Carbon foams and methods of making the same

• US 6,500,401 B2
• Filed: 03/13/2001
• Issued: 12/31/2002
• Est. Priority Date: 07/20/2000
• Status: Expired due to Term

• Current Assignee: Cabot Corporation
• Original Assignee: Cabot Corporation
• Inventors: Massey, Robert K., Reznek, Steven R.
• Primary Examiner(s): Bell, Bruce F.
• Application Number:
  US09/805,264
• Publication Number:
  US 20020028385A1
• Time in Patent Office: 658 Days
• Field of Search: 252/502, 252/519.32, 252/519.33, 429/44, 429/231.8, 429/247, 429/249, 423/445.R, 423/447.2, 423/447.4, 423/447.8, 423/447.9, 423/449.2, 423/460, 204/294, 204/283, 361/502, 361/522, 361/523, 361/524, 361/528, 361/532, 521/27, 521/61, 521/64, 521/181, 502/418, 502/420, 502/432, 502/101
• US Class Current: 423/445.00R
• CPC Class Codes: C04B 14/022 Carbon
• CPC Class Codes: C04B 20/002 Hollow or porous granular materials
• CPC Class Codes: C04B 30/00 Compositions for artificial stone, not containing binders
• 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: C04B 38/0054 the pores being microsized or nanosized
• CPC Class Codes: C04B 38/009 Porous or hollow ceramic granular materials, e.g. microballoons C04B18/027, C04B20/002 take precedence
• CPC Class Codes: C04B 38/04 by dissolving-out added substances
• CPC Class Codes: C04B 38/0605 by sublimating
• CPC Class Codes: C04B 38/061 by melting out
• CPC Class Codes: C08K 3/04 Carbon
• CPC Class Codes: H01G 11/34 characterised by carbonisation or activation of carbon
• CPC Class Codes: H01G 11/44 Raw materials therefor, e.g. resins or coal
• CPC Class Codes: H01G 11/68 characterised by their material
• CPC Class Codes: H01G 11/86 specially adapted for electrodes carbonisation or activation of carbon for the manufacture of electrodes H01G11/34
• CPC Class Codes: H01M 4/583 Carbonaceous material, e.g. graphite-intercalation compounds or CFx
• CPC Class Codes: H01M 4/625 Carbon or graphite
• CPC Class Codes: H01M 4/96 Carbon-based electrodes
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/13 : Energy storage using capacitors
• CPC Class Codes: Y02E 60/50 : Fuel cells
• CPC Class Codes: Y10T 428/12479 : Porous [e.g., foamed, spongy, cracked, etc.]

Abstract

A method of making carbon foam is described which involves pyrolizing a mixture containing at least one pyrolizable substance and at least one unpyrolizable material and then removing the unpyrolizable material to obtain the carbon foam. Carbon foam made by this process is also described. Incorporating the carbon foam in a variety of end use applications including electrodes, thermal insulation material, polymers, and the like is also described.

Claims

1. A method of making carbon foam comprising pyrolizing a mixture comprising at least one pyrolizable substance and at least one unpyrolizable material;

and after pyrolisis,

removing said unpyrolizable material to obtain said carbon foam.

2. The method of claim 1, further comprising grinding said carbon foam into particles.

3. The method of claim 1, wherein said pyrolizable substance is an organic compound.

4. The method of claim 1, wherein said pyrolizable substance comprises at least one carbohydrate.

5. The method of claim 1, wherein said pyrolizable substance is sugar or cellulose.

6. The method of claim 1, wherein said pyrolizable substance comprises at least one hydrocarbon containing material.

7. The method of claim 1, wherein said pyrolizable substance comprises coal.

8. The method of claim 1, wherein said unpyrolizable material is an inorganic material.

9. The method of claim 1, wherein said unpyrolizable material is a salt.

10. The method of claim 1, wherein said pyrolizing occurs at a temperature of from about 300°

C. to about 1600°

C.

11. The method of claim 1, wherein said mixture is rapidly heated.

12. The method of claim 1, wherein said mixture is a fine dispersion.

13. The method of claim 1, wherein said mixture is obtained by milling said pyrolizable substance and unpyrolizable material.

14. The method of claim 1, wherein said mixture is obtained by dissolving at least one pyrolizable substance with at least one unpyrolizable material in a solvent and then precipitating the pyrolizable substance and unpyrolizable material from said solvent.

15. The method of claim 1, wherein said removing of the unpyrolizable material is accomplished by dissolving the unpyrolizable material.

16. The method of claim 1, wherein said removing of the unpyrolizable material is accomplished by evaporation, by melting, by subliming, or combinations thereof.

17. Carbon foam formed by the method of claim 1.

18. The carbon foam of claim 17, wherein said carbon foam particles are from about 5 to about 30 microns in diameter and said cells are from about 0.5 to about 3 microns in diameter.

19. The carbon foam of claim 17, wherein said cells have openings between them.

20. The carbon foam of claim 17, wherein said carbon foam is rigid.

21. A thermal insulating material comprising the carbon foam of claim 17 and/or fragments thereof.

22. A polymer compound comprising the carbon foam of claim 17 and/or fragments thereof.

23. An elastomer compound comprising the carbon foam of claim 17 and/or fragments thereof.

24. An electrode comprising the carbon foam of claim 17.

25. A capacitor electrode comprising the carbon foam of claim 17.

26. A battery electrode comprising the carbon foam of claim 17.

27. A fuel cell electrode comprising the carbon foam of claim 17.

28. A carbon foam having cells bordered by thin sheets, windows, struts, or combinations thereof, wherein said carbon foam has a BET surface area of from about 100 to about 500 m²/g.

29. The carbon foam of claim 28, wherein said carbon foam has a DBP absorption of from about 100 cc/100 g to about 500 cc/100 g.

30. The carbon foam of claim 28, wherein said carbon foam particles are from about 5 to about 30 microns in diameter and said cells are from about 0.5 to about 3 microns in diameter.

31. The carbon foam of claim 28, wherein said cells have openings between them.

32. The carbon foam of claim 28, wherein said carbon foam is rigid.

33. A thermal insulating material comprising the carbon foam of claim 28 and/or fragments thereof.

34. A polymer compound comprising the carbon foam of claim 28 and/or fragments thereof.

35. An elastomer compound comprising the carbon foam of claim 28 and/or fragments thereof.

36. An electrode comprising the carbon foam of claim 28.

37. A capacitor electrode comprising the carbon foam of claim 28.

38. A battery electrode comprising the carbon foam of claim 28.

39. A fuel cell electrode comprising the carbon foam of claim 28.