The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Claes-göran Granqvist - One of the best experts on this subject based on the ideXlab platform.
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electrochromic materials and devices for energy efficiency and human comfort in buildings a critical review
Electrochimica Acta, 2018Co-Authors: Claes-göran Granqvist, Miguel A Arvizu, Bayrak I Pehlivan, Ruitao Wen, Gunnar A. NiklassonAbstract:Abstract 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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oxide based chromogenic coatings and devices for energy efficient fenestration brief survey and update on thermochromics and Electrochromics
Journal of Vacuum Science & Technology B, 2014Co-Authors: Claes-göran GranqvistAbstract:Modern buildings often have large windows and glass facades in order to achieve good day-lighting and desirable indoors–outdoors contact. These glazings are challenging with regard to the buildings' energy efficiency and frequently let in or out too much energy; this phenomenon has to be balanced by energy guzzling cooling or heating. In particular, the cooling requirement has grown strongly in recent years. Chromogenic glazings, based on thermochromism or electrochromism, are emerging technologies that can regulate the inflow of visible light and solar energy between widely separated limits and create better energy efficiency than is possible with static solutions. Thermochromic thin films—in practice based on vanadium dioxide—have a transmittance of infrared solar radiation that is smaller at high temperature than at low temperature. Electrochromic multilayer structures—often incorporating nanoporous thin films of tungsten oxide and nickel oxide—are able to vary the transmittance of visible light and solar energy when a low voltage is applied for a short time so as to shuttle charge between the two oxide films. Furthermore, and importantly, the new chromogenic fenestration technologies are able to improve indoor comfort. This brief tutorial review surveys the fields of oxide-based thermochromics and Electrochromics with particular attention to recent advances.
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chromogenic fenestration for energy efficient buildings recent progress in thermochromics and Electrochromics
2014 MRS Fall Meeting & Exhibit Boston USA November 30-December 5 2014, 2014Co-Authors: Claes-göran GranqvistAbstract:Chromogenic Fenestration for Energy Efficient Buildings: Recent Progress in Thermochromics and Electrochromics
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towards a new paradigm for energy efficient buildings Electrochromics thermochromics and more
TCM2014 - 5th International SYmposium on Transparent Conductive Materials Chania Crete Greece October 12-17 2014, 2014Co-Authors: Claes-göran GranqvistAbstract:Towards a New Paradigm for Energy Efficient Buildings: Electrochromics, Thermochromics, and More
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transparent conducting nanoparticle coatings for energy efficient fenestration applications in Electrochromics and thermochromics
Society of Vacuum Coaters Annual Technical Conference, 2014Co-Authors: Claes-göran Granqvist, Bayrak I Pehlivan, Gunnar A. NiklassonAbstract:Transparent Conducting Nanoparticle Coatings for Energy Efficient Fenestration: Applications in Electrochromics and Thermochromics
Jim Yang Lee - One of the best experts on this subject based on the ideXlab platform.
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plasmonic oxygen deficient tio2 x nanocrystals for dual band electrochromic smart windows with efficient energy recycling
Advanced Materials, 2020Co-Authors: Shengliang Zhang, Sheng Cao, Tianran Zhang, Jim Yang LeeAbstract:Dual-band electrochromic smart windows capable of the spectrally selective modulation of visible (VIS) light and near-infrared (NIR) can regulate solar light and solar heat transmittance to reduce the building energy consumption. The development of these windows is however limited by the number of available dual-band electrochromic materials. Here, plasmonic oxygen-deficient TiO2-x nanocrystals (NCs) are discovered to be an effective single-component dual-band electrochromic material, and that oxygen-vacancy creation is more effective than aliovalent substitutional doping to introduce dual-band properties to TiO2 NCs. Oxygen vacancies not only confer good near-infrared (NIR)-selective modulation, but also improve the Li+ diffusion in the TiO2-x host, circumventing the disadvantage of aliovalent substitutional doping with ion diffusion. Consequently optimized TiO2-x NC films are able to modulate the NIR and visible light transmittance independently and effectively in three distinct modes with high optical modulation (95.5% at 633 nm and 90.5% at 1200 nm), fast switching speed, high bistability, and long cycle life. An impressive dual-band electrochromic performance is also demonstrated in prototype devices. The use of TiO2-x NCs enables the assembled windows to recycle a large fraction of energy consumed in the coloration process ("energy recycling") to reduce the energy consumption in a round-trip electrochromic operation.
