MOF Assisted Preparation Of Inorganic Ternary System For Supercapattery

Metal-organic frame works（MOFs）derived materials have attracted wide attention in electrochemical energy storage due to their high specific surface area,which is conducive to electrolyte transport and easier to regulate nanostructures.However,nanoarray structural materials are regarded as one of the promising electrode materials for electrochemical capacitors due to their stable structure and good conductivity.In this paper,a new type of nano composite array material was prepared by using self-supporting method and MOF auxiliary method through reasonable design,and the superelectrical properties of the inorganic ternary system composite array material derived from it were tested as follows:1.Core–shell Co₃O₄@NiO-ZnO nanocomposite arrays are successfully fabricated by annealing metal–organic framework assisted precursors and are investigated as binder-free battery-type electrodes for supercapacitors with a remarkable enhanced performance.The Co₃O₄@NiO-ZnO electrode delivers ultra high areal capacitance/capacity(4678 m F·cm^-2/1965 C·cm^-2at a current density of 2 m A·cm^-2)and excellent cycling stability（83%retention over 10000 cycles）,due to multiple advantages offered by the intriguing core–shell structure,such as large surface area,fast electrolyte penetration,efficient charge transport,highly exposed active sites,and the synergistic effect between them.Moreover,an assembled supercapattery using Co₃O₄@NiO-ZnO arrays as a positive electrode and active carbon as a negative electrode yields a high energy density of 162μWh·cm^-2at a high power density of 1.676 m W·cm^-2and a superior capacitance retention of 93%over 10000 cycles.These excellent results indicate that this efficient strategy can be extended to prepare core–shell-type multi-metallic oxide arrays for high-performance supercapatteries.2.Transition metal sulfides are important candidates of battery-type electrode materials for advanced supercapatteries due to their high electric conductivity and electrochemical activity.hierarchical Co₉S₈@Ni₃S₂/Zn S composite array is prepared by a metal-organic framework assisted strategy,since the electrochemical properties of composite arrays are governed by the synergistic effects of their diverse structures and compositions.As a battery-type material,Co₉S₈@Ni₃S₂/Zn S electrode expresses ultrahigh areal specific capacity of 8192 C·cm^-2at the current density of 2m A·cm^-2,and excellent cycling stability of 79.7%capacitance retention after 4000 cycles.To design the supercapattery device,Co₉S₈@Ni₃S₂/Zn S array and active carbon（AC）are used as positive and negative electrode,respectively.It’s demonstrates a high energy density of 0.377m Wh·cm^-2at a high power density of 1.517 m W·cm^-2and outstand stability of 95.2%retention after cycling for 5000 cycles.As a result,the obtained Co₉S₈@Ni₃S₂/Zn S has potential application in high-performance supercapatteries.To sum up,this thesis with nanoarray as precursor,design synthesis of MOF auxiliary electrode materials into inorganic ternary system of metal oxide/sulfide arrays of nano composite materials,the composite material combines the advantages of MOF and nanoarray structure,significantly increase the electrochemical properties of the materials for the design of high performance electrode materials provides a train of thought.