Aluminum-doped spinel-type LiMn2O4 cathode active materials have been synthesized by a microwave-assisted sol-gel method. The influence of synthesis conditions on the structural and electrochemical properties of LiAl0.1Mn1.9O4 was investigated by then-no-gravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), and charge/discharge experiments. The powders resulting from the microwave-assisted sol-gel method with good crystallinity and cubic spinel shapes deliver an initial discharge capacity of 120 mAh g(-1), present excellent rate capability, and the Coulombic efficiency of it almost approaches 99% after 30 cycles. These advantages make it attractive particularly for a practical application. In addition, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were employed to characterize the reactions of Li ion insertion into and extraction from LiAl0.1Mn1.9O4 electrodes. (c) 2005 Elsevier B.V. All rights reserved.