Abstract
Single crystals of MnOOH and Mn 3 O 4 were synthesized through a simple sol-gel route. From transmission electron microscopy. Fourier transform infrared. X-ray diffraction, and selected area electron diffraction analyses, manganese oxides prepared in this work are demonstrated to be a mixture consisting of MnOOH and Mn 3 O 4 single crystals. The relative amount of MnOOH in the mixture gradually increased with increasing aspect ratio of the MnOOH nanorods. The aspect ratio controlled growth of MnOOH nanorods without using templates is predictable by an equation correlated with the preparation variables. Thick coatings of manganese oxides with this novel structure are demonstrated to show capacitive-like characteristics for the supercapacitor applications. © 2005 The Electrochemical Society. All rights reserved.