Influence of the reticular polymeric gel—electrolyte structure on ionic and molecular mobility of an electrolyte system salt—ionic liquid: LiBF4—1-ethyl-3-methylimidazolium tetrafluoroborate

Abstract

Peculiarities of the formation of a reticular polymeric gel—electrolyte matrix based on polyethylene glycol diacrylate in a medium of ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIBF₄) were studied by isothermal calorimetry. The influence of the polymeric matrix structure on the ionic and molecular mobility of a LiBF₄ salt—ionic liquid electrolyte system was considered. The self-diffusion coefficients on the ¹H, ⁷Li, and ¹⁹F nuclei were measured by pulsed field gradient NMR. For the all electrolyte compositions, the highest translation mobility of the cationic part of the EMI⁺ ionic liquid molecule is observed on ¹H nuclei, whereas the lowest one corresponds to ⁷Li nuclei. This phenomena is due to the strong association of the lithium salt in a polar medium of the ionic liquid, which is concentrated in cavities of the reticular polymer.