Amorphous Nb/Fe-oxide ion-storage films for counter electrode applications in electrochromic devices
- National Inst. of Chemistry, Ljubljana (Slovenia)
- Univ. of Ljubljana (Slovenia). Faculty of Chemistry
The electrochromic properties of mixed Nb/Fe-oxide films with amorphous structure which were prepared via the sol-gel route were determined. Films with Nb/Fe molar concentration ratios 0.2:1, 0.4:1, and 1:1 exhibit ion-storage capacities up to 18 mC/cm{sup 2} depending on Nb/Fe molar ratio. Electrochromically films behave as optically passive electrodes with a coloration efficiency of nearly zero at {lambda} > 480 nm, while at shorter wavelengths a relatively strong anodic coloring was observed, yielding negative coloration efficiencies up to {minus}20 cm{sup 2}/C. Coloring/bleaching changes of films are correlated with the ex situ IR spectroscopic measurements of charged/discharged films showing distortions of the film structure with Li{sup +} ion insertion/extraction reactions. Electrochemical stability of Nb/Fe (0.4:1)-oxide films was tested up to 2,000 cycles in a sol-gel electrochromic device consisting of sol-gel-derived WO{sub 3} films and hybrid organic/inorganic ionic conductor with ionic conductivity of about 10{sup {minus}4} S/cm serving for lamination of the electrodes.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 653262
- Journal Information:
- Journal of the Electrochemical Society, Vol. 145, Issue 5; Other Information: PBD: May 1998
- Country of Publication:
- United States
- Language:
- English
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