Silver alloying effect on the electrochemical behavior of Si-Zr thin film anodes

To improve the electrochemical performance of Si-Zr thin films, we have investigated the effect of the replacement of Zr by Ag in the films. The Si-Zr-Ag thin films were prepared by co-sputtering from each pure target and then analyzed for structure, composition and electrochemical performance. The Ag-containing films show a plateau like region in the charge-discharge profiles, while the steep slopes are seen in the Si-Zr film. The Si-Zr-Ag films also show high capacity and good rate capability compared to the Si-Zr film, maintaining a comparable capacity retention with cycles. The improved electrochemical performance of Si-Zr-Ag films is attributed to the highly dispersed Si phase in the film, which was induced by formation of Zr-Ag bonds, and the lower impedance exerted by Ag alloying. (c) 2005 Elsevier B.V. All rights reserved.