A Novel Composite Polysaccharide/Inorganic Oxide Electrolyte for High Efficiency Quasi-solid-state Dye-sensitized Solar Cell

A new composite polymer electrolyte consisting of low-molecular mass polysaccharide (agarose) filled with titanium oxide and containing LiI and I2 was developed. The introduction of the inorganic filler (TiO2) into the agarose polymer matrix changes the thermal and ionic conductive properties of host polymer electrolyte. The polysaccharide electrolyte with different inorganic filler TiO2 concentrations (0-30 wt %) is studied systematically by differential scanning calorimetry (DSC) and the AC impedance spectra. Upon addition of the inorganic oxide, the glass transition temperature (Tg) of the electrolyte decreases within the range of 0-2.5 wt % TiO2 changed electrolytes, which results in high conductivity in these electrolytes. Then the Tg increases with the TiO2 content until 30 wt % and the ionic conductivity of the electrolyte decreases in this concentration range. From the electrochemical analysis, it is observed that the electron lifetime in TiO2 of DSSC decreases with inorganic filler contents, which results in lower Voc in the high TiO2 content added DSSC. Based on these results, the optimized efficiency of titania added DSSC is 4.74% at2.5 wt % titania concentration.