One-pot synthesis of Fe3O4/C nanocomposites by PEG-assisted co-precipitation as anode materials for high-rate lithium-ion batteries

Fe3O4/C nanocomposites have been prepared by one-pot PEG-assisted co-precipitation method. The structure and morphology of the as-prepared materials were analyzed by X-ray diffraction and transmission electron microscopy. The results showed that Fe3O4/C nanocomposites were well crystallized. Carbon nanoparticles dispersed among Fe3O4 particles forming a carbon layer, which prevent Fe3O4 particles from contacting each other. Electrochemical performance tests showed that Fe3O4/C nanocomposites keep at a high discharge capacity of 902.4 mAh g−1 at 1 C after 110 cycles. Furthermore, the samples showed much improved rate capability and better cycle stability compared with pure Fe3O4. The excellent electrochemical performance of Fe3O4/C nanocomposites can be attributed to unique nanostructure and existence of amorphous carbon in the composites. The existence of the amorphous carbon not only enhanced electric conductivity, but also buffered volume variation of Fe3O4/C nanocomposites during charge/discharge process.