Investigation of immiscible alloy system of Al-Sn thin films as anodes for lithium ion batteries

The Al-Sn, which is immiscible alloy, film was prepared by e-beam deposition to explore the possibility as anode material for lithium ion batteries for the first time. The film has a complex structure with tiny Sn particles dispersed homogeneously in the Al active matrix. The diffusion coefficients of Li+ in these Al-Sn alloy films were determined to be 2.1-3.2 x 10(-8) cm(2)/s by linear sweep voltammetry. The film electrode with high All content (Al-33wt%Sn) delivered a high initial discharge capacity of 972.8 mA h g(-1), while the film electrode with high Sn content (Al-64wt%Sn) with an initial discharge capacity of 552 mA h g(-1) showed good cycle performance indicated by retaining a capacity of about 381 mA h g(-1) after 60 cycles. Our preliminary results demonstrate that Al-Sn immiscible alloy is a potential candidate for anodic material of lithium ion batteries. (C) 2008 Elsevier B.V. All rights reserved.