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

Theoretical studies on unsymmetrical electrolyte salts, lithium [1,2-benzenediolato(2-)-O,O′ oxalato]borate (LBDOB), and its derivatives, lithium bis[1,2-benzenediolato(2-)-O,O′]borate (LBBB), and lithium bis(oxalate)borate (LBOB) are carried out using density functional theory (DFT) method and B3LYP theory level. Bidentate structures involving two oxygen atoms are preferred. Based on these conformations, a linear correlation was observed between the highest occupied molecular orbital (HOMO) energies 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, thermal stability and the hardness (η). Wave function analyses have been performed by natural bond orbital (NBO) method to further investigate the cation–anion interactions.