The Polymer Society of Korea

Abstract

Deep eutectic solvent-based solid polymer electrolytes (DES-SPE) offer a compelling platform for lithium metal batteries (LMB), uniting the mechanical robustness of polymers with DES-enabled ionic transport. However, their practical deployment remains limited by interfacial incompatibility with cathodes and an incomplete understanding of solvation dynamics. Herein, a DES-SPE is developed, and its solvation environment is elucidated using nuclear magnetic resonance spectroscopy and molecular dynamics simulations. The results reveal a bicontinuous nanostructure in which DES domains are preserved, maintaining DES-like conduction pathways. This phase separation prevents direct contact between DES and lithium metal, effectively suppressing parasitic reactions and improving interfacial stability. To address cathode integration, a porous-structured electrode (PSE) is introduced to promote spontaneous electrolyte infiltration and uniform interfacial contact with high-loading cathodes.