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

Abstract

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 (Al 3+ ) was introduced into the ECDs and compared with Lithium ion ECDs. With acrylate-based UV curable glue as the gel electrolyte curing adhesive, WO 3 and NiO x films as the complementary counter electrode layers, Li + (ECD-1), Al 3+ (ECD-2) and Al 3+ /Li + double ion (ECD-3) as the electrolyte ions, three types of quasi-solid-state ECDs were prepared as Glass/ITO/WO 3 /polymer electrolyte/NiO x /ITO/Glass. The results showed that the optical modulation amplitude ΔT 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 cm 2 /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 ΔT of the Al 3+ /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. • WO 3 //NiO x complementary quasi-solid-state electrochromic devices based on Al 3+ /Li + dual-ion electrolyte. • UV curing adhesive as the gel electrolyte carrier for ECDs. • Al 3+ /Li + dual-ion devices achieve better electrochemical cycle stability.