Electrochromism

About: Electrochromism is a research topic. Over the lifetime, 13097 publications have been published within this topic receiving 294637 citations.

Transparent inorganic multicolour displays enabled by zinc-based electrochromic devices

Abstract: 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. Transparent electrochromic displays with a richer colour palette are now possible. Electrochromic displays, which change their colour due to electrochemistry, are receiving interest due to their low power consumption but a lack of colours is problematic. Wu Zhang and coworkers from the University of Alberta in Canada and Louisiana State University in the USA fabricated multicolour displays using sodium ion stabilized vanadium oxide nanorods (Zn-SVO) as the electrochromic material. Two layers of this material, separated by a layer of zinc and a gel electrolyte were sandwiched between glass coated with indium tin oxide. Application of a small voltage causes the SVO film to exhibit a reversible switch between orange, yellow and green. The use of two independently-controlled films in the display provides a broader range of colours (orange, amber, yellow, brown, chartreuse and green).

Electrocatalytic Enhancement of Methanol Oxidation at Pt−WOx Nanophase Electrodes and In-Situ Observation of Hydrogen Spillover Using Electrochromism

Abstract: A Pt−WOx nanophase electrode showed a considerably more enhanced electrocatalytic activity than Pt itself for methanol oxidation and exactly the reverse change in optical signal intensity with respect to electrochemical cell potential, compared with an electrochromic WOx electrode This provides evidence for hydrogen spillover from Pt to WOx Consequently, it was possible to directly observe the in-situ hydrogen transfer from platinum to tungsten oxide in a fuel cell electrode using electrochromism The transfer of hydrogen ions, produced on the platinum during the electrooxidation of methanol, to the tungsten oxide ensures that the active reaction sites on the platinum remain clean, thus enhancing the electrooxidation current density

Flexible and high-performance electrochromic devices enabled by self-assembled 2D TiO2/MXene heterostructures.

Abstract: Transition metal oxides (TMOs) are promising electrochromic (EC) materials for applications such as smart windows and displays, yet the challenge still exists to achieve good flexibility, high coloration efficiency and fast response simultaneously. MXenes (e.g. Ti3C2Tx) and their derived TMOs (e.g. 2D TiO2) are good candidates for high-performance and flexible EC devices because of their 2D nature and the possibility of assembling them into loosely networked structures. Here we demonstrate flexible, fast, and high-coloration-efficiency EC devices based on self-assembled 2D TiO2/Ti3C2Tx heterostructures, with the Ti3C2Tx layer as the transparent electrode, and the 2D TiO2 layer as the EC layer. Benefiting from the well-balanced porosity and connectivity of these assembled nanometer-thick heterostructures, they present fast and efficient ion and electron transport, as well as superior mechanical and electrochemical stability. We further demonstrate large-area flexible devices which could potentially be integrated onto curved and flexible surfaces for future ubiquitous electronics.