Bi2S3-MoS2/石墨烯复合材料的合成及电化学储锂性能

为了研发高性能的锂离子电池负极材料，采用水热法合成了Bi₂S₃-MoS₂/石墨烯复合材料，利用X-射线衍射（XRD）、扫描电镜（SEM）、高分辨透射电镜（HRTEM）、热重分析（TGA）和X-射线光电子能谱（XPS）对复合材料进行表征，讨论复合材料的微观结构对电化学储锂性能的影响. 特别是，当Bi与Mo的物质的量之比为1∶4时，Bi₂S₃-MoS₂/石墨烯的电化学储锂可逆比容量可以达到1 140 mA·h/g，并具有稳定的循环性能. 当充放电电流密度为1 000 mA/g时，其高倍率特性为886 mA·h/g. Bi₂S₃-MoS₂/石墨烯复合材料优异的电化学储锂性能主要由于MoS₂具有更少的层数和较多的边缘以及Bi₂S₃纳米粒子具有更均匀的粒径，并能很好地分散在石墨烯表面，增强了复合材料容纳锂离子的能力，改善了储锂电极过程的动力学性能.

Synthesis of Bi2S3-MoS2/graphene hybrids and their electrochemical lithium storage performances

Bi₂S₃-MoS₂/graphene hybrids was synthesized via a hydrothermal method, and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS) in order to develop high-performance anode materials for lithium ion battery. The effects of microstructure of hybrids on their electrochemical lithium storage properties were analyzed. Especially, the Bi₂S₃-MoS₂/graphene with Bi to Mo of 1∶4 in molar ratio deliver a reversible specific capacity as high as 1 140 mA·h/g with stable cyclic performance. At the current density of 1 000 mA/g, its high-rate capability is 886 mA·h/g. The excellent electrochemical performance can be contributed to that MoS₂nanosheets exhibited few-layer structure with more edges and Bi₂S₃ nanoparticles displayed more uniform sizes. The nanostructured MoS₂ and Bi₂S₃ were well dispersed on graphene surface. The lithium ion accommodation was enhanced, and the electrode kinetics of lithium storage was improved.