Metal oxide electrode for supercapacitor and manufacturing method thereof

• US 20020036885A1
• Filed: 10/09/2001
• Published: 03/28/2002
• Est. Priority Date: 09/16/1999
• Status: Active Grant

• Current Assignee: Nesscap Company Limited (Tesla Inc.)
• Original Assignee: Ness Capacitor Co., Ltd.
• Inventors: Seong, Woo-Kyeong, Lee, Hee-Young, Kim, Heui-Soo, Kim, Sun-Wook
• Granted Patent: US 6,616,875 B2
• Time in Patent Office: Days
• US Class Current: 361/508
• CPC Class Codes: H01G 11/04 Hybrid capacitors
• CPC Class Codes: H01G 11/46 Metal oxides
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors

Abstract

A metal oxide electrode for a supercapacitor and a manufacturing method thereof are disclosed. Potassium permanganate is absorbed on a conductive material, such as carbon or activated carbon, and mixed with a solution including manganese acetate so as to form amorphous manganese oxide. Amorphous manganese oxide powder is grounded to a powder which is mixed with binder to form an electrode having a predetermined shape. The electrode reduces equivalent serial resistance and enhances high frequency characteristics since the contact area and the adhesion strength between the manganese oxide and the conductive carbon are improved. Also, the electrode has high capacitance suitable for a supercapacitor, which is manufactured therefrom at a greatly reduced cost.

Claims

1. A metal oxide electrode for a supercapacitor comprising:

a manganese oxide powder;

a conductive material; and

a binder for binding said manganese oxide powder to said conductive material.

2. The metal oxide electrode for a supercapacitor as claimed in claim 1, wherein said conductive material is composed of a material having electrical conductivity such as a metal oxide, a metal nitride, a metal carbide, a metal powder on a conducting polymer and said manganese oxide powder is coated on said conductive material.

3. The metal oxide electrode for a supercapacitor as claimed in claim 1, wherein said conductive material is a conductive carbon and said manganese oxide powder is coated on said conductive carbon.

4. The metal oxide electrode for a supercapacitor as claimed in claim 3, wherein said electrode comprises about 20 to about 80% by weight of said conductive carbon.

5. The metal oxide electrode for a supercapacitor as claimed in claim 1, wherein said conductive material is an activated carbon and said manganese oxide powder is coated in pores of said activated carbon and on a surface of said activated carbon.

6. The metal oxide electrode for a supercapacitor as claimed in claim 5, wherein said electrode comprises about 20 to about 80% by weight of said activated carbon.

7. The metal oxide electrode for a supercapacitor as claimed in claim 5, wherein said activated carbon has a specific surface area of about 1500 to 3000 m²/g.

8. The metal oxide electrode for a supercapacitor as claimed in claim 1, wherein said conductive material is composed of a material having electrical conductivity such as a metal oxide, a metal nitride, a metal carbide, a metal powder or a conducting polymer and said manganese oxide powder has a layer structure.

9. The metal oxide electrode for a supercapacitor as claimed in claim 1, wherein said conductive material is a conductive carbon and said manganese oxide powder has a layer structure.

10. The metal oxide electrode for a supercapacitor as claimed in claim 9, wherein said electrode comprises about 30 to about 90% by weight of said manganese oxide powder, about 5 to about 20% by weight of said conductive carbon and about 5 to 50% by weight of said binder.

11. The metal oxide electrode for a supercapacitor as claimed in claim 9, wherein said manganese oxide powder comprises potassium (K) ions.

12. The metal oxide electrode for a supercapacitor as claimed in claim 1, wherein said binder is composed of a polytetrafluoroethylene.

14. The metal oxide electrode for a supercapacitor as claimed in claim 13, wherein said electrode comprises about 20 to about 80% by weight of said conductive carbon.

15. The metal oxide electrode for a supercapacitor as claimed in claim 13, wherein said manganese oxide powder is formed by mixing a first solution having a potassium permanganate absorbed on said conductive carbon after said conductive carbon is dispersed in the first solution with a second solution of a manganese acetate.

17. The metal oxide electrode for a supercapacitor as claimed in claim 16, wherein said electrode comprises about 20 to about 80% by weight of said activated carbon.

18. The metal oxide electrode for a supercapacitor as claimed in claim 16, wherein said activated carbon has a specific area of about 1500 to about 3000 m²/g.

