High energy density electric double-layer capacitor and method for producing the same

• US 20050231892A1
• Filed: 04/19/2005
• Published: 10/20/2005
• Est. Priority Date: 04/19/2004
• Status: Abandoned Application

• Current Assignee: Troy A. Harvey
• Original Assignee: Troy A. Harvey
• Inventors: Harvey, Troy A.
• Application Number:
  US11/109,154
• Publication Number:
  US 20050231892A1
• Time in Patent Office: Days
• US Class Current: 361/502
• CPC Class Codes: H01G 11/32 Carbon-based
• CPC Class Codes: H01G 11/34 characterised by carbonisation or activation of carbon
• CPC Class Codes: H01G 11/38 Carbon pastes or blends; Binders or additives therein
• CPC Class Codes: H01G 11/44 Raw materials therefor, e.g. resins or coal
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors

Abstract

An electric double layer capacitor includes polarizable electrodes immersed in an organic electrolyte, wherein the electrodes are self-binding and the electric double layer capacitor exhibits a high energy density.

Claims

1. A method for producing a double-layer capacitor electrode, the method comprising:

providing a carbonaceous material formed into a electrode pre-form;

providing an alkali containing compound; and

heating the electrode pre-form together with the alkali containing compound in a substantially anoxic environment.

2. The method of claim 1, wherein the carbonaceous material is derived from a carbon bearing pre-cursor heated in a substantially anoxic environment.

3. The method of claim 1, wherein the carbonaceous material is a carbon bearing precursor and wherein the carbonaceous material is carbonized or graphitized and alkali processed in the single heat cycle within the substantially anoxic environment.

4. The method of claim 2, wherein the carbon bearing precursor comprises a substance selected from the group consisting of coal, oil, petroleum, coke, pitch, lignite, high molecular weight oils, high molecular weight waxes, or asphaltenes.

5. The method of claim 4, wherein the carbon bearing pre-cursor is heated to a temperature of greater than 700°

C. and less than 1300°

C.

6. The method of claim 1, wherein the carbon bearing precursor comprises a herbaceous material.

7. The method of claim 6, wherein the herbaceous material is selected from the group consisting of wood, bamboo, cellulose, hemicellulose, lignins, coconut husks, nut shells, peat, fruit pits, corn stalks, and grain husks.

8. The method of claim 2, wherein the carbon bearing precursor is a sugar, polysaccharide or starch.

9. The method of claim 6, wherein the carbon bearing precursor is heated to a temperature that is greater than 1400°

C. and less than 1900°

C.

10. The method of claim 2, wherein binding the carbonaceous material comprises utilizing a bonding agent comprising at least one carbon bearing substance.

11. The method of claim 10, wherein the bonding agent forms a primarily amorphous or glassy carbon in response to heating.

12. The method of claim 10, wherein the bonding agent comprises a thermoset resin.

13. The method of claim 12, wherein the thermoset resin is selected from the group consisting of phenolic resins, furfural resins, and epoxide resins.

14. The method of claim 10, wherein the bonding agent comprises a thermoplastic polymer.

15. The method of claim 14, wherein the thermoplastic polymer is selected from the group consisting of methyl cellulose, polyvinylidene difluoride, polyethylene, polypropylene, and polylactic acid.

16. The method of claim 10, wherein bonding agent is selected from the group consisting of wood, coal, petroleum tar, asphaltene, bitumen, high molecular weight hydrocarbons, hemicellulose, lignin, cellulose, starch, and protein.

17. The method of claim 1, wherein the alkali compound comprises a substance selected from the group consisting of metallic potassium, potassium hydroxide, potassium carbonate, potassium acetate, potassium benzoate, potassium butyrate, potassium formate, potassium peroxide;

metallic sodium, sodium hydroxide, sodium carbonate, sodium acetate, sodium benzoate, sodium butyrate, sodium formate, and sodium peroxide.

18. The method of claim 1, wherein the pre-formed electrode is heated to a temperature sufficient to produce alkali metal vapor.

19. The method of claim 1, further holding the capacitor cell electrode within a rigid container during a charging cycle, whereby containing expansion of the electrode material.

20. A double layer capacitor cell comprising:

a plurality of polarizable electrodes produced according to the method of claim 1;

and

an electrolyte in electrolytic communication with the electrodes.

21. A capacitor cell comprising:

a polarizable electrode produced according to the method of claim 1;

and

an electrolyte in electrolytic communication with the electrode.