Structural and electrochemical evaluation of a Si film electrode fabricated on a Ni buffer layer

Abstract

Si and Si/Ni thin film electrodes less than 1 mu m in total thickness were fabricated on the roughened Cu substrate by rf sputtering. Their surface morphology and crystalline structure were carefully investigated by means of FESEM and XRD. The morphology of films is dependent on the surface feature of substrate, and the grown films were amorphous. The initial capacity and the irreversible capacity loss of a Li/Si film cell were improved with insertion of a Ni buffer layer. The effect of the film morphology on the electrochemical properties of cells was demonstrated based on the observations of film electrodes.