| 摘要 |
PROBLEM TO BE SOLVED: To provide: a negative electrode active material capable of increasing battery capacity and improving cycle characteristics and initial charging/discharging characteristics, when being used as a negative electrode active material for a lithium ion secondary battery; and a lithium ion secondary battery having a negative electrode comprising the negative electrode active material.SOLUTION: A negative electrode active material for a nonaqueous electrolyte secondary battery negative electrode material contains a silicon based material (SiO: 0.5≤x≤1.6) including at least one or more of LiSiO,, LiSiOand LiSiO, and includes a crystallized fluorine compound, a compound having a -CF-CF- unit, or both thereof, in at least a surface layer of the negative electrode active material. |
