One-pot solvothermal synthesis of ZnFe2O4 nanospheres/graphene composites with improved lithium-storage performance

Abstract We report a facile one-pot solvothermal route for synthesizing ZnFe 2 O 4 /graphene nanocomposites. XRD, SEM and TEM results demonstrate that ZnFe 2 O 4 nanospheres with a size of about 100–200 nm are uniformly dispersed on graphene nanosheets. Each ZnFe 2 O 4 nanosphere is assembled by many nanoparticles around 10 nm. When evaluated as anode for Li-ion batteries, ZnFe 2 O 4 /graphene nanocomposites deliver a first discharge capacity of 1400 mAh g −1 and remain a reversible capacity up to 704.2 mAh g −1 after 50 cycles. ZnFe 2 O 4 /graphene nanocomposites also exhibit ameliorative rate capacity of 271.8 mAh g −1 at the current of 800 mA g −1 , which can recover to 814 mAh g −1 when the current density is reduced back to 100 mA g −1 . The enhanced electrochemical performances of the nanocomposites are ascribed to the confining and conducting effects of graphene and the synergistic effects between the conductive graphene and ZnFe 2 O 4 nanospheres.