Ionic Association in CH 3 -(CH 2 -CF 2 ) n -CH 3 (PVDF)-Li + -(CF 3 SO 2 ) 2 N - for n = 1, 4: A Computational Approach.

The ionic conductivity of solid polymer electrolytes is governed by the ionic association caused by the polymer···Li ⁺ and the anion···Li ⁺ interactions. We performed the density functional calculation to analyze the molecular interactions in the CH ₃ -(CH ₂ -CF ₂ ) _n -CH ₃ -Li ⁺ -(CF ₃ SO ₂ ) 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 ⁺ -(CF ₃ SO ₂ ) ₂ N ^- to the vibrational spectrum are studied to understand the ionic association at the molecular level.
Competing Interests: The authors declare no competing financial interest.
(© 2022 The Authors. Published by American Chemical Society.)