The Research Of Flexible Supercapacitor Electrode And Devices Based On Selenide Nickel Composite Materials

With the development of flexible electronic devices,flexible energy storage devices have also been extensively studied.How to make high-performance flexible energy storage device,has become the focus of researchers.Supercapacitor have been widely studied for the characteristics of rapid charging and discharging rate,high power density as well as low maintenance costs,ect.In this thesis,the current substrate materials of flexible supercapacitor as well as the morphology and structure of active materials are reviewed.Then the selenide nickel(NiSe)nanorods are prepared in-situ on prepared flexible nickel foam substrate.The complexes based on nickel selenide have been further prepared as supercapacitor electrode.The main contents of this thesis are as follows:(1)Through one step wet chemical methods,selenide nickel nanorods are in-situ prepared on nickel foam which is functioned as the flexible substrate and nickel source for selenide nickel.Nickel foam keep the original flexibility after the assembly of electrode materials.It is benefiical to electrode materials when used in the flexible devices.NiSe@Nickel foam electrode can directly assemble into supercapacitor which display system solution resistance approximately 0.37? and special capacitance performance around 176.75 mF/cm2.(2)In order to further enhance the electrochemical properties of the supercapacitor,CoNi2S4@NiSe nano arrays with hierarchical structure are in-situ prepared on compressed nickel foam for high performance flexible supercapacitor by a three-step solution-based method which involves one-step solvent thermal process and two-step hydrothermal process.During the preparation process,the nickel foam serves not only as a support but also as the nickel source for NiSe nanorods,which is beneficial to improving the electronic conductivity and reducing the contact resistant of active materials/current collector.The ample active sites and porous structure of CoNi2S4@NiSe nano arrays contribute to increasing the electrochemical performance.CoNi2S4@NiSe@nickel foam electrode can directly assemble into supercapacitor which display system solution resistance about 0.58 ? and special capacitance performance approximately 312.95 m F/cm2.Meanwhile,it also exhibits excellent electrochemical stability even in bending state.(3)In order to optimize the experimental steps and further improve the electrochemical properties of supercapacitor,graphene/NiSe nanocomposite is in-situ grown on nickel foam by one-step solvent thermal process.And the graphene/NiSe/Nickel foam electrode can be directly assembe into supercapacitor which display system solution resistance aroud 0.40 ? and special capacitance performance about 408.04 mF/cm~2.