Abstract: Nano-level Sn-Ni alloy thin-film electrode materials prepared by magnetic sputtering technology are characterized with X-ray diffraction (XRD), atom force microscopy (AFM) and scanning electron microscopy (SEM). The charge/discharge and cyclic voltammograms (CV) of the films electrodes are tested by the battery testing system of high precision. The results indicate that the materials prepared by direct current (DC) and radio frequency (RF) methods differ greatly in their performance. Ni₃Sn₂ alloy phase constitutes the main components prepared by DC method, the particles on the surface are tiny and show steady cycling performance, the deficiency is that they have low initial efficiency and small discharge capacity of 72 % and 108 mA.h/g, respectively. Contrary to the former, Ni₃Sn₄ alloy phase constitutes the main components prepared by RF method, the particles on the surface appear comparatively larger, their discharge capacity did not decline in the first 15 times, keeping above 500 mA·h/g, but began to decline after 15 times.

Key words: Lithium ion battery, Sn-Ni alloy, Electrochemical property