| 摘要 |
This invention provides an active material for a lithium rechargeable battery with a large discharge capacity, particularly an active material for a lithium rechargeable battery that can increase the discharge capacity in a potential region of not more than 4.3 V, a process for producing the active material, a lithium rechargeable battery having a large discharge capacity, and a process for producing the lithium rechargeable battery. The active material for a lithium rechargeable battery comprises a solid solution of a lithium transition metal composite oxide having an αNaFeO-type crystal structure. The active material is characterized in that the composition ratio of Li, Co, Ni, and Mn contained in the solid solution satisfies LiCoNiMn, wherein x + y < 1, 0 < y, and 1-x-y = z); in a Li[LiMn]O(x)-LiNiMnO(y)-LiCoO(z)-type ternary phase diagram, (x, y, z) is represented by values in a range present on or within a line of a heptagon (ABCDEFG), of which the vertexes are point A (0.45, 0.55, 0), point B (0.63, 0.37, 0), point C (0.7, 0.25, 0.05), point D (0.67, 0.18, 0.15), point E (0.75, 0, 0.25), point F (0.55, 0, 0.45), and point G (0.45, 0.2, 0.35); and the intensity ratio between the diffraction peak on plane and plane as measured by X-ray diffractometry at the end of discharge is I/I > 1. The process for producing the active material for a lithium rechargeable battery uses a coprecipitation method. The lithium rechargeable battery comprises a positive electrode containing the active material. |
