Sb-MO_x-C (M = Al, Ti, or Mo) Nanocomposite Anodes for Lithium-Ion Batteries

Sb-MO x -C (M = Al, Ti, and Mo) nanocomposites have been synthesized by a mechanochemical reduction of Sb 2 O 3 with, respectively, Al, Ti, and Mo, in the presence of carbon (acetylene black). X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and scanning transmission electron microscopy (STEM) data reveal that these nanocomposites are composed of uniformly dispersed nanostructured antimony in the amorphous Al 2 O 3, TiO 2, or MoO 3 matrix, along with conductive carbon. These composite electrodes exhibit excellent electrochemical cycling performance and rate capability in lithium cells, compared to pure antimony. Among the three Sb-MO x -C systems studied, the M = Al system with Al 2 O 3 as the amorphous phase exhibits the best electrochemical performance, offering a capacity of >430 mAh/g after 100 cycles. The improvement in the cycling performance, compared to that of pure antimony, is attributed to a homogeneous distribution of the electrochemically active Sb nanoparticles within the ceramic oxide and conductive carbon matrix, resulting in good electrical contact with the current collector, as well as a mechanical buffering effect on the volume expansion−contraction that occurs during cycling.