Electrochemical properties of Si-Ge-Mo anode composite materials prepared by magnetron sputtering for lithium ion batteries

Abstract

Si-Ge-Mo composites are prepared using an RF/DC magnetron sputtering method, and their potential use as anode materials for rechargeable lithium-ion batteries is investigated. The Si-Ge-Mo composite films present an amorphous structure. The reaction mechanism of the Si-Ge-Mo with Li is investigated by various analytical techniques. The fabricated Si(0.41) Ge(0.34)Mo(0.25) composite film shows excellent electrochemical properties, including a high energy density (1st charge: 1193 mAh g(-1)), long cycleability (ca. 870 mAh g(-1) over 100 cycles), and good initial Coulombic efficiency (ca. 96%). Additionally, when coupled with a LiCoO(2) cathode, the Si(0.55)Ge(0.22)Mo(0.23) composite electrode used as an anode shows excellent cycleability with a high energy density. The excellent electrochemical properties demonstrated by the Si-Ge-Mo composite film electrode confirm its potential as an alternative anode material for lithium-ion batteries. (C) 2011 Elsevier Ltd. All rights reserved.