| 摘要 |
Disclosed is a positive electrode active material that provides an improved capacity density. Specifically disclosed is a positive electrode active material for a lithium ion battery with a layered structure represented by Li x Ni y M 1-y )O z (wherein M represents at least one element selected from a group consisting of Mn, Co, Mg, Al, Ti, Cr, Fe, Cu, and Zr; x is in the range from 0.9 to 1.2; y is in the range from 0.3 to 0.95; and z is in the range from 1.8 to 2.4), wherein, when a value obtained by dividing an average of peak intensities observed between 1420 and 1450 cm -1 and between 1470 and 1500 cm -1 by the maximum intensity of a peak appearing between 520 and 620 cm -1 in an infrared absorption spectrum obtained by FT-IR is represented by A, A satisfies the following relational formula: 0.20y-0.05 ‰¤ A‰¤ 0.53y-0.06. |
