PURPOSE: To obtain the non-aqueous electrolyte secondary battery, which has the excellent charge and discharge cycle characteristic, by using Mg included Li.Mn compound oxide, which has LiMnO2, crystal phase, as the positive electrode active material.
CONSTITUTION: In a non-aqueous electrolyte secondary battery provided with a positive and a negative electrodes on the surface and the back surface of a separator dipped with the non-aqueous electrolyte, as the positive electrode active material, Mg included Li.Mn compound oxide, which has the LiMnO2 crystal phase, is used. As the Mg included Li.Mn compound oxide, the compound oxide having at least one crystal phase of MgMn2O4, Mg6MnO6, and Mg2MnO4 is desirable. Inclusion ratio of Mg and Mn in this compound oxide is desirably exists within a range at 0.03-0.25 of atomic ratio. This compound oxide is obtained by mixing the raw material such as oxide of Li, Mg, Mn at the predetermined ratio, and burning it at 400-1350°C in the on-oxidation atmosphere. Elusion of Mn from the LiMnO2, crystal phase at the time of charge is thereby hard to be generated, and lowering of the discharging capacity with the progress of the charge and discharge cycle is reduced.
SHOJI YOSHIHIRO
NISHIO KOJI
SAITO TOSHIHIKO
