scholarly journals Gate-controlled VO2 phase transition for high-performance smart windows

2019 ◽  
Vol 5 (3) ◽  
pp. eaav6815 ◽  
Author(s):  
Shi Chen ◽  
Zhaowu Wang ◽  
Hui Ren ◽  
Yuliang Chen ◽  
Wensheng Yan ◽  
...  
Keyword(s):  
Phase Transition ◽  
Solar Energy ◽  
Energy Saving ◽  
High Performance ◽  
Light Transmittance ◽  
Energy Regulation ◽  
Practical Application ◽  
Theoretical Limit ◽  
Smart Windows ◽  
Infrared Transmittance

Vanadium dioxide (VO2) is a promising material for developing energy-saving “smart windows,” owing to its infrared thermochromism induced by metal-insulator transition (MIT). However, its practical application is greatly limited by its relatively high critical temperature (~68°C), low luminous transmittance (<60%), and poor solar energy regulation ability (<15%). Here, we developed a reversible and nonvolatile electric field control of the MIT of a monoclinic VO2 film. With a solid electrolyte layer assisting gating treatment, we modulated the insertion/extraction of hydrogen into/from the VO2 lattice at room temperature, causing tristate phase transitions that enable control of light transmittance. The dramatic increase in visible/infrared transmittance due to the phase transition from the metallic (lightly H-doped) to the insulating (heavily H-doped) phase results in an increased solar energy regulation ability up to 26.5%, while maintaining 70.8% visible luminous transmittance. These results break all previous records and exceed the theoretical limit for traditional VO2 smart windows, making them ready for energy-saving utilization.

Hydrogel smart windows

2020 ◽  
Vol 8 (20) ◽  
pp. 10007-10025 ◽  
Author(s):  
Yang Zhou ◽  
Xiaoxiao Dong ◽  
Yuanyuan Mi ◽  
Fan Fan ◽  
Quan Xu ◽  
...  
Keyword(s):  
Energy Saving ◽  
Recent Progress ◽  
Light Transmittance ◽  
Solar Light ◽  
Smart Windows

Smart windows are a promising way to modulate solar light transmittance, which is crucial for energy saving buildings. We provide an overview of the recent progress in hydrogel-based smart windows.

scholarly journals Energy-Efficient Smart Window Based on Thermochromic Hydrogel with Ultrahigh Visible Transparency and Unprecedented Infrared Transmittance Modulation

2021 ◽  
Author(s):  
Rong Zhang ◽  
Bo Xiang ◽  
Min Feng ◽  
Liru Xia ◽  
Lei Xu ◽  
...  
Keyword(s):  
Energy Saving ◽  
Superior Performance ◽  
Significant Advance ◽  
Solar Modulation ◽  
Smart Window ◽  
Smart Windows ◽  
Responsive Materials ◽  
Infrared Transmittance ◽  
Potential Applications ◽  
Glass Panels

Abstract Both high visible transparency and strong solar modulating ability are highly required for energy-saving smart windows, but conventional responsive materials usually have low transparency and narrow solar transmittance range. Herein, we report a significant advance toward the design and fabrication of responsive smart windows by trapping novel V0.8W0.2O2@SiO2 doped poly(N-isopropyl acrylamide) (PNIPAm) thermochromic liquid hydrogel within two glass panels. The smart window is highly transparent to allow solar transmittance at low temperatures, while turns opaque automatically to cut off solar energy gain when exposed in sunlight. With a remarkably low content (1.0wt‰) of dopant, V0.8W0.2O2@SiO2/PNIPAm (VSP) hydrogels exhibit ultrahigh luminous transmittance Tlum of 92.48% and solar modulation ∆Tsol of 77.20%. The superior performance is mainly attributed to that V0.8W0.2O2@SiO2 doping induces PNIPAm particles’ size reduction and internal structure change. W-doping decreases the phase transition temperature (Tc) of VO2 from 68 ºC to ~30 ºC (close to the Tc of PNIPAm), contributing to an unprecedented infrared transmittance modulation. Especially, the smart window shows excellent energy-saving during daytime outdoor demonstrations where practically achievable cooling temperature reaches up to 15.1 ºC. In addition, the smart window exhibits outstanding stability, as embodied by unchanged optical performance even after 100 transparency-opaqueness reversible cycles. This new type of thermochromic hydrogel offering unique advantages of shape-independence, scalability together with soundproof functionality promises potential applications in energy-saving buildings and greenhouses.

Energy-Efficient Smart Window Based on Thermochromic Microgel with Ultrahigh Visible Transparency and Infrared Transmittance Modulation

2021 ◽  
Author(s):  
Rong Zhang ◽  
Bo Xiang ◽  
Yuchun Shen ◽  
Liru Xia ◽  
Lei Xu ◽  
...  
Keyword(s):  
Energy Saving ◽  
Energy Efficient ◽  
Smart Window ◽  
Smart Windows ◽  
Responsive Materials ◽  
Infrared Transmittance

Both high visible transparency and strong solar modulating ability are highly required for energy-saving smart windows, but conventional responsive materials usually have low transparency and narrow solar transmittance range. Herein,...

