Nano-vanadium pentoxide films for electrochromic displays

• V2O5 nanopowders synthesized by the polyol process.
• Preparation of V2O5 thin films by the “Doctor Blade” method.
• Colorful electrochromism in Li- and Na-based electrolytes.
• WO3/V2O5-based EC device for display application.

We demonstrate the benefit of homemade nanopowder precursors on the electrochromism of V2O5 films deposited by the “Doctor Blade” method. Using the polyol process, nanostructured V2O5 powder were synthesized. Orthorhombic V2O5 thin films deposited from as-synthesized powder exhibit good cycling stability associated with significant reflectance modulation in both lithium- and sodium-based electrolytes. The orange to green reversible color change appears well suitable for display application. To conclude, the electrochromic performances of complete devices using WO3 as complementary electrode and 0.3 M Lithium Bis(Trifluoromethanesulfonyl)Imide LiTFSI in BMITFSI plastified with polymethylmetacrylate (PMMA) membrane electrolyte are reported.