High voltage EDLC electrodes containing CO2 activated coconut char

Patent metadata

Field	Value
Publication number	US-9318273-B2
Application number	US-201414166457-A
Country	US
Kind code	B2
Filing date	Jan 28, 2014
Priority date	Jul 26, 2013
Publication date	Apr 19, 2016
Grant date	Apr 19, 2016

Abstract

A method for producing activated carbon includes heating a coconut shell carbon precursor at a carbonization temperature effective to form a carbon material, and reacting the carbon material with CO 2 at an activation temperature effective to form the activated carbon. The resulting activated carbon can be incorporated into a carbon-based electrode of an EDLC. Such EDLC can exhibit a potential window and thus an attendant operating voltage of greater than 3V.

First claim

We claim:

1. A method of forming activated carbon, comprising:
carbonizing coconut shell material by heating the coconut shell material at a carbonization temperature effective to form a coconut char; and
activating the coconut char to form activated carbon by heating the coconut char at an activation temperature while exposing the coconut char to carbon dioxide, wherein the activated carbon comprises
pores having a size of ≦1 nm, which provide a combined pore volume of ≧0.2 cm 3 /g;
pores having a size of from >1 nm to ≦2 nm, which provide a combined pore volume of ≧0.05 cm 3 /g; and
<0.05 cm 3 /g combined pore volume of any pores having a size of >2 nm.

2. The method according to claim 1 , wherein the coconut shell material comprises powdered coconut shells.

3. The method according to claim 1 , wherein the carbonization temperature is from 600-800° C.

4. The method according to claim 1 , wherein the activation temperature is from 700-1000° C.

5. The method according to claim 1 , wherein the carbon material has an average particle size of less than 200 microns prior to activation.

6. The method according to claim 1 , wherein the coconut char has an average particle size of from 1 to 10 microns prior to activation.

7. The method according to claim 1 , further comprising modifying the average particle size of the activated carbon to less than 20 microns.

8. The method according to claim 1 , wherein the pores having a size of ≦1 nm provide a combined pore volume of 0.2 to 0.35 cm 3 /g.

9. The method according to claim 1 , wherein the pores having a size of from >1 nm to ≦2 nm provide a combined pore volume of from 0.05 to 0.25 cm 3 /g.

10. The method according to claim 1 , wherein the pores having a size of from >1 nm to ≦2 nm provide a combined pore volume of from 0.1 to 0.2 cm 3 /g.

11. The method according to claim 1 , wherein the activated carbon is free of any pores having a size of >2 nm.

12. The method according to claim 1 , wherein the activated carbon comprises a total pore volume of ≧0.3 cm 3 /g.

13. The method according to claim 1 , wherein the activated carbon comprises a total pore volume of ≧0.4 cm 3 /g.

14. The method according to claim 1 , where the activated carbon comprises a total oxygen content of less than 10 wt %.

15. The method according to claim 1 , wherein the pores having a size of ≦1 nm provide a combined pore volume of 0.3 to 0.4 cm 3 /g.

16. The method according to claim 1 , wherein the activated carbon comprises a total pore volume of ≧0.5 cm 3 /g.

17. A method of forming activated carbon, comprising:
carbonizing coconut shell material by heating the coconut shell material at a carbonization temperature effective to form a carbon material; and
activating the carbon material by heating the carbon material at an activation temperature while exposing the carbon material to carbon dioxide, wherein the activated carbon comprises
pores having a size of ≦1 nm, which provide a combined pore volume of ≧0.2 cm 3 /g;
pores having a size of from >1 nm to ≦2 nm, which provide a combined pore volume of ≧0.05 cm 3 /g; and
<0.25 cm 3 /g combined pore volume of any pores having a size of >2 nm,
wherein the carbon material has an average particle size ranging from 1 to 10 microns prior to activation.

Assignees

• Corning Inc

Inventors

• Gadkaree Kishor Purushottam
• Kumar Atul

Classifications

• C01B32/318

  characterised by the starting materials · CPC title

• Y02E60/13

  Energy storage using capacitors · CPC title

• H01G11/44

  Raw materials therefor, e.g. resins or coal · CPC title

• C01P2006/16

  Pore diameter · CPC title

• H01G11/24

  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 title