Effects of thermal treatments on the supercapacitive performances of PAN-based carbon fiber electrodes

Thermal treatments including oxidative stabilization, carbonization, and activation were performed on poly(acrylonitrile)-based carbon fibers (PAN-CFs) to enhance their supercapacitive performances. In the oxidative stabilization and carbonization process, only the thermal treatment duration was controlled while in the activation process, both thermal treatment duration and pressure of carrier gas were varied to investigate their effects on the morphology and electrochemical performances of PAN-CFs. The activation process is found to favor the formation and dispersion of pores on the surface of the activated PAN-CFs, which increases the specific surface areas and subsequently improves the specific capacitances from 0.25 mF/cm2 for the pristine PAN-CFs to 34.7 mF/cm2 for the activated PAN-CFs, operated at 100 mV/s scan rate.