Enhanced electrochemical performance of MnCo_2O_4 nanorods synthesized via microwave hydrothermal method for supercapacitor applications

摘要

MnCo2O4 nanorods were facilely prepared via microwave hydrothermal method. X-ray diffraction pattern showed pure crystalline spinel phase MnCo2O4 formation for the calcined powder at 400 degrees C. Fourier transform infrared spectroscopy (FTIR) spectrum of the MnCo2O4 powders showed the strong vibrational modes of Mn-O and Co-O bonds. Raman spectrum showed the structural bonding features and crystalline nature of MnCo2O4. Scanning electron microscopy images exposed a morphology that shows the aggregation of several nanorods to form bundles of nanorods 300-400nm in diameter and few microns in length. Energy-dispersive spectrometry analysis confirmed the presence of Mn, Co, O elements for the powder calcined at 400 degrees C. The electrochemical characterization of the MnCo2O4 nanorods with 1M KOH as the electrolyte exhibited an excellent capacitance of 2394.4Fg(-1) at a scan rate of 5mVs(-1) and revealed a highest specific capacitance of 1617.5Fg(-1) from the galvanostatic charge/discharge analysis at a current density of 1Ag(-1). The cycling stability at different current densities revealed the high rate performances and good reversible capacity retention of the calcined MnCo2O4 nanorods. The cycling life study of MnCo2O4 nanorods demonstrated an excellent cycling stability with 88% of the initial specific capacitance retention at 10Ag(-1) after 1000 cycles.