Evaluating Dihydroazulene/Vinylheptafulvene Photoswitches for Solar Energy Storage Applications

TY - JOUR

T1 - Evaluating Dihydroazulene/Vinylheptafulvene Photoswitches for Solar Energy Storage Applications

AU - Wang, Zhihang

AU - Udmark, Jonas

AU - Börjesson, Karl

AU - Rodrigues, Rita

AU - Roffey, Anna

AU - Abrahamsson, Maria

AU - Nielsen, Mogens Brøndsted

AU - Moth-Poulsen, Kasper

PY - 2017/8/10

Y1 - 2017/8/10

N2 - 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 photoconversion 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(CH3CN)4]PF6-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.

AB - 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 photoconversion 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(CH3CN)4]PF6-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.

U2 - 10.1002/cssc.201700679

DO - 10.1002/cssc.201700679

M3 - Journal article

C2 - 28644559

SN - 1864-5631

VL - 10

SP - 3049

EP - 3055

JO - ChemSusChem

JF - ChemSusChem

IS - 15

ER -