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Jean-marie Tarascon - One of the best experts on this subject based on the ideXlab platform.

  • an all plastic wo3 h2o polyaniline Electrochromic Device
    Solid State Ionics, 2001
    Co-Authors: Cremene Marcel, Jean-marie Tarascon
    Abstract:

    We report on the implementation of the plastic battery technology to the elaboration of a flexible Electrochromic Device. More specifically, we studied a system constituted of WO3·H2O monohydrate tungsten oxide switching against polyaniline (PANI) conducting polymer. We first describe the electrochemical and optical properties of each cell component within a non-aqueous organic 1-M LiPF6 EC/DMC liquid electrolyte. Then PVDF-HFP polymer-based stacks, constituted of each plastic electrode separated by a plastic membrane, were built by: (i) holding the layers together by capillarity, and (ii) by hot-lamination of all layers to a single one. Both Devices were investigated for their optical performances. Despite a loss of transmission level, the optical contrast turned out to be higher for the hot-laminated configuration. However, for reasons that will be developed, the Electrochromic efficiency was well below the one expected from solid-state windows.

  • An all-plastic WO3 center dot H2O/polyaniline Electrochromic Device
    Solid State Ionics, 2001
    Co-Authors: Cremene Marcel, Jean-marie Tarascon
    Abstract:

    We report on the implementation of the plastic battery technology to the elaboration of a flexible Electrochromic Device. More specifically, we studied a system constituted of (WO3H2O)-H-. monohydrate tungsten oxide switching against polyaniline (PANI) conducting polymer. We first describe the electrochemical and optical properties of each cell component within a non-aqueous organic 1-M LiPF6 EC/DMC liquid electrolyte. Then PVDF-HFP polymer-based stacks, constituted of each plastic electrode separated by a plastic membrane, were built by: (i) holding the layers together by capillarity, and (ii) by hot-lamination of all layers to a single one. Both Devices were investigated for their optical performances. Despite a loss of transmission level, the optical contrast turned out to be higher for the hot-laminated configuration. However, for reasons that will be developed, the Electrochromic efficiency was well below the one expected from solid-state windows. (C) 2001 Elsevier Science B.V. All rights reserved.

  • An all-plastic WO3??H2O/polyaniline Electrochromic Device
    Solid State Ionics, 2001
    Co-Authors: Cremene Marcel, Jean-marie Tarascon
    Abstract:

    We report on the implementation of the plastic battery technology to the elaboration of a flexible Electrochromic Device. More specifically, we studied a system constituted of WO3??H2O monohydrate tungsten oxide switching against polyaniline (PANI) conducting polymer. We first describe the electrochemical and optical properties of each cell component within a non-aqueous organic 1-M LiPF6 EC/DMC liquid electrolyte. Then PVDF-HFP polymer-based stacks, constituted of each plastic electrode separated by a plastic membrane, were built by: (i) holding the layers together by capillarity, and (ii) by hot-lamination of all layers to a single one. Both Devices were investigated for their optical performances. Despite a loss of transmission level, the optical contrast turned out to be higher for the hot-laminated configuration. However, for reasons that will be developed, the Electrochromic efficiency was well below the one expected from solid-state windows. ?? 2001 Elsevier Science B.V.

  • Design and characterization of a three-electrode Electrochromic Device, based on the system WO3/IrO2
    Electrochimica Acta, 1999
    Co-Authors: S. Taunier, Claude Guery, Jean-marie Tarascon
    Abstract:

    We present here the design and the characterization of a three-electrode Electrochromic Device (ECD) based on the WO3/IrO2 system. An Ag/AgCl pseudoreference was designed to be incorporated in the thin polymeric layer of electrolyte separating the Electrochromic WO3 electrode from the IrO2 counter-electrode. This reference electrode enabled an in situ characterization of the WO3 and IrO2 materials, thereby helping in understanding the electrochemical mechanisms arising at each electrode during cycling. The reliability of such three-electrode measurements was also demonstrated by comparing the results obtained in liquid electrolyte with those obtained in the thin film polymer-based ECD.

John R Reynolds - One of the best experts on this subject based on the ideXlab platform.

  • mapping the broad cmy subtractive primary color gamut using a dual active Electrochromic Device
    ACS Applied Materials & Interfaces, 2014
    Co-Authors: Rayford H Bulloch, Justin A Kerszulis, Aubrey L Dyer, John R Reynolds
    Abstract:

    Although synthetic efforts have been fruitful in coarse color control, variations to an Electrochromic polymer (ECP) backbone are less likely to allow for the fine control necessary to access the variations and shades of color needed in display applications. Through the use of thin films of cyan, magenta, and yellow ECPs, non-emissive subtractive color mixing allows the color of an Electrochromic Device (ECD) to be selected and tailored, increasing access to various subtle shades and allowing for a non-emissive display to exhibit a wide range of colors. Using a dual-active ECD, subtractive color mixing utilizing the cyan–magenta–yellow (CMY) primary system was examined. The bounds of the gamut, or the subset of accessible colors, using these three 3,4-propylenedioxythiophene (PProDOT)-derived materials in combination with the recently recognized 3,4-propylenedioxypyrrole-based minimally color changing polymer (MCCP) were mapped, highlighting the benefit of applying subtractive color mixing toward the deve...

