Li⁺/Al³⁺ Composite Solid Electrolyte Based Electro‐Thermal Dual Responsive Devices with Optimized Optical Contrast and Cycle Durability

Abstract

The limited optical contrast and band adjustment range are the main factors that restrict chromic materials. In this study, Li+/Al3+ composite solid electrolyte is incorporated between VO2 and WO3 chromic functional layers to construct a new type of VO2 based electrothermal dual responsive devices. The dual responsive devices deliver optical contrast over 50% and independent modulation of visible and near infrared band. In addition to displaying four reversible optical states in response to environmental temperature and external voltage, the devices effectively utilize the synergistic effect of Li+/Al3+ hybrid ions. Furthermore, the optimized Li+/Al3+ composite electrolyte is proved to effectively control phase transition of VO2 and significantly improve the electrochromic properties of WO3 as well. Finally, the electro‐thermal dual responsive devices show excellent service stability in simulated outdoor environment of over 10 000 cycles. Combined with the above advantages, it is expected to develop smart windows and derivative products with large size, long life, remarkable energy saving effect and pleasant comfort.

Fast-Switching WO3-Based Electrochromic Devices: Design, Fabrication, and Applications

“…To make this design more responsive, we improved the design of Li + /Al 3+ -based electrothermal dual response devices using a tightly bonded bilayer of solid electrolytes between the VO 2 thermochromic and WO 3 electrochromic layers 16 (Figure 5B). By responding to both voltage and temperature, the device achieved four dynamic dimming modes (i.e., "bright," "cool," "shade," and "strong cool"), which matched the changes in the ambient temperature and light intensity throughout the day; moreover, the response speed was significantly improved.…”

“…(J) Comprehensive performance index of three types of devices. Panels C–J reproduced with permission from ref . Copyright 2022 John Wiley & Sons, Inc.…”

“…(B) Dynamic dimming modes of Li + /Al 3+ base electric-thermal dual responsive devices. Panel reproduced with permission from ref . Copyright 2022 John Wiley & Sons, Inc. (C) A 10 × 10 cm 2 photograph of the ECD in colored and bleached states at ±2.5 V. Panel reproduced with permission from ref .…”

“…It is evident that the response speed of ECDs with synergistic Al 3+ /Li + all-solid structure significantly improved in comparison to those containing only one transport ion. Based on this hybrid ion synergetic structure, we designed and prepared Li + /Al 3+ -based electrothermal dual response devices (Figure C). These devices with increased rate of change of Li + /Al 3+ -based optical contrast outperformed those with continuously decreasing Li + -based optical contrast.…”

Dual-Band Electrochromic Smart Window Based on Single-Component Nanocrystals

“…Tungsten oxide is the most classical and commonly used EC material. − In recent years, it has been found that tungsten oxide NCs have LSPR absorption in the NIR region between 780 and 1500 nm, which just matches the solar thermal energy distribution of sunlight . However, the LSPR effect of intrinsic WO 3 NCs is weak because of the low free carrier concentration, and its plasmonic EC ability is reported to be poor.…”