Electrode Materials of Electric Double Layer Capacitor Prepared by Steam Activation of Phenolic Formaldehyde Resin

Activated carbon for electric double-layer capacitor(EDLC)application was prepared by steam activation of resole phenolic formaldehyde resin through changing the activating time(PFR(1- 5)H).The BET specific surface area and pore structure parameter f all samples obtained were determined by the low temperature gas adsorption isotherm.It is found that the BET specific surface area and the mesopore ratio of the activated carbon are increased with the activating time increasing.The electrochemical test indicates that the model EDLC prepared by PFR5H(5h activating time)shows the highest specific capacitance of 106.5F/g in organic system with the constant discharge current of 50mA/g.When the constant discharge current is 1000mA/g,its specific capacitance remains 99.7F/g and only decreases 6.4% in the same system.And the model EDLC prepared by PFR5H shows good rate capability.AC impedance analyses show that the model EDLC prepared by PFR5H has the lowest resistance,so it has remarkable specific capacitance and good power capability.