Computational Screening of Electroactive Biobased-Phthalimide Molecules for Redox Flow Batteries

In the search of sustainable materials for energy storage, phthalimide-based compounds have shown great potential as anolytes for redox flow batteries (RFBs). Here, we conducted a high-throughput computational screening of 5,705 phthalimide derivatives, including a strategically designed subset of biobased candidates derived from renewable platform chemicals. Structure-property analyses, grounded in principles of physical organic chemistry, were employed to elucidate key trends related to redox potential, radical stability, and solubility, properties critical to RFB performance. Statistical modeling and clustering analysis further refined the selection of optimal candidates. From these efforts, a promising biobased compound was identified, and a closely related derivative was synthesized via a sustainable Diels-Alder route. Electrochemical characterization revealed quasi-reversible redox behavior, high solubility in acetonitrile, and exceptional cycling stability over 2,000 redox events without chemical degradation. These results underscore the utility of computational strategies in accelerating the discovery of robust, renewable, and high-performance organic materials for next-generation energy storage systems.