Ionic conductivity improvement in poly (propylene) carbonate-based gel polymer electrolytes using 1-butyl-3-methylimidazolium iodide (BmimI) ionic liquid for dye-sensitized solar cell application

Gel polymer electrolytes (GPEs) are prepared by mixing poly (propylene) carbonate (PPC) with various weight percentages of 1-butyl-3-methylimidazolium iodide (BmimI) ionic liquid. The GPEs consist of PPC host polymer, NaI iodide salt, ethylene carbonate (EC), propylene carbonate (PC), BmimI ionic liquid, and iodine (I-2). The optimum BmimI ionic liquid content was found to be 60 wt% with respect to the wt% of PPC polymer with the highest ionic conductivity of 4.79 x 10(-3) S cm(-1). Temperature-dependent ionic conductivity studies exhibited that gel polymer electrolytes obey Arrhenius thermal-activated model. X-ray diffraction (XRD) study confirms the complexation between host polymer (PPC polymer), sodium iodide salt, and BmimI ionic liquid. Dye-sensitized solar cells are fabricated and GPEs are sandwiched between the working and counter electrodes and tested under the one Sun illumination. The highest energy conversion efficiency of 6.14% is achieved with the addition of 60 wt% of BmimI.