Investigation and Manipulation of Zinc Electrodeposition Morphology for the Construction of Reversible Zinc Electrodeposition Dynamic Windows

Reversible metal electrodeposition (RME) is an underexplored and promising method for the design of dynamic windows with electronically controllable transmission. RME enables the construction of dynamic windows with fast switching and color-neutral tinting. A variety of metals have been explored, but each has thus far been associated with negative attributes. In this work, we investigate Zn RME due to its ability to produce viable windows despite the negative reduction potential of Zn. By systemically studying the chemical composition of aqueous Zn electrolytes and the structure of Zn electrodeposits on tin-doped indium oxide electrodes, we are able to create high contrast reversible 25 cm2 windows that possess >99% Coulombic efficiency. X-ray diffraction and scanning electron microscopy analyses allow us to link window optoelectronic performance to the electrolytes’ composition and Zn electrodeposit morphology. Through the use of polymers such as polyethylene glycol , we are able to manipulate the deposited Zn morphology. This change in morphology allows for a large increase in cycle life from less than 100 cycles to more than 1,000 cycles with retention of other beneficial properties. With this increase in cycle life as well as a high contrast ratio, Zn RME is a viable option for further development of metal-based dynamic windows.