The Synthesis And Application Of Electrode For Supercapacitor

This dissertation reports the synthesis, characterization and electrochemical studies of hierarchical porous carbons, tungsten oxide and walnut active carbon. N2 adsorption, Scanning Electron Microscope, Transmitssion Electron Microscopy, X-Ray Diffraction and FT-IR testing have been used to characterize those materials. Cyclic voltammetry, constant current charge-discharge and frequency response analysis have also been used to systematically investigate the electrochemical properties of those materials. Finally, the structure parameters of those materials obtained from structure characterizations are correlated to their electrochemical properties, and obtained some inspiration results.Self-assembly approach was used to prepare mesoporous carbon (MC). Structure characterizations show the large surface area and large pore volume of MC, and then post-activation approaches were used to activate the MC. Pore structure analysis shows that a series of micro-meso hierarchical porous carbons (HPCs) was prepared. As evidenced by electrochemical measurements, HPCs has high capacitance of 168.9 F/g at high sweep rate of 100 mV/s. In addition, HPCs has very excellent capacitance at high frequency of 1 Hz, reach up to 180 F/g.A serious of tungsten oxide were synthesized by microwave irradiation and direct heating, it is the first time used tungsten oxide as the supercapacitor electrode material. As evidenced by tests, the microwave irradiation-derived tungsten oxide (WO3-M) shows superior capacitive performances to thermal heating-derived tungsten oxide. The volumetric capacitance value as 257 F/g was obtained after 6500th cycling test, which highlights its potential application as an electrode material in a supercapacitor.One kind of biomass material was used as the carbon source, using KOH and ZnCl2 as the active agent to synthesize a series of carbons which have high surface area and functional groups. The electrochemical performance was related with the surface functional groups of the carbon. The KOH derived carbon have the better performance compare with ZnCl2 derived carbon.