Lithium iodide anhydrous

The working electrodes were made by screen-printing TiO₂ PST-18NR paste (Solaronix) onto an FTO substrate with a film thickness of 16 μm with no blocking layer and scattering layer. After annealing at 500 °C for 60 min under an air atmosphere, the TiO₂ photoanodes were immersed in N719 dye at a concentration of 0.5 mM for 24 h. Previous work^{4 (link)} was used to guide the manufacture of the N719 dye solution (Solaronix S.A.) and the ${\text{I}}^{-}/{\text{I}}_3^{-}$ electrolyte used in this study. N719 dye was prepared using 0.5 mM ruthenizer 535-bisTBA (solaronix) and 50 ml tert-Butanol (> 99.70%, Sigma Aldrich) in 50 ml acetonitrile (99.8%, LiChrosolv). An ${\text{I}}^{-}/{\text{I}}_3^{-}$ electrolyte was prepared using 0.1 M lithium iodide anhydrous (99.99%, Alfa Aesar), 0.05 M iodine (> 99.8%, Riedel–de Haen), 0.6 M 1-propyl-3-methylimidazolium iodide (> 98%, Sigma-Aldrich), 2.5 mM lithium carbonate (99.99%, Sigma-Aldrich) and 0.5 M tert-butylpyridine (96%, Sigma-Aldrich Corp.) in acetonitrile.
A semi-closed approach was used to assemble the WE and CE with a parafilm as a separator and a drop of ${\text{I}}^{-}/{\text{I}}_3^{-}$ electrolyte for the DSSC asymmetrical cell assembly (Fig. 1). In the case of the CE:CE symmetric cells, two FA CEs with an active area of 0.5 cm² were assembled using a parafilm separator and then filled with the same ${\text{I}}^{-}/{\text{I}}_3^{-}$ electrolyte to perform EIS and Tafel tests on the CE catalysts.