least one negative electrode is polarizable.

31. The method of claim 28, wherein said lead-based material consists essentially of a mixture of Pb, Pb₃O₄ and PbO powders.

32. The method of claim 28, wherein said dopant is an admixture of titanium oxide.

33. The method of claim 28, wherein said dopant is an admixture of bismuth.

34. The method of claim 28, wherein said forming process causes the formation of β

-phase acicular crystals substantially throughout said lead-based material.

35. The method of claim 34, wherein said forming process is selected to produce β

-phase acicular crystals of between about 10.0 μ

m and about 12.0 μ

m in length.

36. The method of claim 28, further comprising providing a matching layer between said active mass and said current collector of said negative electrode.

37. The method of claim 36, wherein said matching layer consists essentially of a polymer that is chemically stable in a sulfuric acid electrolyte and an amount of a conductive titanium oxide compound.

38. The method of claim 36, wherein said matching layer consists essentially of a polymer that is chemically stable in a sulfuric acid electrolyte and an amount of a conductive material selected from the group consisting of c-SiTi₂N₄, TiCN, TiC, TiN and carbon.

39. A double electric layer heterogeneous electrochemical capacitor, comprising:

a sealable case for housing the components of said capacitor;

at least one positive electrode comprised of a mixture of Pb, Pb₃O₄ and PbO powders, said mixture doped with a combination of Ti₇O₁₃ and Ti₈O₁₅;

at least one negative electrode having a porous active mass of an activated carbon material, said active mass affixed to a current collector comprised of a lead-tin alloy and coated with a conductive polymer matching layer;

a porous separator separating said at least one positive and negative electrode; and

an aqueous sulfuric acid electrolyte which penetrates into pores in each of said electrodes and said separator;

wherein said active mass of said at least one negative electrode has a specific surface area of between about 1,200 m²/g and about 1,700 m²/g; and

wherein approximately 60% to approximately 90% of a developed surface area of said active mass of said at least one negative electrode contains pores of between about 5 Å and

about 50 Å

in diameter.

40. A method of constructing a multi-cell double electric layer heterogeneous electrochemical capacitor, comprising:

providing a sealable case for housing the components of said capacitor;

forming a plurality of positive electrodes from an active material mixture of Pb, Pb₃O₄ and PbO powders doped with a combination of Ti₇O₁₃ and Ti₈O₁₅;

locating said plurality of positive electrodes within said case;

forming a plurality of negative electrodes by affixing a porous active mass of an activated carbon material to a current collector that is comprised of a lead-tin alloy and is coated with a conductive polymer matching layer, approximately 60% to approximately 90% of a developed surface area of said active mass containing pores of between about 5 Å and

about 50 Å

in diameter;

locating said plurality of negative electrodes within said case;

placing a porous separator between each positive and negative electrode within said case;

connecting current collector portions of each electrode to a corresponding terminal on said case;

substantially filling said case with an aqueous sulfuric acid electrolyte which penetrates into pores in each of said electrodes and said separator;

subjecting said plurality of positive electrodes to a forming process, whereby substantially all of said active material thereof is formed into β

-phase acicular crystals of between about 10.0 μ

m and about 12.0 μ

m in length; and

sealing said case;

wherein said positive and negative electrodes are located within said case in an alternating arrangement, such that there is one more negative electrode than positive electrode present.