| 摘要 |
PROBLEM TO BE SOLVED: To provide a positive electrode active material for lithium ion secondary battery containing a nickel manganese composite oxide of spinel crystal structure and a metal oxide of layered crystal structure, and excellent in durability.SOLUTION: In a positive electrode active material for lithium ion secondary battery, primary particles composing the positive electrode active material includes a phase consisting of a nickel manganese-containing composite oxide of spinel crystal structure containing at least nickel and manganese as a transition metal element, and a phase consisting of a metal oxide of layered crystal structure. |
