A Chemically Coupled Antimony/Multilayer Graphene Hybrid as a High-Performance Anode for Sodium-Ion Batteries

Sodium-ion batteries have recently attracted considerable attention as a promising alternative to lithium-ion batteries owing to the natural abundance and low cost of sodium compared with lithium. Among all proposed anode materials for sodium-ion batteries, antimony is a desirable candidate due to its high theoretical capacity (660 mA h g(-1)). Herein, an antimony/multilayer graphene hybrid, in which antimony is homogeneously anchored on multilayer graphene, is produced by a confined vapor deposition method. The chemical bonding can realize robust and intimate contact between antimony and multilayer graphene, and the uniform distribution of antimony and the highly conductive and flexible multilayer graphene can not only improve sodium ion diffusion and electronic transport but also stabilize the solid electrolyte interphase upon the large volume changes of antimony during cycling. Consequently, the antimony/multilayer graphene hybrid shows a high reversible sodium storage capacity (452 mA h g(-1) at a current density of 100 mA g(-1)), stable long-term cycling performance with 90% capacity retention after 200 cycles, and excellent rate capability (210 mA h g(-1) under 5000 mA g(-1)). This facile synthesis approach and unique nanostructure can potentially be extended to other alloy materials for sodium-ion batteries.