花瓣状微球MoS_2/石墨烯复合材料的制备及其电化学性能

Synthesis and Electrochemical Properties of MoS_2/Graphene Composites with Petal-Shaped Microspheres

采用有利于二维层状结构形成的L-半胱氨酸作为硫源,钼酸钠作为钼源,制备聚乙烯基吡咯烷酮(PVP)辅助水热合成花瓣状微球形貌的MoS2/还原氧化石墨烯复合电极材料(PVP-MoS2/RGO).X射线衍射(XRD)及透射电子显微镜(TEM)证实,经过PVP的适量添加,MoS2有序堆垛结构的片层数目明显减少.扫描电子显微镜(SEM)显示,添加适量PVP的MoS2/石墨烯材料具有分散性更好的花瓣状微球形貌.上述的少层有序堆垛结构及复合材料的良好分散性缩短了MoS2中锂离子的嵌入/脱出路径,使其具有更高的容量、循环稳定性和倍率性能.

MoS2/graphene composites were synthesized using L-cysteine and sodium molybdate as the sources of sulfur and molybdenum, and L-cysteine was found to be beneficial for two-dimensional layered structure formation. Polyvinylpyrrolidone （PVP）-assisted hydrothermal synthesis gave petal-shaped MoS2/ reduction of graphene oxide （RGO） composite electrode materials （PVP-MoS2/RGO）. X-ray diffraction and transmission electron microscopy confirmed that MoS2 changed to a less ordered layer structure from the multi- layer stacking structure after moderate addition of PVP. Scanning electron microscopy showed that the moderate PVP-assisted MoS2/RGO material had a petal-shaped microsphere morphology with good dispersion. The ordered stacking structure with less layers and good dispersion of the composite materials shorten the embedded in/out path of lithium ions in MoS2, which obviously improved their capacity, cycle stability, and rate performance as lithium ion battery anode materials.