To improve the electrochemical performance of Si thin film, we have investigated the effect of the addition of At in the film. The Si-Al thin film were prepared by co-deposition from Si target embedded with At rods on Cu foil. The atomic ratio of Al in the film is 18.69% estimated by energy-dispersive spectroscopy. The XRD and TEM analysis revealed that the Si-Al thin film was a complete amorphous structure. The electrochemical performance of the Si-Al thin film as anode material for lithium ion battery was investigated by the cyclic voltammetry and charge/discharge tests. The Si-Al thin film delivered a high reversible capacity of 2257.8 mAh g(-1) and ail initial Coulombic efficiency of 85.9% at 0.05C rates. Compared with pure Si thin film with the same thickness, Si-Al thin film showed Superior rate capability and cycle performance. And the Li+ diffusion coefficient of Si-Al thin film is much higher than that of Si thin film. (c) 2008 Elsevier Ltd. All rights reserved.