4:30pm - 5:30pm
Room 209 Havemeyer
New York, NY 10027
When: Friday, April 28, 2017 at 4:30 PM
Where: 209 Havemeyer
Abstract: Large scale energy storage is increasingly a problem for the modern electrical grid. The intermittency of energy sources such as wind and solar can only be mitigated by efficient battery systems. Redox flow batteries (RFBs) are a versatile solution because their power and capacity can be scaled separately. However, aqueous RFBs are limited by the potential window of water while organic RFBs suffer from poor cyclability and low capacity. Here we report a series of compounds derived from perylene diimide (anolyte) and ferrocene (catholyte) that can be tailored for aqueous or organic systems and have demonstrated good stability in static cells. The molecules have high solubilities in many organic solvents and accept/give up multiple electrons, rivalling the energy density of the current state of the art, vanadium batteries. A zwitterionic perylene diimide does not undergo drastic changes in solubility when reduced, unlike originally neutral molecules. Furthermore, since the commercial viability of RFBs is often curtailed by the cost of the membrane, we used an inexpensive size-exclusion membrane that is compatible with the redox potentials of the compounds. The membrane inhibits crossover effectively, leading to a very high Coulombic efficiency. These perylene diimide and ferrocene derivatives are inexpensive aromatic molecules whose stable redox properties allow them to be used in batteries.
Department of Chemistry, Columbia University, Havemeyer Hall, 3000 Broadway, New York, NY 10027, USA | 212-854-2202 | http://chem.columbia.edu/