The Synthesis Of MoS₂ Based Composite Material And Its Application In Electrochemical Energy Storage

Considering the confinement of the non renewable energy sources in the practical application,developing the renewable energy energy sources is highly desirable.Considering the natural renewable energy sources such as solar energy,tidal energy,and wind energy are greatly affected by the weather,and energy supply deviations,developing the other energy storage system which is free of such limitations is particularly important.Up to present,the lithium ion battery has played an important role in all kinds of enegy storage mobile devices.However,the traditional lithium-ion battery is limited by lithium resources,the sodium-ion and potassium-ion battery are attracting more attention.In this paper,MoS₂ is rended as the active material and was incorporated with other heterojunctions to improve the interface performance and enhance the electrochemical performance of the MoS2composites.Consequently,the Coulombic efficiency,specific capacity,cycle stability and other electrochemical properties are greatly improved.The research contents and results are as follows:First,the molybdenum disulfide composited with the carbon layers,carbon quantum dots,iron cores?Fe@C@CQD@MoS₂?electrode materials was designed and characterized by XRD,Raman,XPS,TEM,SEM,BET,and evaluated for sodium ion batteries.Fe@C@CQD@MoS₂ electrode exposed to simulated sunlight at a current density of 50 mA g^-1 delivered an exceptionally high discharge capacity of693.7 mAh g^-1 and a high charge capacity of 631.3 mAh g^-1 with a high coulombic efficiency of 91.2%.99.8%of its original capacities were maintained after 500 loops at 0.5 A g^-1,indicating the outstanding stability of the MoS₂ based composite.The application of by light and magnetic fields assists in forming the robust SEI film and inhibiting the growth of dendritic sodium during the charge and discharge process.Next,in order to improve the carrier and mass trasportanion capabilities,a hierarchical MoS₂ porous composite was further builted based on prussian blue nanosstructure.The three dimensional?3D?core-shell material Co₃O₄@C@MoS₂were fabricated and applied in potassium ion batteries.As expected,the Co₃O₄@C@MoS₂ delivered the excellent charge capacity of 394 mAh g^-1 and a discharge capacity of 505 mAh g^-11 with a Coulombic efficiency of 78%at 50 mA g^-1.After the 100 loops at 100 mA g^-1,the maintained capacity of Co₃O₄@C@MoS₂ and C@MoS₂ were 92.7%and 87.5%,respectively.However,pure MoS₂ showed a serious capacity decay after 100 cycles.With the modification Co₃O₄ and C,88.3%of the original capacity for the Co₃O₄@C@MoS₂ after 500 cycles was preserved,indicating its excellent cycle performance.As regards in this case,the enlarged interplaner space is beneficial for the adapment to the huge volume variations during the repeated?de?insertion process.The hierarchical pores are favorable for the charge and ion transport as well as mass transportation and the electron reservoirs.The elevated electrocheimical conductivity,the specific surface area supplied enriched electrochemical active sites and excellent contact between electrode and electrolyte also entrust the prominent electrochemical performances of the MoS₂ based composites.