Electrochemical Properties of Si Film Electrodes Containing TiNi Thin-Film Current Collectors

Abstract

A 50.3Ti-49.7Ni thin film fabricated by DC sputtering was employed as a current collector of Si film electrode. The structural and electrochemical properties of Si/TiNi film electrode were compared with those of a Si/Cu film electrode. The TiNi film with cluster-like structures composed of B2 austenitic phase at room temperature displayed the high electrochemical stability for Li ions. The amorphous Si film deposited on the TiNi film also consisted of cluster-like structures on the surface. The Si film grown on the TiNi film current collector (Si/TiNi electrode) demonstrated a high columbic efficiency of 87% at the first cycle (363 mu Ah/cm(2) of charge capacity and 314 mu Ah/cm(2) of discharge capacity). The Si/TiNi electrode exhibited better electrochemical properties in terms of capacity, cycle performance, and structural stability compared to the Si electrode with a conventional Cu foil current collector.