Enhanced electrochemical properties of nanostructured bismuth-based composites for rechargeable lithium batteries

Nanostructured Bi/C and Bi/Al2O3/C composites, prepared by high-energy mechanical milling (HEMM), are investigated as anode materials for Li-ion rechargeable batteries. X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) reveal that the Bi/C nanocomposite is composed of nano-sized Bi and amorphous C, while the Bi/Al2O3/C nanocomposite (obtained by the mechanochemical reduction of Bi2O3 and Al) is composed of nano-sized Bi, amorphous Al2O3, and amorphous C. The electrochemical reaction mechanism of the Bi/C nanocomposite electrode is identified by ex situ XRD analyses combined with a differential capacity plot. Electrochemical tests show that the Bi/C and Bi/Al2O3/C nanocomposites exhibit enhanced electrochemical performances compared with that of the pure Bi electrode.