Effect of Si addition to thin-film SnO2 microbattery anodes on cycling performance

Thin-film SnO2 and Si-doped SnO2 microbattery anodes are deposited on a Mo/Si substrate by e-beam evaporator at room temperature. The deposited film are characterized by energy dispersion X-ray spectroscopy (EDS), X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM) atomic force microscopy (AFM), and transmission electron microscopy (TEM). Constant-current galvanostatic charge-discharge tests of half cells are performed. Both the SnO2 film Consist of short-range ordered small grains (nano-scale) and exhibit good ability to and extract Li+ ions. Electrochemical cycling performance is dependent on the cut-off voltage. Tin oxide film anodes which are cycled in the voltage range 0.1-0.8 V show the highest reversible capacity (302 muA h/cm(2) mum for Si-doped film; 200 muA h/cm(2) mum for pure SnO2 film) and the longest cycle-life. Its a papers that Si plays an important role as a glass former element in the Li-Si-O network by suppressing the growth of Sn grains, reducing the surface roughness, and enhancing film adhesion. Thus, Si-doped films are strong candidates for microbattery anodes with improved electrochemical cycling performance. (C) 2001 Elsevier Science B.V. All rights reserved.