Particulate positive electrode active material for a lithium secondary cell

Abstract

A particulate positive electrode active material for a lithium secondary cell which satisfies high charge and discharge cyclic durability, high safety, high temperature storage properties, a high discharge average voltage, large current discharge properties, a high weight capacity density, a high volume capacity density, etc. in a well-balanced manner is provided. A particulate positive electrode active material for a lithium secondary cell, which is represented by the formula LipCoxMyOzFa (wherein M is at least one element selected from Groups 2 to 8, 13 and 14 of the Periodic Table, 0.9≦p≦1.1, 0.980≦x≦0.9999, 0.0001≦y≦0.02, 1.9≦z≦2.1, 0.9≦x+y≦1 and 0.0001≦a≦0.02), wherein fluorine atoms and element M are unevenly distributed on the particle surface, the atomic ratio of fluorine atoms to cobalt atoms (a/x) is from 0.0001 to 0.02, and in powder X-ray diffraction using CuKα-ray, the half value width of the angle of diffraction on (110) plane is from 0.06 to 0.13°, and the half value width of the angle of diffraction on (003) plane is from 0.05 to 0.12°.

Dependencies are inferred from the claim text.