Role of Crosslinking and Backbone Segmental Dynamics on Ion Transport in Hydrated Anion‐Conducting Polyelectrolytes

Abstract Understanding the structure‐property relationships governing ion transport in hydrated polyelectrolytes is crucial for the design and optimization of electrochemical devices. By combining experiments and simulation, the influence of polymer chain segmental dynamics and water concentration on ion transport in polyelectrolytes is investigated. The segmental dynamics of a series of thermally crosslinked poly(2‐vinylpyridine)‐based polyelectrolytes have been systematically modified by varying the degree of crosslinking. The experimental and simulation results indicate that segmental dynamics have a limited influence on ion transport in hydrated polyelectrolytes. Instead, ion transport is primarily dictated by the water concentration within the hydrated polyelectrolytes. Both crosslinked and non‐crosslinked polyelectrolytes exhibit similar conductivities when normalized for water concentrations. Compared to the widely used crosslinking method with alkyl‐diamine linkage, the thermal crosslinking approach employed here not only provides an ideal platform for studying structure‐transport relationships in polyelectrolytes but also offers a promising strategy to enhance their mechanical properties by preserving backbone rigidity without sacrificing ionic conductivity.