Unravelling Ultrafast Li Ion Transport in Functionalized Metal-Organic Framework-Based Battery Electrolytes

Nonaqueous fluidic transport and ion solvation propertiesundernanoscale confinement are poorly understood, especially in ion conductionfor energy storage and conversion systems. Herein, metal-organicframeworks (MOFs) and aprotic electrolytes are studied as a robustplatform for molecular-level insights into electrolyte behaviors inconfined spaces. By employing computer simulations, along with spectroscopicand electrochemical measurements, we demonstrate several phenomenathat deviate from the bulk, including modulated solvent molecularconfigurations, aggregated solvation structures, and tunable transportmechanisms from quasi-solid to quasi-liquid in functionalized MOFs.Technologically, taking advantage of confinement effects may proveuseful for addressing stability concerns associated with volatileorganic electrolytes while simultaneously endowing ultrafast transportof solvates, resulting in improved battery performance, even at extremetemperatures. The molecular-level insights presented here furtherour understanding of structure-property relationships of complexfluids at the nanoscale, information that can be exploited for thepredictive design of more efficient electrochemical systems.