摘要 |
In a method of manufacturing a lithium ion secondary battery, first, lithium nickel manganese oxide which is a positive electrode active material is exposed to fluorine-based gas to form a coating film containing amorphous lithium fluoride on a surface of the positive electrode active material. Next, a phosphate compound is added to the positive electrode active material on which the coating film containing the lithium fluoride is formed. After a lithium ion secondary battery which includes a positive electrode including the positive electrode active material is formed, the lithium ion secondary battery is charged to form a coating film containing amorphous lithium phosphate on the surface of the positive electrode active material. |