The Preparation And Electrochemical Properties Of Molybdenum Disulfide Composites

Supercapacitors are a kind of clean energy storage device that has emerged in recent years.Because of its remarkable advantages such as less charging time,high power density and good cycle life,it is bound to become the first choice for energy storage devices in various fields in the future.The electrode material is the"heart"of the supercapacitor and plays a decisive role in the performance of the supercapacitor.Molybdenum disulfide,as a newcomer to electrode materials,has been pushed to the forefront by researchers because of its layered structure resembling graphene.However,the disadvantages of molybdenum disulfide itself,such as easy agglomeration and poor stability,seriously hinder the molybdenum disulfide becoming an ideal electrode material.By combining with other electrode materials,the preparation of composite materials with different morphologies is an effective way to promote the avoidance of molybdenum disulfide.1.We have proposed a sea urchin-like hollow MoS₂/PANI composite material by hydrothermal and in-situ polymerization.The hollow molybdenum disulfide-polyaniline microspheres have a particle size of 1³?m and a specific surface area of 39.2 m²/g,mainly composed of sheet-like molybdenum disulfide and rod-shaped polyaniline exposed to?100?and?110?crystal faces.The melamine resin was used as a template to form molybdenum disulfide microspheres,and the template was removed by calcination,and then the in-situ polymerization of aniline was carried out to obtain a hollow structure microsphere composite.The hollow structure increases the specific surface area of the composite material and increases the transport rate of ions during charge and discharge,so that it can maintain a high capacitance during charge and discharge at high current density.A series of characterization results of SEM,TEM,XPS and XRD indicate that polyaniline succeeded in the surface of molybdenum disulfide microspheres,and the electrochemical properties exhibited by the different amounts of polyaniline supported by the composite materials were slightly different.The composite electrode material prepared when the mass ratio of molybdenum disulfide to aniline added was 1:2 exhibited the best electrochemical performance.According to the cyclic voltammetry test,the maximum capacitance is 364 F/g at a sweep speed of 5 mV/s,and the cycle capacity retention rate is up to 85%after charging and discharging at 8000 cycles under 10 A/g conditions,The energy density is 23.1 Wh/kg as the power density reaches 8320 W/kg.The assembled symmetrical supercapacitors showed high specific capacitances of 231 and 139 F/g at 0.2 and 0.5 A/g,respectively.The cycle retention rate of 5000 cycles at 1 A/g is 80.4%,demonstrating excellent cycle stability.2.The electrochemical impedance value of the electrode material has a very important influence on its electrochemical performance.Therefore,in order to reduce the resistance of the composite material as much as possible,we designed and synthesized the Layered rod-like CC/MoS₂/PANI composite material using carbon cloth as a template.The carbon cloth is treated to have a certain hydrophilicity,and then the hydrothermal reaction is carried out to uniformly cover the molybdenum disulfide on the carbon cloth,and finally the CC/MoS₂/PANI composite material can be obtained by in-situ polymerization of aniline.A series of characterization results such as SEM,TEM,XPS and XRD show that the molybdenum disulfide sheet has been successfully grown on carbon cloth,and polyaniline has been successfully wrapped on molybdenum disulfide.The composite material obtained by electrochemical test has a specific capacitance of 419 F/g at a current density of 1 A/g.At 10A/g current density,the capacity retention rate of the charge and discharge cycle after 1000cycles is still 73%.The composite material has high specific capacitance and good cycle stability.