molecular solar thermal energy storage in photoswitch oligomers increases energy densities and storage times - electrical energy storage systems

Molecular optical switches can be highly heterogeneous through light-energy, meta-stable isomers;
We propose a molecular design strategy to realize optical switches with high energy density and long storage time.
High measured energy density of up to 559 K-1 (155u2009Whu2009kg−1)
Storage life of up to 48 years.
For 5 days, a high quantum yield of up to 94% per sub-unit conversion rate was shown in norbornadiene/four-ring (NBD/QC)photo-
The thermal switch pairs contained in the two-Poly and three-Poly structures.
By changing the linker unit between NBD units, we cantune light-
The collection and energy density of dimers and trimers, so that they exceed their monomer analogs.
As a result, these new aggregates meet several criteria that the best molecules need to eventually enter the actual equipment that can go through a solar closed cycle.
Harvesting, energy storage and heat release.
Solar energy is a feasible and inexhaustible source of power generation and heating.
In this case, energy storage is a major challenge due to strong daily and seasonal changes in the supply of sunlight.
Molecular solar thermal energy (MOST)
Systems are a promising way to collect and store solar energy.
In this method, molecules are transformed into higher-
Energy heterogeneous, capable of storing energy until the release of a thermal trigger or catalyst-
A stable homogeneous object for the original light-
Harvesting heterogeneous objects
Due to the high energy difference between norbornadiene, Norbornadienes has proved to be the most promising candidate ()
And four rings ()
Optical heterogeneity of about 96 k _ mol (Fig. )
And the system has been proven to be hot-
Release through the action of cobaltBased on the catalyst.
For these systems, it has been previously shown that the donor-receptor is replaced by red-
The longest moving time
Wavelength absorption, improve the matching of solar spectrum;
Compounds and examples of such derivatives.
For a useful majority of systems, two key challenges are to achieve high enough energy storage density, ideally higher than 300j_kg and Lightroom-
Harvest in visible areas.
Modification of norbornadiene with donor and receptor units has been used to regulate the absorption maximum, but this positive effect on solar absorption is the opposite
Balance by higher molecular weight and lower energy density.
In addition, the positive effects on solar absorption usually also adversely affect the energy storage time, and the energy storage time decreases when the absorption has a red shift.
A possible solution to overcome this opposition
The correlation between the redshift and the energy density we propose here is the coupling of a mass cell with several optical switches.
Here, in the context of/systems, we find that it is attractive to form a dimer or trimer in which units share the same donor and/or receptor.
Previously, dimers of optical switches such as dihydrogen nitrogen benzene, dithienylethenes, even benzene and screw ring were reported.
Even other norbernadiene dimers connected via the phthalatamide bond or the conjugate ketone have been prepared and studied, but the quantum yield is very low.
The idea of this work is to design the stability of high-energy optical heterogeneous objects by having two electronic coupled photoelectric switches with separate thermal conversion barriers (Fig. ).
The reason for this is that there is a blue shift after the first heterogeneity (to )
, Resulting in higher heterogeneous energy for the second switching event (to ).
At the same time, there is a shared donor that can reduce the molecular weight of each Norber Diene unit.
We chose to synthesize two series of dimers and a trimer similar to the previously synthesized donor-acceptor monomer and absorb 358 and 374 nm, respectively.