High-performance of quasi-solid-state complementary electrochromic devices based on Al3+/Li+ dual-ion electrolyte

Monovalent lithium ion has been successfully employed in quasi-solid-state electrochromic devices (ECDs), but it still needs to be optimized in terms of cost, life stability and so on. Herein, a novel electrolyte containing multivalent Aluminum ion (Al3+) was introduced into the ECDs and compared with Lithium ion ECDs. With acrylate-based UV curable glue as the gel electrolyte curing adhesive, WO3 and NiOx films as the complementary counter electrode layers, Li+ (ECD-1), Al3+ (ECD-2) and Al3+/Li+ double ion (ECD-3) as the electrolyte ions, three types of quasi-solid-state ECDs were prepared as Glass/ITO/WO3/polymer electrolyte/NiOx/ITO/Glass. The results showed that the optical modulation amplitude Delta T of three devices is 54.3%, 51.6%, and 53.2%, respectively, while the coloring efficiency (CE) is 62.2, 64.6, and 62.2 cm2/C. The cycle stability test results displayed that during 2000 CA cycles (lasting for 40,000 s, 20 s for one cycle), the optical modulation amplitude Delta T of the Al3+/Li+ devices only decays 16%, which has the excellent cycle durability compared with Li+ devices. This article is an effective attempt to expand the quasi-solid-state electrochromic electrolyte with multivalent ions species, which can broaden the application range of the devices.

Automated summary

In this study, a novel electrolyte containing multivalent Aluminum ion was introduced into electrochromic devices and compared with Lithium ion. The results showed that the multivalent ion electrolyte exhibited better cycle stability and durability compared to the monovalent ion electrolyte.