Supercapacitors based on carbon foams

• US 5,260,855 A
• Filed: 01/17/1992
• Issued: 11/09/1993
• Est. Priority Date: 01/17/1992
• Status: Expired due to Term

• Current Assignee: Lawrence Livermore National Security LLC (Government of the United States of America)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Pekala, Richard W., Mayer, Steven T., Kaschmitter, James L.
• Primary Examiner(s): GRIFFIN, DONALD
• Application Number:
  US07/822,438
• Time in Patent Office: 662 Days
• Field of Search: 361/303, 361/304, 361/305, 361/502, 502/418, 29/25.03, 264/28, 264/29.1
• US Class Current: 361/502
• CPC Class Codes: C04B 2111/00844 for electronic applications
• CPC Class Codes: C04B 35/52 based on carbon, e.g. graphite
• CPC Class Codes: C04B 38/0022 obtained by a chemical conversion or reaction other than those relating to the setting or hardening of cement-like material or to the formation of a sol or a gel, e.g. by carbonising or pyrolysing preformed cellular materials based on polymers, organo-metallic or organo-silicon precursors
• CPC Class Codes: C04B 38/0045 by a process involving the formation of a sol or a gel, e.g. sol-gel or precipitation processes
• CPC Class Codes: C08G 8/04 of aldehydes
• CPC Class Codes: C08G 8/20 with polyhydric phenols
• CPC Class Codes: H01G 11/26 characterised by their structure, e.g. multi-layered, porosity or surface features
• CPC Class Codes: H01G 11/34 characterised by carbonisation or activation of carbon
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors

Abstract

A high energy density capacitor incorporating a variety of carbon foam electrodes is described. The foams, derived from the pyrolysis of resorcinol-formaldehyde and related polymers, are high density (0.1 g/cc-1.0 g/cc) electrically conductive and have high surface areas (400 m² /g-1000 m² /g). Capacitances on the order of several tens of farad per gram of electrode are achieved.

Claims

1. A capacitor having an electrode comprising a carbon foam.

2. An electrode comprising a carbon foam derived from the pyrolysis of mixtures consisting of resorcinol-furfural, resorcinol-formaldehyde, phenol-resorcinol-formaldehyde, catechol-formaldehyde, and phloroglucinol-formaldehyde, the foam having a density of between about 0.1 g/cc to about 1.2 g/cc and a surface area of between about 100 m² /g to about 1200 m² /g.

3. An electrode according to claim 2, wherein the carbon foam is an aerogel.

4. An electrode according to claim 2, wherein the carbon foam is a xerogel.

5. An electrode according to claim 2, wherein the carbon foam is a xerogel-aerogel hybrid.

6. An electrode according to claim 2, wherein the carbon foam comprises an electrically conductive additive.

7. An electrode according to claim 2, wherein the carbon foam comprises a formatted carbon matrix.

8. An electrode according to claim 2, wherein the carbon foam includes electroactive surface groups.

9. An electrode according to claim 2, wherein the carbon foam comprises an activated carbon matrix.

10. An electrode according to claim 2, wherein the carbon foam comprises a carbon matrix having electroactive surface groups.

11. A capacitor, comprising:

a) a first electrode, the first electrode comprising a conductive material;

b) a second electrode, the second electrode comprising a carbon foam; and

c) an electrode separator disposed between the electrodes, the electrode separator comprising an electrically nonconductive, ionically conductive material.

12. A capacitor according to claim 11, wherein the carbon foam of the second electrode comprises a carbon aerogel.

13. A capacitor according to claim 11, wherein the carbon foam of the second electrode comprises a carbon xerogel.

14. A capacitor according to claim 11, wherein the carbon foam of the second electrode comprises a carbon aerogel-xerogel hybrid.

15. A capacitor according to claim 11, wherein the carbon foam of the second electrode comprises a formatted carbon matrix.

16. A capacitor according to claim 11, wherein the carbon foam of the second electrode comprises an electrically conductive additive.

17. A capacitor according to claim 11, wherein the carbon foam of the second electrode comprises a carbon matrix having electroactive surface groups.

18. A capacitor according to claim 11, wherein the carbon foam of the second electrode comprises an activated carbon matrix.

19. A capacitor according to claim 11, wherein the capacitor further comprises a metal layer, the layer being disposed on the second electrode to establish electrical contact.

20. The capacitor of claim 11, wherein the first electrode comprises a carbon foam.

21. A capacitor of claim 11, wherein the second electrode comprises a carbon form derived from the pyrolysis of mixtures consisting of resorcinol-furfural, resorcinol-formaldehyde, phenol-resorcinol-formaldehyde, catechol-formaldehyde, and phloroglucinol-formaldehyde, the foam having a density of between about 0.1 g/cc to about 1.2 g/cc and a surface area of between about 100 m² /g to about 1200 m² /g.

22. A capacitor, the capacitor comprising:

a) a plurality of cells, each cell comprising;

i) a first electrode, the first electrode comprising a conductive material;

ii) a second electrode, the second electrode comprising a carbon foam; and

iii) an electrode separator disposed between the electrodes, the electrode separator comprising an electrically nonconductive, ionically conductive material; and

b) an electrical connection between the cells.

23. A capacitor according to claim 22, wherein the capacitor further includes an environmental seal to protect the capacitor from ambient conditions.

24. A capacitor, comprising:

a) a first cell, the first cell comprising;

i) first and second electrodes, the electrodes comprising carbon aerogels;

ii) a first electrode separator disposed between the electrodes, the first electrode separator being comprised of an electrically nonconductive, ionically conductive material;

iii) a first metal coating adhering to the electrodes;

iv) a first solder-wettable coating provided on the first metal coatings; and

b) a second cell, the second cell comprising;

i) first and second electrodes, the electrodes comprising carbon aerogels;

ii) a second electrode separator disposed between the electrodes, the second electrode separator being comprised of an electrically nonconductive, ionically conductive material;

iii) a second metal coating adhering to the electrodes;

iv) a second solder-wettable coating provided on the second metal coatings; and

c) an electrical connection between the first and second cells.

25. A capacitor according to claim 24, wherein at least one of the electrodes comprises a carbon aerogel.

26. A capacitor according to claim 24, wherein at least one of the electrodes comprises a carbon xerogel.

27. A capacitor according to claim 24, wherein at least one of the electrodes comprises a carbon aerogel-xerogel hybrid.

28. A capacitor according to claim 24, wherein at least one of the electrodes comprises a formatted carbon matrix.

29. A capacitor according to claim 24, wherein at least one of the electrodes comprises an electrically conductive additive.

30. A capacitor according to claim 24, wherein at least one of the electrodes comprises a carbon matrix having electroactive surface groups.

31. A capacitor according to claim 24, wherein at least one of the electrodes comprises an activated carbon matrix.

32. A capacitor according to claim 24, wherein the capacitor further includes an environmental seal disposed around the cells to provide protection against ambient conditions.

33. In a process for preparing high density carbon aerogels derived from the pyrolysis of organic aerogels, the improvement comprising:

a) exchanging the gel with a solvent under predetermined nonsupercritical temperature and pressure conditions; and

b) extracting the gel under predetermined nonsupercritical temperature and pressure conditions to form an aerogel.