Mechanism of graphene oxide regulating the electrochemical properties of fly ash-based manganese silicate/manganese oxide composite
Supercapacitors are high-performance energy storage devices with high power density,excellent cycling performance and high safety.However,their low energy density limits their development.In order to further improve the energy density of supercapacitors and meet the growing demand for energy storage,improving the electrochemical performance of electrode materials is the key.In order to improve the electrochemical performance of fly ash-based manganese silicate/manganese oxide,graphene oxide and fly ash-based manga-nese silicate/manganese oxide composites were synthesized by electrostatic assembly method,and their electrochemical performance was optimized by adjusting the amount of graphene oxide added.The mechanism of the effect of graphene oxide on the electrochemical perform-ance of fly ash-based manganese silicate/manganese oxide was also studied.The morphology and structure of the materials were character-ized by XRD,SEM,XPS and FTIR,and the properties of the materials and devices were tested by Cyclic Voltammetry,Galvanostatic Charge-Discharge and Electrochemical Impedance Spectroscopy.The results show that the charge transfer rate of FA@MS/MO/GO-2 is greatly improved after optimization,and FA@MS/MO/GO-2 has a specific capacitance of 737.4 F/g at a current density of 0.5 A/g,which is higher than that of FA@MS/MO not compounded with graphene oxide(293.4 F/g).FA@MS/MO/GO-2 has the best capacity retention rate(67％)when the current density increases from 0.5 A/g to 8.0 A/g,which is higher than that of FA@MS/MO(44％).Af-ter FA@MS/MO/GO-2 and commercial activated carbon are respectively assembled as positive and negative electrodes for asymmetric su-percapacitors,the energy density of the device can reach 15.75 Wh/kg(power density is 375 W/kg),and the capacity retention rate and coulombic efficiency can reach 100％at 10 000 cycles at 5 A/g,which shows that the electrode material has the potential of long-term recycling and has a good practical application prospect.
NETL
NSTL
万方数据
