Nanostructured SnSb/MOx (M = Al or Mg)/C composites: hybrid mechanochemical synthesis and excellent Li storage performances

Abstract

A simple, inexpensive, fast, and scalable method of transforming micron-sized metal oxides into new intermetallic compound nanocomposites by a hybrid mechanochemical synthesis using a high-energy mechanical milling technique was developed. The SnSb/MO_x (M = Al or Mg)/C nanocomposites, synthesized by the mechanochemical reduction of SnO and Sb₂O₃ with Al or Mg, respectively, in the presence of carbon, were confirmed, by using various analytical techniques, to be composed of extremely small SnSb nanocrystallites, amorphous Al₂O₃ or nanocrystalline MgO, and amorphous carbon. Among the fabricated nanocomposites, the SnSb/MgO/C nanocomposite showed excellent electrochemical properties, such as a high energy density (1st charge: 572 mA h g⁻¹ or ca. 3800 mA h cm⁻³), cycling durability (above 490 mA h g⁻¹ or ca. 3300 mA h cm⁻³ over 150 cycles), good initial coulombic efficiency (ca. 81.3%), and a fast rate capability (1C: 480 mA h g⁻¹, 3C: 420 mA h g⁻¹). These excellent electrochemical properties demonstrated by the SnSb-based nanocomposite electrodes confirmed their potential as alternative anode materials for Li-ion batteries.