Spinel LiMn2O4 samples are prepared by heating a Li2CO3/MnCO3 mixture in air at various temperatures, and their structure and chemical performance are studied by using thermal analysis, X-ray diffraction, microelectrode voltammetry, and charge-discharge measurements. It was found that the electrochemical properties of the LiMn2O4 samples are very sensitive to the synthesis temperature. The LiMn2O4 powder obtained at 800 degrees C yields a high initial capacity of similar to 15 mAh g(-1), excellent cyclability, and has a good high-rate capability.