High performance super-capacitor based on rod shaped ZnO nanostructure electrode.

In this paper, we have studied electrochemical performance of rod shaped ZnO nanostructure (NS) for supercapacitor application. We have performed the electrochemical performance by using cyclic voltammetry (CV) and chrono charge-discharge galvanostatic with three electrode systems. Herein we have synthesized the ZnO NS by using leaf extract of Tabernaemontana divericata as capping/stabilizing agent at 40°C. The morphology of synthesized ZnO NS has been determined by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) and powder x-ray diffraction (PXRD) have been used for elemental composition. The band gap has been calculated 3.01eV with talc plot by using data of UV-Visible spectrum. The specific capacitance of the drop casted ZnO supercapacitor on glassy carbon electrode (GCE) has been investigated by using CV curves at the voltage scan rates 20 mV/s, 40 mV/s, 60 mV/s, 80 mV/s and 100 mV/s. The obtained values of specific capacitance are 535.7142 F g⁻¹, 401.7857 F g⁻¹, 304.7619 F g-1, 229.9107 F g-1 and 189.2857 F g-1 respectively. The values of energy density and power density have also been calculated. The obtained values at the abovementioned scan rates are 36.4583Wh/kg and 65.6249W/kg, 27.3438 Wh/kg and 49.218820 W/kg, 20.7407 Wh/kg 37.3332 W/kg, 15.6470, Wh/kg and 28.1646 W/kg, 12.8819 Wh/kg and 23.1874 W/kg respectively. [ABSTRACT FROM AUTHOR]