| abstract |
Suitable as active cathode material for an electrochemical lithium secondary cell are oxygen-deficient spinels Li1+xMn2-xO4-delta , where 0<=x<=0.33 and 0.01<=delta<=0.5. Their region of existence in a phase diagram laid out between the corner points MnO, MnO2 and Li2MnO3 for lithium manganese oxide compounds is defined by the corner compounds LiMn2O4, Li2Mn4O7, Li8Mn10O21 and Li4/3Mn5/3O4, all the compounds along the lines LiMn2O4-Li4/3Mn5/3O4 and LiMn2O4-Li2Mn2O4 being excepted. The spinels are produced by a modified ceramic process from a mixture of Li-containing and Mn-containing starting substances whose reaction product is reduced by roasting in an Ar/H2 atmosphere. The Li components x can be replaced partially or completely by foreign monovalent or multivalent cations from the series consisting of Co, Mg, Zn, Ni, Ca, Bi, Ti, V, Rh or Cu. |