Preparation And Performance Of Ionic Liquid Gel Electrolytes For Dye-Sensitized Solar Cells

Dye-sensitized solar cells (DSSC) have been considered as an ideal alternative to silicon photovoltaic device due to its high efficiency, simple assemble technology and low cost. The over all conversion efficience of 11% has been obtained for DSSC with liquid electrolyte. However, the long-term durability of DSSC with liquid electrolyte is limited by leakage of liquid electrolyte. Gel electrolyte is one of the effective ways to solve problem of sealing of electrolyte. In this paper, mesoporous materials were used as the gelator to prepared gel electrolyte for DSSC. The characteristics of these gel electrolytes were investigated.Order mesoporous silica was prepared by sol-gel method using P123 as the template. Their characteristics were analyzed by N2 adsorption techniques, scan electron microscopy and transmission electron microscopy. Mesoporous silica exhibited ordered rod-like pore structure. Gel-electrolytes for DSSC were fabricated by solidifying binary ionic liquid (1-propyl-3-methyl imidazolium iodide and 1-hexylim-3-methyl idazolium iodide) with order mesoporous silica. Ionic conductivity achieved 2.27mS/cm, and the conversion efficiency of 5.22% were achieved. Compare with the pure ionic liquid electrolyte, conversion efficiency of DSSC was improved 5.5%.Order mesoporous carbon was synthesized by two methods (direct synthesis technique and hard template technique). N2 adsorption tests show that the synthesized order mesoporous carbon posses abundant mesoporous and centralized mesopore distribution. Scan electron microscopy show that MC-3 synthesized using hard template technique exhibited ordered linear pore structure. Mesoporous carbon were mixed with gel electrolyte by solidifying 1-methyl-3-hexylimidazolium iodide with 5wt.% PVDF. Fill factor of DSSC with this gel electrolyte increase dramatically. Conversion efficiency of 5.18% was obtained in light density of 100mW/cm2 when the mesoporous carbon content is lwt.%. Compare with the cell based on gel electrolyte without mesoporous carbon, conversion efficiency of DSSC was improved 30%.