| 摘要 |
Disclosed is a negative electrode active material for lithium-ion secondary batteries which contributes to high capacity, high energy density, and safety and a lithium-ion secondary battery provided with the negative electrode active material. The negative electrode active material is an oxide containing Li and Fe and having crystalline and amorphous phases of LiFeO2 such that there is a specific ratio ranging from 13.2 to 100 between peak value of X-ray diffraction due to the plane of the crystalline phase and peak value of X-ray diffraction due to the amorphous phase. The negative electrode active material is produced by preparing a mixture of LiOH.H2O and FeOOH and heating it together with distilled water in an autoclave at 180 to 220° C. for 10 to 20 hours, thereby giving an oxide having the crystalline and amorphous phases of LiFeO2 or an oxide having the crystalline and amorphous phases of LiFeO2 and LiFe5O8. |
