Solution‐Phase Electrochromic Devices and Systems

Byker, Harlan J.

doi:10.1002/9783527679850.ch14

Cited by 4 publications

(5 citation statements)

References 20 publications

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“…Oxide-based EC materials are far from the only alternatives for "smart" glazings [31], but it appears that they are currently the main ones used in buildings. Other options include devices based on reversible electroplating [50], suspended particles [51], polymer-dispersed liquid crystals [52], metal hydrides [53], plasmonic effects in wide-bandgap electrically conducting nanoparticles [54][55][56], and solution-based systems [57]. It should also be noted that oxidebased materials are far from the only ones with EC properties and, in particular, there are a plethora of organic EC materials [58][59][60][61].…”

Section: Introductionmentioning

confidence: 99%

Electrochromic materials and devices for energy efficiency and human comfort in buildings: A critical review

Granqvist

Arvizu

Pehlivan

et al. 2018

Electrochimica Acta

416

192

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Electrochromic (EC) materials can be integrated in thin-film devices and used for modulating optical transmittance. The technology has recently been implemented in large-area glazing (windows and glass facades) in order to create buildings which combine energy efficiency with good indoor comfort. This critical review describes the basics of EC technology, provides a case study related to EC foils for glass lamination, and discusses a number of future aspects. Ample literature references are given with the object of providing an easy entrance to the burgeoning research field of electrochromics.

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Section: Introductionmentioning

confidence: 99%

Electrochromic materials and devices for energy efficiency and human comfort in buildings: A critical review

Granqvist

Arvizu

Pehlivan

et al. 2018

Electrochimica Acta

416

192

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“…Electrochromism refers to that materials undergo electrochemical reactions accompanied by the changes of their optical characteristics. , The gadgets utilizing the variations of optical properties of electrochromic (EC) materials are called electrochromic devices (ECDs). This technology enables several useful applications, including smart windows for sunlight attenuation, − antiglare rear view mirrors in vehicles, , and EC displays. − Comparing to other chromatic technologies, for instance, liquid crystals, thermochromism, and photochromism, , ECDs feature in users-controllable colors upon applying different potential biases. In fact, ECDs offer small operating potentials (usually smaller than 3 V), , short switching times, and most importantly a high coloration efficiency .…”

Section: Introductionmentioning

confidence: 99%

“…Viologens exhibit three redox states, including dication state (V 2+ ), radical cation state (V +• ), and neutral state (V 0 ) (Figure S1). The reduction of V 2+ (bleached) to V +• (colored) brings a dramatic color change that enables viologens for several applications, such as antiglare mirrors or EC displays. , Meanwhile, viologens offer different optical characteristics, varying with the substituent groups on the bipyridiniums. , During cycling, certain side reactions/processes, like comproportionation, dimerization, and recrystallization would damage the reversibility of viologens, − giving rise to a poor stability of the viologen-based ECD.…”

Section: Introductionmentioning

confidence: 99%

Achieving Low-Energy Driven Viologens-Based Electrochromic Devices Utilizing Polymeric Ionic Liquids

Kao

et al. 2016

ACS Appl. Mater. Interfaces

101

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Herein, three kinds of viologens-based electrochromic devices (ECDs) (heptyl viologen (HV(BF)), octyl viologen (OV(BF)), and nonyl viologen (NV(BF))) were fabricated utilizing ferrocene (Fc) as a redox mediator. Among them, the NV(BF)-based ECD exhibits the highest coloration efficiency (36.2 cm/C) owing to the lowest driving energy. Besides, switching between 0 and 1.2 V, the NV(BF)-based ECD shows a desirable initial transmittance change (ΔT = 56.7% at 605 nm), and long-term stability (ΔT = 45.4% after 4000 cycles). Furthermore, a UV-cured polymer electrolyte containing polymeric ionic liquid (PIL, 1-allyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide) and ethoxylated trimethylolpropane triacrylate (ETPTA) was introduced to the NV(BF)-based ECD. By controlling the weight percentage of the PIL, different curing degrees of the polymer electrolytes were obtained and led to an improved stability of the NV(BF)-based ECD because of the immobilization of NV(BF). This observation was explained by calculating the apparent diffusivity (D) of the redox species in the NV(BF)-based ECD under various curing degrees. In addition, increasing the amount of PIL leads to a lower driven energy needed for the NV(BF)-based ECD, following the same trend as the value of D. Among all NV(BF)-based ECDs, 20 wt % of PIL addition (20-PIL ECD) exhibits large transmittance change (ΔT = 55.2% at 605 nm), short switching times (2.13 s in coloring and 2.10 s in bleaching), high coloration efficiency (60.4 and 273.5 cm/C at 605 nm, after excluding the current density at the steady state), and exceptional cycling stability (ΔT = 53.8% after 10,000 cycles, or retained 97.5% of its initial ΔT).

