Electrochemical Role of Li‐Ligands at the Triple‐Phase Boundary in Li‐O₂ Batteries

The increasing global energy demand drives interest in high-energy-density alternatives to lithium-ion batteries, with Li-O₂ batteries emerging as promising candidates due to their exceptionally high theoretical energy density. However, the gap between the theoretical and practical energy densities remains significant, primarily due to the limited formation of Li₂O₂, attributed to restricted mass transfer at the reaction interface. To mitigate this limitation, a metal-organic framework (MOF) is functionalized with an aligned lithium ligand by a facile acid-base reaction method, aiming to improve reaction kinetics. The incorporation of the lithium-ligand enhances interfacial Li⁺ transfer along the pore channels, thereby improving localized Li⁺ transfer at the triple-phase boundary. As a result, lithium-functionalized MIL-121@Li exhibits an enhanced discharge capacity and more regulated Li₂O₂ spatial distribution, effectively mitigating side reactions caused by Li₂O₂-carbon contact. This controlled deposition minimizes charge-transfer resistance and improves overall electrode stability, highlighting the impact of lithium-ligand coordination on Li-O₂ battery performance.