Fabrication of Nanoplate Nickel Manganese Oxide (NiMnO3) Supercapacitor Electrodes Using Hydrothermal Synthesis Method

The use of environmentally friendly energy storage systems is known as the best solution to reduce the fossil fuels consumption. Supercapacitors have received more attention than other energy storage devices (batteries and fuel cells) due to their high power density, high cycling stability and optimal energy density. The use of inexpensive and available electrode material is the key to the development of supercapacitors in the industrial and commercial scales. Nickel and manganese oxides have a high theoretical specific capacity, in addition to their availability and lower price. A type of morphology with many electrochemically active sites can be achieved by using these two metal oxides, together. In this research, nickel manganese oxide electrode material (NiMnO3) was synthesized using hydrothermal method. Then, the characterization tests of XRD, FT-IR and SEM were used to determine the crystallographic and morphological properties. Characterization analyses showed that the rhombohedral NiMnO3 nanoparticles with mesoporous structure were obtained. The electrochemical tests of CV, GCD and EIS showed that the NiMnO3 electrode has an excellent supercapacitive performance with the specific capacity of 444 F/g at a current density of 1 A/g. The great performance of NiMnO3 electrode can be related to the abundant and available electrochemical active sites of NiMnO3 electrode with appropriate mesoporous structure which led to the charge storage reactions.