The influence of microstructure on the electrochromic properties of Li[sub [ital x]]WO[sub 3] films: Part II. Limiting mechanisms in coloring and bleaching processes

Journal Article · Fri Oct 01 04:00:00 EDT 1993 · Journal of Materials Research; (United States)

DOI:https://doi.org/10.1557/JMR.1993.2657· OSTI ID:6077719

Zhang, J; Benson, D K; Tracy, C E; Deb, S K ^[1]

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1. National Renewable Energy Laboratory, Golden, Colorado 80401-3393 (United States)

Various factors affecting the coloring and bleaching processes of Li[sub [ital x]]WO[sub 3] films have been studied. The rate of the coloring process is limited by the decreasing electromotive force in the Li[sub [ital x]]WO[sub 3] film and by the components of the series circuit resistance, including the electrolyte resistance and the diffusion impedance within the film. The bleaching process in a thick film is limited by either the space charge or by the diffusion impedance, depending on the experimental conditions. A more complete and quantitative model of the coloring/bleaching process has been developed and shows good agreement with experimental results. Our analysis also indicates that the lithium concentration value of [ital x] near the Li[sub [ital x]]WO[sub 3]/electrolyte interface can greatly exceed its reversible limit during the coloring process, even though the average [ital x] value within the film remains much lower than the reversible limit. The phenomenon may introduce some irreversible structural changes in the film, which in turn may constitute one of the films degradation mechanisms.

• DOE Contract Number: AC02-83CH10093
• OSTI ID: 6077719
• Journal Information: Journal of Materials Research; (United States), Journal Name: Journal of Materials Research; (United States) Vol. 8:10; ISSN JMREEE; ISSN 0884-2914
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ALKALI METAL COMPOUNDS
BLEACHING
ELECTRO-OPTICAL EFFECTS
ELECTROCHROMISM
ELECTROMOTIVE FORCE
FILMS
LITHIUM COMPOUNDS
LITHIUM TUNGSTATES
MATHEMATICAL MODELS
MICROSTRUCTURE
SPACE CHARGE
TUNGSTATES