▎ 摘　　要

This study presents nanorod FeS2@3DGF by in situ synthesized converted from alpha-FeOOH on the 3D graphene foam (GF) by one-step method. X-ray diffraction (XRD), Scanning electron microscope (SEM), and Transmission electron microscopy (TEM) results show that FeS2 nanorods are evenly distributed above the 3D graphene foam interlayer, forming a grass-like nanostructured composite. The insertion of FeS2 nanorods into the substrate column improves the structural stability of 3D graphene foam to prevent the re-accumulation of nanorods in the process of sodium insertion/extraction process. The nanorods can also shorten the sodium-ion migration path and increase the active region. As the anode electrode materials of sodium-ion battery, FeS2@3DGF has excellent electrochemical performance. The alpha-FeOOH@3DGF precursor achieved by hydrothermal method creates appropriate morphology of nanorods, which is beneficial for obtaining ultra-small FeS2@3DGF nanorods during sulfidation and electron and sodium ion transferring. Therefore, the FeS2@3DGF capacity keeps 502.2 mAh g(-1) up to 250 cycles. The synergistic effect of FeS2 on 3D graphene foam promotes the nanostructure stability of FeS2@3DGF, demonstrating well electrochemical performance of sodium-ion batteries.