Dynamic Windows Using Reversible Zinc Electrodeposition in Neutral Electrolytes with High Opacity and Excellent Resting Stability

Abstract Dynamic windows, which electronically switch between clear and dark states, can play a vital role in energy‐efficient buildings by reducing lighting, heating, and cooling demands. In this manuscript, reversible Zn electrodeposition on tin‐doped indium oxide electrodes is studied and a mechanism is proposed that explains the deposition and dissolution processes. This mechanistic understanding enables the construction of 100 cm 2 two‐electrode devices that transition from clear (80% transmission at 600 nm) to highly opaque ( < 0.1% transmission at 600 nm) in less than 20 s. Additionally, the dynamic windows utilize a pH‐neutral electrolyte, which enables them to switch without degradation over the course of four weeks. The high opacity and stability of the Zn‐based devices represent significant improvements over existing switchable thin films based on the reversible electrodeposition of more noble metals such as Bi and Cu.