  • black to transmissive switching in a pseudo three electrode Electrochromic Device
    Chemistry of Materials, 2009
    Co-Authors: Ece Unur, Pierre M Beaujuge, Stefan Ellinger, Juneho Jung, John R Reynolds
    Abstract:

    We introduce the first π-conjugated polymer-based, black-to-transmissive and multicolored switching Electrochromic Device (ECD) constructed in a Pseudo 3-Electrode Electrochromic Device (P3-ECD) architecture. In this ECD, the non-Electrochromic, yet electroactive, polymer poly(3,4-propylenedioxypyrrole-N-propionitrile) (PProDOP-N-EtCN) serves as a counter electrode material. This transmissive polymer helps eliminate the contrast limitations seen in dual polymer ECDs that use combinations of anodically and cathodically coloring polymers. The P3-ECD adds colors by transmitting light through two independently controlled working electrodes (coated with two different Electrochromic polymer films) and two counter electrodes (coated with PProDOP-N-EtCN) stacked together with a gel electrolyte. The two cathodically coloring EC polymers that were used in this work are, a diester-substituted poly(3,4-propylenedioxythiophene) (PProDOT-(CH2CO2C12H25)2) for the first one, namely PProDOT-ester, and a donor−acceptor ana...

  • perfluoroalkanoate substituted pedot for Electrochromic Device applications
    Advanced Functional Materials, 2003
    Co-Authors: Irina Schwendeman, C L Gaupp, J M Hancock, L Groenendaal, John R Reynolds
    Abstract:

    The recent emergence of organic Electrochromics on both the scientific and industrial levels has expedited the synthesis of new materials with varied electrochemical and optical properties. The structural versatility and broad usage of poly(3,4-ethylenedioxythiophene) (PEDOT) has stimulated many research groups to focus on the potential of PEDOT derivatives. Here we report the first synthesis of pentadecafluoro-octanoic acid 2,3-dihydro-thieno(3,4-b)(1,4)dioxin-2-ylmethylester (EDOT-F), along with its electrochemical polymerization, characterization, and incorporation into Electrochromic Devices (ECDs). PEDOT-F is a cathodically coloring polymer that exhibits sub-second switching time between a dark-blue neutral state and a transmissive sky-blue oxidized state, and expresses a 63 % change for both transmittance at λmax and colorimetrically determined luminance. Hexafluorophosphate-doped free-standing films of PEDOT-F possess conductivities of up to 65 S cm–1. Variable transmittance ECDs constructed with PEDOT-F and poly[3,6-bis(2-(3,4-ethylenedioxythienyl))-N-methylcarbazole] (PBEDOT-NMeCz) exhibit an optical contrast of 60 % at λmax (580 nm) and an overall luminance change of 60 %. Indicating the hydrophobicity of this polymer, doped PEDOT-F exhibits a water contact angle of 110°, significantly higher than the 30° exhibited for the doped PEDOT parent.

Chunye Xu - One of the best experts on this subject based on the ideXlab platform.

  • high performance black to transmissive Electrochromic Device with panchromatic absorption based on tio2 supported viologen and triphenylamine derivatives
    Organic Electronics, 2016
    Co-Authors: Duo Weng, Jianming Zheng, Chunye Xu
    Abstract:

    Abstract A novel black-to-transmissive Electrochromic Device based on TiO 2 -supported viologen and triphenylamine derivatives was designed and constructed via the absorption-complementary approach. In the Device, cathodically coloring Electrochromic material 1,4-bis[(( N -phosphono-2-ethyl)-4,4′-bipyridinium)-methyl]-benzene tetrachloride acted as working electrode and novel anodically coloring Electrochromic material (4-((4-(dimethylamino)-phenyl)(4-methoxyphenyl)-amino)-benzyl) phosphonic acid acted as counter electrode. The assembled Electrochromic Device achieved panchromatic absorption over entire visible spectrum with almost zero transmittance in colored state. The optical contrast (ΔT) of the Device realized in this work was comparable to the highest value (60%) among all reported black-to-transmissive ECDs. Furthermore, excellent cycling stability was achieved, which maintained almost 80% of the initial ΔT value at 570 nm after continuous 100,000 switchings. These outstanding comprehensive Electrochromic performances potentially make this Device a promising candidate for Electrochromic Device applications.

