Fabrication and electrochemical performance of spinel copper manganese oxide nanocomposites for supercapacitor application

In this study, the spinel copper manganese oxide (CMO) nanocrystals were synthesized by simple chemical co-precipitation method and was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscopy (TEM). The morphology of the material found from TEM is to be spherical in shape with the crystallite size of 3.51 nm. The electrochemical characterizations of the CMO were performed by cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy. The specific capacitance of CMO was found to be 280 F g(-1) at a current density of 1 A g(-1). To enhance its capacitance value, it was doped with multi-walled carbon nanotube and poly(3,4-ethylenedioxythiophene) polystyrene sulphonate (PEDOT:PSS) and their electrochemical characterizations were recorded and compared with CMO. Doped material (CMO/MWCNT/PEDOT:PSS) exhibits a high specific capacitance of 1087 F g(-1) at current density of 1 A g(-1) with a good rate performance and retained an excellent electrochemical stability of 104% capacitance retention and coulombic efficiency of 101% over 10,000 cycles at a current density of 5 A g(-1). This work recommends an idea for such advanced electrode material for efficient supercapacitors.