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

Abstract

Extractingfrom the vast space of organic compoundsthe 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-to-now elusive key incidences of introducing oxygen in vicinity to the carbonyl redox center within 6MRsas embedded in the A0 core central unit common to all A-type compoundshas 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.

Carbonyl Chemistry for Advanced Electrochemical Energy Storage Systems

“…Lambert et al. have predicted the capabilities of a series of carbonyl-based redox-active compounds by DFT calculations, including the family of pyrano[3,2- b ]pyran-2,6-dione (PPD) derivatives fused with various kinds of rings (benzene, fluorinated benzene, thiophene, and merged thiophene/benzene) . It was found that the PPD compounds are suitable as the anode materials due to the low calculated redox potentials.…”

“…The DFT-based computational redox potentials are in good agreement with the experimental results within an uncertainty of ∼0.3 V, which implies the reliability of DFT method. The redox potential is decreased with the increase of aromaticity. , In addition, the redox potential can be increased by attaching electron-withdrawing functional groups. Bachman et.…”

“…Lambert et al have predicted the capabilities of a series of carbonyl-based redoxactive compounds by DFT calculations, including the family of pyrano[3,2-b]pyran-2,6-dione (PPD) derivatives fused with various kinds of rings (benzene, fluorinated benzene, thiophene, and merged thiophene/benzene). 227 It was found that the PPD compounds are suitable as the anode materials due to the low calculated redox potentials. Moreover, it has been underlined that the extended PPD molecule, including five-membered thiophene rings well separated from the central redox centers by benzenic rings delivers the lowest voltage.…”

“…The redox potential is decreased with the increase of aromaticity. 227,232 In addition, the redox potential can be increased by attaching electron-withdrawing functional groups. Bachman et.…”