High-rate, high-density FeSb-TiC-C nanocomposite anodes for lithium-ion batteries

High-density, high-rate FeSb-TiC-C nanocomposite alloy anodes composed of varying amounts of FeSb, TiC, and conductive carbon black have been synthesized by heating the metallic precursors first followed by high-energy mechanical milling (HEMM) of the product with carbon black. The synthesis method allows for a systematic variation of the TiC and carbon contents within the electrode so that the effects of each component on the electrochemical performance can be understood. The FeSb-TiC-C samples display high tap density (2.9 g cm(-3)), high reversible specific capacity (450 mA h g(-1)), superior volumetric capacity (1300 mA h cm(-3)), and high rate capability (89% retention of the C/5 capacity at 10 C rate). However, realizing a cycle life of >500 cycles requires increased contents of carbon and TiC, which lead to a reduction in reversible capacity and tap density. Incorporation of additives, such as fluoroethylene carbonate (FEC) or vinylene carbonate (VC), into the electrolyte provides moderate improvements in cycle life. The FeSb-TiC-C nanocomposite anodes with a high volumetric capacity at a moderate operating voltage offer an attractive alternative to graphite anodes with safety advantages.