Reversible metal electrodeposition (RME) is an emerging and promising method for designing dynamic windows with electrically controllable transmission, excellent color neutrality, and wide dynamic range. Despite its very negative deposition voltage, Zn is a viable option for metal-based dynamic windows due to its fast switching kinetics and reversibility. In this manuscript, we describe the construction of Zn RME dynamic windows using water-in-salt electrolytes (WISe). By systematically comparing different electrolytes, we study the effects of different WISe components on Zn RME spectroelectrochemistry. This insight allows us to design practical two-electrode 25 cm2 Zn dynamic windows, the first examples of RME devices with WISe. We also establish a link between the morphology of the Zn electrodeposits and the optical contrast of the transparent electrodes during switching. Taken together, these studies highlight a potential design strategy for the construction of RME dynamic windows.
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Bi-Cu Electrolytes with Aminocarboxylate Chelators for Reversible Metal Electrodeposition at High pH for Dynamic Windows
Dynamic windows, which possess electronically tunable light transmission, increase both the energy efficiency and aesthetics of spaces such as buildings and automobiles. Although reversible metal electrodeposition affords a promising approach to constructing high-performing dynamic windows, the acidic nature of the aqueous electrolytes frequently used in these windows has prevented their commercialization due to tin-doped indium oxide (ITO) etching. In this manuscript, we design neutral and alkaline electrolytes that support the reversible electrodeposition of Bi and Cu at rates comparable to existing acidic electrolytes. In these electrolytes, Bi 3+ and Cu 2+ are solubilized by using aminocarboxylate chelating ligands. By evaluating a series of ligands with varying denticities, we demonstrate that N-(2-hydroxyethyl)ethylenedianmine-N,N’,N’-triacetic acid (ED3A-OH) provides the optimal metal ion binding strength that enhances solubility while simultaneously supporting rapid metal electrodeposition. These results allow us to design alkaline ED3A-OH electrolytes that are compatible with ITO even after four weeks of immersion at 85 °C. This manuscript thus demonstrates that chelating ligands can be utilized to design alkaline reversible metal electrodeposition electrolytes that support dynamic windows with robust shelf lives.
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- Award ID(s):
- 2127308
- PAR ID:
- 10440162
- Date Published:
- Journal Name:
- Journal of The Electrochemical Society
- Volume:
- 170
- Issue:
- 6
- ISSN:
- 0013-4651
- Page Range / eLocation ID:
- 062505
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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