Sb2Te3-TiC-C nanocomposites for the high-performance anode in lithium-ion batteries

Abstract

A nanocomposite comprised of a bimetallic alloy of antimony (III) telluride embedded in a hybrid matrix of titanium carbide with amorphous carbon is synthesized via facile, scalable, and inexpensive high energy mechanical milling. The Sb2Te3-TiC-C nanocomposite is composed of nanosized Sb2Te3 and TiC particles homogeneously dispersed in amorphous carbon, as characterized by X-ray diffraction and high-resolution transmission electron microscopy. Electrochemical measurements show that the Sb2Te3-TiC-C exhibits enhanced electrochemical reversibility, great cyclability, and high-rate capability compared to Sb2Te3-C and Sb2Te3. Additionally, the optimum TiC content is determined based on electrochemical performances. Among all Sb2Te3-TiC-C nanocomposites tested, Sb2Te3-TiC(30%)-C exhibits the best performances in terms of reversible volumetric capacity (463 mAh cm(-3) over 600 cycles, 80% retention) and high rate capability (5000 mA g(-1), 80% of its capacity at 100 mA g(-1)). The improvement of electrochemical performance with optimal TiC content is attributed to the appropriate amount of TiC-C that acted as a mechanical buffer and highly conductive matrix during cycling while minimizing capacity sacrifices. The mechanism of lithium ion storage on Sb and Te in Sb2Te3-TiC-C is also investigated during the charge/discharge process. (c) 2018 Elsevier Ltd. All rights reserved.