Process of producing activated carbon for electric double layer capacitor electrode
The present invention provides a process of producing an activated carbon for an electric double layer capacitor, which can produce easily and inexpensively an activated carbon free from fusing of carbon particles during activation and having a small diameter, a uniform particle diameter, and a relatively large specific surface area on a commercial scale. The process comprises the steps of calcining an easily graphitizable carbon material so that the reduction rates of the hydrogen/carbon atomic ratio (H/C) and the volatile components in the carbon material are 4 percent or more and 5 percent or more, respectively after calcination and activating the carbon material thereby producing an activated carbon for an electric double layer capacitor, having an average particle diameter of 0.5 to 7 μm and a BET specific surface area of 1500 to 3000 m 2 /g.
1. A process of producing an activated carbon having an average particle diameter of 0.5 to 7 μm and a BET specific surface area of 1500 to 3000 m 2 /g, for an electric double layer capacitor electrode, comprising the steps of:
calcining an easily graphitizable carbon material so that the reduction rates of the hydrogen/carbon atomic ratio (H/C) and the volatile components in the carbon material are 4 percent or more and 5 percent or more, respectively after calcination; and
activating the carbon material.
2. The process according to claim 1 , wherein the calcination temperature is from 500 to 700° C.
3. The process according to claim 1 wherein the average particle diameter of the easily graphitizable carbon material is 3 μm or smaller.
4. An activated carbon for an electric double layer capacitor produced by the process according to claim 1 .
5. An electric double layer capacitor comprising the activated carbon according to claim 4 .
6. An activated carbon for an electric double layer capacitor produced by the process according to claim 2 .
7. An electric double layer capacitor comprising the activated carbon according to claim 6 .
8. An activated carbon for an electric double layer capacitor produced by the process according to claim 3 .
9. An electric double layer capacitor comprising the activated carbon according to claim 8 .