Core–shell Fe@Fe3C/C nanocomposites were prepared by adopting α-FeOOH nanorods as the Fe precursor though a simple and green route. The obtained core–shell nanospheres consisted of single crystalline Fe cores (20–50nm) coated with well-proportioned Fe3C shell (∼8nm) in amorphous carbon. The composites delivered a reversible capacity of ∼500mAh g−1 after 30 cycles. However, no obvious changes were observed in the XRD patterns of Fe@Fe3C/C electrodes before and after the discharge process, indicating that Fe and Fe3C are inactive for lithium storage. Many characterizations were performed to propose a reasonable explanation about the Li storage capacity.