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 × 10−8 cm2/s by linear sweep voltammetry. The film electrode with high Al 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.