聚乙烯吡咯烷酮基碘凝胶电解质的制备及在染料敏化太阳能电池中的应用

采用聚乙烯吡咯烷酮(PVP)和聚偏氟乙烯(PVDF)为凝胶剂, 以碘化锂和碘单质为碘源, 碳酸乙烯酯(EC)和碳酸丙烯酯(PC)为溶剂, 制备了染料敏化太阳能电池(DSSCs)用凝胶聚合物电解质(GPE). 使用拉曼光谱、 循环伏安曲线和交流阻抗谱等对GPE进行表征. 结果表明, 聚合物的配比与浓度及碘与碘化锂比例对该电解质性能有很大影响, 当聚合物质量分数为10%、 PVP与PVDF质量比为80∶20、 I₂浓度为0.042 mol/L且LiI与I₂摩尔比为30∶1时, 制备的GPE在室温下电导率达最大值(3.27 mS/cm). 使用该GPE组装的DSSCs在100 mW/cm²的模拟太阳光照射下, 开路电压为0.64 V, 短路电流为13.6 mA/cm², 填充因子为0.595, 能量转化效率为5.18%, 并在30 d内表现出了良好的稳定工作性能.

Preparation of PVP-based Iodine-iodide Gel-electrolyte and Its Application in DSSCs†

In the preparation of gel polymer electrolyte(GPE) for dye-sensitized solar cell(DSSCs), lithium iodide was used as the I^- source, ethylene carbonate(EC) and propylene carbonate(PC) were used as the solvent, polyvinyl pyrrolidone(PVP) and polyvinylidene fluoride(PVDF) were used as the gelling agent. Raman spectroscopy, cyclic voltammetry and alternate current(AC) impedance were used to characterize the gel electrolyte. The results show that the concentration(mass fraction) of polymer and the ratios of PVP to PVDF and iodine to iodide have great influence on the performance of the GPE. The prepared GPE comes to the highest ion conductivity of 3.27 mS/cm at room temperature when the concentration of polymer is 10%m(PVP)/m(PVDF)=80∶20] and the molar ratio of LiI/I₂ is 30∶1 with the concentration of iodide as 0.042 mol/L. DSSC with the PVP-based GPE achieves a good output performance with open circuit voltage of 0.64 V, short circuit current density of 13.6 mA/cm², fill factor of 0.595, the overall photoelectric conversion efficiency of 5.18% under 100 mW/cm² of simulated sunlight and exhibits a good stability during the test time of 30 d. The new GPE which is cheap and available overcomes the problem of liquid electrolytes leakage in DSSCs.