SnS2/reduced graphene oxide nanocomposites with superior lithium storage performance

Abstract

A facile one-step hydrothermal route was developed to prepare SnS2/reduced graphene oxide nanocomposites (TSG) with hexagonal SnS2 nanoplates and ultrafine nanocrystals grown and distributed uniformly on the graphene nanosheets. The lateral size and thickness of the nanoplates laid on the graphene sheets with a preferential c-axis were about 140nm and 25nm, whereas the average size of the nanocrystals was about 6nm. Electrochemical Li-ion storage performance of the TSG nanocomposites was investigated by using cyclic voltammetry, galvanostatical charge-discharge, and electrochemical impedance spectroscopy. The results showed that the TSG electrode exhibited exceptional high reversible capacity with good cycling stability (1005 mAh g-1 after 200 cycles at the current density of 100mA g-1), and extraordinary rate capability (612 mAh g-1 at the rate of 2000mA g-1). The superior performance could be attributed to the large available surface area, high conductivity and fast transportation of electrons and Li ions, which were benefited from the unique structure of the material and the synergistic effect between SnS2 and graphene.