Nanostructured Co3O4 electrodes for supercapacitor applications from plasma spray technique

Among different transition metal oxides cobalt oxide (Co3O4) has attracted considerable attention for supercapacitor applications because of its superior electrochemical characteristics at relatively low cost. Nanostructured Co3O4 electrodes are usually prepared from powders using sol-gel and hydrothermal techniques, which require multi-step procedures and longer processing times. Here, we report synthesis and characterization of Co3O4 supercapacitor electrode films deposited directly on current collectors via a single step solution precursor plasma spray route. In this approach, an aqueous solution containing cobalt acetate is axially fed into plasma plume to produce nanoparticulates of Co3O4 via accelerated thermo-chemical conversion process, which are eventually deposited on a current collector substrate. Thus, developed Co3O4 electrodes showed nano particulate structure with porosity. The phase structure and crystallinity of Co3O4 electrode films were analyzed by X-ray diffraction and differential scanning calorimetry-thermogravi merry (DSC-TGA) studies. Electrochemical performance of these coatings showed a specific capacitance of similar to 162 F g(-1) with a retention capacity of 72.2% after 1000 cycles for a specific current rate of 2.75 A g(-1) in 6M KOH electrolyte.(C) 2012 Elsevier B.V. All rights reserved.