Design of superionic polymer electrolytes

•Ionic transport and segmental dynamics in polymers can be strongly decoupled.•Degree of decoupling is controlled by frustration in local packing (fragility).•Polyethers have intrinsic limitations due to coupled ion and segmental dynamics.•Decoupling approach provides a new paradigm for design of polymer electrolytes.

Despite potential significant advantages of polymer based batteries, the poor ionic conductivity of dry polymer electrolytes at ambient and low temperatures has limited their application. This review describes the approach for improving conductivity by decoupling ionic transport from polymer segmental relaxation. It is emphasized that the decoupling approach is the key for design of superionic polymer electrolytes.