Characterization and electrochemical performance of the spinel LiMn2O4 prepared from ε-MnO2

The preparation and characterization of the spinel LiMn2O4 obtained by solid state reaction from quasi-amorphous epsilon-MnO2 is reported. A well-defined highly pure spinel was characterized from X-ray diffractograms. The average manganese valence of E-MnO2 and spinel samples was found to be 3.89+/-0.01 and 3.59+/-0.01, respectively. The electrochemical performance of the spinel was evaluated through cyclic voltammetry and chronopotentiometry. The voltammetric profiles obtained at 1 mV/s for the LiMn2O4 electrode in 1 M LiClO4 dissolved in a 2:1 mixture of ethylene carbonate and dimethyl carbonate showed typical peaks for the lithium insertion/extraction reactions. The charge capacity of this electrode was found to be similar to 110 mA h g(-1) for the first charge/discharge cycles. (C) 2000 Elsevier Science B.V. All rights reserved.