Binder-free Ruthenium Oxide/MXene/Carbon Nanofiber Ternary Composite Electrode for Supercapacitors

Abstract

Carbon nanofiber-based electrodes are generally embedded with either metal oxides or two-dimensional materials to enhance their specific capacitance and rate performance. For the first time in this study, a flexible carbon nanofiber electrode consisting of metal oxide (RuO2) and two-dimensional MXene was prepared to realize the synergetic effect on the electrochemical performance. This ternary composite electrode was prepared by electrospinning RuO2, and MXene dispersed polyacrylonitrile precursor solution, followed by thermal treatment. The distribution of RuO2 nanoparticles and delaminated MXene sheets within a carbon nanofiber matrix was examined using X-ray diffraction (XRD) and transmission electron microscopy (TEM), while morphological analysis was carried out using scanning electron microscopy (SEM). The electrode with pseudocapacitive RuO2 and layered MXene facilitated charge storage by faradic reactions and intercalation of electrolyte ions. Electrochemical studies demonstrated that the prepared ternary composite electrodes exhibit a specific capacitance of 322 F g−1 with a capacitance retention of 90% after 2500 cycles at 1 A g−1. Additionally, the ternary composite showed an excellent rate capability with a minimal drop in capacitance when the current density was varied from 2 A g−1 to 10 A g−1.