On the Mechanism of Ion Transport through Polyphosphazene Solid Polymer Electrolytes 1: NMR, IR, and Raman Spectroscopic Studies and Computational Analysis of 15N Labeled Polyphosphazenes
Comprehensive investigation of lithium ion complexation with 15N-labeled polyphosphazenes- 15N-poly[bis(2-(2-methoxyethoxy)ethoxy)phosphazene] (15N-MEEP) and 15N-poly-[((2-allylphenoxy)0.12(4-methoxyphenoxy)1.02(2-(2-methoxyethoxy)ethoxy)0.86)phosphazene] (15N-HPP)-was performed by NMR, IR, and Raman spectroscopies. Previous studies characterized the ionic transport through the polymer matrix in terms of "jumps" between neighboring polymer strands utilizing the electron lone pairs of the etherial oxygen nuclei with the nitrogen nuclei on the polyphosphazene backbone not involved. However, noteworthy changes were observed in the NMR, IR, and Raman spectra with the addition of lithium trifluoromethanesulfonate (LiOTf) to the polyphosphazenes. The data indicate that the preferred association for the lithium ion with the polymer is with the nitrogen nuclei,more »