Hydrothermal Preparation Of NiO Nanomaterials And Study On Electrochemical Performance

At present,as a new type of clean energy storage equipment,supercapacitors can effectively alleviate the energy crisis,so the preparation of high-capacity energy storage super capacitors has become the goal of researchers.In daily applications,supercapacitors have been applied in many fields.The electrode material is an important factor that determines the performance of the capacitor,so the preparation of electrode material is very meaningful for the development of supercapacitors.One of the transition metal oxides in the electrode material has caused many laboratories to study because of its wide range of species,abundant resources and low cost.However,most transition metal oxides will experience volume expansion or contraction during charging/discharging,resulting in reduced service life.Therefore,designing and preparing composite electrode materials with high activity,large specific surface area or multi-components is the basic premise of high-performance supercapacitors.Nickel oxide?NiO?stands out among many metal oxides.The reason is that it has a high theoretical capacity,abundant reserves,affordable environmental protection and other outstanding features.It has been widely concerned in the field of new energy storage systems.This article takes NiO nano-electrode materials as the research object to study the internal relationship between the synthesis conditions of NiO and its composites and the product morphology,structure and electrochemical performance.The main contents are as follows:The main contents are as follows:NiO nanocubes were prepared by a simple hydrothermal route.Due to its unique structure,the synthesized product,as an electrode material,shows better electrochemical performance than previous materials.The specific performance is that a specific capacitance of 1012 mF cm^-22 can be achieved at a current density of 1 m A cm^-2.At the same time,the assembled device showed good cycle performance.After 10,000 cycles,the retention rate of the capacitor was 85.3%.This indicates that the prepared product can be used as an effective energy storage device.The electrochemical performance of the electrode material depends heavily on its conductivity and shape structure.Based on the work in the previous step,this time we synthesized NiO/Ni_xS_y microspheres through a simple hydrothermal route and a vulcanization process.In order to test whether there is commercial use,the obtained NiO/Ni_xS_y microsphere products are used as the positive electrode material of supercapacitors.NiO/NixSy provides a capacitance of 1529.3 F g^-11 at 1 A g^-1.An asymmetric capacitor using Ni O/Ni_xS_y as the positive electrode is assembled.The composite capacitor can maintain a capacitance retention rate of85.23%?10,000 cycles?.The excellent electrochemical performance of NiO/Ni_xS_y microsphere electrode can be attributed to the successful addition of sulfur element and the synergy between NiO and Ni_xS_y structure.It shows that the prepared products have potential for electrode materials of emerging energy storage devices.Through hydrothermal synthesis and electrodeposition,a layer of NiO nanowires was first synthesized on the nickel foam surface.Using the synthesized product as a precursor,a layer of MnO₂ nanosheets was compounded on the surface to form a NiO/MnO₂ nanorod structure,and finally a layer of polypyrrole?PPy?was deposited.Then use the final NiO/MnO2/PPy product to assemble an asymmetric supercapacitor.The test shows that the two metal oxides are compounded and successfully deposited.PPy has excellent capacitance,and the capacity retention rate is 88.2%after 10,000 physical cycles.