| 摘要 |
The present invention provides a positive electrode active material for lithium ion battery which has a high capacity and good rate characteristics can be provided. The positive electrode active material for lithium ion battery has a layer structure represented by the compositional formula: Li x (Ni y M 1-y )O Z (wherein M represents at least one type selected from the group consisting of Mn, Co, Al, Mg, Cr, Ti, Fe, Nb, Cu and Zr, x denotes a number from 0.9 to 1.2, y denotes a number from 0.70 to 0.79, and z denotes a number of 1.9 or more), wherein the coordinates of the lattice constant a and compositional ratio (Li/M) are within the region enclosed by three lines given by the equations: y = 1.108, y = -37.298x + 108.27, and y = 75.833x - 217.1 on a graph in which the x-axis represents a lattice constant a and the y-axis represents a compositional ratio (Li/M) of Li to M, and the lattice constant c is 14.2 to 14.25. |
