Strategies for Balancing Non-Covalent Interactions to Enhance the Performance of Polymer Electrolytes in Lithium Batteries

Solid polymer electrolytes (SPEs) are central to the advancement of next-generation lithium batteries, offering intrinsic safety and compatibility with high-energy-density lithium metal anodes. However, their performance remains constrained by low ionic conductivity, limited lithium transference numbers, and hindered interfacial charge transfer. Recent studies reveal that these limitations are intimately tied to the ensemble of non-covalent interactions involving polymer chains, lithium cations, and counteranions. In this perspective, we highlight how rational control of such interactions can mitigate crystallinity, facilitate charge transfer, and enhance the overall performance of lithium batteries. We discuss representative strategies including reduced Li–polymer interaction, enhanced anion–polymer interaction, and altered Li–ether solvation structure, with emphasis on their mechanistic impact on ion transport in poly(ethylene oxide) (PEO) systems. Beyond PEO, we examine single-ion conductors and alternative polymer structures. Finally, we propose data-driven approaches that leverage high-quality databases and predictive descriptors to accelerate the rational design of polymer electrolytes. By integrating molecular-level insights with computational strategies, non-covalent interaction engineering emerges as a powerful paradigm for achieving high-performance, safe, and scalable lithium batteries.