Effect of i-methyl-3-propylimidazolium iodide ionic liquid on bio-based polyurethane gel polymer electrolyte for solid-state dye-sensitized solar cell

Abstract

This research focuses on the effects of iodide based ionic liquid in palm-based polyurethane (PU) gel polymer electrolytes for solid-state dye sensitized solar cell (DSSC) application. In this investigation, the effect of 1-methyl-3-propylimidazolium iodide (MPII) ratios on palm?? based PU polymer electrolyte is explored. Palm-based PU polymer electrolyte is synthesized under nitrogen gas atmosphere by pre-polymerization reactions between palm kernel oil monoester-OH (PKO-p) and methylene diphenyl diisocyanate (MDI) at different MPII weight ratios. The effects of MPII weight ratios on ionic conductivities, chemical interaction, thermal properties and photo voltaic characteristics (short circuit current density, open circuit voltage, fill factor and power conversion efficiency), of solid-state DSSC is examined by electrochemical impedance spectroscopy (EIS), Fourier transform infra-red spectroscopy (FTIR), thermo gravimetric analysis (TGA), differential scanning calorimetry (DSC) and light-current-voltage (LIV) measurements. The highest ionic conductivity values of PU-MPII are found at 9.07xlO-4 S/cm with 25 wt.% MPII. FTIR analysis indicated that there is significant shift of wavenumber at N-H stretching, N-H bending and C=O stretching, respectively. The thermal stability measured by TGA showed that PU-MPII showed the occurrence of polymer-MPII complexation. Meanwhile, DSC thermograms indicated that the glass transition temperature (T g) decreased with the decreased of MPII weight ratios. The current-voltage characteristic of FTO/Ti02-dyeIPU-MPII-h/Pt at 25 wt.% MPII demonstrated highest power conversion efficiency of 1.00 % under a standard AM 1.5G illumination. These promising results could be a first step toward a new generation of low-cost and effective solid-state DSSC from palm-based polymer electrolytes.