Ionic Liquid@MOF Composite Electrolytes for Enhanced Lithium-Ion Battery Performance at Low Temperatures

Abstract

Low-temperature operation of lithium-ion batteries is limited by reduced ionic conductivity and unstable interfacial behavior. This study introduces a composite electrolyte that embeds ionic liquids (IL) into a metal–organic framework (MOF) to ensure stable performance at subzero temperatures. ZIF-8 serves as the MOF host, whose nanoporous structure confines the IL, effectively suppressing freezing and guiding lithium-ion transport. As a result, the composite maintains high ionic conductivity and enhanced electrochemical stability in cold environments. Cryogenic transmission electron microscopy (Cryo-TEM) confirms the formation of a uniform and stable solid electrolyte interphase (SEI) at the electrode interface. These findings suggest that IL@MOF composite electrolytes are a promising solution for reliable lithium-ion battery operation in extreme conditions, offering improved performance through controlled ion pathways and stabilized interfaces.