| 1. |
- Dreos, Ambra, 1987, et al.
(författare)
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Liquid Norbornadiene Photoswitches for Solar Energy Storage
- 2018
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Ingår i: Advanced Energy Materials. - : Wiley. - 1614-6832 .- 1614-6840. ; 8:18
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Tidskriftsartikel (refereegranskat)abstract
- Due to high global energy demands, there is a great need for development of technologies for exploiting and storing solar energy. Closed cycle systems for storage of solar energy have been suggested, based on absorption of photons in photoresponsive molecules, followed by on-demand release of thermal energy. These materials are called solar thermal fuels (STFs) or molecular solar thermal (MOST) energy storage systems. To achieve high energy densities, ideal MOST systems are required either in solid or liquid forms. In the case of the latter, neat high performing liquid materials have not been demonstrated to date. Here is presented a set of neat liquid norbornadiene derivatives for MOST applications and their characterization in toluene solutions and neat samples. Their synthesis is in most cases based on solvent-free Diels-Alder reactions, which easily and efficiently afford a range of compounds. The shear viscosity of the obtained molecules is close to that of colza oil, and they can absorb up to 10% of the solar spectrum with a measured energy storage density of up to 577 kJ/kg corresponding to 152 kJ mol(-1) (calculated 100 kJ mol(-1)). These findings pave the way towards implementation of liquid norbornadienes in closed cycle energy storage technologies.
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| 2. |
- Wang, Zhihang, 1989, et al.
(författare)
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Evaluating Dihydroazulene/Vinylheptafulvene Photoswitches for Solar Energy Storage Applications
- 2017
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Ingår i: Chemsuschem. - : Wiley. - 1864-5631 .- 1864-564X. ; 10:15, s. 3049-3055
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Tidskriftsartikel (refereegranskat)abstract
- Efficient solar energy storage is a key challenge in striving toward a sustainable future. For this reason, molecules capable of solar energy storage and release through valence isomerization, for so-called molecular solar thermal energy storage (MOST), have been investigated. Energy storage by photo-conversion of the dihydroazulene/vinylheptafulvene (DHA/VHF) photothermal couple has been evaluated. The robust nature of this system is determined through multiple energy storage and release cycles at elevated temperatures in three different solvents. In a nonpolar solvent such as toluene, the DHA/VHF system can be cycled more than 70 times with less than 0.01% degradation per cycle. Moreover, the [Cu(CH(3)CN4] P-6-catalyzed conversion of VHF into DHA was demonstrated in a flow reactor. The performance of the DHA/VHF couple was also evaluated in prototype photoconversion devices, both in the laboratory by using a flow chip under simulated sunlight and under outdoor conditions by using a parabolic mirror. Device experiments demonstrated a solar energy storage efficiency of up to 0.13% in the chip device and up to 0.02% in the parabolic collector. Avenues for future improvements and optimization of the system are also discussed.
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