The Design And Electrochemical Characterization Of 3D Porous Ferric Oxide、Sulfide Nickel Compound Materials

With the development of the technology and economic,the design of traditional capacitor and cells could not satisfy the requirement of energy devices under all occasions.Supercapacitors,as one energy devices between traditional capacitors and cells,have been widely concerned because of its own fast charge-discharge progress,high power density,friendly and chemical stable.Meanwhile,electrode materials,as one most important factor of supercapacitors devices,have been the mainly way to explore and prove the electrochemical performance of the designed supercapacitors.Among the electrode materials,transition metal compounds are considered to be the most potential materials in the supercapacitors devices cause of its own high theoretical specific capacity,abundant and multiphase.However,the low electronic conductivity limits the electrochemical performance,while better electronic conductivity can promote the electronic transmission.From the point,we choose different good conductivity matrix to lift the conductivity of as-prepared materials and through ion change methods to achieved composite materials design.The main works as follows:（1）First,we synthesized the nanosphere Fe₃O₄ by a simple solvothermal method,and the nanosphere was composed of many nanoparticles.Then,melamine carbon foam after carbonization was used as the conductivity matrix to combine with the as prepared Fe₃O₄ to form the composite compound Fe₃O₄/CF.In the electrochemicalmeasurements,the specific capacity of Fe₃O₄/CF could reach to 130.59 F g-1while the Fe₃O₄ nanospheres was only 55.66 F g-1 at a current density of 1 A g-1,and exerts good cycling stability.Compared to the literature,the carbon foam could be a better choice as the conducitivity matrix to improve the electrochemical performance for the transition metal compound in the process of commercialization.（2）A novel nest-like Ni@Ni₃S₂ material with 80 nm nanowire building blocks was successfully prepared by an in situ growth solvent thermal method with the use of NF as the partially self-sacrificial template.Residual nickel inside the skeleton not only bestows remarkable electrical conductivity but also provides a flexible template for active materials.To improve the electrochemical performance of the Ni@Ni₃S₂,we introduced th cobalt ion as the beneficial metal ion to involve the ion exchange progress and achieved the double metal sulfide design and the retain of nest-like structure.All the as prepared materials were tested in the two electrode supercapacitors system as the positive materials,AC as the negative materials.The electrochemical measurements results revealed that the rate performance and specific capacity was all greatly improved under the synergistic effect of double metal ions.Another way,the unreacted nickel foam could as an effective flexible substrate for the novel flexible supercapacitors design.（3）In this work,a multiphase Ni@Ni₃S₂/Co₉S₈/Ni Se with lavender-like nanoarry structure was achieved by a sequential partial ion exchange.First,the hierarchical structure of Ni@Ni₃S₂ was synthesized by an in situ growth solvent thermal method,and the hierarchical structure was composed of 1D nanorods and 2D nanoflakes together.Se and Co,as the benefit cation and anion ion respectively to involve the sequential partial ion exchange with remain genetic of lavender-like structure.According to the revelation electrochemical measurements,specific capacity and cycling stability was improved after the ion exchange.Generally speaking,ion exchange could be benefit way to explore the synthesized of composite compound according to electrochemical results.