FeSb₂-Al₂O₃-C nanocomposite anodes for lithium-ion batteries

FeSb2-Al2O3-C nanocomposite synthesized by ambient-temperature high-energy mechanical milling (HEMM) of Sb2O3, Fe, Al, and C has been investigated as an anode material for lithium-ion batteries. The FeSb2-Al2O3-C nanocomposites are characterized with X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM). The characterization data reveal it to be composed of crystalline FeSb2 nanoparticles finely dispersed in an amorphous matrix of Al2O3 and carbon. The FeSb2-Al2O3-C nanocomposite exhibits an initial discharge (lithiation) capacity of 877 mAh g(-1) and an initial charge (delithiation) capacity of 547 mAh g(-1), yielding an initial coulombic efficiency of 62%. The extended cycling performance for this composite is far superior to that of the intermetallic FeSb2 or a similarly prepared FeSb2-C composite. FeSb2-Al2O3-C retains a specific capacity of ∼350 mAh g(-1) after 500 lithiation/delithiation cycles.