Patent ID: 9543055
Date: 2017-01-10
CPC Classifications: C01G,C01P,H01B,H01M,Y02E,Y02P,Y02T

Claim:
1. A positive active material for a nonaqueous electrolyte secondary battery containing a lithium transition metal composite oxide which has a crystal structure of an α-NaFeO 2 type, is represented by a compositional formula Li 1+α Me 1−α O 2 wherein Me is a transition metal element including Co, Ni and Mn, α>0, and has a molar ratio Li/Me of Li to the transition metal element Me of 1.250 to 1.350, wherein a molar ratio Co/Me of Co in the transition metal element Me is 0.040 to 0.195, a molar ratio Mn/Me of Mn in the transition metal element Me is 0.625 to 0.707, the lithium transition metal composite oxide is observed as a single phase attributed to a space group R3-m on an X-ray diffraction chart when it is electrochemically oxidized up to a potential of 5.0 V (vs. Li/Li in the lithium transition metal composite oxide, an oxygen position parameter, determined by crystal structure analysis by a 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 0.260 or less, and a tapped density of the positive active material is 0.52 to 1.98 g/cm