Sn-Sb and Sn-Bi Alloys as Anode Materials for Lithium-Ion Batteries

Sn/SnSb, Sn/Bi, and Sn/SnSb/Bi multi-phase materials were synthesised via reduction of cationic precursors with NaBH(4) and with Zn, and were tested for their suitability as anode materials for Li-ion batteries by galvanostatic cycling. The rapid reduction with NaBH(4) yielded the finer materials with the better cycling stabilities, whereas the reduction with Zn yielded the purer materials with the lower irreversible capacities in the first cycle. Reversible capacities of similar to 600 mAh g(-1), similar to 350 - 400 mAh g(-1), and similar to 500 mAh g(-1) were obtained for Sn/SnSb, Sn/Bi, and Sn/SnSb/Bi, respectively. The cycling stability of the materials decreased in the order Sn/SnSb > Sn/SnSb/Bi > Sn/Bi, which is in part attributed to the presence / absence of intermetallic phases which undergo phase-separation during lithiation.