Revealing structure correlation between ionic liquid and metal-organic framework matrix

Abstract

Solid-state batteries are rising rapidly in response to the fast-increasing energy demand. Metal-organic framework (MOF) loaded with ionic liquids has brought new opportunities for solid-state batteries owing to its good interfacial compatibility and high ionic conductivity. MOF-808 is selected to be filled with Li-contained ionic liquid for structure and ion dynamics investigation using nuclear magnetic resonance (NMR) and X-ray diffraction. This study finds that the introduced ionic liquid would partially soften the matrix of MOF-808 and thus yield amorphous phase. By selective isotope replacement under cycling symmetric ⁶Li metal cell, Li⁺ ion is observed to mainly go cross ionic liquid in the open channel of matrix under potential polarization.