Spinel-typed LiMn2O4 cathode active materials have been prepared for different microstructures by the melt-impregnation method using different forms of manganese. The effect of the starting materials on the microstructure and electrochemical properties of LiMn2O4 is investigated by X-ray diffraction, scanning electron microscopy, and electrochemical measurements. The powder prepared from nanostructured γ-MnOOH, with good crystallinity and a regular cubic spinel shape, provided an initial discharge capacity of 114mAhg−1 with excellent rate and high capacity retention. These advantages render LiMn2O4 attractive for practical and large-scale applications in mobile equipment.