Preparation And Electrochemical Performance Of Transition Metal Sulfide And Its Composites

In this work,transition metal sulfides and their composite with spinel structure were prepared with diverse tactics.For further observe the materials details,choose high resolution transmission electron microscopy,X-ray diffraction,X-ray photoelectron spectroscopy and field emission scanning electron microscopy to character the morphology and structure.At the same time,to explore the electrochemical properties of the samples,different measures were been used in this work,such as cyclic voltammetry,galvanostatic charge/discharge,and electrochemical impedance spectroscopy.The experiments of this work can be divide into three parts.1)Choose the nitrate and trimesic acid dissolve in DMF solution to obtain the MOFs precursor microsphere,at the process of hydrolysis of thioacetamide,the spinel Ni Co₂S₄hollow sphere were obtained.After that,different mass of glucose were load the hollow sphere surface when the glucose were hydrothermal carbonization.To explore the best mass load of glucose with hybrid materials,through a variety of characterization tests the structure,morphology,basic element composition and proportion of the samples were analyzed.In the electrochemical test,the composites loaded with 20 mg glucose exhibit excellent capacitor behavior.2)Nickel-cobalt coordination polymer precursor microsphere were prepared using nickel chloride,cobalt chloride and 1,3,5-benzoic acid as raw materials.The coordination polymer was annealed at 450℃in tubular furnace with nitrogen to obtain bimetallic oxides.Then,metal oxides and sodium molybdate were dissolved in deionized water and TAA was selected as vulcanizing agent to prepare Ni Co₂S₄/Mo S₂ hybrid materials.It was found that layered Mo S₂ grew on the surface of the material through characteristics were further studied.The electrochemical test result exhibit that the material has excellent electrochemical performance.3)To obtain the hexagon vanadate cobalt precursors,taking a certain quality of ammonium vanadate and hexamethylenetetramine were dissolved in deionized water in a water bath heated to 85℃then adding cobalt nitrate stirring 5 h.The precursors annealing in 500℃for 2 h in the air,then nickel compound were loaded in Co₂V₂O₇.At last,the hybrid materials Co₃S₄/Ni Co₂S₄ were obtained by hydrothermal sulfide with sodium sulfide.At the electrochemical characterization of performance evaluation results show that the composites exhibited great supercapacitor properties.