Electrochimica Acta, Vol.48, No.14-16, 2105-2112, 2003
Synthesis of a Lewis-acidic boric acid ester monomer and effect of its addition to electrolyte solutions and polymer gel electrolytes on their ion transport properties
A polymerizable anion receptor based on a boric acid ester was synthesized. When the anion receptor was added to different electrolyte solutions consisting of an aprotic solvent and a lithium salt, the ionic conductivity of certain electrolyte solutions, composed of low polar solvents or salts with low dissociation abilities, was enhanced appreciably. Viscosity measurements for the electrolyte solutions, with and without the added anion receptor, indicated that the conductivity enhancement was caused by an increase in the ionic dissociation due to the addition of the anion receptor. Pulse-field-gradient spin-echo (PGSE) NMR and B-11-NMR spectra supported that the ionic dissociation was facilitated by interaction between the Lewis-acidic anion receptor and Lewis-basic anions. The polymerizable anion receptor was crosslinked with a polyether macromonomer in different electrolyte solutions. Ionic conductivity of the resulting polymer gel electrolytes was also altered like that of the electrolyte solutions containing the anion receptor monomer. (C) 2003 Elsevier Science Ltd. All rights reserved.