Mechanochemical synthesis and electrochemical characteristics of Mg2Sn as an anode material for Li-ion batteries

Mg2Sn prepared by mechanochemical process was examined as an alternative an ode material for Li-ion batteries. Electrochemical tests demonstrated that the initial charge and discharge capacity of Mg2Sn was 556 and 460 mAh/g, r espectively. Ex-situ XRD and differential capacity plots showed that lithiu m inserted into the Mg2Sn lattice first followed by alloying with Sn. Contr ary to the isostructural Mg-based intermetallic compound, Mg2Si, alloying r eaction between Li and Mg was not observed during lithiation of Mg2Sn. Mg2S n showed better capacity retention characteristic than that of Mg2Si. It is thought that this may be attributed to that Mg formed at Mg2Sn electrode d id not react with lithium, and also active materials of Mg2Sn electrode cha nged from Mg2Sn to Sri with the increase of cycles. Also Mg2Sn showed impro ved cycle performance under restricted voltage range due to prevention Sn f rom aggregation into larger clusters. (C) 2001 Elsevier Science B.V. All ri ghts reserved.