Enhanced performance of a dye-sensitized solar cell with an amphiphilic polymer-gelled ionic liquid electrolyte

Abstract

A novel amphiphilic copolymer, poly(oxyethylene)-amide–imide (POEM), was synthesized and utilized for gelling an ionic liquid electrolyte. The polymer-gelled ionic liquid (PG-IL) electrolyte containing 1-methyl-3-propylimidazolium iodide (PMII), 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIBF₄) and POEM has been employed as a quasi-solid-state electrolyte in DSSCs. By adding the POEM to a room temperature ionic liquid (RTIL) electrolyte up to 5 wt%, the binary electrolyte exhibited a quasi-solid-state. The structure of the PG-IL electrolyte with POE segments, which have lone pair electrons, could cause the ionic pair separation and enhance mobility of the counter I⁻ ions. When fabricated into a quasi-solid-state dye-sensitized solar cell, the cell performance exhibited a high power conversion efficiency of 6.28% and long-term durability over 1000 h.