Synthesis and characterization of a copper-substituted manganese oxide with the Na0.44MnO2 structure

NaxCu0.11Mn0.89O2 (X = 0.4-0.5) with the Na0.44MnO2 structure was prepared by sol-gel, glycine-nitrate combustion synthesis and solid-state routes. Li0.45-xCu0.11Mn0.89O2 was prepared by ion exchange from the glycine-nitrate sodium-containing precursor. Rietveld refinement of X-ray diffraction power patterns indicates that Cu substitutes in the MO-position. The electrochemical characteristics of LixCu0.11Mn0.89O2 are changed by Cu-substitution, resulting in a somewhat lower capacity between fixed voltage limits compared to the unsubstituted material. (C) 2002 Elsevier Science B.V. All rights reserved.