A new comb-like copolymer and its blend with poly(ethylene oxide) for solid electrolytes and application in dye-sensitized solar cells

Poly(N-propyl-vinylimidazolium iodide-co-poly(ethylene glycol) methyl ether methacrylate) with a comb-like configuration was synthesized. The copolymer and its blend with poly(ethylene oxide) (PEO) were used to prepare the polymer electrolytes for solid dye-sensitized solar cells. The amorphous characteristics and the ion-crosslinking effects of the copolymer and its blend electrolyte were analyzed by WAXS, DSC and FT-IR. The copolymer and PEO in the blend electrolyte were shown to play the roles of decreasing the crystallinity and breaking the ion-crosslinking, respectively. The blend electrolytes thus presented the highest ionic conductivity among the prepared electrolytes. The as-prepared DSSCs yielded the energy conversion efficiency of 3.46% at 100 mW cm−2. The impedance results indicated the improved photovoltaic performance of the blend electrolyte was originated from the increased ionic diffusion coefficient and the prevented downward movement of the conduction band edge of TiO2.

► A comb-like copolymer with PEGMA and imidazolium iodide moieties was synthesized.
► Copolymer/poly(ethylene oxide) blend electrolytes yields the highest conductivity.
► Blending makes polymer electrolyte to be amorphous and reduces ion-crosslinking.
► An efficiency of 3.46% for the blend electrolyte based DSSC was obtained.