Phase transformation of ?-MnO2 to ß- MnO2 induced by Cu doping: Improved electrochemical performance for next generation supercapacitor

Abstract

With the advent of wearable/portable electronics and hybrid electric vehicles, supercapacitors have gained much interest owing to their high-power density. This work deals with ultralong MnO2 nanowires reinforced with different Cu contents as a new electrode material for supercapacitors fabrication. X-ray diffraction (XRD) results showed the MnO2 phase transformation from ?-MnO2 to ß- MnO2 induced by Cu doping. ß-MnO2 due to its highest structural stability is expected to show the excellent cyclic stability of the electrode material. Field emission scanning electron microscopy (FESEM) confirmed the ultralong nanowires morphology. Ultralong nanowires with extremely interconnected network enable efficient electron transport between them, further enhancing the electrical conductivity of the material. Redox peaks present in the CV profile revealed that the preferred charge storage follows faradic mechanism, which was further confirmed by rate law. Nanosized morphology and spongy structure of the current collector exposed the maximal electrode area in conjunction with shielding from electrode pulverization. © 2023 Elsevier B.V.