Nanostructured amorphous Mn oxide, for use as an electrode material in supercapacitors, was prepared by a facile precipitation method using ethanol. After thermal treatment at various temperatures, the structural characteristics and electrochemical properties of the prepared Mn oxide were investigated. Importantly, the experimental results revealed that the alkyl chain of ethanol prevented the excessive crystallization of Mn oxide, resulting in the production of nanostructured Mn oxide. In addition, electrochemical properties of synthesized material were highly dependent on the structural characteristics. Mn oxide thermally treated at 300 degrees C, which had an optimized crystalline structure, showed the highest specific capacitance of 161 F/g in this study. (C) 2012 Elsevier B. V. All rights reserved.