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“…Electrochromic materials have the property of a change, evocation, or bleaching of color, as effected by an applied electrical potential, sufficient to induce an electrochemical redox process. , Applications of electrochromic materials include “smart” windows for architectural applications, and antiglare car mirrors, based on the modulation of transmitted and reflected visible radiation, respectively. The development of smart windows is the subject of intensive research, as implementation of such technology would lead to a significant reduction in energy consumption in highly glazed buildings by reducing cooling loads, heating loads, and the demand for electric lighting, as well as improving indoor comfort because of less glare and thermal discomfort …”

Section: Introductionmentioning

confidence: 99%

Electrochromic and Colorimetric Properties of Nickel(II) Oxide Thin Films Prepared by Aerosol-Assisted Chemical Vapor Deposition

Sialvi

Mortimer

Wilcox

et al. 2013

ACS Appl. Mater. Interfaces

112

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Aerosol-assisted chemical vapor deposition (AACVD) was used for the first time in the preparation of thin-film electrochromic nickel(II) oxide (NiO). The as-deposited films were cubic NiO, with an octahedral-like grain structure, and an optical band gap that decreased from 3.61 to 3.48 eV on increase in film thickness (in the range 500–1000 nm). On oxidative voltammetric cycling in aqueous KOH (0.1 mol dm–3) electrolyte, the morphology gradually changed to an open porous NiO structure. The electrochromic properties of the films were investigated as a function of film thickness, following 50, 100, and 500 conditioning oxidative voltammetric cycles in aqueous KOH (0.1 mol dm–3). Light modulation of the films increased with the number of conditioning cycles. The maximum coloration efficiency (CE) for the NiO (transmissive light green, the “bleached” state) to NiOOH (deep brown, the colored state) electrochromic process was found to be 56.3 cm2 C–1 (at 450 nm) for films prepared by AACVD for 15 min followed by 100 “bleached”-to-colored conditioning oxidative voltammetric cycles. Electrochromic response times were <10 s and generally longer for the coloration than the bleaching process. The films showed good stability when tested for up to 10 000 color/bleach cycles. Using the CIE (Commission Internationale de l’Eclairage) system of colorimetry the color stimuli of the electrochromic NiO films and the changes that take place on reversibly oxidatively switching to the NiOOH form were calculated from in situ visible spectra recorded under electrochemical control. Reversible changes in the hue and saturation occur on oxidation of the NiO (transmissive light green) form to the NiOOH (deep brown) form, as shown by the track of the CIE 1931 xy chromaticity coordinates. As the NiO film is oxidized, a sharp decrease in luminance was observed. CIELAB L*a*b* coordinates were also used to quantify the electrochromic color states. A combination of a low L* and positive a* and b* values quantified the perceived deep brown colored state.

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Solution‐Phase Electrochromic Devices and Systems

Cited by 4 publications

References 20 publications

Electrochromic materials and devices for energy efficiency and human comfort in buildings: A critical review

Electrochromic materials and devices for energy efficiency and human comfort in buildings: A critical review

Achieving Low-Energy Driven Viologens-Based Electrochromic Devices Utilizing Polymeric Ionic Liquids

Electrochromic and Colorimetric Properties of Nickel(II) Oxide Thin Films Prepared by Aerosol-Assisted Chemical Vapor Deposition

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