Sustainable carbon coated ZrO2 electrodes with high capacitance retention for energy storage devices

The rapid development of modern technology starves for future research to attain high-energy, high-power, and high cyclic stable energy-storage devices. Carbonaceous electrodes in supercapacitors provide a large-power device, which stores the charge between the surface of the carbonaceous electrode and the electrolyte layer. The commercially available electrode based on pure carbon suffers from low energy density. To overcome the mentioned issue, major efforts have been dedicated to enhancing the charge storage of carbonaceous electrodes by the addition of both pure capacitive material (such as Carbon and its derivative) and pure battery-type material (transition-metal oxide, hydroxides, etc). Mesoporous carbon due to its advanced feature along with ZrO2 good fit on performance and environmental aspect parameters. In this report, we have prepared environmentally friendly mesoporous carbon ZrO2 composite by the facile method, initially, ZrO2 is prepared hydrothermally after that mixing is done at room temperature to obtain the final product mesoporous carbon@ZrO2. The material structural, and microstructural examinations are done by x-ray diffraction analysis, and field emission scanning electron microscopy. The galvanostatic charging-discharging (GCD) analysis shows the specific capacitance of the device is 125 F g(-1) and the energy density of the device is 25 Wh kg(-1) at a current density of 0.5 A g(-1). The GCD shows an extreme power density of 1201 W kg(-1) at 1 mA. The cyclic voltammetry analysis shows the maximum specific capacitance of 54.5 F g(-1) at 10 mV s(-1). The long-term cyclic stability of up to 10 000 cycles is tested through GCD. The device shows high capacitance retention and Coulombic efficiency till the last GCD cycle at 82% and 100% respectively. The capacitive contribution is 55% for optimized electrodes. The prototype device formation and load light emitting diode (LED) testing are done at the laboratory. Based on experimental findings we have proposed a charge storage mechanism for a better understanding of readers.