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al3 intercalation de intercalation enabled dual band electrochromic smart windows with a high optical modulation quick response and long cycle life
Energy and Environmental Science, 2018Co-Authors: Shengliang Zhang, Sheng Cao, Tianran Zhang, Adrian C Fisher, Jim Yang LeeAbstract:Dual-band electrochromic smart windows with independent control of the transmittance of near-infrared (NIR) and visible (VIS) light can contribute significantly to the reduction of building energy consumption. Cost and inadequate electrochromic performance are the current technical challenges. We present here a dual-band electrochromic smart window design based on the intercalation/de-intercalation of Al3+ cations to replace the common use of monovalent cations in electrochromic applications. The Al3+ intercalation/de-intercalation-enabled electrochromic smart window delivers not only efficient and independent control of NIR and VIS light transmittance, but also impressive electrochromic performance – a high optical modulation of the full solar spectrum (93.2%, 91.7%, 88.5%, and 86.8% at 633, 800, 1200, and 1600 nm, respectively), high coloration efficiencies (254 and 121 cm2 C−1 at 1200 and 633 nm, respectively), fast switching times (8/5 s and 16/13 s at 1200 and 633 nm, respectively, for coloration/bleaching), and high bistability and cyclability (a 5.5% capacity loss after 2000 cycles). The good electrochromic performance can be attributed to the effective diffusion of Al3+ in the electrochromic material (as good as that of Li+); and a shallow intercalation/de-intercalation depth enabled by the ability of Al3+ to support three-electron redox reactions. The performance of Al3+ intercalation/de-intercalation-enabled dual-band electrochromism was also verified in laboratory prototype devices to confirm its suitability for dual-band smart windows.
Shengliang Zhang - One of the best experts on this subject based on the ideXlab platform.
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plasmonic oxygen deficient tio2 x nanocrystals for dual band electrochromic smart windows with efficient energy recycling
Advanced Materials, 2020Co-Authors: Shengliang Zhang, Sheng Cao, Tianran Zhang, Jim Yang LeeAbstract:Dual-band electrochromic smart windows capable of the spectrally selective modulation of visible (VIS) light and near-infrared (NIR) can regulate solar light and solar heat transmittance to reduce the building energy consumption. The development of these windows is however limited by the number of available dual-band electrochromic materials. Here, plasmonic oxygen-deficient TiO2-x nanocrystals (NCs) are discovered to be an effective single-component dual-band electrochromic material, and that oxygen-vacancy creation is more effective than aliovalent substitutional doping to introduce dual-band properties to TiO2 NCs. Oxygen vacancies not only confer good near-infrared (NIR)-selective modulation, but also improve the Li+ diffusion in the TiO2-x host, circumventing the disadvantage of aliovalent substitutional doping with ion diffusion. Consequently optimized TiO2-x NC films are able to modulate the NIR and visible light transmittance independently and effectively in three distinct modes with high optical modulation (95.5% at 633 nm and 90.5% at 1200 nm), fast switching speed, high bistability, and long cycle life. An impressive dual-band electrochromic performance is also demonstrated in prototype devices. The use of TiO2-x NCs enables the assembled windows to recycle a large fraction of energy consumed in the coloration process ("energy recycling") to reduce the energy consumption in a round-trip electrochromic operation.
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al3 intercalation de intercalation enabled dual band electrochromic smart windows with a high optical modulation quick response and long cycle life
Energy and Environmental Science, 2018Co-Authors: Shengliang Zhang, Sheng Cao, Tianran Zhang, Adrian C Fisher, Jim Yang LeeAbstract:Dual-band electrochromic smart windows with independent control of the transmittance of near-infrared (NIR) and visible (VIS) light can contribute significantly to the reduction of building energy consumption. Cost and inadequate electrochromic performance are the current technical challenges. We present here a dual-band electrochromic smart window design based on the intercalation/de-intercalation of Al3+ cations to replace the common use of monovalent cations in electrochromic applications. The Al3+ intercalation/de-intercalation-enabled electrochromic smart window delivers not only efficient and independent control of NIR and VIS light transmittance, but also impressive electrochromic performance – a high optical modulation of the full solar spectrum (93.2%, 91.7%, 88.5%, and 86.8% at 633, 800, 1200, and 1600 nm, respectively), high coloration efficiencies (254 and 121 cm2 C−1 at 1200 and 633 nm, respectively), fast switching times (8/5 s and 16/13 s at 1200 and 633 nm, respectively, for coloration/bleaching), and high bistability and cyclability (a 5.5% capacity loss after 2000 cycles). The good electrochromic performance can be attributed to the effective diffusion of Al3+ in the electrochromic material (as good as that of Li+); and a shallow intercalation/de-intercalation depth enabled by the ability of Al3+ to support three-electron redox reactions. The performance of Al3+ intercalation/de-intercalation-enabled dual-band electrochromism was also verified in laboratory prototype devices to confirm its suitability for dual-band smart windows.
A Y Elezzabi - One of the best experts on this subject based on the ideXlab platform.
