Carbonyl-Based Redox-Active Compounds as Organic Electrodes for Batteries: Escape from Middle–High Redox Potentials and Further Improvement?

Extracting from the vast space of organic compoundsthe best electrode candidates for achieving energy material breakthrough requires the identification of the microscopic causes and origins of various macroscopic features, including notably electrochemical and conduction properties. As a first guess of their capabilities, molecular DFT calculations and quantum theory of atoms in molecules (QTAIM)-derived indicators were applied to explore the family of pyrano[3,2- b]pyran-2,6-dione (PPD, i.e., A0) compounds, expanded to A0 fused with various kinds of rings (benzene, fluorinated benzene, thiophene, and merged thiophene/benzene). A glimpse of up-tonow elusive key incidences of introducing oxygen in vicinity to the carbonyl redox center within 6MRsas embedded in the A0 core central unit common to all A-type compoundshas been gained. Furthermore, the main driving force toward achieving modulated low redox potential/band gaps thanks to fusing the aromatic rings for the A compound series was discovered.