Electrolyte design for zinc dynamic windows with fast switching that cycle more than 11,000 times with high optical contrast

Abstract

The widespread adoption of electronically adjustable dynamic windows promises to significantly improve the energy efficiency of buildings. In this manuscript, we develop robust dynamic windows based on the reversible metal electrodeposition (RME) of Zn from DMSO electrolytes. We systematically interrogate the role of anions, cations, and polymer additives on electrolyte properties and develop design rules to increase the electrochemical and optical reversibility of these systems. This fundamental understanding allows us to develop an electrolyte that facilitates reversible Zn electrodeposition with unprecedented speed and reversibility with a Coulombic efficiency of 99.5%. We implement this electrolyte into practical two-electrode 25 cm2 dynamic windows and demonstrate that these devices switch more than 11,000 times without degradation in optical performance and without altering the switching speed or voltage profile. This outstanding durability is unprecedented in the field of RME windows and brings metal-based dynamic windows substantially closer to successful commercialization.