Based On Electrochemical Capacitors Of The Ionic Liquid And Its Influencing Factors,

Ionic liquids (ILs) are salts composed of ions, which are liquid at low temperatures, usually including the region around room temperature. Compared with traditional organic solvents, ILs show many special physics and chemical properties. The recognition of room-temperature ionic liquids as neoteric green solvents has prompted a fast-growing literature. During recent years, more and more attentions have been paid on the applications of RTILs in electrochemistry and other relative research fields. This thesis focused on synthesis and measuration of physical and chemical properties of a series of new room-temperature ionic liquids, the effect of water on the double layer capacity of room temperature ionic liquid, the effect of solvent's property of BMIMPF6/organic solvent mixture on electrochemical capacity of polythiophene film, production and performance testing of supercapacitor. The results are listed as following.1)1-butyl-3-methylimidazolium hexafluoro-phosphate (BmimPF6) and 1-butyl-3-methylimidazolium tetrafluoroborate (BmimBF4) were synthesized and use as solvents in the following experiments. Triethylamine p-tolunesulfonate ionic liquids and triethylamine N-methylimidazole ones were also mixed at different molar ratios. Viscosity, conductivity, electrchemical potential window and thermal stability of the mixtures were reviewed.2) In ionic liquids, adding a small amount of water or organic solvents or changing the temperature may significantly change its physical and chemical properties. The effect of small amount of water or organic containing in ionic liquid, BmimPF6, on the interfacial double-layer capacitance of ionic liquid / glassy carbon electrode was measured by AC impedance techniques. And the structure of the water molecular in BmimPF6 was measured by IR spectroscopy. The increasing of double–layer capacitance were considered to be due to the promotion of ion dissociation in the ionic liquid by water molecular containing in BmimPF6.3) The polythiophene film was prepared by electropolymerization at glass carbon(GC) electrode using cyclic voltammetry and the electrochemical behavior of polythiophene film in neat ionic liquid BMIMPF6,BMIMPF6 /acetonitrile(ACN) and BMIMPF6 /propylene carbonate(PC) mixtures was measured. The viscosities and conductivities of the mixtures were also investigated. Results showed that the electrochemical capacity of polythiophene linearly increased with the increasing of the solution conductivity. The maximum electrochemical capacity of polythiophene film were observed in BMIMPF6/ACN (25/75 v/v) mixture, which is about 7 times greater than that observed in neat BMIMPF6.4) Introduced a system of activated carbon-based electrolyte supercapacitor of the production process, adding a comparative study of ionic liquids and assembled into a super-capacitors, test of its electrochemical properties. Experiment using cyclic voltammetry and constant current charge-discharge method of electrode capacitors and performance testing. The results show that: the addition of activated carbon in the amount of ionic liquids are made of activated carbon / ionic liquid than the simple electrodes made of activated carbon from the electrode resistance to small, this production capacity of the capacitor relatively large charge-discharge efficiency has also improved. The purchase and the commercialization of activated carbon, use of laboratory synthesis of new materials as a mesoporous carbon electrode materials, access to more than capacitors, but compared with the activated carbon, the material produced by the capacitors into the larger resistance.