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RESEARCH PRODUCT

<title>Performance problems of electrochromic coatings</title>

subject

description

The performance is actual problem of electrochromic coatings. The service and shelf life and cycling capacity are main performance characteristics. By solid-state ionics point of view any electrochromic cell based on phenomena with ion insertion - extraction processes is functioning as solid-state rechargeable battery. The main performance characteristics of electrochromic cells are similar. Performance of electrochromic coatings based on amorphous WO3 films and protons conducting electrolytes is limited by reversibility of ion insertion-extraction reactions, which causes degradation of cell components. The migration of water in the cell and hydration together with ion insertion-extraction reactions of the WO3 film have main role in formation of new phases, which determine the value of cycling capacity. The cycling capacity at constnat coloration intensity is limited by initial total number of active tungsten ion sites for induced color centers at inner surface of porous WO3 film. The more probable transformation of phases in hydrated WO3 films during cycling, which can be related to loss of active tungsten ion sites, is transformation of octrahedral structural units of HxWO3nH2O to tetrahedral H2WO4mH2O.© (2003) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.