Carbon-coated copper-tin alloy anode material for lithium ion batteries

Carbon-coated copper-tin alloy powders were prepared by heating of mixtures of thermoplastic poly(vinyl alcohol) and nano-sized copper-tin alloy particles in argon atmosphere. The products were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The electrochemical properties of the carbon-coated copper-tin alloy powders as anode materials for lithium batteries were studied by cyclic voltammetry (CV) and galvanostatic method. The anode showed high charge capacity up to 460 mAh g(-1) and stable cyclic performance even after 40 cycles. This could be ascribed to the existence of inactive matrix Cu which buffered the large volume change in the course of Li-Sn alloying-dealloying process, and the presence of carbon layer of alloy particles which enhanced dimensional stability during Li-Sn alloying-dealloying electrochemical process. (C) 2009 Published by Elsevier B.V.