  • aiee active and Electrochromic bifunctional polymer and a Device composed thereof synchronously achieve electrochemical fluorescence switching and Electrochromic switching
    ACS Applied Materials & Interfaces, 2015
    Co-Authors: Sai Mi, Jianming Zheng, Jingchuan Wu, Zhangping Xu, Xingming Wu, Chunye Xu
    Abstract:

    A novel alternating polymer, ProDOT-TPE, with aggregation-enhanced fluorescent emission and Electrochromic properties based on thiophene and tetraphenylethene derivatives was designed, synthesized, and characterized. The polymer displays weak photoluminescence in tetrahydrofuran, but its corresponding film prepared by spray-coating exhibits yellow-green fluorescent light at 540 nm. The color of the polymer film could be switched from bright yellow to navy blue by applying a relatively low voltage. An Electrochromic Device (ECD) of the polymer was fabricated that differs from common ECDs because both its color and fluorescent state could be synchronously switched by an applied voltage, making the polymer a unique candidate for electrochemical fluorescence and Electrochromic applications.

  • highly contrasted and stable Electrochromic Device based on well matched viologen and triphenylamine
    Organic Electronics, 2014
    Co-Authors: Mei Li, Jianming Zheng, Chunye Xu
    Abstract:

    Abstract An Electrochromic Device (ECD) can change color absorption when subjected to an appropriate voltage. Such a Device includes three components: a working electrode, a counter electrode and an electrolyte. Compatibility of these three components is important for ECD’s stability. In this study, two novel compatible Electrochromic materials, cathodic 1-(9-hexyl-9H-carbazole)-1′-(propylphosphonic acid)-4,4′-bipyridilium dichloride and anodic (4-(diphenylamino)phenyl)methylphosphonic acid were designed, synthesized and fabricated into Electrochromic electrodes using a chemisorption method. We characterized the Electrochromic performance of these two electrodes, including the degree of color change, color changing voltage and charge capacity; the results indicated that they matched each other very well. An Electrochromic Device fabricated using these two electrodes, as expected, exhibited rapid, vivid color changes and proved highly stable for up to 100,000 cycles.

  • flexible Electrochromic Device based on poly 3 4 2 2 dimethylpropylenedioxy thiophene
    Electrochimica Acta, 2008
    Co-Authors: Minoru Taya, Chunye Xu
    Abstract:

    In this study, the design, fabrication and characterization of a flexible Electrochromic Device based on indium tin oxide (ITO) coated polyethylene terephthalate (PET) plastic is discussed. The working Electrochromic material film was poly (3,4-(2,2-dimethylpropylenedioxy)thiophene) (PProDOT-Me2), while the counter layer of the Device was vanadium oxide titanium oxide (V2O5/TiO2) composite film, which serves as an ion storage layer. A solution type electrolyte was used as the ionic transport layer and was sandwiched between the working and counter layers. The Device exhibited tuneable light transmittance between transparent and deep blue color, with a maximum contrast ratio at 580 nm wavelength. Other important properties, such as switching speed, life time, and coloration efficiency have been improved.

Claes-göran Granqvist - One of the best experts on this subject based on the ideXlab platform.

  • Oxide Electrochromics: An introduction to Devices and materials
    Solar Energy Materials and Solar Cells, 2012
    Co-Authors: Claes-göran Granqvist
    Abstract:

    Electrochromics is introduced as a key green technology for producing massive energy savings in the built environment, jointly with indoor comfort and financial benefits. The paper discusses basic Electrochromic Device designs, useful oxide materials and their nanostructures, and elements of a theoretical description of the Electrochromic phenomenon. It also surveys critical manufacturing technologies and their pros and cons. Focus is then put on Electrochromic foil technology, which is shown to be capable of mass fabrication via roll-to-roll web coating and continuous lamination. © 2011 Elsevier B.V. All rights reserved.

  • Electrochromic tungsten oxide films: Review of progress 1993
    Solar Energy Materials and Solar Cells, 2000
    Co-Authors: Claes-göran Granqvist
    Abstract:

    W oxide (WO3) films are of critical importance for Electrochromic Device technology, such as for smart windows capable of varying the throughput of visible light and solar energy. This paper reviews the progress that has taken place since 1993 with regard to film deposition, characterization by physical and chemical techniques, optical properties, as well as Electrochromic Device assembly and performance. The main goal is to provide an easy entrance to the relevant scientific literature. (C) 2000 Elsevier Science B.V. All rights reserved. [References: 612]

  • Electrochromism and smart window design
    Solid State Ionics, 1992
    Co-Authors: Claes-göran Granqvist
    Abstract:

    An Electrochromic Device (ECD) has in its center an electrolyte or ion conductor, which is in contact with films that provide optical modulation, ion storage, and (transparent) electrical conduction. We review designs and properties of ECDs, giving special emphasis to transparent Devices, i.e. smart windows. The ECDs are categorized according to the type of electrolyte or ion conductor: liquid, solid inorganic in bulk- or thin-film form, or solid organic (polymer). The Electrochromic film is W oxide; this material is used in the majority of all studied ECDs.

