SiO2-assisted synthesis of layered MoS2/reduced graphene oxide intercalation composites as high performance anode materials for Li-ion batteries

Abstract

Layered MoS₂/reduced graphene oxide (MoS₂/rGO) intercalation composites are synthesized via a SiO₂-assisted hydrothermal method. This strategy discards addition of any amorphous carbon precursor for the synthesis of intercalation composites, and may reduce the defect degree and irreversible lithium storage sites in the final products. The structure and morphology characterization of the layered MoS₂/rGO intercalation composites shows that the MoS₂ composed of single layer or 2–4 layers display a highly exfoliated structure and disperse on the surface of graphene homogeneously and tightly, some of the interlayer spacing of MoS₂ are enlarged, ranging from 0.7 to 1.17 nm with the intercalation of graphene. Electrochemical tests demonstrate that the MoS₂/rGO-0.5 delivers a high reversible capacity of 1260.5 mA h g⁻¹ in the initial cycle and retains 94.9% capacity after 50 cycles at 100 mA g⁻¹. Furthermore, the capacity can reach 988.3 mA h g⁻¹ even at a high current density of 1000 mA g⁻¹. The excellent electrochemical performance of the MoS₂/rGO intercalation composite could be attributed to the excellent match between the structure and morphology of layered MoS₂ and graphene and the partial electron transfer from graphene to MoS₂, which would maximize the synergistic interaction of the MoS₂/rGO composite for reversible lithium storage.