Supercapacitor Electrodes Based on Carbon Derivatives of Poorly Caking Coal

Abstract

The influence of two chemical activators (KOH and ZnCl₂) on the properties of porous carbon materials derived from naturally oxidized poorly caking coal (SS coal) is compared. It follows from cyclic voltammetry and low-temperature nitrogen sorption that potassium hydroxide produces an electrode material with excellent unit capacitance. That may be attributed to the highly developed surface and optimal pore structure (with a predominance of micropores) of the resulting carbon material, ensuring effective charge storage in a double electric layer. The rectangular voltammetric curve and weak dependence of the unit capacitance on the rate of potential scanning confirm the predominance of double layer charge storage and the satisfactory kinetic characteristics of the material produced. These results indicate that KOH-activated carbon materials based on SS coal may be used as highly efficient electrodes for supercapacitors.