Synthesis of micro-sized porous antimony via vapor dealloying for high-performance Na-ion battery anode

Abstract Antimony (Sb) is a promising sodium-ion anode material due to sustaining a high theoretical capacity of 660 mAh g−1. However, the huge volumetric change of 293% leads to serious pulverization and poor cycling stability. Herein, we design micro-sized porous Sb (P Sb) via one-step chemical vapor dealloying. The as-prepared P Sb owns three-dimensional nano-skeleton and interconnected pores, which enables P Sb a high tap density (2.33 g cm−3), high electrochemical properties and robust ability to alleviate the volumetric expansion of sodiation. The P Sb anode exhibits initial charge and discharge capacities of 834 and 517 mAh g−1 at a current density of 50 mA g−1, corresponding to an initial Coulombic efficiency (ICE) of 61.8%. And a high capacity retention of 80% is obtained after 120 cycles at a current density of 50 mA g−1. Moreover, the P Sb sustains an outstanding rate performance with a capacity of 300 mAh g−1 even at a large current density of 3000 mA g−1. Compared with micro-Sb, the P Sb exhibits a lower electrode swelling of 63.96% because the unique porous structure can effectively alleviate the volume variation and pulverization of Sb during cycling. The enhanced performance of P Sb enables it as a promising anode material for advanced Sodium-Ion Batteries.