Two types of spinel cathode powders, LiMn 2 O 4 and LiAl 0.1 Mn 1.9 O 3.9 F 0.1 , were synthesized by solid-state reaction. X-ray diffraction (XRD) patterns of the prepared samples were identified as the spinel structure with a space group of Fd m. The cubic lattice parameter was determined from least-squares fitting of the XRD data. The LiAl 0.1 Mn 1.9 O 3.9 F 0.1 sample showed a little lower initial capacity, but better cycling performance than the LiMn 2 O 4 sample at both room temperature and an elevated temperature. The Vanderbilt method was used to test the electrochemical conductivity of the LiMn 2 O 4 samples. The electrochemical impedance spectroscopy (EIS) method was employed to investigate the electrochemical properties of these spinel LiMn 2 O 4 samples.