Synthesis and Properties of Si/Ag and Si/Ag/CMS Composites as Anode Materials for Li-ion Batteries

In this study, the structure and electrochemical performance of the binary nanocomposite Si/Ag and the ternary nanocomposite Si/Ag/carbon-microspheres (CMSs) were investigated. The microstructure and the phase components of the composites were characterized via TEM and XRD, respectively. The electrochemical behaviour of the samples was studied using a galvanostatic charge/discharge test, electrochemical impedance spectroscopy and cyclic voltammetry. The results indicate that Ag nanoparticles are distributed in the form of crystalline particles on the surface of the Si particles for ternary nanocomposite Si/Ag/CMSs and that a layer of CMSs coats the surface of the Si/Ag particles. Electrochemical measurements demonstrate that compared with the binary nanocomposite Si/Ag, the anode material made from the ternary nanocomposite Si/Ag/CMSs exhibited a lower electrochemical resistance, a weaker polarization and a significantly improved reversibility and cycling life. The reversible capacity of the electrochemical reaction was maintained at 395.1 mAhg(- 1) after 50 cycles.