Synthesis and electrochemical performance of porous carbon derived from medium and low temperature coal pitch

Porous activated carbon is widely used as electrode material for supercapacitors due to a series of characteristics such as its superior electrical conductivity, low preparation cost and no pollution to the environment, especially it has a good prospect in the application of electrode material for double layer supercapacitors. In this work, a series of porous carbon materials were prepared by KOH activation method using medium and low temperature coal pitch as raw material. Studies have shown that coal pitch contains a large number of hydrophilic functional groups such as -OH and -COOH and nitrogenous functional groups such as -NO 2 . The former can improve the dispersion of coal pitch in aqueous solution, while the latter can be used as a nitrogen precursor in the preparation of carbon materials. The results show that the porous carbon materials activated by KOH have the structural characteristics of coexistence of graphite microcrystals and amorphous carbon. The surface of the carbon material is rich in microporous structure and also has good electrochemical properties. The experimental results showed that the porous carbon exhibited excellent capacitive properties (210 F/g with 10.1 A/g) and good cycling stability under low temperature activation conditions at 500°C. In addition, the supercapacitor assembled from porous carbon has an energy density of 7.15 Wh/kg at a current density of 0.1A/g in 6 M KOH electrolyte.