Facile synthesis of sulfur coated SnO2–graphene nanocomposites for enhanced lithium ion storage

A simple and low temperature hydrothermal synthesis approach has been developed to prepare sulfur coated SnO2–graphene nanocomposites as an anode material for lithium–ion batteries. The electrochemical performance of the composites was characterized by galvanostatic charge–discharge tests, cyclic voltammetry and electrochemical impedance spectroscopy measurements. Results show that the composite material exhibits a reversible capacity of 819 mAh g−1 after 200 cycles at 500 mA g−1 and an excellent rate capability of 580 mAh g−1 at a high current density of 4000 mA g−1. The extraordinary performance could be ascribed to the positive synergistic effect of the combination of the nanosized particles of SnO2, the excellent conductivity of graphene and the effects of the coating layer of sulfur.

► Sulfur coated SnO2–graphene were synthesized through hydrothermal method.
► The addition of sulfur prevents the agglomeration of SnO2 particles.
► The composites exhibit a high reversible capacity of 819 mAh g−1 after 200 cycles.
► The synergistic effect enhances electrochemical performance of SnO2–graphene.