Solid Polymer Electrolytes Studied by NMR Spectroscopy and DFT Calculations

Summary: Results obtained recently on polymer electrolytes poly(ethylene oxide) (PEO)/LiCF₃SO₃ and poly(2-ethyl-2-oxazoline) (POZ)/AgCF₃SO₃ by a combination of solid-state ¹³C and ¹H NMR spectroscopy and DFT quantum-chemical calculations are discussed. Essentially the same local structure was found for the amorphous and crystalline phases of semicrystalline PEO/LiCF₃SO₃ polymer electrolyte. The amorphous POZ/AgCF₃SO₃ complex has a defined stoichiometry with two POZ monomeric units per one AgCF₃SO₃. A close contact between the metal salt and polymer was determined for both investigated systems from the Lee-Goldburg cross-polarization ¹H → ¹³C dynamics.