| 摘要 |
PROBLEM TO BE SOLVED: To obtain a layered lithium-nickel-manganese composite oxide, and a positive electrode material for lithium secondary battery, and a lithium secon dary battery using the composite oxide. SOLUTION: In the layered lithium-nickel-manganese composite oxide in which the molar ratio between nickel and manganese lies in the range of 0.7<=Ni/Mn<=9, a part of the sites of nickel and manganese is substituted with the other elements (wherein, when aluminum is used as a substitution element, 0.8<=Ni/Mn<=1.2 is satisfied), and the composite oxide is particularly expressed by the following formula (1) of LiXNiYMnZQ(1- Y- Z) O2 (wherein, X denotes the number in the range of 0<X<=1.2. Y and Z satisfy the relations of 0.7<=Y/Z<=9, and 0<(1-Y-Z)<=0.5, and Q denotes at least one kind selected from the groups consisting of Al, Co, Fe, Mg and Ca). The positive electrode material for the lithium secondary battery and the positive electrode contain the above composite oxide. |
