Mechanisms Underlying Ion Transport in Polymerized Ionic Liquid-Ionic Liquid Blends

We use atomistic molecular dynamics simulations to study molecular mechanisms underlying ion transport in ionic liquid electrolytes with varying loading of their counterpart polymerized electrolytes. Our results reveal that in pure polymerized ionic liquid systems, anion transport occurs along the polymer backbone via the formation and breaking of the ion-pairs involving four polymerized cationic monomers of two different polymer chains. For such situations, we demonstrate that the anion mobilities are quantitatively correlated to the lifetime of anion-polymerized cation pairs. Surprisingly, even for the blend systems, we observe that the anions associated with the polymerized cation move by the same mechanism unearthed for the pure polymerized ionic liquids. For the blend systems the anion mobilities are shown to be correlated to the ion-pair relaxation time of the non-polymerized cation-anion pairs.