应用共沉淀法并以原位聚合苯胺包覆四氧化三铁作碳源制备四氧化三铁/碳的复合材料.XRD、SEM、TEM 等测试显示，样品中四氧化三铁纳米颗粒（40 ～ 80 nm）均匀的分散在无定形碳的内部.在50 mA?g-1 的电流密度下，经过30循环充放电测试，该材料的容量仍保持在1000 mAh?g-1左右.

The Fe3O4/Carbon composites have been synthesized through coprecipitation pathway and by insitu aniline polymerization as a carbon source. Structural characterization and morphological study of the composites were investigated by using XRD, SEM and TEM techniques. The results showed that the nanosized Fe3O4 particles (40 ~ 80 nm) were encapsulated in the amorphous carbon. During the electrochemical tests, the Fe3O4/C composites exhibited high capaticity and excellent cycle ability, the retention of capaticity was about 1000 mAh?g-1 after 30 cycles of charge/discharge tests at 50 mA?g-1.