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

Abstract

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 819mAhg−1 after 200 cycles at 500mAg−1 and an excellent rate capability of 580mAhg−1 at a high current density of 4000mAg−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.