Nanostructured Sn–Ti–C composite anodes for lithium ion batteries

Abstract

Nanostructured Sn–Ti–C composites have been synthesized by a facile, inexpensive high energy mechanical milling process and investigated as an anode material for lithium-ion cells. Characterization data collected with X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) reveal an uniform dispersion of Sn nanoparticles within the conductive, amorphous (or poorly crystalline) TiC + C matrix. Among the three Sn–Ti–C compositions investigated, the Sn 11Ti 31C 58 composite exhibits the best electrochemical performance, with a capacity of ∼370 mAh/g and excellent capacity retention over 300 cycles studied. It also exhibits excellent cycle life with LiMn 2O 4 spinel cathode, suggesting a tolerance of the Sn–Ti–C anodes toward poisoning by the manganese leached out from the spinel cathode. The superior electrochemical performance of Sn 11Ti 31C 58 composite is attributed to a homogeneous distribution of the electrochemically active amorphous Sn, suppression of Sn grain growth, and the mechanical buffering effect provided by the conductive TiC + C matrix toward the volume expansion-contraction occurring during cycling.