Facile synthesis of Fe3O4@C quantum dots/graphene nanocomposite with enhanced lithium-storage performance

Abstract

Carbon-coated Fe3O4 quantum dots/graphene composite was prepared via a hydrothermal and calcining process. XRD and TEM analysis revealed that carbon-coated Fe3O4 quantum dots with a size around 7–10nm were distributed uniformly on graphene nanosheets. The carbon shell can preserve structural stabilization of Fe3O4 nanoparticles by preventing the aggregation and buffering the volume expansion during charge/discharge processes. In addition, the graphene nanosheets formed a three-dimensional network for the transportation of Li+ ions and electrons. When evaluated as anode material for lithium-ion batteries, the nanocomposite showed an improved lithium-storage performance with high cycling stability and good rate capacity. Furthermore, it exhibited an initial discharge capacity of 1300mAh/g and retained a reversible capacity of about 940mAh/g after 100 cycles at a current density of 150mA/g.