Li-ion transport and morphology study of ion-condensed, liquid-crystalline polymer electrolytes

Metal-ion containing ionomers are well-known for their high strength, high toughness, and slow relaxations due to the physical cross-linking by ionic aggregates. However, recent coarse-grained simulations on melt ionomers by Frischknecht, Winey, and co-workers have shown that there is a possible extremely fast metal-ion transport mechanism that can occur within a percolate grain. In such a mechanism, the metal-ion hops successively between two adjacent sites, decoupled from segmental relaxation. Meanwhile, certain metal oxide glasses present conductivity as high as ~ 10 mS/cm at ambient temperature through a similar hopping mechanism. We have designed and synthesized a series of ion-condensed, anion-tethered, liquid crystalline polymers to study the relationship between transport mechanisms and polymer architecture. In our work, we investigate various backbone, ionic group tethered polymers with different polarities to modulate the ionic phase morphology. By utilizing broadband dielectric spectrometry, we probe ionic motion in various length and time scales to interpret the Li-ion transport mechanism. We correlate the ion dynamics with the morphology of the ionic phase.