Fe3O4 nanoflakes-RGO composites: A high rate anode material for lithium-ion batteries.

• Morphology transition contributes to a perfect synergistic effect. • RGO enhances conductivity, rate capacity and cycling stability of composite. • Novel-innovative synthetic route decreases the energy consumption. • FeCO 3 and Fe 3 O 4 -RGO perform LIBs anodes improving product utilization. • Fe 3 O 4 -RGO exhibits a satisfied capacity of 925.3 mAh g−1 and 68.8% retention. In this paper, broccoli-like multichannel FeCO 3 microspheres were synthesized via one-pot hydrothermal process at low temperature. Then, a successful phase and morphology transformation from FeCO 3 to Fe 3 O 4 was realized to form the Fe 3 O 4 -RGO composites via a low temperature hydrolysis reaction in the presence of graphene and hydrazine. The multichannel structure of FeCO 3 microspheres benefits for the permeation of alkaline solution, improves the dispersion of Fe2+ and further makes Fe 3 O 4 homogeneously anchored on RGO sheets. Therefore, the Fe 3 O 4 -RGO composites show a satisfied property of 925.3 mAh g−1 at 100 mA g−1. Moreover, this anode material still delivers capacity of 636.1 mAh g−1 after 1000 cycles at 500 mA g−1. This work provides a new route for synthesizing metal oxide and their composites, which will find potential application in the field of energy storage. [ABSTRACT FROM AUTHOR]