Soft-chemical synthesis and electrochemical characterization of multicomponent Mn 1-x-yCo xNi yO 2 Nanostructures

Abstract

Nanostructured Mn 1-x-yCo xN yO 2 metal oxides are synthesized by one-pot hydrothermal reaction at low temperature. From powder X-ray diffraction and field emission-scanning electron microscopic analyses, it is found that the crystal structure and crystal morphology of the present materials are tunable by the control of the composition of precursor. 1D nanowires with α-MnO 2-type structure are prepared with low substitution rate of Co and Ni, while the increase of substituent contents leads to the formation of δ-MnO 2-structured 3D nanospheres consisting of 2D nanoplates. According to X-ray absorption near edge spectroscopy and chemical analyses, mixed valent Co III/Co IV and divalent Ni II ions are stabilized in the octahedral Mn sites of α-MnO 2- and δ-MnO 2-structures. The electrochemical measurements clearly demonstrate that the present nanostructured materials show promising electrode performances for lithium secondary batteries. Copyright © 2007 American Scientific Publishers All rights reserved.