Orthorhomic LixMnO2 was synthesized by rheological phase reaction method. The thermal decomposition of the precursor was characterized by thermogravimetry analysis (TG). The product was characterized by X-Ray diffraction (XRD). Scan Electron Microscope (SEM), and electrochemical measurements. The electrodes of Li1.05MnO2 and Li1.10MnO2 showed a discharge capacity of 114.7 mAh·g-1, and 118.5 mAh·g-1, respectively after 40 cycles.