Researchers at University of Rochester, working with colleagues at the University at Buffalo, believe they have found a promising compound that could transform the energy storage landscape.
In a paper published in Chemical Science, an open access journal of the Royal Society of Chemistry, researchers in the lab of Ellen Matson, assistant professor of chemistry, describe modifying a metal-oxide cluster, which has promising electroactive properties, so that it is nearly twice as effective as the unmodified cluster for electrochemical energy storage in a redox flow battery.
The cluster was first developed in the lab of German chemist Johann Spandl, and studied for its magnetic properties. Tests conducted by VanGelder showed that the compound could store charge in a redox flow battery, “but was not as stable as we had hoped.”
The key to a redox flow battery is finding chemicals that can not only “carry” sufficient charge, but also be stored without degrading for long periods, thereby maximizing power generation and minimizing the costs of replenishing the system.
By making what Matson describes as “a simple molecular modification”— replacing the compound’s methanol-derived methoxide groups with ethanol-based ethoxide ligands—the team was able to expand the potential window during which the cluster was stable, doubling the amount of electrical energy that could be stored in the battery.
“The straightforward, efficient synthesis of this system is a totally new direction in charge-carrier development that, we believe, will set a new standard in the field,” said Matson.
The electrochemical testing required for this study involved equipment and techniques not previously used in the Matson lab. Hence the collaboration with Timothy Cook, assistant professor of chemistry at the University of Buffalo, and Anjula Kosswattaarachchi, a fourth-year graduate student in the Cook lab. VanGelder visited the Cook lab for training on testing equipment, and in turn helped Kosswattaarachchi with synthesizing compounds.
Matson stressed the “crucial role” played by lead author Lauren VanGelder, a third-year PhD student in Matson’s lab. VanGelder conducted the initial testing and experiments on the clusters while Matson was on maternity leave.
The two groups have applied for a National Science Foundation grant as part of an ongoing collaboration to further refine the clusters for use in commercial redox flow batteries.
A University Furth Fund Award that Matson received last year enabled the lab to purchase electrochemical equipment needed for the study. Patrick Forrestal ’19 of the Matson lab also contributed to the study.
Photo: Ellen Matson, left, assistant professor of chemistry, and PhD student Lauren VanGelder at work in Matson's lab. (University of Rochester photo / Bob Marcotte)