Enhanced electrochemical properties of zinc and manganese co-doped NiO nanostructures for its high-performance supercapacitor applications

In electrochemical energy storage devices, improving the availability of ions in the electrodes for charge storage and rate performance is a challenging task in the present era. So, in this report, an attempt was made to prepare Zn and Mn co-doped NiO nanostructures with improved electrochemical performance. The structural study revealed pure, and co-doped NiO nanostructures crystallize into face-centred cubic geometry with space group Fm3m. A prominent decrease in grain size was noticed with the increase in Mn concentration, showing an inverse relation with the optical bandgap. The room temperature ferromagnetism was improved by Mn doping. The electrochemical study proves the pseudocapacitive nature, with enhanced specific capacitance (846.71 Fg(-1)) in Ni0.9Zn0.04Mn0.06O nanoparticles. The galvanostatic charge-discharge study revealed a power density of 8900 W/kg at an energy density of 12.47 Wh/kg in Ni0.9Zn0.04Mn0.06O nanostructures. The improved specific capacitance, fascinating charging-discharging ability, and high-power density of Ni0.9Zn0.04Mn0.06O nano structures makes it a special candidate for high-performance supercapacitor.