Abstract: Eight typical ways were used to synthesize chemical manganese dioxide(CMD) from which eight types of Li-Mn oxide were prepared. The structures of CMDand Li-Mn oxide were all investigated by XRDexperiment. The results of the electrochemical characterization show that except the structure type, the composition of CMDwhich was used in the preparation can also have a significant influence on the electrochemical performance of the final product—Li-Mn oxide. Even the CMDmaterial was of the same type, the difference under the synthesizing condition could bring out some microcosmic or local change in the structure, which may finally cause the great difference in the electrochemical behavior. Because of its instability at the high temperature, δ-MnO₂ was unsuitable to be used as the manganese source for the preparation of the spinel material, although it was characteristic of large tunnel in its structure.

Key words: CMD, Li-Mn oxide, Alkaline cation, δ-MnO₂