Interfacial and intradomain effects on transport in copolymer and inorganic-polymeric ion conductors

Molecular-scale and nanoscopic effects largely drive transport processes in ion conductors and separations membranes. A variety of nanoscopic heterogeneities can be introduced into polymer-based ion conductors by making copolymers, by forming inorganic-polymeric composites, and by simply incorporating polymer electrolytes into real devices like batteries or electrolyzers. Such systems depend sensitively on dynamics of the interfacial polymer chains, on chemical desolvation/solvation processes, and/or on dynamics of other polar molecules or ions. In terms of governing transport, all of these effects involve many-body non-covalent interactions. We experimentally quantify (and often simulate) the dynamics and populations of most or all of the ions, of the polymer chains, of any composite elements and of any other component molecules, and thus can gain fine insights into the mechanisms that dominate local (and often bulk average) transport. In this talk, we will discuss (1) precise Li⁺ populations and exchange rate measurements between organic and inorganic (LATP and argyrodyte) components in composite battery electrolytes, (2) slowed PEO chain (and ion) dynamics as a function of position across the salt-doped conducting domain of a copolymer, and (3) CO₂ sorption and diffusion in composite gas sorption membranes.