双功能型吡啶基离子液体的性质及在染料敏化太阳电池中的应用

Properties and Application of Dual Function Pyridinium-based Ionic Liquid in Dye-sensitized Solar Cell

采用高压釜无溶剂法合成了一种吡啶碘离子液体1-乙基-4-叔丁基吡啶碘(TBEPI),并将其应用到染料敏化太阳电池(DSC)中.利用电化学阻抗谱(EIS)、循环伏安(CV)和傅里叶变换衰减全反射红外光谱(ATR-FTIR)研究了TBEPI作为碘源的电解质的电化学性质、在TiO2膜上的吸附特性及抑制TiO2/染料/电解质界面电子复合的动力学过程.结果表明,TBEPI作为碘源可提供充足的碘离子,其电解质的电导率、电化学窗口及氧化还原电对的扩散能力都满足电池工作的需要.TBEPI可有效吸附在TiO2表面形成阻挡层,抑制TiO2/染料/电解质界面的电子复合过程,与传统的以1,2-二甲基-3-丙基咪唑碘(DMPII)作为碘源的DSC相比,光电转换效率(η)由7.1%提高到7.5%.

1-Ethyl-4-tert-butyl pyridinium iodide（TBEPI） was synthesized under solvent-free condition in the autoclave. The adsorption of TBEPI on the TiO2 surface was measured by the attenuated total reflection.Fourier thansform infrared spectroscopy（FTIR） analysis. The influence of TBEPI and 1,2-di-methyl-3-propylimidazolium iodide（DMPII） on redox behavior and the electron recombination in the dyed-TiO2/electrolyte interface were investigated by cyclic voltammetry（CV） and electrochemical impedance spectroscopy（EIS） in the dark. It is found that TBEPI can be used as the iodine resource and effectively forms the blocking layer to restrain the electron recombination. The performance of dye-sensitized solar cell is improved by modification of TBEPI as a result. This study will provide a perspective to the low cost and high efficiency of DSC by electrolyte optimization.