Aluminum-carbon composite electrode

• US 5,777,428 A
• Filed: 07/26/1996
• Issued: 07/07/1998
• Est. Priority Date: 10/07/1994
• Status: Expired due to Term

• Current Assignee: Tesla Inc.
• Original Assignee: Maxwell Energy Products Incorporated
• Inventors: Dispennette, John M., Farahmandi, C. Joseph
• Primary Examiner(s): O'Shea, Sandra L.
• Assistant Examiner(s): HAYNES, MACK NELSON
• Application Number:
  US08/686,579
• Time in Patent Office: 711 Days
• Field of Search: 313/352, 313/356, 313/353, 323/370, 361/328, 361/329, 361/330, 361/502, 361/522, 361/541, 361/517-520, 361/535-539, 361/433
• US Class Current: 313/352
• CPC Class Codes: H01G 11/24 characterised by structural features of the materials making up or comprised in the electrodes, e.g. form, surface area or porosity; characterised by the structural features of powders or particles used therefor
• CPC Class Codes: H01G 11/26 characterised by their structure, e.g. multi-layered, porosity or surface features
• CPC Class Codes: H01G 11/28 arranged or disposed on a current collector; Layers or phases between electrodes and current collectors, e.g. adhesives
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors

Abstract

A high performance double layer capacitor having an electric double layer formed in the interface between activated carbon and an electrolyte is disclosed. The high performance double layer capacitor includes a pair of aluminum impregnated carbon composite electrodes having an evenly distributed and continuous path of aluminum impregnated within an activated carbon fiber preform saturated with a high performance electrolytic solution. The high performance double layer capacitor is capable of delivering at least 5 Wh/kg of useful energy at power ratings of at least 600 W/kg.

Claims

1. An aluminum/carbon composite electrode comprising:

an activated carbon fiber preform;

a non-fibrous aluminum impregnant within said activated carbon fibers; and

a conductive foil current collector pressed against a surface of said activated carbon fiber preform so as to be in contact with said aluminum impregnant.

2. The aluminum/carbon composite electrode of claim 1 wherein said carbon fiber preform is a carbon cloth preform.

3. The aluminum/carbon composite electrode of claim 1 wherein said carbon fiber preform is a carbon paper preform.

4. The aluminum/carbon composite electrode of claim 1 wherein said activated carbon fibers have a surface area in a range of about 500-3000 m² /g.

5. The aluminum/carbon composite electrode of claim 1 wherein said activated carbon fibers have a surface area greater than 2000 m² /g.

6. The aluminum/carbon composite electrode of claim 1 wherein said aluminum impregnant to carbon weight ratio is in a range of about 1.3 to 0.5.

7. The aluminum/carbon composite electrode of claim 1 wherein said aluminum impregnant to carbon weight ratio is less than 1.0.

8. The aluminum/carbon composite electrode of claim 7 wherein said aluminum/carbon composite electrode exhibits a resistivity of less than 1.5 Ω

cm².

9. The aluminum/carbon composite electrode of claim 1 wherein said conductive foil current collector comprises a layer of aluminum foil having a thickness in a range of about 0.5 mils to 3.0 mils.

10. An aluminum/carbon composite electrode comprising:

a carbon cloth preform fabricated from activated carbon fiber material;

aluminum impregnated into at least one side of the activated carbon fiber material so as to form a porous aluminum matrix therein, with the weight ratio of the aluminum to carbon comprising between about 1.3 to 0.5; and

a current collector plate secured to the at least one side of the activated carbon fiber material wherein the aluminum is impregnated.

11. The aluminum/carbon composite electrode as set forth in claim 10 wherein the activated carbon fiber material is made from carbon fibers having a diameter of approximately 8-10 μ

m, and wherein the fiber material has a surface area of approximately 500 to 3000 m² /g.

12. The aluminum/carbon composite electrode as set forth in claim 10 wherein the aluminum to carbon weight ratio is less than 1.0.

13. The aluminum/carbon composite electrode as set forth in claim 10 wherein the current collector plate comprises non-porous aluminum foil having a thickness of between about 0.5 mils and 3.0 mils.