Density functional theory study on LDFBDB and its derivatives: Electronic structures, energies, and molecular properties

Highlights: → A correlation between ionic conductivity and binding energy is established. → A correlation between solubility and theoretical set of parameters of anion is established. → A strong correlation between the adiabatic ionization potential and the electrochemical stability is established. - Abstract: Theoretical studies on unsymmetrical electrolyte salts, lithium difluoro(1,2-benzene-diolato(2-)-o,o')borate (LDFBDB), and its derivatives, lithium bis[1,2-benzene-diolato(2-)-O,O']borate (LBBB) and lithium fluoroborate (LiBF4) are carried out using density functional theory (DFT) method and B3LYP theory level. Bidentate structures are preferred. Based on these conformations, a linear correlation was observed between adiabatic ionization potential Ip and the limiting oxidation potentials measured by linear sweep voltammetry, which supports experimental results that strongly electron-withdrawing substituent anions are more resistant against oxidation. The correlations were also observed between ionic conductivity and binding energy, solubility and theoretical set of parameters of anion. Wave function analyses have been performed by natural bond orbital (NBO) method to further investigate the cation-anion interactions.