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

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 Si0.41Ge0.34Mo0.25 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 LiCoO2 cathode, the Si0.55Ge0.22Mo0.23 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.

► Cycle performance of Si–Ge–Mo film electrode/ LiPf6 EC-DEC/Li-metal cell. ► Impedance results of the six Si–Ge–Mo electrodes. ► Effects of ternary elements of the Si–Ge–Mo on electrochemical performance. ► SEM images of surface of Si–Ge–Mo anode after 50 cycle test.