3D Porous γ-Fe₂O₃@C nanocomposite as high-performance anode material of Na-ion batteries

A simple and template-free method for preparing three-dimensional (3D) porous γ-Fe₂O₃@C nanocomposite is reported using an aerosol spray pyrolysis technology. The nanocomposite contains inner-connected nanochannels and γ-Fe₂O₃ nanoparticles (5 nm) uniformly embedded in a porous carbon matrix. The size of γ-Fe₂O₃ nanograins and carbon content can be controlled by the concentration of the precursor solution. The unique structure of the 3D porous γ-Fe₂O₃@C nanocomposite offers a synergistic effect to alleviate stress, accommodate large volume change, prevent nanoparticles aggregation, and facilitate the transfer of electrons and electrolyte during prolonged cycling. Consequently, the nanocomposite shows high-rate capability and long-term cyclability when applied as an anode material for Na-ion batteries (SIBs). Due to the simple one-pot synthesis technique and high electrochemical performance, 3D porous γ-Fe₂O₃@C nanocomposites have a great potential as anode materials for rechargeable SIBs. A 3D porous γ-Fe2O3@C nanocomposite, prepared by a simple and template-free aerosol-assisted method and composed of very fine γ-Fe2O3 nanoparticles (5 nm) uniformly embedded in a porous carbon matrix, shows a reversible capacity of 740 mAh g-1 after 200 cycles at 200 mA g-1 and 358 mAh g-1 after 1400 cycles at 2000 mA g-1 when used as the anode material for sodium-ion batteries.