Reporting on flow battery environment using the intrinsic fluorescence of an organic redoxmer
Reporting on flow battery environment using the intrinsic fluorescence of an organic redoxmer
Lily A. Robertson
Chemical Sciences & Engineering Division, Argonne National Laboratory
Abstract: To meet increasing discrepancies between the supply and demand of the electric grid, large-scale energy storage devices are needed. Redox flow batteries are frequently proposed to fill this gap as their liquid-filled tanks of redox-active material are highly scalable. Liquid electrolytes using nonaqueous solvents are of particular interest due to their wide electrochemical stability windows with inexpensive organic compounds acting as the redox-active species. In general, methods to track the state of health of the batteries lag far behind the development and study of new materials. The questions of how and why materials fail and whether batteries may be cured like a patient are pertinent. Most monitoring techniques examine state of charge changes and/or require aliquots of the flow battery solution. Not as many focus on in situ methods or other health issues such as species crossover. Therefore, we pursued a detailed study of new organic redox-active species (鈥渞edoxmers鈥) that are both strong flow battery performers and have an orthogonal 鈥渟elf-reporting鈥 property that does not interfere with battery operation.[i] Here, we show that an organic anolyte redoxmer, 2,1,3-benzothiadiazole, can be synthetically modified using 蟺-extending acetamide groups to have strong emissive properties useful for self-reporting. The redoxmer design had substantial impact on electrochemical performance with simple N-alkylation of the acetamide group giving optimal performance. Strong ion-molecule interactions were observed depending on supporting electrolyte choice in both states of charge. Finally, we used the strong emission of the redoxmer to track crossover of several practical flow solution conditions in real time. To our knowledge, our study is the first time fluorescence has been used to monitor a state of health property in a flow cell design.
[i] Robertson, L. A.; Shkrob, I. A.; Agarwal, G.; Zhao, Y.; Yu, Z.; Assary, R. S.; Cheng, L.; Moore, J. S.; Zhang, L. Fluorescence-enabled Self-reporting for Redox Flow Batteries. ACS Energy Lett. 2020, 5, 3062鈥3068.
Bio: Morgan Stefik obtained a B.E. in Materials Engineering from Cal Poly SLO in 2005 and a Ph.D. in Materials Science from Cornell University in 2010. After postdoctoral research at 脡cole Polytechnique F茅d茅rale de Lausanne, he joined the University of South Carolina in 2013 in the Department of 糖心vlog官方入口 and Biochemistry. He was awarded an NSF-CAREER in 2018 and is the founding director of the South Carolina SAXS Collaborative. He was highlighted as a 鈥渞ising star of materials chemistry鈥 by RSC in 2017, was recognized as a Breakthrough Star by USC in 2018, and was elected to the council of the International Mesostructured Materials Association in 2018. Most recently, he was promoted to Associate Professor with tenure in 2019.
Bio: Jonathan Pham is an Assistant Professor of Materials Engineering at the 糖心vlog官方入口. He received a PhD in Polymer Science and Engineering from the University of Massachusetts Amherst where he investigated nanoparticle assembly and mechanics. During this time, he was a Chateaubriand fellow at ESPCI-ParisTech investigating deformation of microscale helical filaments in microfluidics. Prior to joining Kentucky, he was a Humboldt Postdoctoral Fellow at the Max Planck Institute for Polymer Research working on a range of topics, including cell-surface interactions and liquid drop impact.
