纳米Co-Sn金属间化合物的合成、表征及电化学吸放锂行为

用溶剂热法合成了三种纳米尺寸的Co-Sn金属间化合物, 即CoSn2、CoSn和Co3Sn2, 并研究了它们作为锂离子二次电池新型负极材料的电化学性能. 合成的粉末经过了X射线衍射(XRD), 透射电镜(TEM)和场发射扫描电镜(FESEM)的表征. 研究发现, 这三种金属间化合物均显示出较高的充放电稳定性. 由于低的锂离子扩散速率, 在嵌锂过程中锂离子不能深入到晶粒内部, 导致它们的电化学活性较低, 尤其是Co3Sn2, 其首次充电容量仅为 93 mAh?g?1.

Preparation, Characterization and Electrochemical Li-absorption/extraction Behaviors of Nanosized Co-Sn Intermetallic Compounds

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.