| 摘要 |
Provided are a negative electrode active material which is excellent in charge/discharge characteristics, specific capacity and charge/discharge cycle characteristics, its preparation method, and a lithium secondary battery containing the negative electrode active material. The negative electrode active material comprises Fe(1-x) Mn_x Si2, wherein 0<=x<=1. Preferably, Fe(1-x) Mn_x Si2 is alloyed with graphite or is coated with carbon. The method comprises the steps of mixing Fe, Si and Mn to prepare a Fe(1-x) Mn_x Si2 composite; mixing the Fe(1-x) Mn_x Si2 composite with graphite to prepare a Fe(1-x) Mn_x Si2-graphite composite; and mixing the Fe(1-x) Mn_x Si2-graphite composite with a carbon precursor and carbonizing the carbon precursor to prepare a Fe(1-x) Mn_x Si2-graphite composite coated with carbon. |
