Preparation And Electrochemicalp Roperties Of MoS₂@PRGO-Based Composites

At present,TMDCs are one of the most popular research directions in anode electrode materials for lithium-ion batteries.MoS₂,two-dimensional layered structure of S-Mo-S and high active sulfur content,has a higher theoretical capacity of sodium intercalation（670 m Ah/g）than that of graphite anode,which is widely used at present.Meanwhile,sulfur,which has the theoretical specific capacity of 1675 m Ah/g,the battery theory composed of lithium metal has specific energy up to 2600 Wh/g.However,both two anode materials suffer from low conductivity and severe volume expansion during the electrochemical process,which is unfavorable to the performance of cycle and magnification.Graphene with high conductivity and large specific surface area can not only improve the electrochemical performance of graphene-based composites,but also be expected to be applied to the next generation of high power and high energy density batteries.The preparation and electrochemical properties of three-dimensional flower-like MoS₂@PRGO and S/PRGO@MoS₂spherical layered spatial structure composites are studied:（1）MoS₂@PRGO composites were synthesized by a simple hydrothermal method.The PRGO,with a three-dimensional layered spatial framework obtained by controlling the amount of PEO and GO,provides a multidimensional conductive channel for the MoS₂@PRGO composites to enhance the overall conductivity of the composites.Thirdly,flower-like MoS₂were synthesized in PGO by hydrothermal synthesis method.The structure and morphology of the composites were characterized by XRD,XPS,SEM and TEM,which was observed that MoS₂@PRGO composites maintained a good 3D flower-like structure and large surface area.The composite shows a reversible capacity of 1036 m Ah/g after 500 cycles at a current density of 100m A/g.（2）S/PRGO@MoS₂composites were synthesized by situ self-assembly method.PEO connectes not only graphene sheets with molybdenum disulfide but also controling the size of the nanosulfur and relieving the volume expansion of sulfur during discharge.The S/PRGO@MoS₂composites show a reversible capacity of 951m Ah/g after 80 cycles at a current density of 0.2C.