Molecular interactions and vibrations in CH3(OCH2CH2)2OCH3-M+-X− (M = Li, Na, K and X = PF6, AsF6, SbF6): An ab initio study

Molecular interactions are one important factor governing the ionic conductivity of solid polymer electrolytes (SPE). In order to understand the role of interactions in SPE, ab initio Hartree-Fock calculations have been carried out on diglyme-M+-X− (diglyme = CH3(OCH2CH2)2OCH3, M = Li, Na, K and X = PF6, AsF6, SbF6) electrolytes. These calculations predict stronger binding for the lithium ion towards the ether oxygens of diglyme in these electrolytes. Consequences of diglyme-MX interactions to the infrared spectra are presented. Theoretically predicted results are in good agreement with experimental observations. Molecular electron density topology has been used to study the molecular interactions present in the 1:1:1 electrolytes.