| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a lithium-ion secondary battery using lithium nickel complex oxide as cathode activator having cycle property improved than before in case of repeating intermittent cycle. <P>SOLUTION: A cathode of the lithium ion secondary battery comprises an active material particle represented by the general formula: Li<SB>x</SB>Ni<SB>l-y</SB>M<SB>y</SB>Me<SB>z</SB>O<SB>2+δ</SB>, and the active material particle comprises a lithium complex oxide expressed by a general formula:Li<SB>x</SB>Ni<SB>1-y</SB>M<SB>y</SB>O<SB>2</SB>(wherein, 0.95≤x≤1.1, 0<y≤0.75, 0.001≤z≤0.05). An element M is selected from the group consisting of alkali earth elements, transition elements, rare earth elements, group IIIb elements and group IV elements, an element Me is selected from the group consisting of Mn, W, Nb, Ta, In, Mo, Zr, and Sn, the element Me is contained in the surface layer part of the active material particles, and 0.85≤x≤-0.013Ln(z)+0.871 is satisfied at lithium content x in the lithium complex oxide in the discharge ended state in constant-current discharging at 25°C, at a current value 1C, and at the final voltage of 2.5 V. <P>COPYRIGHT: (C)2007,JPO&INPIT |
