In order to develop a smart variable emittance thermal control coating, we here report on a flexible
solidstate electrochromic device(ECD) based on soluble polyaniline by simple fabrication process. Devices were assembled in sandwich configuration of electrochromic materials on flexible PET substrate and a Li+ doped polyacrylonitrile as a solid polymer electrolyte. The initial surface emissivity characteristics related to oxidation states, doping concentration, doping agent and thickness were discussed. The smart thermal management of this ECD was characterized
by its emittance in view of the thickness of active layer and the applied voltage. The emittance of our ECD can be
tuned from 0. 46 to 0. 75 without any fine optimization, which is similar to that of other solidstate ECDs. The major
advantage of this work is that the electrochromic variable emittance coating can be preparedby using simple process,
such as spin coating and spray coatings. These methods do not require any special equipments and vacuum working
conditions, and are easily applied for large area process as well. This study may open new avenues in the development
of flexible electrochromic devices for spacecraft thermal control.