Electrochemical characterization of γ-Fe2O3 and a reduced graphene oxide composite as a sustainable anode material for Na-ion batteries†

In this paper we report the synthesis and characterization of a γ-Fe₂O₃/reduced graphene oxide composite anode for Na-ion batteries. The nanocomposite anode is synthesized by a facile and green method. Structural and morphological characterization highlights a small γ-Fe₂O₃ particle size and their successful embedding in the carbonaceous matrix. Electrochemical characterization reveals a high specific capacity of ≈300 mA h g⁻¹ at 1000 mA g⁻¹, while at 5 A g⁻¹ a capacity of 113 mA h g⁻¹ is retained. Cyclic voltammetry at different scan rates, impedance spectroscopy, and ex situ Raman measurements evidence a redox pseudocapacitive behavior and full reversibility of the conversion reaction. The green synthesis coupled to the high specific capacity and rate capability make the proposed γ-Fe₂O₃/rGO nanocomposite a very promising candidate anode material for sustainable Na-ion batteries.