Vertically distributed VO2nanoplatelets on hollow spheres with enhanced thermochromic properties

2018 ◽  
Vol 6 (29) ◽  
pp. 7896-7904 ◽  
Author(s):  
Huiyan Xu ◽  
Zhengfei Dai ◽  
Chen Wang ◽  
Kewei Xu ◽  
Fei Ma ◽  
...  
Keyword(s):  
Phase Transition ◽  
Energy Saving ◽  
Vanadium Dioxide ◽  
Hollow Spheres ◽  
Smart Windows ◽  
Thermochromic Properties

Vanadium dioxide (VO2) is a phase-transition material exhibiting great potential in the field of smart windows for energy saving.

WO3/TiO2 core–shell nanostructure for high performance energy-saving smart windows

2015 ◽  
Vol 133 ◽  
pp. 32-38 ◽  
Author(s):  
Bohr-Ran Huang ◽  
Tzu-Ching Lin ◽  
Ying-Ming Liu
Keyword(s):  
Energy Saving ◽  
High Performance ◽  
Core Shell ◽  
Smart Windows

Research and Development of Solar Energy Automatic Bird Expeller Device

2012 ◽  
Vol 466-467 ◽  
pp. 1181-1185
Author(s):  
Guang Jian Chen
Keyword(s):  
Solar Energy ◽  
Energy Saving ◽  
Software Design ◽  
Emission Reduction ◽  
Solar Photovoltaic ◽  
Practical Application ◽  
New Energy ◽  
Voice Technology ◽  
Development And Utilization ◽  
Application Prospects

In respond to the national energy saving, emission reduction, and development and utilization of new energy, and with the objective of practical application, a set of solar energy automatic bird expeller device is designed with solar photovoltaic technology, singlechip technology, and digital voice technology. The paper proposes systematic integral design scheme, and focuses on the description of system hardware and software design. The bird expeller device designed is energy-saving, environmentally-friendly, convenient to use, and has good application prospects.

Efficient Co-Harvesting of Solar Energy and Low-Grade Heat by Molecular Photoswitches for High Energy Density, Long-Term Stable Solar Thermal Battery

2019 ◽  
Author(s):  
Zhao-Yang Zhang ◽  
Tao LI
Keyword(s):  
Energy Density ◽  
Solar Energy ◽  
High Performance ◽  
High Energy ◽  
Solar Thermal ◽  
High Energy Density ◽  
Low Grade ◽  
Thermal Battery ◽  
Low Grade Heat

Solar energy and ambient heat are two inexhaustible energy sources for addressing the global challenge of energy and sustainability. Solar thermal battery based on molecular switches that can store solar energy and release it as heat has recently attracted great interest, but its development is severely limited by both low energy density and short storage stability. On the other hand, the efficient recovery and upgrading of low-grade heat, especially that of the ambient heat, has been a great challenge. Here we report that solar energy and ambient heat can be simultaneously harvested and stored, which is enabled by room-temperature photochemical crystal-to-liquid transitions of small-molecule photoswitches. The two forms of energy are released together to produce high-temperature heat during the reverse photochemical phase change. This strategy, combined with molecular design, provides high energy density of 320-370 J/g and long-term storage stability (half-life of about 3 months). On this basis, we fabricate high-performance, flexible film devices of solar thermal battery, which can be readily recharged at room temperature with good cycling ability, show fast rate of heat release, and produce high-temperature heat that is >20<sup> o</sup>C higher than the ambient temperature. Our work opens up a new avenue to harvest ambient heat, and demonstrate a feasible strategy to develop high-performance solar thermal battery.

Efficient Co-Harvesting of Solar Energy and Low-Grade Heat by Molecular Photoswitches for High Energy Density, Long-Term Stable Solar Thermal Battery

2019 ◽  
Author(s):  
Zhao-Yang Zhang ◽  
Tao LI
Keyword(s):  
Energy Density ◽  
Solar Energy ◽  
High Performance ◽  
High Energy ◽  
Solar Thermal ◽  
High Energy Density ◽  
Low Grade ◽  
Thermal Battery ◽  
Low Grade Heat

Solar energy and ambient heat are two inexhaustible energy sources for addressing the global challenge of energy and sustainability. Solar thermal battery based on molecular switches that can store solar energy and release it as heat has recently attracted great interest, but its development is severely limited by both low energy density and short storage stability. On the other hand, the efficient recovery and upgrading of low-grade heat, especially that of the ambient heat, has been a great challenge. Here we report that solar energy and ambient heat can be simultaneously harvested and stored, which is enabled by room-temperature photochemical crystal-to-liquid transitions of small-molecule photoswitches. The two forms of energy are released together to produce high-temperature heat during the reverse photochemical phase change. This strategy, combined with molecular design, provides high energy density of 320-370 J/g and long-term storage stability (half-life of about 3 months). On this basis, we fabricate high-performance, flexible film devices of solar thermal battery, which can be readily recharged at room temperature with good cycling ability, show fast rate of heat release, and produce high-temperature heat that is >20<sup> o</sup>C higher than the ambient temperature. Our work opens up a new avenue to harvest ambient heat, and demonstrate a feasible strategy to develop high-performance solar thermal battery.

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