纳米SnS/C复合物作为锂电池负极材料的研究

Research for SnS/C nanocomposite as lithium-ion battery anode materials

采用高能球磨法制备了纳米SnS/C复合材料,通过XRD、SEM和TEM等结构和形貌实验表明可以通过高能球磨法直接合成SnS纳米颗粒,并实现碳的均匀包覆。恒流充放电实验显示SnS/C复合材料的可逆比容量为1 107m Ah/g,达到理论比容量的97.4%,基本实现可逆的转化反应和合金化反应。这种材料在800 mA/g的电流密度下仍能达到854 m Ah/g的可逆比容量,显示了高的倍率性能。这些优异的电化学性能主要由于通过电化学还原反应生成的纳米Sn具有高的电化学活性。以及生成物Li2S的隔离作用和导电碳网络的缓冲作用,有利于保持材料结构的稳定和电化学反应的可逆进行。这种高性能纳米SnS/C复合材料为高比能锂离子电池的发展提供了可选体系。

A SnS/C nanocomposite was prepared by simply mechanically bail-milling Sn, S and C powders. The XRD, SEM and TEM results demonstrate that the SnS nanocomposite with carbon coating can be prepared through mechanically ball-milling methods. The SnS/C electrode can deliver a high reversible specific capacity of 1 107 mAh/g with 97.4% of the theoretical capacity, basically realizing the reversible conversion and alloying reaction. Particularly, the composite can demonstrate a reversible specific capacity of 854 mAh/g at the rate of 800 mNg, showing high rate capability. These excellent electrochemical performances attribute to the high electrochemical activity of nano Sn powders produced during the electrochemical reduction reaction, buffer effect of Li2S and conductive carbon, which maintains the structural stability of the composite. Therefore, the SnS/C nanocomposite provides an altemative anode material for the high-energy lithium-ion batteries.