Efficient reduced graphene oxide grafted porous Fe3O4 composite as a high performance anode material for Li-ion batteries

Abstract

Here, we report facile fabrication of Fe₃O₄–reduced graphene oxide (Fe₃O₄–RGO) composite by a novel approach, i.e., microwave assisted combustion synthesis of porous Fe₃O₄ particles followed by decoration of Fe₃O₄ by RGO. The characterization studies of Fe₃O₄–RGO composite demonstrate formation of face centered cubic hexagonal crystalline Fe₃O₄, and homogeneous grafting of Fe₃O₄ particles by RGO. The nitrogen adsorption–desorption isotherm shows presence of a porous structure with a surface area and a pore volume of 81.67 m² g⁻¹, and 0.106 cm³ g⁻¹ respectively. Raman spectroscopic studies of Fe₃O₄–RGO composite confirm the existence of graphitic carbon. Electrochemical studies reveal that the composite exhibits high reversible Li-ion storage capacity with enhanced cycle life and high coulombic efficiency. The Fe₃O₄–RGO composite showed a reversible capacity ∼612, 543, and ∼446 mA h g⁻¹ at current rates of 1 C, 3 C and 5 C, respectively, with a coulombic efficiency of 98% after 50 cycles, which is higher than graphite, and Fe₃O₄–carbon composite. The cyclic voltammetry experiment reveals the irreversible and reversible Li-ion storage in Fe₃O₄–RGO composite during the starting and subsequent cycles. The results emphasize the importance of our strategy which exhibited promising electrochemical performance in terms of high capacity retention and good cycling stability. The synergistic properties, (i) improved ionic diffusion by porous Fe₃O₄ particles with a high surface area and pore volume, and (ii) increased electronic conductivity by RGO grafting attributed to the excellent electrochemical performance of Fe₃O₄, which make this material attractive to use as anode materials for lithium ion storage.