Bismuth iron manganese oxide nanocomposite for high performance asymmetric supercapacitor

In this study, we successfully employed a sol-gel/ultrasonic-assisted coprecipitation method to synthesize nanocomposites of bismuth iron manganese oxide (Bi2Fe2Mn2O10) with varying Mn concentrations: 10% Mn (BFM-1), 20% Mn (BFM-2), and 30% Mn (BFM-3). Our investigation focused on examining the impact of Mn concentrations on the structural, morphological, and electrochemical properties of Bi2Fe2Mn2O10.The formation of Bi2Fe2Mn2O10 nanocomposites was confirmed through X-ray diffraction (XRD), while transmission electron microscopy (TEM) micrographs revealed a transition in nanoparticle morphology from spherical to mixed spherical shape as the Mn concentration increased. Electrochemical investigations demonstrated that the BFM-3 exhibited a specific capacitance of 664 F g−1 in 6 M KOH at a current density of 0.35 A g−1 with a three-electrode assembly. Furthermore, we fabricated an asymmetric supercapacitor using BFM-3 and activated carbon (AC), which exhibited a specific capacitance of 135 Fg−1 at a current density of 0.6 Ag−1 and delivered an energy density of 48 Wh kg−1 at a power density of 480 W kg−1. The device also demonstrated exceptional capacitance retention, with a rate of 93.3% over 5000 charge-discharge cycles Overall, our study highlights the potential of Bi2Fe2Mn2O10 as a highly redox-active cathode material in asymmetric supercapacitors for renewable energy storage.