Carbon/Ba–Fe–Si alloy composite as high capacity anode materials for Li-ion batteries

A novel Ba–Fe–Si/C composite was prepared by mechanical ball milling and lithium insertion reactions on the composite electrode were investigated by cyclic voltammetry, charge–discharge measurements, XRD and XPS spectroscopy. It is demonstrated that the composite electrode not only possesses sufficiently high reversible capacity of ca. 420 mA h/g, but also exhibits strong capacity retention with indiscernible capacity decay during charge–discharge cycling. The improved cycling ability of the composite is suggested from a cooperative action by inactive FeSi2 and BaSi2 matrix and outer graphite shell, which both buffer the volumetric changes of the active Si phase and provide a good connection for electronic and ionic conduction during lithium insertion and extraction processes. [Copyright &y& Elsevier]