Preparation And Properties Of Cobalt Oxide Composites For Supercapacitor

Supercapacitor research focuses on the preparation of high-performance electrode materials and electrolytes. This paper selected ordered mesoporous as templates, cobalt nitrate for cobalt source, using infusion process-solvothermal method to prepare cobalt oxide/ordered mesoporous supercapacitor composite electrode materials with the cobalt oxide for active component. Nitrogen isothermal adsorption-desorption, X-ray diffraction (XRD) and electronic transmission electron microscopy (TEM) were used to characterize the microscopic structure and morphology of composite electrode materials. Cyclic voltammetry (CV) and constant current charge-discharge studies were performed to estimate the specific capacitance of the synthesized materials. Based on the above data discussed the relationship between structure and electrochemical performance of the composite electrode materials.N2adsorption-desorption tests show that, orderly mesoporous carbon (OMC) material has rich pore structure and centralized in pore distribution. Synthesis of cobalt oxide/ordered mesoporous supercapacitor composite electrode materials repeated the template structure, as well as high specific surface area and pore volume. XRD studies founded that through infusion process-solvothermal method cobalt nitrate decompose an basic cobalt nitrate in the pore of OMC in situ reaction, with which a wide diffraction peak and small particle size. While using high-temperature calcinations got good crystallized Co3O4crystals. The TEM image confirms that OMC has a CMK-3typical high degree of ordered porous texture delivering arranged P6mm hexagonal structure. Nanoscale metal oxide filled to the orderly pore of OMC, making it possible for the structures of composites exist both in orderly and disordered structure simultaneously.Using single factor analysis methods research the loading amount of OMC, solvent thermal temperature and time impact on composites electrochemical performance. It is found that the specific capacitance of composites electrode materials have great attachment with these above mentioned conditions. At the factor20wt.%OMC loading amount,175 ℃solvent thermal temperature and4h, the single composite electrode materials obtained a specific capacitance as high as1102F/g at the scanning rate of5mV/s in6mol/L KOH electrolyte in three electrodes system. This value is much higher than that of template OMC, as well as that of ruthenium oxide. When the scan rate increases to10mV/s, the specific capacitance still reached270F/g, showing good stablity. And the mechanism of high energy storage capacity of the composite electrode materials is also discussed. On this basis, electrochemical performance of the binary metal oxide/OMC composite electrode materials derived from cobalt and other transition metal (Sn, Mn, La) were researched. Among these, the single electrode tin oxide-cobalt oxide/OMC binary compound electrode material achieved1105F/g.