Abstract
The ionic conductivity of solid polymer electrolytes is governed by the ionic association caused by the polymer center dot center dot center dot Li+ and the anion center dot center dot center dot Li+ interactions. We performed the density functional calculation to analyze the molecular interactions in the CH3-(CH2-CF2)(n)-CH3-Li+-(CF3SO2)(2)N- for n = 1,4 systems. The gauche conformation is predicted in the lowest energy conformer of pure polymer except for n = 1. The lithium coordination number with the polymer is changed from 3 to 2 in the presence of anion for n = 2, 4 systems. The consequences of the Li+ ion and Li+- (CF3SO2)(2)N(- )to the vibrational spectrum are studied to understand the ionic association at the molecular level.