Zinc oxide-doped carbon nanofibrous binder-free membrane for the development of supercapacitor electrode

Zinc oxide-doped carbon nanofiber composite electrodes are fabricated using a one-step electrospinning process followed by thermal treatment. The composite electrodes were characterized using X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy and contact angle measurements. The electrochemical performance of the composite electrodes was studied using three electrode and two electrode measurements in 6 M aqueous KOH electrolyte solution. The capacitive performance of the electrode increased with the increasing of zinc oxide content. The largest specific capacitance is found to be 184 Fg −1 at 0.5 Ag −1 and 90 Fg −1 at 0.5 Ag −1 current density in three electrode and two electrode measurements, respectively. The excellent electrochemical activity is due to the improvement in hydrophilic behaviour and interconnected structure, which offer low resistance paths towards ionic transportation. Furthermore, the composite electrode exhibits an energy density of 12.5 Wh kg −1 at a power density of 500 Wh kg −1 . Additionally, the supercapacitor electrode exhibits excellent cycle life with capacitance retention of about 100% of its initial value after 2000 cycles at 2 Ag −1 current density. This excellent cycling stability and high performance will have the potential for promising applications in supercapacitor electrode materials.