Synthesis and electrochemical properties of polymer solution prepared MnCo2O4 nanoparticles

Abstract

In this work, spinel MnCo2O4 nanoparticles with a particle size of about 40–160\xa0nm were prepared by a simple polymer solution method. The resulting precursor was calcined at 500\xa0°C, 600\xa0°C, 700\xa0°C, and 800\xa0°C to obtain a spinel MnCo2O4 phase. The results of X-ray diffraction and transmission electron microscopy with selected electron diffraction analysis indicated that the MnCo2O4 nanoparticles have a cubic structure. The X-ray absorption near edge structure and X-ray photoelectron spectroscopy spectra have confirmed the mixed valence state of Mn3+/Mn4+ and Co2+/Co3+ in all samples. The electrochemical properties were investigated by using a three-electrode cell system in 6.0\xa0M KOH electrolyte. The sample calcined at 600\xa0°C exhibits the highest specific capacitance value of 282\xa0F/g and 208\xa0F/g at a scan rate of 2\xa0mV/s and at a current density of 1.0\xa0A/g, respectively, and the best capacitance retention with long-term cycling stability over 70% after 1000\xa0cycles. Clearly, calcination temperatures affect to the specific surface area and pore diameter, which can improve the electrochemical performance of the MnCo2O4 nanoparticles.