碳钠米管-Sn_2Sb纳米复合材料的电化学吸放锂性能

Electrochemical intercalation of lithium in carbon nanotubes-Sn_2Sb nanocomposites used as anode of lithium lion batteries

用化学还原的方法制备了碳钠米管-Sn2Sb合金的纳米复合材料.SEM和TEM观察结果表明,Sn-Sb合金纳米粒子均匀地分布在碳钠米管的网络中,部分合金包覆在碳钠米管的表面.充放电试验结果显示,碳钠米管-Sn2Sb合金纳米复合材料具有良好的电化学吸放锂性能,其可逆容量显著大于碳钠米管,而循环稳定性优于Sn-Sb合金.这种循环性能的改善主要是由于碳钠米管改善了电过程中电极结构的稳定性.

Nanocomposites of carbon nanotubes-Sn_2Sb alloy were prepared by chemical reduction using KBH_4 as reducing agent. TEM imaging showed that most of the Sn-Sb alloy nanoparticles were uniformly dispersed in the CNT web, whereas some Sn-Sb alloy was coated on the outside surface of CNTs. Electrochemical experiments demonstrated that the nanoicomposites exhibited improved cyclability compared to unsupported Sn-Sb alloy and higher reversible specific capacities than CNTs. The improved cyclability may be attributed to the existence of CNTs, which improve the structural stability of electrode materials during charge/discharge cycling.