Preparation And Electrochemical Energy Storage Of Low-Dimensional Nanomaterials/Transition Metal Sulfide Composite Structures

Designing and preparing low-dimensional nanomaterials/transition metal sulfide composites structures has become an effective method to meet the needs of high-performance electrochemical energy storage electrode materials.This paper mainly emphasizes the buliding of high-performance hybrid consrtuction supercapacitors through the interface design between transition metal sulfides and low-dimensional nanomaterials as well as the control of the low-dimensional nanomaterial content.M_xCo_3-xS₄?M=Ni,Fe?nanomaterials were prepared by one-step hydrothermal method and compounded with several low-dimensional nanomaterials to obtain high-performance supercapacitor electrode materials.This work described in this provides a new strategy for development of high-performance energy storage materials.The main research contents of this paper are as follows:?1?The NiCo₂S₄ nanoparticles were prepared by one-step hydrothermal method.Meanwhile,the CNTs@NiCo₂S₄ nanocomposite structures with three kinds of interfaces were prepared using a one-step hydrothermal method by adding the pristine CNTs,surface-oxidized CNTs and nickel-coated CNTs,respectively.Benefiting from the unique nickel interface structure that adequately realizes the effective utilization of the conductive CNTs owing to the homogeneous dispersion of individual nanotubes throughout the matrix as well as the strong interface adhesion by a bridging role.The CNTs:Ni@NiCo₂S₄ nanocomposite structures exhibits a high specific capacitance of2015 F g^-1at a current density of 1 A g^-1,assembled into an asymmetric supercapacitor exhibits a high energy density of 60.7 Wh kg^-11 at a power density of 800 W kg^-11 and an excellent cycling stability of 88%capacitance retention after 10000 cycles at 10 A g^-1.?2?The Ti₃C₂@Ni_1.5Co_1.5S₄ composite structures with different MXene contents have been synthesized through in-situ growing Ni_1.5Co_1.5S₄ nanoparticles on few-layer Ti₃C₂ nanoflflakes using a simple one-step hydrothermal method.Owing to achieving the maximum of synergistic effects at multi-scales,the Ti₃C₂@Ni_1.5Co_1.5S₄-5electrode shows a high specifific capacitance of 1502 F g^-11 at the current density of 1A g^-1.Assembled into an asymmetric supercapacitor exhibits a high energy density of49.8 Wh kg^-11 at a power density of 800 W kg^-11 and an excellent cycling stability of90%capacitance retention after 8000 cycles at 10 A g^-1.?3?The FeCo₂S₄ nanoparticles were prepared by one-step hydrothermal method.Meanwhile,Gr:Ni@FeCo₂S₄ nanocomposite structures were prepared by adding different proportions of nickel-plated graphene?Gr:Ni?by one-step hydrothermal method.By utilizing the unique nickel interface,the FeCo₂S₄ nanoparticles were better attached to the surface of graphene,adequately realizes the effective utilization of the conductive graphene.The results shown that the Gr:Ni@FeCo₂S₄-15 electrode exhibit the best electrochemical performance when the content of graphene is 15 wt.%,and the high specific capacitance of 1657 F g^-11 at a current density of 1 A g^-1.