Al–Si Thin-Film Negative Electrodes for Li-Ion Batteries

Thin-film Al 1 − x Si x ( 0 < x < 1 ) libraries were characterized for structure, composition, and electrochemical performance using combinatorial and high-throughput techniques. The electrochemical performance of a given composition of Al 1 − x Si x cannot be treated as a simple combination of separate reactions of Li with Al and Si because ternary Al–Li–Si phases are present for some compositions and have a significant influence on observed capacities and capacity retention. Al 0.25 Si 0.75 or Al 20 Si 0.80 appear to be very promising compositions of Al 1 − x Si x for Li-ion negative electrode applications.