SUBSTITUTIONAL EFFECTS ON THE NA-INVOLVED ELECTROCHEMICAL PROPERTIES OF ISOMERIC BENZOQUINONES

Abstract

The possibility of the isomeric benzoquinones, 1,2-benzoquinone (1,2-BQ) and 1,4-benzoquinone (1,4-BQ) with electron withdrawing functional groups (-PO3H2, –COOH, –NO2 and –CN), as prospective cathodes in sodium ion batteries is explored applying Density Functional Theory (DFT) approach. In order to investigate the redox behavior of the first and second discharged states, the sodiation of the considered derivatives with one and two number of sodium ions are made. The obtained redox potentials ( of bare quinones are in good agreement with the experimental. A linear correlation fit with R2>∼0.95 is found to exist between the obtained LUMO (lowest unoccupied molecular orbital) energies and In general, higher of ∼ 4.2 V with charge capacities of 186mAh/g and 258mAh/g is observed for NO2 and CN containing BQ derivatives. Unexpected deviation in of phosphonate derivatives emphasizes the role of intramolecular hydrogen bonds, conformational changes and steric hindrance on the redox properties.