High-performance symmetric supercapacitor using cost-efficient iron oxide (Fe<inf>3</inf>O<inf>4</inf>) nanoparticles

We investigated Fe3O4 nanoparticles (NPs) for a symmetric supercapacitor (SSC) under ambient conditions from synthesizing material to device fabrication. The prepared Fe3O4 NPs are characterized using different characterization, X-ray diffraction, Raman and FTIR spectroscopy. The electrochemical performance of supercapacitor (SC) is measured in two electrode systems using coin-cell assembly at various scan rates varying from 10–100 mV s−1, and cyclic voltammetry measurements are investigated from −0.8 to 0.6 V window. The Fe3O4 NPs based SSC shows an energy density of 24.99 Wh kg−1 with the high specific capacitance of 91.82 F g−1 at 10 mV s−1 scan rate. At a current rate of 4 A g−1, the power density reaches 2000 W kg−1. The Fe3O4 NPs based SSC exhibits a quick charge and discharge mechanism at various current rates and is stable over 500 galvanostatic chargingdischarging cycles at a current rate of 4 A g−1. The fabricated SSC showed >60% capacitance retention even after operating for 1000 cyclic voltammetry cycles at a scan rate of 100 mV s−1. A reasonable choice for SSC electrodes with high power density, and the outstanding resilience of electrodes is further shown by cyclic stability and impedance study exhibiting a negligible change in the different impedance elements. The potential of the fabricated SSC is demonstrated by lightening a light emitting diode (LED) light as a practical aspect for future applications.