STUDY ON THE CAPACITIVE PROPERTIES OF ACTIVATED CARBON ELECTRODES OBTAINED FROM OIL TAR

Activated carbons (AC) with different surface areas were made from oil tar using KOH activation. And the electrochemical characterization has been carried out with several activated carbons used as polarizable electrodes of electric double layer capacitors (EDLC) in an aqueous electrolytic solution. The porous structure and electrochemical double layer capacitance of the activated carbons were investigated by nitrogen gas adsorption and constant current cycling (CCC) methods. The relations among the surface area, structure of activated carbons and specific double layer capacitance were discussed. It was found that the specific capacitance of the AC increased linearly with the surface area rise when the pore structure distributions were roughly the same. And 0.6?nm micropore of AC is accessible to the aqueous electrolytic solution.