| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a lithium ion secondary battery in which energy density of the battery is improved and which is superior in a cycle life. <P>SOLUTION: When charging is carried out in the lithium ion secondary battery which includes a positive electrode containing a lithium-transition metal complex oxide and a negative electrode containing a carbonaceous material, as the lithium-transition metal complex oxide, what is shown by a formula (1) LiXNiYMnZQ<SB>(1-</SB>Y<SB>-</SB>Z<SB>)</SB>O<SB>2</SB>is used, and the upper limit voltage of the charge is made to be 4.15 to 4.4 V. In the formula, X represents the number satisfying a relationship of 0<X≤1.2, Y and Z represent 0.7≤Y/Z≤9 and 0≤(1-Y-Z)≤0.5, and Q represents at least one kind of element selected among the transition metals of the fourth period, B, Al, Ga, Zn, Be, Mg and Ca. <P>COPYRIGHT: (C)2003,JPO |
