Electrochromism

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

Ion-Transport Design for High-Performance Na+-Based Electrochromics

Abstract: Sodium ion (Na+)-based electrochemical systems have been extensively investigated in batteries and supercapacitors and also can be quality candidates for electrochromic (EC) devices. However, poor diffusion kinetics and severe EC performance degradation occur during the intercalation/deintercalation processes because the ionic radii of Na+ are larger than those of conventional intercalation ions. Here, through intentional design of ion-transport channels in metal–organic frameworks (MOFs), Na+ serves as an efficient intercalation ion for incorporation into a nanostructured electrode with a high diffusion coefficient of approximately 10–8 cm2 s–1. As a result, the well-designed MOF-based EC device demonstrates desirable Na+ EC performance, including fast switching speed, multicolor switching, and high stability. A smart “quick response code” display is fabricated using a mask-free laser writing method for application in the “Internet of Things”. In addition, the concept of ion transport pathway design can ...

Poly(3,4-ethylenedioxythiophene)-ionic liquid functionalized graphene/reduced graphene oxide nanostructures: Improved conduction and electrochromism

Abstract: Nanocomposite assemblies of poly(3,4-ethylenedioxythiophene) (PEDOT), embedded with (a) fluoro alkyl phosphate based ionic liquid functionalized graphene (ILFG) and (b) reduced graphene oxide (RGO) prepared from a modified Hummers’ method, have been synthesized. Defect free graphene nanosheets within the size of a few nanometers were achieved in the PEDOT−ILFG nanocomposite. In contrast, structures comprising graphene oxide wrinkles interspersed with the amorphous polymer were obtained in the PEDOT−RGO nanocomposite. X-ray photoelectron spectroscopy showed that neat ILFG was considerably less oxidized as compared to the neat RGO, which ratified the superiority of the ionic liquid functionalization strategy over the conventional chemical approach, for exfoliating graphite. Substantially higher electrochemical activity, improved ionic/electronic conductivity, much faster switching rates, and an almost ballistic enhancement in the electrochromic coloration efficiency attained for the PEDOT−ILFG nanocomposite...

Electrochromic Metallo-Organic Nanoscale Films: Fabrication, Color Range, and Devices

Abstract: In this study, we demonstrate a versatile approach for the formation of electrochromic nanoscale assemblies on transparent conductive oxides on both rigid and flexible substrates. Our method is based on the application of alternating spin-coated layers of well-defined metal polypyridyl complexes and a palladium(II) salt to form electrochemically addressable films with a high chromophore density. By varying the central metal ion of the polypyridyl complexes (Os, Ru, and Fe) and their ligands and by mixing these complexes, coatings with a wide range of colors can be achieved. These coatings cover a large area of RGB color space. The coloration intensities of these nanoscale films can be tuned by the number of deposition steps. The materials have very attractive ON/OFF ratios, electrochemical stabilities, and coloration efficiencies. Reversible color-to-colorless and color-to-color transitions were demonstrated, and the films were further integrated into sandwich cells.

DIP-COATED TiOz-CeO 2 FILMS AS TRANSPARENT COUNTER-ELECTROD E FOR TRANSMISSIVE ELECTROCHROMIC DEVICES

Abstract: The dip-coating process is an attractive way for the preparation of thin films used in the field of electrochromism. The scope of the present paper is focused on the TiO2-CeO 2 compounds since they exhibit a reversible electrochemical insertion of lithium ions maintaining a high optical transmissivity. These films can be used as transparent counter-electrode in an all solid state electrochromic transmissive device with, for example, WO 3 as electrochromic material and a lithium conductive polymer as electrolyte.