Thin-Film Cu[sub 6]Sn[sub 5] Electrodes: Synthesis, Properties, and Current Collector Interactions

Thin-film anodes were created using a radio frequency magnetron sputtering technique. Several films were studied demonstrating different compositional variables, namely, as-deposited, nanocrystalline on stainless steel, annealed on stainless steel, and film electrodes. The annealed films showed enhanced grain growth compared to the as-deposited samples, were found to have higher crystallinity, and exhibited a lower lithium cycling capacity than the nanocrystalline samples. Films incorporating a Pt underlayer between the current collector and the film were evaluated and showed a higher cycling capacity than the annealed samples or typical bulk laminates. Understanding the interaction between the interlayer and the displaced copper is postulated to be an important variable in extending cycle life.