Abstract

Starch and cellulose have long been used in various industrial applications as gelating agents. In this work, the intrinsic adhesive properties of these biopolymers are exploited for application as electrolytes in DSSC. Firstly, potato starch was chemically modified into phthaloyl starch in a facile esterification process. Fabrication of polymer electrolyte with phthaloyl starch (PhSt) and hydroxyethyl cellulose (HEC) incorporated with dimethylformamide and tetrapropylammonium iodide produced homogeneous gels with diminished crystallinity. Infusion of different weight percentages of 1-butyl-3-methylimidazolium iodide (BMII) into the gels were revealed to further suppress polymer crystallinity and elevate ionic conductivity. Rheological analysis revealed that addition of up to 6 wt% of ionic liquid aid in elevating the rigidity, strength and tackiness of the gels. The improved adhesiveness of the gels can be correlated to effective reduction of interfacial resistance and restraining of recombination reactions based on electrochemical impedance spectroscopy. Quasi-solid DSSC fabricated with PhSt-HEC with 8 wt% of BMII exhibited enhanced short-circuit current density, J_SC and fill factor, contributing to an optimized efficiency of 5.20%.

Graphic abstract

中文翻译：

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离子液体注入的淀粉-纤维素衍生物基准固体染料敏化太阳能电池：利用天然聚合物的流变特性

摘要

淀粉和纤维素长期以来已在各种工业应用中用作胶凝剂。在这项工作中，这些生物聚合物的固有粘合性能被用作DSSC中的电解质。首先，在容易的酯化过程中将马铃薯淀粉化学改性为邻苯二甲酰淀粉。用邻苯二甲酰淀粉（PhSt）和羟乙基纤维素（HEC）掺入二甲基甲酰胺和碘化四丙基铵制备聚合物电解质可制得结晶度降低的均质凝胶。揭示了将不同重量百分比的碘化1-丁基-3-甲基咪唑鎓盐（BMII）注入凝胶中，以进一步抑制聚合物的结晶度并提高离子电导率。流变学分析表明，最多添加6 wt％的离子液体有助于提高刚性，凝胶的强度和粘性。凝胶的改进的粘附性可以与基于电化学阻抗谱的界面电阻的有效降低和重组反应的抑制相关。用PhSt-HEC和BMII的8 wt％制备的准固态DSSC表现出增强的短路电流密度J_SC和填充系数，可实现5.20％的优化效率。

图形摘要