Synthesis Of Ni/Co Based Electrode Materials And Their Properties On Supercapacitors

In recent years,growing demands for clean,efficient and sustainable energies has prompted people to accelerate the study on storing and transformation of clean energy.Supercapacitors are considered as one of the most promising energy storage devices because of its fast charge/discharge rate,high power density and long cycle life.From this view,the study for supercapacitor electrode materials is of great significance.Metal compounds based on cobalt/nickel become important supercapacitor electrode materials due to their ideal pseudo-capacitance performances.This thesis aimed at developing of high-performance electrode materials based on cobalt/nickel and following studies were carried out.?1?Polypyrrole?PPY?carbon nanotubes were synthesized using methyl orange as template.The ternary PPY@TMC metal composites were prepared by supporting CoFe₂O₄,NiSe₂ and CoSe₂ on the as-prepared carbon nanotubes by a simple one-pot method.Compared with the single component CoFe₂O₄,NiSe₂ or CoSe₂,the PPY@TMC composite exhibited an excellent electrochemical performance.The specific capacitance of 804 F/g has been obtained at a current density of 1 A/g.The as-prepared composite also exhibited good stability and the capacitance retained 87.6%after 1200 cycles at 2 A/g.?2?The spherical Ni?OH?₂/Co?OH?₂ flower electrode material?noted as NCOH?was synthesized in simple hydrothermal method at a low temperature.The electrode material exhibited an excellent electrochemical performance.The specific capacitance of 1502 F/g has been obtained at a current density of 1A/g.The as-prepared electrode material also exhibited good stability and the capacitance retained 61.2%after 2800 cycles at 20 A/g.?3?Three-dimensional ordered mesoporous Co₃O₄ materials with high specific surface areas were prepared by impregnation in vacuum using KIT-6 molecular sieve as template.Compared with the sample prepared by conventional impregnation and the one prepared without template,the as-prepared mesoporous Co₃O₄ materials exhibited an excellent electrochemical performance.The specific capacitance of 245 F/g has been obtained at a current density of 1 A/g.The material also exhibited good stability and the capacitance retained 83.3%after 1200 cycles at 3 A/g.