| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an active material for a lithium secondary battery which can obtain a discharging capacity of 200 mAh/g or more even if a charging method, in which a maximum reached voltage potential of a positive electrode at a time of charging becomes 4.3 V(vs. Li/Li+) or less, is adopted. <P>SOLUTION: The active material for the lithium secondary battery contains a solid solution of a lithium transition metal composite oxide having a crystal structure of an α-NaFeO<SB>2</SB>type. Composition ratios of a lithium element and transition metal elements contained in the solid solution in a composition formula Li<SB>1+p</SB>Co<SB>a</SB>Ni<SB>b</SB>Mn<SB>c</SB>(a>0, b>0, c≥0) are as follows. Regarding the formula, 2a+b+3c is 2 (an error range +/-0.1), and when α=a+2b, a value of p is (1-α)×1/3 (an error range +/-0.1), and a value of 1-α is more than 1/3 and 2/3 or less. <P>COPYRIGHT: (C)2009,JPO&INPIT |
