Preparation And Electrochemecial Properties Of CeO₂/Ni?OH?₂?NiO?micro-?NaNo-? Structures

Supercapacitor has shown a huge commercial potential as a new type of energy storage and conversion devices.Electrode materials are one of the key factors in determining the performance of supercapacitors.How to prepare the electrode material that meets the requirement becomes an urgent issue.Based on the present situation,the dissertation has reported the preparation of a number of electrode materials with unique structures and morphologies showing good pseudo-capacitance characteristics.The main contents are as follows:?1?Preparation and electrochemical properties of flower-like CeO₂/Ni?OH?₂ microspheres: The CeO₂/Ni?OH?₂ composite microspheres with high specific surface areas have been prepared via a one pot hydrothermal method using nickel sulfate as nickel source and cerium ammonium nitrate as cerium source.The effects of temperature and cerium content on the morphology and electrochemical properties of the CeO₂/Ni?OH?₂ composite microspheres were investigated.The charge and discharge experimental results showed that the specific capacity can reach 1335 F?g-1 and can still reaches 1215 F?g-1 after 500 cycles.?2?Preparation and electrochemical properties of flower-like CeO₂/NiO: Flower-like CeO₂/NiO composite microspheres have been obtained by calcining the CeO₂/Ni?OH?₂ precursors.The composite microspheres have the hierarchical structures with large specific surface area?168 m2·g-1?and uniform size.The effects of the synthesis temperature of the precursor,the surfactant,and the amount of cerium on the morphologies and pseudocapacitance properties of the electrode were investigated.It has been found that the CeO₂/NiO composite electrode has a specific capacity of 1890 F·g-1 at current density of 1 A·g-1 and 95% capacity maintenance can be achieved after 1000 cycles of charge-discharge.?3?Synthesis and electrochemical performance of PANI/CeO₂/Ni?OH?₂ composites: PANI/Ni?OH?₂ and PANI/CeO₂/Ni?OH?₂ composites have been prepared,respectively,via a one pot hydrothermal method using ammonium persulfate as the oxidant with the molar ratio of 1:1 of aniline to ammonium persulfate.The composites have a morphology of flower-like microspheres assembled with curled nanosheets and show specific surface area of 189 m2?g-1.PANI/CeO₂/Ni?OH?₂ composite electrode has a specific capacity of 2868 F·g-1 under current density of 1 A·g-1,and 95% capacity maintenance can be achieved after 1000 cycles of charge-discharge.