The Effect of TiO2 on the Electrochemical Performance of Sb2O3 Anodes for Li-Ion Batteries

Abstract

Antimony (Sb) and its composites have been recognized as potentially good anode materials for lithium-ion batteries (LIBs) due to their relatively high theoretical capacity of 660 mAh g−1 and to their low cost. However, Sb-based anodes suffer from a high-volume change during the lithiation/delithiation process that results in capacity fading and anode degradation after prolonged charge/discharge cycles. To address this issue, Sb2O3/TiO2 nanocomposite electrodes can be synthesized and used as anodes for LIBs with high capacity and good electrochemical stability. In the present work, TiO2@Sb2O3 composites with different (TiO2:Sb2O3) ratios of 0:1, 1:1, 1:4 and 3:1 were synthesized and directly used as anode materials for LIBs. The electrochemical performance of the TiO2/Sb2O3 composite anode with different ratios of TiO2 to Sb2O3 was evaluated by galvanostatic charge/discharge, rate performance and cyclic voltammetry. The 3:1 (TiO2:Sb2O3) composite anode delivered the highest capacity compared to those of the TiO2, SbO3, 1:1 (TiO2:Sb2O3) and 1:4 (TiO2:Sb2O3) electrodes. The TiO2@Sb2O3 composite anode with a 3:1 ratio exhibited a stabilized capacity of 536 mAh g−1 after 100 cycles at 100 mA g−1 and showed excellent rate performance, with current densities between 50 and 500 mA g−1. The improved electrochemical performance was attributed to the synergistic effect of TiO2 (i.e., the coating of Sb2O3 with TiO2) on reducing the volume change of the Sb anode material after prolonged charge/discharge cycles and on maintaining a stable interface between the electrolyte and the composite electrode material.