Hierarchically structured carbon nanofibers with embedded MXene and coated with cobalt oxide as a high-performance electrode for supercapacitors

This study demonstrates the synthesis of a hollow MXene-embedded carbon nanofibrous (HMCNFs) binary composite, further layered with a textured Co3O4 coating to form a ternary composite. X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and field emission scanning electron microscopy (FESEM) analysis are utilized to examine the physicochemical characteristics of both the ternary composite and the Co3O4-absent binary composite electrodes. The electrochemical performance of the symmetric cells fabricated using these electrodes is assessed through constant galvanostatic charge-discharge (GCD) experiments, cyclic voltammetry (CV), and electrochemical impedance measurements (EIS). The ternary composite with a hierarchical Co3O4 layer exhibits excellent specific capacitance and superior rate capability compared to the Co3O4-absent binary electrode. The ternary composite delivers a specific capacitance of 374.4 F g−1 at 0.5 A g−1, maintaining stability throughout 5000 charging-discharging cycles with an 88.5 % capacity retention.