Controllable synthesis of Sb/reduced graphene oxide nanocomposite by oxygen-containing groups for ultra-stable lithium/sodium storage

Abstract Due to its high theoretical capacity and appropriate operated potential, elemental Sb is one of the most promising electrodes for lithium-/sodium-ion batteries. However, it suffers poor cycling stability, which is mainly caused by large volume change during charge/discharge processes. Building strong interactions between Sb and electronic conductor is the key to improve electrochemical performance of Sb-based electrode. Hence, Sb nanocrystals were anchored uniformly on reduced graphene oxide (rGO) sheets herein using Sb2O3 as raw material through an ambient reduction followed by heat treatment. The oxygen-containing groups on rGO sheets play different roles on the formation of the composite, including oxidizing Sb into Sb2O3 during the ambient reduction process and boosting the in-situ reduction of Sb2O3 during the heat treatment, resulting in the strong interactions between Sb nanocrystals and rGO sheets. Benefiting from its unique structure, the Sb/rGO electrodes deliver superior cycling stability with over 80% capacity retentions even after 1000 cycles at 2000 mA g−1 for lithium storage and 500 mA g−1 for sodium storage. These findings would shed light on developing a simple method to synthesize functional materials with high structural stability.