An SbO_<i>x</i>/Reduced Graphene Oxide Composite as a High-Rate Anode Material for Sodium-Ion Batteries

Abstract

Antimony has attracted enormous attention as anode materials for sodium-ion batteries owing to its high theoretical gravimetric capacity (∼660 mA h g^–1). Despite the outstanding gravimetric capacity advantage, antimony suffers from unsatisfactory electrochemical performance originating from its huge volume changes during repeated sodium insertion/extraction. Herein, we synthesize an SbO_<i>x</i>/reduced graphene oxide (SbO_<i>x</i>/RGO) composite through a wet-milling approach accompanied by redox reaction between Sb and GO. When used as an anode material for sodium-ion batteries, SbO_<i>x</i>/RGO exhibits high rate capability and stable cycling performance. A reversible capacity of 352 mA h g^–1 was obtained even at a current density of 5 A g^–1. More than 95% capacity retention (409 mA h g^–1) was achieved after 100 cycles at a current density of 1 A g^–1. The excellent electrochemical performance is due to the Sb–O bonding between nanometer-sized SbO_<i>x</i> particles surface and highly conductive RGO, which can not only effectively prevent SbO_<i>x</i> nanoparticles from aggregation upon cycling but also promote the electrons and sodium ions transportation