Abstract: Three nanosized Co-Sn intermetallic compounds, namely, CoSn2, CoSn, and Co3Sn2, were prepared by solvothermal route and studied as new candidate anode materials for secondary lithium-ion batteries. The as-prepared powders were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM). It was found that these three intermetallic compounds showed a high charge-discharge stability. However, they exhibit low electrochemical activity, especially for Co3Sn2, whose first charge capacity is only 93 mAh•g−1, because Li-ions cannot reach the interior of the crystal due to the low Li-ions diffusion rate.

Key words: Lithium-ion batteries, Anode materials, Solvothermal method, Electrochemical performances