Optimization of plastic crystal ionic liquid electrolyte for solid-state dye-sensitized solar cell

An efficient plastic crystal-based electrolyte is prepared by employing succinonitrile as solid solvent and binary ionic liquids as charge transfer mediators for dye-sensitized solar cells (DSSCs). It was found that combining succinonitrile with ionic liquids could improve the mechanical property of electrolyte and avoid the fluidity of ionic liquid, and the fabricated solid-state solar cell shows an overall conversion efficiency of 2.14%, which can be further improved to 5.50% after optimizing the addition amount of lithium perchlorate (LiClO4) as charge transfer promoter into the plastic crystal electrolyte, and the role of LiClO4 in the plastic crystal ionic liquid electrolyte is evaluated through electrochemical and photoelectrochemical measurements. The knowledge obtained from this plastic crystal-based electrolyte exhibits new eyeshot to find solid-state electrolyte for DSSCs with high performance.

Graphical abstractLiClO4 was incorporated into the iodine-free plastic crystal electrolyte to inhibit the crystallization of succinonitrile, and increase the charge transfer through enhancing charge exchange reaction between I−/I3−, therefore improve the conversion efficiency of DSSC.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Succinonitrile plastic crystal ionic liquid electrolyte was developed for solar cell. ► Succinonitrile can improve the mechanical property of ionic liquid electrolyte. ► Wiping out of I2 can avoid its light absorption and volatility. ► LiClO4 can promote the charge transfer of the plastic crystal-based electrolyte. ► Li+ ions can enhance the charge exchange between I−/I3− in the electrolyte.