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rechargeable aqueous electrochromic batteries utilizing ti substituted tungsten molybdenum oxide based zn2 ion intercalation cathodes
Advanced Materials, 2019Co-Authors: Liam Mcrae, C J Firby, A Y ElezzabiAbstract:Batteries are used in every facet of human lives. Desirable battery architectures demand high capacity, rechargeability, rapid charging speed, and cycling stability, all within an environmentally friendly platform. Many applications are limited by opaque batteries; thus, new functionalities can be unlocked by introducing transparent battery architectures. This can be achieved by incorporating electrochromic and energy storage functions. Transparent electrochromic batteries enable new applications, including variable optical attenuators, optical switches, addressable displays, touch screen devices, and most importantly smart windows for energy-efficient buildings. However, this technology is in the incipient state due to limited electrochromic materials having satisfactory optical contrast and capacity. As such, triggering electrochromism via Zn2+ intercalation is advantageous: Zn is abundant, safe, easily processed in aqueous electrolytes and provides two electrons during redox reactions. Here, enhanced Zn2+ intercalation is demonstrated in Ti-substituted tungsten molybdenum oxide, yielding improved capacity and electrochromic performance. This technique is employed to engineer cathodes exhibiting an areal capacity of 260 mAh m-2 and high optical contrast (76%), utilized in the fabrication of aqueous Zn-ion electrochromic batteries. Remarkably, these batteries can be charged by external voltages and self-recharged by spontaneously extracting Zn2+ , providing a new technology for practical electrochromic devices.
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nanohybridization of molybdenum oxide with tungsten molybdenum oxide nanowires for solution processed fully reversible switching of energy storing smart windows
Nano Energy, 2018Co-Authors: Liam Mcrae, C J Firby, Mohamed Alhussein, A Y ElezzabiAbstract:Abstract A multi-functional electrochromic material which modulates light over a wide spectral range and stores electrical energy is an intriguing substance, which would lead to a variety of novel applications, such as smart windows for energy-efficient buildings, solar power storage, nonemissive displays, electronic paper, optoelectronic switches, and variable-reflectance mirrors/surfaces. Developing such a versatile material entails merging the electrochromic phenomenon with electrical-chemical energy conversions in an electrochromic-battery platform. However, the challenges related to transition metal oxide electrochromic-batteries include poor energy storage, low optical contrast, and high fabrication cost. Here, we demonstrate the synthesis of aqueous nanocrystalline colloidal molybdenum oxide in a matrix of tungsten molybdenum oxide (MoO3-W0.71Mo0.29O3) for solution-processed fully reversible switching electrochromic-battery electrodes. The hybrid material exhibits both 50% optical contrast modulation over a wide optical bandwidth and an improved Columbic efficiency. An 8 × 8 cm2 energy storing smart (ESS) window is assembled to demonstrate a functional prototype that can power an LED for more than 10 min when charged under −2.5 V for 1 min. The enhanced electrochromic performance, high energy storage capacity, simple solution processability, versatility for large area fabrication, and low cost make this nanocrystalline MoO3-W.71Mo.29O3 composite a promising material with the potential to be deployed ubiquitously in energy-efficient smart window architectures.
M L Keshtov - One of the best experts on this subject based on the ideXlab platform.
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fast switching electrochromic nanocomposite based on poly pyridinium salt and multiwalled carbon nanotubes
Electrochimica Acta, 2018Co-Authors: Roman D Pichugov, E E Makhaeva, M L KeshtovAbstract:Abstract This paper represents a simple approach to modulate electrochromic properties of poly (4,4′-(1,4-phenylene)bis (2,6-diphenylpyridinium) triflate) (PV) by the formation of composite material with multiwalled carbon nanotubes. The polymer acts as a functionalizing agent for MWCNTs to prevent their agglomeration enabling the formation of stable dispersions. They were further used to prepare uniform electrochromic films by spin-coating method. The films were characterized by electrochemical and spectroelectrochemical methods. To evaluate the influence of MWCNTs on the electrochromic properties of PV the dispersions with various PV/MWCNTs compositions were studied. Upon the addition of MWCNTs the absorption bands and redox peak potentials of polymer did not change. However, the decrease of the peak separation between reductive and oxidative waves and the significant improvement of switching times (one of the most important properties of electrochromic materials) were demonstrated. At the practically identical optical contrast both coloration and bleaching times decreased that can be explained by the composite film morphology. This effect became significant for high PV concentrations in the initial solution. The decrease of coloration and bleaching times reached 30% and 50%, respectively. The resulting composite material exhibited fast (200–400 ms) response times and could be used as a promising candidate for novel electrochromic devices.
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synthesis of aromatic poly pyridinium salt s and their electrochromic properties
Materials Chemistry and Physics, 2013Co-Authors: M L Keshtov, Levent Toppare, Arslan Y Udum, V S Kochurov, A R KhokhlovAbstract:Abstract Synthesis of a series of new conjugated electrochromic polymeric pyridinium salts containing main-chain triphenylamine and their electrochromic properties were demonstrated. All polymers exhibit intense UV absorptions at 336–338 nm in DMF and 340–343 nm in thin film form and fluorescence centered at 410–438 nm in DMF and 460–461 nm in thin film form. The electrochromic properties of the films were investigated by electrochemical and spectroelectrochemical methods. Reversible redox signals with stable electrochromic characteristics were obtained via cyclic voltammetry. The electrochromic properties of the polymers remain highly stable after 50 cycles between 0 and 1.2 V.