Copper-Antimony-Based Alloy Nanocomposites as Anodes for Lithium-Ion Batteries: Effects of Heat Treatment and Mass Loading

Abstract

Copper-antimony-based alloy nanocomposites were synthesized by high-energy ball milling (HEBM) and evaluated as anode materials for lithium-ion batteries. The reduction of Sb2O3 with metallic Cu and Al and addition of carbon sources (Super P or acetylene black) during the HEBM process led to the formation of Cu2Sb-Al2O3-C nanocomposites. Their novel nanostructure was determined by X-ray diffraction and transmission electron microscopy. The as-prepared composites comprised crystalline Cu2Sb nanoparticles dispersed in amorphous Al2O3 and a carbon matrix, which is capable of accommodating large volume changes during battery cycling, resulting in good electrochemical performance. Furthermore, the introduction of a heat treatment step decreased irreversible capacity loss in the first cycle, which increased the initial coulombic efficiency from 68% to 76%, and led to improved electrochemical performance of the electrodes, Finally, the effect of the mass loading of the active material on the electrochemical performance was evaluated, revealing that high mass loading of the active material leads to gradual capacity decay.