| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a lithium manganese nickel compound oxide useful as a positive electrode active substance for a lithium ion secondary battery, and its manufacturing method, and the lithium ion secondary battery using the same. <P>SOLUTION: An atomic ratio of manganese to nickel in the lithium manganese nickel compound oxide is substantially 3:1, and expressed by the composition formula: Li[Mn<SB>3/2</SB>Ni<SB>1/2</SB>]O<SB>4</SB>. The crystal structure thereof is of a highly crystalline spinel (the space group is Fd3m), and has a lattice constant of ≥8.18 Å, and has a microstructure characterized by 400 to 800 cm<SP>-1</SP>absorption in the infrared absorption spectrum. The specific surface area thereof is ≤1.0 m<SP>2</SP>/g. Further, the charge/discharge curve exhibits a very flat one and a low polarization. The ratio of a discharge capacity at a coexisting 4 V-class potential to that at a 5 V-class one is controllable over a wider range according to the below described manufacturing method. <P>COPYRIGHT: (C)2004,JPO |
