Studies On Electrode Materials Of Nickel And Manganese Based Oxide For Supercapacitors

In the past few decades,as a clean energy conversion and storage devices of supercapacitor,because of its high power density,charging time is short,high safety and reliability and long cycle life and other characteristics,has attracted researchers pay close attention and extensive research.Nowadays,transition metal oxides materials,due to the low cost,abundant mineral resources and friendly to environment,are widely used as supercapacitor electrode materials,and caused the researchers of great interest.Recently,researches about cobalt nickel composite oxide electrode materials are also more and more.In this work,the Ni O-NiCo O₂-Co₃O₄ composite oxide electrode materials were prepared for adding 0.5 ml ethanol amine and calcining at 300 ? by a simple hydrothermal synthesis method.The NiO-Ni CoO₂-Co₃O₄ composites obviously present three different microstructures including nanosheets,nanoparticles and nanowires,and the composite oxide electrode materials show a high specific capacitance of 990 F/g and 580 F/g at the current densities of 1.0 and 10 A/g,respectivel y.About 50% of the maximum specific capacitance can still be retained after 1000 continuous CD cycles at 10 A/g.It reveals a great potential of Ni O-NiCoO₂-Co₃O₄ composites used in high-performance energy-storage systems.Transition metal oxide electrode materials,due to the good redox properties and high specific capacitance theory value,are the favour of the researchers.In addition,the preparation and electrochemical performance study of Ni Co O₂ electrode materials are also emerge in endlessly.In this study,we successfully synthesized micro-spheres NiCo O₂ by a simple hydrothermal method,followed by calcining at 350 ? under nitrogen atmosphere.The NiCoO₂ exhibited a specific capacitance of 760 and 470 F/g at the current densities of 1.0 and 16 A/g in three electrode measurements,respectively.The NiCo O₂ materials exhibit good cyclic stability,maintaining 87% of its total specific capacitance after 1000 charge-discharge cycles at the current density of 10 A/g.The excellent value of specific capacit ance along with reasonable cycling stability makes the Ni CoO₂ promising candidate electrodes materials for supercapacitor in practical applications.In this paper,LaMnO₃ powder was prepared by a simple sol-gel method using common chemical reagents.The structural and electrochemical properties of lanthanum manganate?LaMn O3?powder prepared by the sol-gel method are researched in this article.The powder calcined at 600 ? showed amorphous,and the powder calcined at 700-800 ? showed the pure phase of the LaMn O3.The grains with the size of about 80-120 nm were agglomerating together.Cyclic voltammetry and galvanostatic charge-discharge were used to characterize the electrochemical properties in alkaline environment.The electrochemical properties calcined at 700 ? showed a specific capacitance of 73 F/g at the current density of 0.5 A/g.The raw materials for preparing the LaMn O3 powder are cheap,and the operation method is simple.