A two-dimensional hybrid of SbOx nanoplates encapsulated by carbon flakes as a high performance sodium storage anode

Abstract

Metallic Sb has been extensively researched as a Na storage anode due to its high capacity and low cost, but it suffers from poor cycling stability stemming from its huge volume change (∼390%) during cycling. Herein, a unique two-dimensional hybrid structure of SbO_x nanoplates encapsulated by carbon flakes (SbO_x@CF) was fabricated by templating with soluble NaCl. Benefiting from its two-dimensional structure providing rapid Na⁺ ion uptake and removal and uniform coating endowing a stable buffer layer, the hybrid presents a high reversible capacity (451 mA h g⁻¹) and excellent rate capability (114 mA h g⁻¹ at 4 A g⁻¹), as well as stable cycling (442 mA h g⁻¹ after 100 cycles with 98% capacity retention). This work opens up a facile, controllable, economical and extendable approach to prepare advanced two-dimensional metal oxides for batteries and supercapacitors.