Organosoluble, esterified starch as quasi-solid biopolymer electrolyte in dye-sensitized solar cell

Abstract

Fabrication of quasi-solid state polymer electrolytes are recently being endorsed by electrochemists due to its superior electrical and physical properties. With the aspiration to develop a sustainable electrolyte component, this study is a novel attempt to fabricate quasi-solid electrolyte based on esterified starch. Potato starch was chemically modified via simple phthaloylation method. The resulting amorphous, hydrophobic starch derivative was used as a polymer base to prepare cost effective thermoplastic gel electrolytes via incorporation of propylene carbonate, dimethylformamide and lithium iodide. Fourier transform infrared spectroscopy and X-ray diffraction characterizations verified the impact of phthaloylation and plasticization in suppressing the crystallinity and hydrophilicity of starch. The biopolymer gel with 40 wt.% LiI recorded the highest room temperature ionic conductivity of 4.82 mS cm−1. The sample with highest ionic conductivity recorded the best efficiency of 3.56%, which is one of the highest values for starch electrolyte-based dye-sensitized solar cells (DSSC). The optimized efficiency indicate that starch-based electrolyte has good prospects for fabrication of quasi-solid DSSC.

Keywords

• Phthaloylation
• Esterified starch
• Thermoplastic
• Quasi-solid electrolyte
• Dye-sensitized solar cell