Electrochromic devices for satellite thermal control

This paper gives information regarding a new solid-state thin film electrochromic device (ECD) designed for IR emissivity modulation. The variable emissive properties make the new ECD an ideal spacecraft antenna thermal management system. Specific attention is focused on a new electrochromic system (an Eclipse Energy Systems, Inc. proprietary technology) designed for the infrared (IR) spectral region. Reflectance modulation of the new IR-ECD system for the 4.2 to 27 micron region is about 60%. In non-absorbing mode, the IR-ECD system exhibits a 90% flat IR reflectance spectrum (0.1 emissivity). Upon the application of a 1.6V D.C. voltage (top electrode negative), the device is switched to absorbing mode and the emissivity is increased to up to 0.98 value. The IR-ECD system switches back to its maximum reflectance condition upon the application of a 0.6V reverse voltage. The IR-ECD can be used as a smart thermal modulator for the thermal control of satellites and spacecraft by controlling the amount of energy emitted from surfaces.