Design of antimony nanocomposite for high areal capacity sodium battery anodes

Antimony (Sb) is attractive as a high-capacity anode for sodium-ion batteries, but undergoes structural degradation and instability of the solid-electrolyte interphase caused by the large volume change during cycling. Here, we demonstrate a unique Sb-based composite anode by embedding the Sb nanoparticles into the conductive hierarchical porous graphitic carbon (HPGC) that leaves enough room for volume change and is further encapsulated by a uniform conductive nitrogen-doped carbon (NC) layer to act as an electrolyte barrier. Such a design enables the [email protected]/NC composite to exhibit a high capacity of 639 mAh g−1, stable cycling stability, and a commercial-level areal capacity of 3.11 mAh cm−2. In addition, full cells by coupling with sodium vanadium phosphate cathode deliver a high energy density of 223.4 Wh kg−1 with superior rate performance. This work provides a bright way for the rational design and construction of Sb-based anode materials for advanced SIBs.