Variable transmittance electrochromic windows for passive solar application. Annual progress report, July 23, 1983-July 22, 1984

Technical Report · Thu Nov 01 00:00:00 EST 1984

OSTI ID:5172273

This program is aimed at the development of electrochromic windows to control radiant solar energy transfer into building interiors. Electrochromic windows are multilayered structures that act as variable absorption or variable reflectance light apertures. An electrochromic window has the general structure EL/sub 1//EC/sub 1//IC/EC/sub 2//EL/sub 2/, where EL/sub 1/ and EL/sub 2/ are transparent electrode layers, EC/sub 1/ and EC/sub 2/ are electrochromic layers, and IC is an electronically insulating ion conductor. The second year of the program was aimed at the optimization of the optical properties of WO/sub 3/ and the development of counter electrodes and ion conductors for hydrogen and lithium based electrochromic systems. We have shown that infrared reflectivities on the order of 55% can be obtained in c-WO/sub 3/. The reflectivity was found to be structure sensitive and is probably limited by incomplete stoichiometryand the defect structure in c-WO/sub 3/. The low coloration efficiency compounds TiO/sub 2/ and Nb/sub 2/O/sub 5/ were found to undergo hydrogen and lithium insertion, respectively, and may be suitable as counter electrodes. Hydrogen insertion in TiO/sub 2/ was found to occur at relatively low cathodic potentials with low coloration efficiency. These results suggest that TiO/sub 2/ may be appropriate as a counter electrode in H based electrochromic windows. IrO/sub 2/ and NiO/sub x/ have been investigated as complementary, anodically coloring, counter electrodes. Ion conductor development has centered on polyAMPs and Ta/sub 2/O/sub 5/ for hydrogen based windows and LiAlF/sub 4/ for lithium based windows.

• Research Organization: EIC Labs., Inc., Norwood, MA (USA)
• DOE Contract Number: AC03-82CE30746
• OSTI ID: 5172273
• Report Number(s): DOE/CE/30746-4; ON: DE86015741
• Resource Relation: Other Information: Portions of this document are illegible in microfiche products
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
PASSIVE SOLAR HEATING SYSTEMS
WINDOWS
ELECTROCHROMISM
ABSORPTIVITY
ELECTRODES
IONIC CONDUCTIVITY
LIGHT TRANSMISSION
REFLECTIVITY
SPECTRAL RESPONSE
TUNGSTEN OXIDES
VOLTAMETRY
CHALCOGENIDES
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRO-OPTICAL EFFECTS
ENERGY SYSTEMS
EQUIPMENT
HEATING SYSTEMS
OPENINGS
OPTICAL PROPERTIES
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
REFRACTORY METAL COMPOUNDS
SOLAR EQUIPMENT
SOLAR HEATING SYSTEMS
SURFACE PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TUNGSTEN COMPOUNDS
140901* - Solar Thermal Utilization- Space Heating & Cooling