高相转变温度的离子凝胶电解质基准固态染料敏化太阳电池

染料敏化太阳电池(DSC)以其低价、高效等优势,成为学术界和工业界的研究热点.传统液态电解质由于易挥发、易泄漏等问题,导致基于液态电解质的电池难以保持长期稳定,影响光伏技术的应用.本文合成了N,N'-1,5-戊二基双月桂酰胺,将其作为有机小分子胶凝剂(LMOG)胶凝离子液体电解质(ILE)制备了离子凝胶电解质(IGE)并组装成准固态电池(QS-DSCs).差示扫描量热测试显示该凝胶电解质的相转变温度(Tgel)为104.7°C,具有良好的本征热稳定性.利用循环伏安法、电化学阻抗谱、调制光电压/光电流谱分别研究了液态电池和准固态电池内部电子传输和复合动力学过程.结果表明,凝胶电解质的三维网络结构加速了TiO2光阳极/电解质界面电子与电解质中I3-的复合过程,使电子寿命降低,导致准固态电池的光电转换效率略低于液态电池.在AM 1.5(100 mW?cm-2)及50°C条件下的加速老化测试结果显示,持续老化1000 h 后其光电转换效率(η)无衰减,而液态电池的光电转换效率衰减为初始值的86%,表明准固态电池具有良好的光热稳定性.

Quasi-Solid-State Dye-Sensitized Solar Cell Fabricated fromIonic Gel Electrolyte with High Gel-to-Solution Transition Temperature

Dye-sensitized solar cells (DSCs) have aroused much interest because of their low cost and comparatively high power conversion efficiency. Stability is paramount for any photovoltaic technology. Traditional liquid electrolytes tend to leak and evaporate, which limits the long-termperformance of the DSC. N,N''-1,5-Pentanediylbis-dodecanamide was synthesized and used as a low molecular mass organogelator (LMOG), to gelate an ionic liquid electrolyte (ILE) and fabricate a quasi-solid-state DSC(QS-DSC). Differential scanning calorimetry indicated that the gel-to-solution transition temperature of the ionic gel electrolyte (IGE) was 104.7℃, which indicated good intrinsic stability. Electron transport and recombination were investigated by cyclic voltammetric (CV) and electrochemical impedance measurements, and intensity-modulated photocurrent and photovoltage spectroscopy (IMPS and IMVS) measurements. Electron recombination at the TiO₂ photoanode/ electrolyte interface was accelerated by the cross-linked gel network. The shorter electron recombination lifetime decreased the photoelectric conversion efficiency of the QS-DSC, compared with the ILE-based DSC. The photoelectric conversion efficiency of the QS-DSC exhibited no change during accelerated aging test for 1000 h, while that of the ILE-based DSC decreased to 86% of its initial value.