Segmental dynamics of PEO/LiClO₄ complex crystals and their influence on the Li⁺-ion transportation in crystal lattices: A ¹³C solid-state NMR approach

The structure and chain dynamics of polyethylene oxide (PEO)/LiClO ₄ complex crystals were studied by employing state-of-the-art solid-state ¹³C NMR techniques. Remarkable helical jump motions of the PEO segments in the complex crystals at ambient temperatures were clearly demonstrated. The jump motions are believed to induce the transportation of the coordinated Li⁺ ions along the crystallographic c axis, providing a novel mechanism of ionic conductivity of the complex crystals. In addition, this work also shows that solid-state high-resolution ¹³C NMR spectroscopy can be a powerful and general tool for elucidating phase structures, dynamics, and subsequently the conduction mechanism of crystalline polymer electrolytes.