The electrochemical characterization of electrochemically synthesized MnO2-based mixed oxides for supercapacitor

With more challenges facing utilities and others responsible for reliable electricity service, considering the broadest range of technically and economically viable solutions is more important than ever. Electrical energy storage is a well known solution to many of the common energy problems which developed rapidly in recent years. Electrical energy storage is an emerging technology,storage devices can be used to improve power quality or mitigate reliability problems which affect sensitive equipment, optimize configuration of power grid, firm up that intermittent renewable energy resources generation capacity, and so on. It can believe that electrical energy storage will used widely in power grid in the future. In recent, many new types energy storage systems come forth continuously, including the following technologies: advanced battery systems (including vanadium flow batteries, NaS batteries, Li-ion batteries, Ni-MH batteries, and so on), supercapacitors, flywheels, SEMS and compressed air energy systems, etc. Thereinto, Supercapacitors is followed with interest widly which considered to mitigate power quality suitably because of great power density, very short respond times, very long lifetimes, environmental protection. 500kW and 1MW demonstrative supercapacitor storage devices have be used in a micro-grid of USA and railway distribution grid of Germany. Electrode materials are one key technologies of Supercapacitor, research of high performance and low cost electrode materials is the basis of supercapacitor electrical energy storage head for practicality. In this paper, high performance and low cost electrode materials of supercapacitors, composited manganese oxides (MnO₂) powders used for supercapacitor were anodically deposited onto titanium substrates with an IrO₂ interlayer (Ti/IrO₂ anode). Cyclic voltammetry (CV) and Cycle stabilization was employed to study the electrochemical characteristics of these oxide elctrode mater- - ials in aqueous 0.5 M Na₂SO₄ solution, Influence of the specific capacitances were studied by adding active carbon into manganese oxides (MnO₂). The results shows that the specific capacitances of these oxide elctrode materials were significantly influenced by the contect of actived carbon, the composited manganese oxides adding 20 percent actived carbon has the highest specific capacitance, which about 109.7 F/g at 5mv/s scan rate. And, the manganese oxides materials have preferable stabilization, after 3000 cycles, the specific capacitance of the manganese oxides only reduced 1%.