Top-Down Coarse-Grained Framework for Characterizing Mixed Conducting Polymers

Organic polymers that exhibit both ionic and electronic conduction are of interest for energy storage devices and emerging bioelectronic applications. Nevertheless, organic mixed conductors are at an early stage of development with nascent design rules and relatively few material chemistries having been experimentally characterized. Here, we report a coarse-grained modeling framework that is sufficiently flexible to represent a range of mixed conducting chemistries while retaining the molecular physics necessary to interrogate structure-function relationships. A detailed overview of the framework is presented, accompanied by an applied study of the effect of hydration and oxidation levels on a representative mixed conductor. The model recapitulates experimental trends related to the macroscopic ionic and electronic conductivities, including the nonlinear suppression of the electronic mobility with respect to the oxidation level and the direct relationship between the ionic mobility and the hydration level, while revealing the complex interplay of polymer morphology, ionic-electronic coupling, and electrolyte distribution that govern these relationships. These results provide a validation of this framework for future applications in establishing structure-function relationships in this important material class and suggest several near-term opportunities for tailoring mixed conduction via a side-chain design.

Automated summary

This study presents a coarse-grained modeling framework flexible enough to explore the structure-function relationships of organic mixed conductors exhibiting both ionic and electronic conductivity. The model successfully replicates experimental trends and reveals the complex interplay between polymer morphology, ionic-electronic coupling, and electrolyte distribution. This framework provides validation for future applications in establishing structure-function relationships in this important material class and suggests near-term opportunities for tailoring mixed conduction via side-chain design.