Kuochuan Ho - One of the best experts on this subject based on the ideXlab platform.

  • an Electrochromic Device based on prussian blue self immobilized vinyl benzyl viologen and ferrocene
    Solar Energy Materials and Solar Cells, 2016
    Co-Authors: Hsinche Lu, Tinghsiang Chang, Chungwei Kung, Kuochuan Ho
    Abstract:

    Abstract In this study, the Electrochromic property of vinyl benzyl viologen (VBV) was first investigated and incorporated in an Electrochromic Device (ECD). The polymerizable vinyl moiety of VBV enables a self-immobilization through UV-curing under potential bias. Immobilized VBV (I-VBV) was obtained on the electrode and grafted with polymer electrolyte. An ECD consisted of Prussian blue (PB), I-VBV, and ferrocene (Fc) was fabricated (PB/Fc/I-VBV ECD) in which Fc acted as a redox mediator. With the utilization of polymer electrolyte, Fc, and immobilization of VBV, the proposed PB/Fc/I-VBV ECD with a UV-curing time of 40 s (PB/Fc/I-VBV-40) exhibited the best cell performance among all conditions in terms of long-term stability. It gives 60.6% transmittance change (∆ T ) at 615 nm initially when switched between 1.2 V and −0.8 V. Short bleaching and coloring times of 1.32 s and 2.13 s were achieved respectively. Moreover, good long-term stability was obtained, maintaining 86.5% of its original ∆ T after 10,000 cycles. The PB/Fc/I-VBV ECD also exhibited a unique memory characteristic among all viologens-based ECDs reported in literatures and allowed the possibility for tuneable multi-electrochromism.

  • a complementary Electrochromic Device based on polyaniline and poly 3 4 ethylenedioxythiophene
    Solar Energy Materials and Solar Cells, 2006
    Co-Authors: Kuochuan Ho
    Abstract:

    Abstract In this study, two conducting polymers, polyaniline (PANI) and poly(3,4-ethylenedioxythiophene) (PEDOT), were used to construct an Electrochromic Device (ECD). PANI was employed as the anodic coloring polymer while PEDOT was used as the cathodic coloring polymer. The electrochemical and optical properties of PANI, which has a coloration efficiency of 25 cm 2 /C at 570 nm, were coupled with the complementary coloring material, PEDOT, which has a coloration efficiency of 206 cm 2 /C at 570 nm. A suitable operating potential window was switched between −0.6 and 1.0 V to explore the cycle life of the ECD. We tested the PANI–PEDOT ECD, which consisted of PANI, PEDOT, and an organic electrolyte containing 0.1 M LiClO 4 in propylene carbonate and 1 mM HClO 4 . The transmittance of the ECD at 570 nm changed from 58% (−0.6 V) to 14% (1.0 V) with a coloration efficiency of 285 cm 2 /C. Within the selected operating voltage range, the PANI–PEDOT ECD could be cycled for up to 2×10 4 cycles.

  • the influences of operating voltage and cell gap on the performance of a solution phase Electrochromic Device containing hv and tmpd
    Solid State Ionics, 2003
    Co-Authors: Kuochuan Ho, Yuwen Fang, Yingchan Hsu, Linchi Chen
    Abstract:

    Abstract Electrochromic (EC) behaviors of 1,1′-diheptyl-4,4′-bipyridinium (heptyl viologen; HV) and N , N , N ′, N ′-tetramethyl-1,4-phenylenediamine (TMPD) were studied spectroelectrochemically. Suitable darkening potentials for HV and TMPD were determined to be −1.3 and −0.3 V (vs. Ag/AgClO 4 ), respectively, according to voltammetric and spectroelectrochemical measurements. A solution-phase Electrochromic Device (ECD) was fabricated by sandwiching both HV and TMPD in between two parallel indium tin oxide (ITO) electrodes with an intervening space. The influences of the applied voltage and the cell gap on the single-compartment ECD performance are discussed. The transmittance transients measured at 615 nm suggest that there is no need to darken the ECD beyond 1.0 V, while the ECD can be bleached at 0 V. Self-bleaching was possible with an open circuit. At 615 nm, a typical transmittance change of over 75% was observed. The reversible electrochromism was achieved only when the cell gap was maintained at 0.28 mm or less. Once reversible operating conditions were maintained, a coloration efficiency of 169 cm 2 /C at 615 nm for the ECD was obtained.