Poly(arylene ether)-Based Single-Ion Conductors for Lithium-Ion Batteries

Single-ion conducting electrolytes present a unique alternative to traditional binary salt conductors used in lithium-ion batteries. It has been shown theoretically that single-ion electrolytes can eliminate the salt concentration gradient and polarization loss in the cell that develop in a binary salt system, resulting in substantial improvements in materials utilization for high power and energy densities. Here, we describe synthesis and characterization of a class of single-ion electrolytes based on aromatic poly(arylene ether)s with pendant lithium perfluoroethyl sulfonates. The microporous polymer film saturated with organic carbonates exhibits a nearly unity Li⁺ transference number, very high conductivities (e.g., > 10^-3 S m^-1 at room temperature) over a wide range of temperatures, great electrochemical stability, and outstanding mechanical properties. Excellent cyclability with almost identical charge and discharge capacities has been demonstrated at ambient temperature in the batteries assembled from the prepared single-ion conductors.