Amorphous Nb/Fe-oxide ion-storage films for counter electrode applications in electrochromic devices

Journal Article · Fri May 01 04:00:00 EDT 1998 · Journal of the Electrochemical Society

DOI:https://doi.org/10.1149/1.1838525· OSTI ID:653262

Orel, B; Macek, M; Lavrencic-Stangar, U ^[1]; Pihlar, B ^[2]

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1. National Inst. of Chemistry, Ljubljana (Slovenia)
2. 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, Journal Name: Journal of the Electrochemical Society Journal Issue: 5 Vol. 145; ISSN 0013-4651; ISSN JESOAN
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
36 MATERIALS SCIENCE
ELECTROCHROMISM
ELECTRODES
IONIC CONDUCTIVITY
IRON OXIDES
NIOBIUM OXIDES
WINDOWS