Zinc alloy dynamic windows with excellent cyclability and thermal stability

Abstract

Electronically switchable dynamic windows have the promise to significantly reduce energy consumption within buildings and automotive devices. In this paper, we develop Zn electrolytes for reversible metal electrodeposition (RME) windows and improve their thermal bistability and cyclability. By formulating electrolytes that facilitate the reversible electrodeposition of zinc alloys, the dark-state stability of the metal films is significantly improved versus the unalloyed systems due to the higher tolerance of the alloys towards water impurities in the DMSO electrolytes. In particular, Zn alloys with Sn and Ni exhibit high dissolution times exceeding 55 h at the ASTM-mandated temperature of 85 °C, 99.2% coulombic efficiency, and 11 000 cycles in 25 cm² windows without significant deterioration in optical contrast or switching speed. These innovations bring RME dynamic windows closer to practical adoption and commercialization.