Hydrogen-bond-regulated ion transport in PEO electrolytes enabled by amino-functionalized MOFs

Achieving high energy density together with intrinsic safety in Li-metal batteries requires solid electrolytes that can concurrently alleviate ion-transport bottlenecks and interfacial instability. Among various polymer electrolyte candidates, PEO-based composites have received widespread attention owing to their straightforward preparation and favorable compatibility with lithium-metal electrodes. However, the pronounced tendency of PEO chains to crystallize restricts ion migration, thereby limiting their practical applications. posing a fundamental bottleneck for practical applications. To simultaneously tailor polymer microstructure and ion transport behavior, amino-functionalized ZIF-8 (ZIF-8-NH 2 ) was designed to function as a multifunctional MOF filler in this study. The ether oxygen atoms along the PEO chains interact with the amino groups (–NH 2 ) of the MOF framework via hydrogen bonding, consequently reducing polymer chain ordering and enhancing segmental mobility. while the porous structure and coordinatively active sites facilitate lithium salt dissociation and ion migration. The optimized PLMN PEO-LiTFSI-ZIF-8-NH 2 ) electrolyte exhibits improved thermal and mechanical stability. At 60 °C, the electrolyte exhibits an ionic conductivity reaches 1.1 × 10 −3 S/cm, with a Li + transference number of 0.44, and an electrochemical stability window up to 5.0 V. Moreover, the electrolyte realizes stable lithium plating/stripping over 800 h with reduced polarization. These superior performances reveal that amino-functionalized MOFs can effectively orchestrate the interplay between polymer amorphization and ion transport dynamics, thereby offering a reliable framework for designing composite polymer electrolytes based on structure–property relationships and presenting a feasible strategy for developing highly dependable solid-state lithium-metal batteries.