Electricity from renewable energy sources such as sun or wind is only available when the wind blows and the sun shines. If little electricity is needed at this time, it is very difficult to store the remaining electricity. New concepts are in demand – and the researchers at FAU in the Department of Chemistry and Pharmacy are focusing on chemical concepts for energy storage.
In two joint projects, the scientists are looking for new ideas for molecular solar energy storage and are investigating molecules and processes that enable both efficient storage and controlled energy release. It is even conceivable that the stored chemical energy could be directly converted into electrical energy. A vision that would enable the construction of an “energy-storing solar cell”.
The research work is based on the so-called “norbornadiene quadricyclane storage system”. The substances norbornadiene (NBD) and quadricyclane (QC) are hydrocarbons and have long been discussed by experts as potential candidates for the storage of solar energy: Under the influence of light, the molecule norbornadiene can transform into quadricyclane in a reaction within the molecule. This achieves an energy density equivalent to that of a high-performance battery. Because of this property, quadricyclane is also known as “solar fuel”.
The sub-project “Photochemically and magnetochemically triggered storage / release of solar energy in strained organic compounds” is headed by Dirk Guldi and Andreas Hirsch. The scientists are working on the production of various new families of NBD and QC derivatives. In addition, they systematically investigate the influence of photosensitizers and electron acceptors as well as solvents and magnetic fields within this process. The long-term goal of the researchers is to realize a closed system fuel cycle for molecular storage media.
In the sub-project “Catalytic and electrochemical reproduction of solar energy stored in tense organic compounds” Julien Bachmann, Jörg Libuda and Christian Papp are together developing new catalyst systems and electrodes with which chemical energy can be converted directly into electrical energy. Their goal: They want to prove this functional principle conceptually by means of hybrid interfaces with suitable electronic structure, chemical structure and electrochemical stability.
The results of both subprojects together could form the basis for the construction of an “energy-storing solar cell”. The electricity generated in sunshine could be stored intelligently via intramolecular reactions and used highly efficiently.
This research project was funded by the German Research Foundation.