The internal pressure of electrochemical double layer capacitors (EDLCs) using 1.0 mol dm−3 triethylmethylammonium tetrafluoroborate (TEMABF4) in acetonitrile at different voltages at 70℃ was measured and sources of the internal pressure were clarified. The PCLV (precharge at low voltage) method was used to weaken the gas evolution and decrease internal pressure. It was found that the EDLC dealt with the PCLV had lower pressure at high voltage than that which was not. Electrochemical impedance spectroscopy was used to measure the capacitance and resistance of the EDLC after ageing. Elemental composition and morphology of the electrodes were analyzed by FESEM-EDX. The gas products generated at 3.0 V were identified by GC-MS. The reaction mechanisms of gas evolution are discussed.
AgInS2 thin films are prepared by vacuum evaporation from two commercially available binary compounds (Ag2S, In2S3). The prepared thin films are characterized for their structural and optical properties. Good quality films are prepared at a mixing ratio of Ag2S: In2S3 = 1: 1.5, which is suggested as a candidate for the window layer of a CuInS2 solar cell.
The effects of 1,3-alkylimidazolium iodide derivatives in the electrolytic solution of dye-sensitized solar cell were investigated. The combination of lithium iodide and 1-ethyl-3-methylimdazolium iodide was revealed to exhibit higher effciency (8.6%) than 1-methyl-3-propylimidazolium iodide or 1-butyl-3-methylimidazolium iodide. The influence of guanidine thiocyanate was examined for the electrolyte of 1-ethyl-3-methylimidazolium iodide.