19. The metal oxide electrode for a supercapacitor as claimed in claim 16, wherein said manganese oxide powder is formed by mixing a first solution having a potassium permanganate absorbed in the pores of said activated carbon and on the surface of said activated carbon after said activated carbon is dispersed in the first solution with a second solution of a manganese acetate.

13. A metal oxide electrode for a supercapacitor comprising:

a conductive carbon;

an amorphous manganese oxide powder coated on said conductive carbon; and

a binder for binding said manganese oxide powder to said conductive carbon.

16. A metal oxide electrode for a supercapacitor comprising:

an activated carbon;

an amorphous manganese oxide powder coated in pores of said activated carbon and on a surface of said activated carbon; and

a binder for binding said manganese oxide powder to said activated carbon.

20. A method for manufacturing a metal oxide electrode for a supercapacitor comprising the steps of:

forming a conductive material solution by dispersing a conductive material in deionized water;

forming a first solution by adding potassium permanganate to the conductive material solution;

forming a second solution comprising a manganese acetate;

forming an amorphous manganese oxide by mixing the first solution with the second solution; and

forming the metal oxide electrode comprising said amorphous manganese oxide.

21. The method for manufacturing a metal oxide electrode for a supercapacitor as claimed in claim 20, wherein said conductive material is composed of a material having electrical conductivity such as a metal oxide, a metal nitride, a metal carbide, a metal powder or a conducting polymer.

22. The method for manufacturing a metal oxide electrode for a supercapacitor as claimed in claim 20, wherein said step of forming the conductive material solution is performed after dissolving a surfactant in the deionized water.

23. The method for manufacturing a metal oxide electrode for a supercapacitor as claimed in claim 22, wherein the surfactant comprises polyvinylpyrrolidone.

24. The method for manufacturing a metal oxide electrode for a supercapacitor as claimed in claim 20, wherein the conductive material is carbon or activated carbon.

25. The method for manufacturing a metal oxide electrode for a supercapacitor as claimed in claim 20, wherein the first solution is a potassium permanganate solution wherein the potassium permanganate is absorbed on the conductive material.

26. The method for manufacturing a metal oxide electrode for a supercapacitor as claimed in claim 20, wherein said step of forming the metal oxide electrode further comprises:

extracting an amorphous manganese oxide powder from the first solution and the second solution;

grinding the amorphous manganese oxide powder;

forming a mixture by adding a binder to the ground amorphous manganese oxide powder; and

forming an electrode having a predetermined shape by using the mixture.

27. The method for manufacturing a metal oxide electrode for a supercapacitor as claimed in claim 26, said step of extracting the amorphous manganese oxide powder further comprises:

filtering the amorphous manganese oxide powder from a mixture of the first solution and the second solution;

washing the filtered amorphous manganese oxide powder; and

drying the washed amorphous manganese oxide powder.

28. The method for manufacturing a metal oxide electrode for a supercapacitor as claimed in claim 26, wherein the binder is composed of a polytetrafluoroethylene.

30. The method for manufacturing a metal oxide electrode for a supercapacitor as claimed in claim 29, wherein the furnace is heated to a temperature of about 450 to about 550°

C.

31. The method for manufacturing a metal oxide electrode for a supercapacitor as claimed in claim 29, wherein said step of thermally decomposing the ground potassium permanganate is performed to form a manganese oxide having a layer structure and comprising potassium ions.

32. The method for manufacturing a metal oxide electrode for a supercapacitor as claimed in claim 29, wherein said step of quenching the product is performed by rapidly cooling the product below a room temperature.

33. The method for manufacturing a metal oxide electrode for a supercapacitor as claimed in claim 29, wherein the conductive material is composed of a material having electrical conductivity such as a metal oxide, a metal nitride, a metal carbide, a metal powder or a conducting polymer.

34. The method for manufacturing a metal oxide electrode for a supercapacitor as claimed in claim 29, wherein the conductive material is a conductive carbon and the binder is a polytetraflouroethylene.

29. A method for manufacturing a metal oxide electrode for a supercapacitor comprising the steps of:

grinding potassium permanganate;

heating a furnace to a predetermined temperature;

thermally decomposing the ground potassium permanganate in the furnace;

quenching the product;

washing and filtering the product; and

mixing the product with a conductive material, a binder and a solution.