Work

Pore-Engineering Enhances Low-Temperature Mixed Ionic-Electronic Conduction in Two-Dimensional Polymer Lithium Ion-Battery Electrodes

Year: 2026

Type: preprint

Abstract: Understanding the fundamental relationships between ionic and electronic charge transport in polymer systems is essential for the systematic development of bioelectronic, optoelectronic, and energy-storage devices that leverage these materials. A classic strategy to improve ionic conductivity in mixed conducting materials involves attaching ionophilic oligoethylene glycol (OEG) groups to charge-carrying polymers. However, installation of oxygen heteroatoms into the framework of mixed ionic-electronic conductors also induces unintended structural changes in both the native and operational states, thereby adding complexity to structure-property relationships. Two-dimensional polymers (2DPs) are crystalline, planar macromolecules with well-defined one-dimensional channels that can be functionalized without significantly disrupting the crystalline scaffold. We designed topologically equivalent 2DPs with either ionophobic or ionophilic pore structures and studied these materials as lithium-ion battery cathodes. We observed that OEG pore-functionalized 2DP electrodes exhibit higher redox potentials, lower charge-transfer resistances, and higher overall achievable capacities than ionophobic-functionalized 2DP electrodes. Additionally, we found that pore-functionalized 2DP electrodes have higher capacity retention at Arctic temperatures (-30 °C) than commercially available inorganic cathode materials. Our findings demonstrate that pore functionalization is a viable strategy for enhancing the performance of 2DP mixed ionic-electronic conductors and engineering them for extreme environment deployment.

Source: ChemRxiv

DOI: 10.26434/chemrxiv.15009754/v1