Abstract: LiMn₂O₄ powder as a cathode materials for rechargeable lithium-ion batteries was prepared by solid-state reaction from LitCO₃ 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 Fd3m. The lattice parameters almost remain the same as the sintering periods increase. The sample with a sintering period of 32 h shows good cycling performance at both low and nigh 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 investigate the electrochemical properties of spinel LiMn₂0₄.