Enhanced performance in electrochromic devices with high-contrast and long-term stability via synergistic effect of Cl−/NO3− dual-anion electrolyte

Abstract

In this work, the effect of hybrid dual-anion electrolyte on electrochromic devices was investigated. We fabricated aluminum-ion electrochromic devices with Cl−/NO3− dual-anion electrolytes, and the performance of electrochromic devices was significantly improved. There are high optical contrast (73.4 % at 650 nm) and long-lived cycle stability (after 100 cycles, the color rendering range is not lower than 99 % of the initial state) in electrochromic devices with the electrolyte proportion at 9:1 (Cl−/NO3−). The investigation indicates that the environment and coordination of the cations are changed derived from the local nitrate ions replacement of the solvated shell of cations, when an appropriate amount of nitrate ions are migrating in the electrolyte, which makes the process of the embedding and shedding of ions in the electrochromic layer are more stable, and improving the performances of electrochromic devices. This approach paves the way for designing and enhancing electrochromic devices with hybrid dual-anion electrolyte. And we believe that electrochromic research would benefit from the new approach.