Preparation and enhanced electrochemical performance of MnO 2 nanosheets for supercapacitors

MnO 2 nanosheets have been synthesized by using a redox reaction of manganese nitrate tetrahydrate and potassium permanganate without any surfactants. The morphology and microstructure of the as-prepared material were characterized by field emission scanning electron microscopy, transmission electron microscopy and X-ray diffraction (XRD). Electrochemical performances as electrode materials for supercapacitor were evaluated using cyclic voltammetry and galvanostatic charge-discharge in 1 M Na 2SO 4 aqueous electrolyte. It was found that MnO 2 nanosheets showed an excellent capacitive behaviour with good cycling stability. The specific capacitance of the MnO 2 nanosheet electrode can reach up to 332.8 Fg -1 at a current density of 500 mA/g and a stable cycling performance. © 2012 The Chemical Society Located in Taipei & Wiley-VCH Verlag GmbH & Co. KGaA,Weinheim.