Fabrication and characterization of monodispersed Mn0.8Ni0.2Co2O4 mesoporous microspheres for supercapacitor application

The monodispersed Ni doped MnCo2O4 mesoporous microspheres were synthesized through a simple ammonium bicarbonate-assisted solvothermal route. The spinel-type crystal structure with a lattice parameter of 8.199 Å for Mn0.8Ni0.2Co2O4 composition was obtained by using X-ray diffraction analysis. The Brunauer−Emmett−Teller (BET) specific surface area of the sample was found to be 75.78 m2 g−1 with an average pore diameter of 9.88 nm. Electron microscopy studies revealed that the stable mesoporous microspheres are constituted by well-connected aggregates of nanoparticles. The influence of Ni doping on the pseudo-capacitance of MnCo2O4 electrode was investigated by means of cyclic voltammetry in 6 M KOH electrolyte. We found that the spinel-type Mn0.8Ni0.2Co2O4 mesoporous microspheres exhibit specific capacitances of 1822 F g−1 at a scan rate of 5 mV/s. Furthermore, the electrochemical impedance spectroscopy analysis revealed the low resistance and good electrochemical stability of the sample.