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).