Si–Zr alloy thin-film anodes for microbatteries

Zr–Si thin films were deposited on copper substrates by co-sputtering method of two pure targets. The structure and surface morphology of the films have been characterized by X-ray diffraction (XRD) and atomic force microscopy (AFM). The composition was measured by Rutherford backscattering spectroscopy (RBS) and energy-dispersive X-ray spectroscopy (EDS). The electrochemical results showed that alloying with Zr improves the cycling performance, while as a result the reversible capacity decreases. It appears that the electrochemical cycling performance can be further improved by controlling the film deposition conditions such as substrate temperature and bias sputtering.