| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an active material for nonaqueous electrolyte secondary batteries having large discharge capacity and excellent high rate discharge performance. <P>SOLUTION: The active material for nonaqueous electrolyte secondary batteries contains a lithium transition metal composite oxide having an α-NaFeO<SB POS="POST">2</SB>type crystal structure, a composition represented by a formula Li<SB POS="POST">1+α</SB>Me<SB POS="POST">1-α</SB>O<SB POS="POST">2</SB>(Me: a transition metal element including Co, Ni and Mn, α>0) and a composition ratio Li/Me of lithium Li to a transition metal element Me of 1.2-1.6. The lithium transition metal composite oxide has 0.260 or less of an oxygen position parameter obtained from a crystal structure analysis by a Rietveld method when the space group R3-m is used for a crystal structure model on the basis of an X-ray diffraction pattern in a discharge end and is observed as a single phase belonging to the space group R3-m in the X-ray diffraction pattern when electrochemically oxidized to an electric potential of 5.0 V (vs.Li/Li<SP POS="POST">+</SP>). <P>COPYRIGHT: (C)2013,JPO&INPIT |
