| Summary: | 碩士 === 明志科技大學 === 化學工程研究所 === 100 === In this study, we prepared a composite poly(vinylidenefluoride-co-hexafluoropropylene) (P(VDF-HFP)) co-polymer electrolyte membrane and used on dye-sensitized solar cell (DSSC) applications. The P(VDF-HFP) polymer possesses excellent physical and chemical properties. The SBA15 is a mesoporous molecular sieve, which shows a high surface area and a highly hydrophilic property. We use 3-Glycidoxypropyl-trimethoxysilane (GPTMS) to do SBA15 powder surface modification, to become more hydrophobic, the modified SBA15 referred to as m-SBA15. The m-SBA15 powder has a better dispersion property in P(VDF-HFP) polymer solution. Most liquid electrolytes were used on dye-sensitized solar cells, in which contains large amounts of organic solvents. The major two problems are the solvent evaporation and leakage problems. In order to solve those two problems, the as-prepared solid polymer electrolyte (SPE) membrane was applied on DSSC to overcome the solvent evaporation and leakage problems. When a suitable amount of m-SBA15 powders was added into the P(VDF-HFP) co-polymer, the thermal stability and mechanical properties were greatly improved. When an appropriate proportion of m-SBA15 fillers can also significantly improve the ionic conductivity of the P(VDF-HFP) composite polymer electrolyte membrane. The thermal gravimetric analysis (TGA), scanning electron microscopy (SEM), elemental analyzer (EA) and AC impedance spectroscopy were used to examine the characteristic properties of the SPE membrane. In particular, it was found that the P(VDF-HFP)/3wt.% m-SBA15 SPE showed the ionic conductivity of 2.94×10-3 S cm-1 at 25℃ and the electrolyte absorption and the swelling ratios were 75% and 300%, respectively.
A sunlight simulator was used to examine the electrochemical properties performances of the DSSCs comprised of liquid electrolyte and the as-prepared composite polymer electrolyte membrane. As seen from the experimental results, it was found that the efficiency (η) of the DSSC with ACN liquid electrolyte was 6.01% at first day. But η dropped to 3.02% after 14 days. However, the efficiency of the DSSC with the P(VDF-HFP)/3wt.% m-SBA15 composite polymer membrane showed 4.86% at first day and it decreased to 3.23% after 14 days. The results demonstrated that the performance of the DSSC with SPE is better than that of the DSSC with liquid electrolyte. The as-prepared P(VDF-HFP)/m-SBA15 composite membrane can be used on DSSCs to improve the long-term stability property.
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