ELECTROLYTE FOR DURABLE DYNAMIC GLASS BASED ON REVERSIBLE METAL ELECTRODEPOSITION

Electrochromic "smart" windows allow control of solar and heat flux through the window without sacrificing the view. Despite such appeal, traditional technologies lack the inability to simultaneously achieve fast switching with color neutral tinting and a wide optical dynamic range at low cost. Reversible metal electrodeposition (RME) addresses the drawbacks of existing metal-oxide electrochromic technologies. Several possible RME electrolytes at various pHs with different supporting anions were studied (NO3−, SO42−, ClO4, Cl−, Br−). Acidic perchlorate electrolytes work particularly well, permitting fully reversible metal electrodeposition without harming the substrate or introducing irreversible side reactions. The perchlorate electrolyte shows promising long-term durability in terms of both cycle life and shelf-life, demonstrating 10,000 stable cycles with no evidence of electrode etching. In addition, the use of this perchlorate electrolyte widens the deposition voltage window, enabling construction of relatively large area dynamic windows that tint relatively uniformly with fast, color-neutral switching at low cost.