| 摘要 |
The subject of the present invention is to provide an active material for a nonaqueous electrolyte secondary battery which has a large discharge capacity and is excellent in high rate discharge performance. Provided are an active material for a nonaqueous electrolyte secondary battery containing a lithium transition metal composite oxide which has a crystal structure of an ±-NaFeO 2 type and is represented by a compositional formula Li 1+± Me 1-± O 2 (Me is a transition metal element including Co, Ni and Mn, ± > 0), and a method for producing the active material. In the lithium transition metal composite oxide, a compositional ratio Li/Me of lithium Li to the transition metal element Me is 1.25 to 1.425, and an oxygen positional parameter, determined from crystal structure analysis by Rietveld method at the time of using a space group R3-m as a crystal structure model based on an X-ray diffraction pattern in a state of a discharge end, is 0.262 or less. |
