Facile synthesis of Fe3O4 hollow spheres/carbon nanotubes composites for lithium ion batteries with high-rate capacity and improved long-cycle performance

Fe3O4 hollow spheres/carbon nanotubes (Fe3O4-HSs/CNTs) composites were synthesized by a facile solvothermal method, without any template. Compared to the Fe3O4 hollow spheres (Fe3O4-HSs), the Fe3O4-HSs/CNTs composites showed a better suitability as anode materials for lithium-ion batteries. After 70 cycles, the Fe3O4-HSs/CNTs composites exhibited a reversible capacity of 1153.8 mAh g−1 at 0.1 A g−1 as well as good cycling performance. When the current density was 0.4, 0.7 and 1.0 A g−1, the composites still displayed reversible capacity of 1038.4, 848.8 and 778.5 mAh g−1, respectively. In addition, the Fe3O4-HSs/CNTs composites showed improved long-life cycling performance even at high current.