| 摘要 |
A composite oxide suitable for an active material of a positive electrode for a lithium secondary cell which can be used in a wide range of voltage, has a large electric capacity and excellent low temperature performance and is excellent in the durability for charge-discharge cycles and highly safe, a process for its production, and a positive electrode and a cell employing it, are presented. The composite oxide is a lithium-cobalt composite oxide which is represented by the formula LiCo<SUB>1-x</SUB>M<SUB>x</SUB>O<SUB>2</SUB>, (wherein 0<=x<=0.02 and M is at least one member selected from the group consisting of Ta, Ti, Nb, Zr and Hf), and which has a half-width of the diffraction peak for (110) face at 2theta=66.5±1°, of from 0.070 to 0.180°, as measured by the X-ray diffraction using CuK<SUB>alpha</SUB> as a ray source. |
