Temperature-Contingent Electrochemical Capacitive Concert of Nanospheres Iron Oxide (Fe2O3) as a Supercapacitor Electrode
Abstract
The iron oxide (Fe2O3) thin films were synthesized by a Successive Ionic Layer Adsorption and Reaction (SILAR) technique. The thin films were characterized through X-ray diffraction (XRD), confirming a hexagonal crystal structure, and field emission scanning electron microscopy (FE-SEM), revealing a granular morphology. Electrochemical evaluations through cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) studies demonstrated that the Fe2O3 thin film synthesized at 623 K exhibited the highest specific capacitance (Cs) of 605.7 F/g at 5 mV/s, superior specific energy (SE) of 38.9 Wh/kg, and specific power (SP) of 0.7 kW/kg at 1 mA/cm², along with the lowermost internal resistance of 1.44 Ω, indicating optimal charge transfer kinetics. The (Fe2O3||1M KOH||Fe2O3) solid-state electrochemical storage device (SESD) shows 78.6 % of capacitance retention after 6000 cycles. This comprehensive analysis underscores the critical influence of synthesis temperature on the electrochemical property of the Fe2O3 electrode, highlighting the potential of the Fe2O3 electrode for higher-performance supercapacitor applications.