Paper Title
Boosting The Ion Transport in Polymer Composite Gel Electrolyte by Incorporation of Flake-Like Cobalt Oxide For Dye-Sensitized Solar Cells

Abstract
The implementation of renewable and clean energy sources to generate electricity is highly desirable to mitigate global reliance on fossil fuels. Energy conversion such as dye-sensitized solar cell (DSSC) plays a crucial role as an intermediate step toward efficient, clean and cost effective energy applications. This work reports on the formulation of composite gel polymer electrolyte (CGPE) as an alternative to overcome thelow ionic conductivity of conventional gel polymer electrolyte (GPE)-based DSSCs. Different amounts offlake-like cobalt oxide (Co3O4) (which is synthesized via sonochemicalmethod)is introduced intopolymer electrolyte system which consists of poly (1-vinylpyrrolidone-co-vinyl acetate), P (VP-co-VAc),polyacrylonitrile, (PAN) and sodium iodide (NaI) salt. A CGPE containing 3 wt. % of Co3O4 has achieved the highest ionic conductivity of 4.6 x 10-3S cm-1associated with 34% enhancement diffusion coefficient of triiodide ions as compared to GPE without Co3O4. This enhancement is due to the separated polymer chains caused by the inclusion of Co3O4, resulting in reduced degree of polymer matrix crystallinity as well as increasedin free volume required for ions transportation. DSSC employing the optimized CGPE is fabricated and its performance is evaluated. High photocurrent density and photovoltaic efficiency with the value of 16.53 mA cm-2and 6.46%, respectively,are observed under light illumination of 100 mWcm-2.