Li-Si thin films for battery applications produced by ion-beam co-sputtering

Abstract

Amorphous lithium–silicon compounds are promising materials in order to improve pure silicon as a high-capacity anode material in lithium-ion batteries. We demonstrated that it is possible to produce amorphous LixSi (x ~ 0.4) thin films by reactive ion-beam cosputtering of a segmented solid state target composed of metallic lithium and elemental silicon. At the surface a graded LixSiOy layer of some nanometer thickness is formed by contact with air which seems to prevent decomposition of the LixSi.