Composite silicon film with connected silicon nanowires for lithium ion batteries

Composite silicon film, which is composed of silicon nanowires, Si–Au eutectic and Si particles as the melding spots, was prepared as anode for lithium ion batteries by a special secondary deposition process with vapor–liquid–solid (VLS) mechanism. Au–Si eutectic particles act as the melding spots between silicon nanowires. An attractive electrochemical performance with 88% of the coulombic efficiency in the first cycle was obtained in the charge–discharge tests. The connection among silicon nanowires by dispersed Si–Au particles is the key factor for the enhancement of its electrochemical reversibility.