SiC–Sb–C nanocomposites as high-capacity and cycling-stable anode for sodium-ion batteries

SiC–Sb–C nanocomposites with core–shell structure were prepared by simple mechanical ball-milling method. This core–shell structure is composed of rigid SiC nanoparticles as inner core, Sb nanoparticles as an electrochemical active layer anchored on the surface of SiC, and carbon outlayer. The electrochemical experiments show that the SiC–Sb–C electrode improve electrochemical utilization and cycling stability of Sb during Na-storage reaction in comparison with Sb–C composites, indicating that such core–shell structure can effectively buffer the volume change and remain structural stability. Particularly, after incorporating Cu into Sb layer, the SiC–Sb–Cu–C electrode exhibits higher capacity and cycling stability (595 mAh g−1 after 100 cycles) than the SiC–Sb–C electrode. Therefore, the core–shell structure can provide a viable strategy to develop high capacity and stable cycling alloy anode for sodium ion batteries.

► SiC–Sb–C nanocomposites with core–shell structure were prepared by simple mechanical ball-milling method as anode materials for Na-ion batteries.
► Such core–shell structure of the SiC–Sb–C electrode can effectively buffer the volume change and remain structural stability.
► After adding Cu, the SiC–Sb–Cu–C electrode exhibits higher capacity of 511 mAh g−1 at 800 mA g−1 and 595 mAh g−1 after 100 cycles.