Development of organic flow batteries based on abundant raw materials
Flow batteries offer direct scalability, long-duration discharge and flexibility in service mode. They are a technological alternative for relieving expected strains to the future supply of Li-ion batteries for stationary applications. State-of-the-art vanadium flow batteries have demonstrated outstanding performance, but they are presently too expensive for most regions of the world and are dependent on critical minerals.
As a result, flow batteries based on organic molecules with redox activity have been subject of growing attention. It is expected that these compounds, being produced from abundant and widely available chemical commodities, could eventually prove competitive in stationary energy storage. Low cost, high capacity, ease of synthesis and chemical stability are fundamental questions. Selection of compatible, stable chemistries and membranes, improvement of energy density and power output as well as performance at the pilot scale in realistic service conditions are important ongoing tasks.
This project pursuits improvements to flow batteries based on sulfonated anthraquinone, which is available as an industrial redox-mediator for gas desulfurization. This compound is at the moment one of the few available commercially and is thus a benchmark for the development of its synthetic derivatives. Routes are sought in which this compound could be paired with low-cost, semi-organic or inorganic redox species, particularly non-critical elements. Activities involve also the collaborative introduction of new Viologen derivatives along the Institute for Organic Chemistry (TU Clausthal). In this case, synthetic strategies are wanted for the improvement of energy density and capacity retention. It would be possible to take advantage of the large-scale production of this type of compounds achived by the agrochemical industry. Experimental work comprises electrochemical characterizations of redox-active molecules and the evaluation of energy storage performance in laboratory flow batteries.
Dr. Luis Fernando Arenas is sponsored by the Alexander von Humboldt Foundation.