LiMn204 powder as a cathode materials for rechargeable lithium-ion batteries was prepared by solid-state reaction from Li2CO3 and electrolytic MnO2 at different sintering periods (2, 6, 18, and 32 h). X-ray diffraction (XRD) patterns of the prepared samples are identified as the spinel structure with a space group of Fd3 m. The lattice parameters almost remain the same as the sin-tering periods increase. The sample with a sintering period of 32 h shows good cycling performance at both low and high current densities, and also elevated temperature. It is believed that the excellent electrochemical behavior of this sample results from its good crystallinity and large grain size compared with other samples. Different electrochemical measurements were conducted to investi-gate the electrochemical properties of spinel LiMn2O4.