Si–Ni alloy–graphite composite synthesized by arc-melting and high-energy mechanical milling for use as an anode in lithium-ion batteries

A Si–Ni alloy and graphite composite is synthesized by arc-melting followed by high-energy mechanical milling. The alloy particles consist of an electrochemically active silicon phase with inactive phases such as NiSi2 and NiSi distributed uniformly on the surface of the graphite. The inactive phases can accommodate the large volume changes of Si during cycling of the composite as an anode material for lithium batteries. The cycle-life of the composite increases with increase in Si content. A large reversible capacity (about 800 mAh g−1) and good cycleability suggest that the composite may prove to be an alternative to conventional graphite-based anode materials for lithium-ion secondary batteries.