Effect of ball milling and KOH activation on electrochemical properties of pitch-based carbon fibers

Ball-milled and chemically activated pitch-based carbon fibers (PCF) were prepared for use as electrode materials. Ball milling altered the structure of PCF from fibers to micro-sized particles with loss of porosity. In contrast, chemical activation using KOH facilitated the development of pore structures. The supercapacitive behavior of treated PCF was assessed using cyclic voltammetry and galvanostatic charge/discharge experiments in 6 M KOH electrolytic solution. BAPCF900, the sample subjected to combined ball milling and chemical treatment, activated at 900°C, exhibited a specific capacitance of about 80 F/g at a current density of 0.2 A/g; this good capacitance is attributed to a specific surface area of 803 m²/g and a total pore volume of 0.352 cm³/g, and is related to the appropriate pore structure for electrode application, comprising mesopores and micropores.