| 摘要 |
PROBLEM TO BE SOLVED: To provide a new lithium manganese oxide which can form a lithium secondary cell of high capacity when the oxide is used as the positive electrode of the lithium secondary cell, to provide its producing method, and to provided lithium secondary cell having high capacity using the compd. as the active material for the positive electrode. SOLUTION: The lithium manganese oxide having a spinel crystalline structure is expressed by the formula of Li1+xMn2-yO4+z (wherein x, y, z satisfy 0<=x<=1/3, 0<=y<=1/3 and -0.14<=z<=0.5) and has the inhomogeneous distortion value η of the crystal measured by Hall's method satisfying 0.0005<η<0.005. In the producing method the lithium manganese oxide, a mixture of a manganese compd. having >=3.0 average oxide number of manganese and a lithium compd. is calcined at <=500 deg.C, and then further calcined at >500 deg.C and <=950 deg.C. In the lithium secondary cell, the obtd. lithium manganese oxide having the spinel crystalline structure is used for the positive electrode. |
