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.