Graphene-Assisted Exfoliation of Molybdenum Disulfide to Fabricate 2D Heterostructure for Enhancing Lithium Storage

Graphene-molybdenum sulfide composite materials are attracting considerable interest as a promising candidate of anode for lithium-ion batteries because of their excellent electrical properties. However, few studies have been conducted on the lithium-storage mechanism and process of dynamics of these materials. In this work, the lithium-storage mechanism of these materials is examined by structural characterization and kinetic analysis. Structural characterization results show that the prepared G/MoS2 is a heterostructure and contains C-S bonds after treatment with a novel layered graphene oxide-assisted ultrasonic method. The existence of C-S bond benefits the transport of lithium ion and electrons and enhances the electro-chemical properties of G/MoS2 electrode. Kinetic analysis further reveals that the lithium-ion diffusion effect plays a major role in charge and discharge processes. This synthesis method and analysis strategy may also apply to other composite materials for high-performance lithium-ion storage.