Effect of annealing temperature on charge storage kinetics of an electrospun deposited manganese oxide supercapacitor

Nanofibers (NFs) Mn2O3 thin films are prepared by facial and cost effective single-nozzle electrospinning method. The effect of annealing temperature on structural, morphological and surface analysis of NFs coated thin films are investigated. XRD measurement reveals, the formation of cubic crystalline Mn2O3 above 400 °C annealing temperature. Vibration bonds at 515 and 624 cm−1 confirms the presence of Mn2O3 from Fourier transform infrared spectroscopy studies. Field emission scanning electron spectroscopy analysis shows the NFs like morphology of Mn2O3 are observed after heat treatment. The synthesized NFs have high specific surface area with pore size, which is beneficial for charge storage application. Electrochemical performance of electrospunn Mn2O3 NFs are evaluated by using cyclic voltammetry (CV), galvanostatic charge–discharge (GCD) and electrochemical impedance spectroscopy (EIS) techniques. The sample annealed at 300 °C shows maximum specific capacitance of 526 F g−1 at 0.5 mA cm−2 in 1 M aq. Na2SO4 electrolyte. In addition, the NFs sample shows 96% retention in specific capacitance measured up to 1000 CV cycles. The storage of charge due to diffusion and capacitive controlled process are analysed in detail with their percentage contribution. It confirms that, the amorphous Mn2O3 NFs structure have high specific surface area and excellent capacitive performance as compared to crystalline Mn2O3.