Facile Synthesis of a MoS₂ and Functionalized Graphene Heterostructure for Enhanced Lithium-Storage Performance

A facile strategy was designed for the in situ synthesis of MoS₂ nanospheres on functionalized graphene nanoplates (MoS₂@f-graphene) for use as lithium-ion battery anode materials. A modified Birch reduction was used to exfoliate graphite into few-layer graphene followed by modification with functional groups. Compared to the most common approach of mixing MoS₂ and reduced graphene oxide, our approach provides a way to circumvent the harsh oxidation and destruction of the carbon basal planes. In this process, alkylcarboxyl functional groups on the functionalized graphene (f-graphene) serve as sites where MoS₂ nanospheres crystallize, and thus create bridges between the MoS₂ nanospheres and the graphene layers to effectively facilitate electronic transport and to avoid both the aggregation of MoS₂ and the restacking of graphene. As anode materials, this unique MoS₂@f-graphene heterostructure has a high specific capacity of 1173 mAh g^-1 at a current density of 100 mA g^-1 and a good rate capacity (910 mAh g^-1 at 1600 mA g^-1).