Fast and Stable Zinc Anode‑Based Electrochromic Displays Enabled by Bimetallically Doped Vanadate and Aqueous Zn^(2+)/Na^(+)Hybrid Electrolytes

Vanadates are a class of the most promising electrochromic materials for displays as their multicolor characteristics.However,the slow switching times and vanadate dissolution issues of recently reported vanadates significantly hinder their diverse practical applications.Herein,novel strategies are developed to design electrochemically stable vanadates having rapid switching times.We show that the interlayer spacing is greatly broadened by introducing sodium and lanthanum ions into V_(3)O_(8)interlayers,which facilitates the transportation of cations and enhances the electrochemical kinetics.In addition,a hybrid Zn^(2+)/Na^(+)electrolyte is designed to inhibit vanadate dissolution while significantly accelerating electrochemical kinetics.As a result,our electrochromic displays yield the most rapid switching times in comparison with any reported Zn-vanadate electrochromic displays.It is envisioned that stable vanadate-based electrochromic displays having video speed switching are appearing on the near horizon.

An overview of recent progress in the development of flexible electrochromic devices

Electrochromic materials are capable of reversibly switching their colors or optical properties through redox reactions under applied voltages,which have shown great potential applications including smart windows,nonemissive displays,optical filters,among others.Although the current rigid electrochromic devices have shown emerging interest and developed rapidly,many applications(e.g.,wearable/deformable optoelectronics)are blocked due to their inflexible features.Herein,the adaption of rigid electrochromic devices to flexible ones is of particular interest for the new era of smart optoelectronics.In this review,the current state-of-the-art achievements of flexible electrochromic devices(FECDs)are highlighted,along with their design strategies and the choice of electrochromic materials.The recent research progress of FECDs is reviewed in detail,and the challenges and corresponding solutions for real-world applications of FECDs are discussed.Furthermore,we summarize the basic fabrication strategies of FECDs and their potential applications.In addition,the development trend,the perspectives,and the outlook of FECDs are discussed at the end of this Review,which may provide recommendations and potential directions to advance the practical applications of FECDs.

Transparent inorganic multicolour displays enabled by zinc-based electrochromic devices

Electrochromic displays have been the subject of extensive research as a promising colour display technology.The current state-of-the-art inorganic multicolour electrochromic displays utilize nanocavity structures that sacrifice transparency and thus limit their diverse applications.Herein,we demonstrate a transparent inorganic multicolour display platform based on Zn-based electrochromic devices.These devices enable independent operation of top and bottom electrochromic electrodes,thus providing additional configuration flexibility of the devices through the utilization of dual electrochromic layers under the same or different colour states.Zn-sodium vanadium oxide(Zn-SVO)electrochromic displays were assembled by sandwiching Zn between two SVO electrodes,and they could be reversibly switched between multiple colours(orange,amber,yellow,brown,chartreuse and green)while preserving a high optical transparency.These Zn-SVO electrochromic displays represent the most colourful transparent inorganic-based electrochromic displays to date.In addition,the Zn-SVO electrochromic displays possess an open-circuit potential(OCP)of 1.56 V,which enables a self-colouration behaviour and compelling energy retrieval functionality.This study presents a new concept integrating high transparency and high energy efficiency for inorganic multicolour displays.