Electrochemical Supercapacitor Studies of Nanostructured α-MnO[sub 2] Synthesized by Microemulsion Method and the Effect of Annealing

Nanometer-scale particles of have been synthesized by microemulsion route for electrochemical supercapacitor studies. The has been found to be in α-cyrstallographic form with tetragonal unit cell. Particles in the spherical/hexagonal shape with about size have been observed in scanning electron microscopy and transmission electron microscopy studies. Cyclic voltammograms have exhibited rectangular shape between 0 and vs saturated calomel electrode at sweep rates up to due to nanoparticles of . From galvanostatic charge-discharge studies, specific capacitance of has been obtained, which is greater than about usually reported for this material. The samples have been annealed at several temperatures, and nanoparticles and nanorods ( diameter) of varying dimensions have been obtained. The effect of annealing at different temperatures on crystallographic nature and electrochemical properties are reported.