Optical and electrochemical performance of electrospun NiO–Mn3O4 nanocomposites for energy storage applications

NiO-Mn₃O₄ ribbons were synthesized through electrospinning and subsequently compared with NiO nanoparticles and Mn₃O₄ octahedral particles to evaluate their optical and electrochemical properties. XRD analysis confirmed the presence of cubic and tetragonal phases of NiO and Mn₃O₄, respectively, within the nanocomposite. UV-Vis diffuse reflectance spectroscopy (DRS) revealed a bandgap of 3.53 eV for the nanocomposite, while photoluminescence emission quenching indicated an enhancement in surface defects. The ribbons exhibited superior electrochemical performance, achieving a specific capacitance of 372 F g^-1 at a current density of 1 A g^-1, along with 94% capacitance retention after 3000 cycles at 7 A g^-1. Furthermore, the assembled NiO-Mn₃O₄//AC asymmetric supercapacitor device exhibited a maximum energy density of 40 Wh kg^-1 at a power density of 2400 W kg^-1. These findings suggest that NiO-Mn₃O₄ ribbons hold significant promise for high-performance energy storage devices.