Journal of the Korean Physical Society

pISSN 0374-4884 eISSN 1976-8524

Article

Application and Devices

Published online September 15, 2006    

Copyright © The Korean Physical Society.

Electrochemical Properties of Aluminum-Doped Silicon Films as Anode Materials for Lithium-Ion Batteries

Young-Jae Kim, Myung-Hoon Kim, Jae-Hun Yang and Jong-Wan Park

J. Korean Phys. Soc. 49(3), 1196 (2006)

Abstract

In search of new non-carbonaceous materials for lithium-ion batteries, silicon has been tested as a possible candidate. In order to examine the intrinsic properties of this metal versus a lithium electrode at 298 K, we deposited silicon thin film by using a radio-frequency magnetron sputtering system. And then, we analyzed physical and electrochemical properties of the thin films. Discharge capacities of about 1700 mAhg$^{-1}$ were measured for films with thicknesses ranging from 2 to 4 $mu$m. These discharge capacities were due to the formation of amorphous Li-Si alloys, as was indicated by X-ray diffraction analysis. The alloy films had huge stresses caused by volume changes during cycling. After a few cycles, the silicon films lost their discharge capacities whereas aluminum-doped silicon films maintained their discharge capacities because the films could endure the stress in lithiation and delithiation. Aluminum as a doping material helped silicon retain its discharge capacity and overcome volume expansion in cycling. Aluminum-doped silicon appears to be a good material for a negative electrode for lithium-ion batteries.