Review of MOF-guided ion transport for lithium metal battery electrolytes

Achieving rechargeable lithium metal batteries (LMBs) is crucial for augmenting the energy density of lithium-based secondary batteries. However, severe electrolyte-interface reactions and the formation of lithium dendrites hinder the practical application of LMBs. Metal-organic frameworks (MOFs) exhibit significant potential in facilitating uniform lithium deposition and suppressing interface side reactions owing to their ordered and adjustable pore structures. Consequently, the application of MOFs in lithium metal battery electrolytes gains considerable attention. This review focuses on two types of MOF-guided ion transport in LMBs: 1) MOFs serve as channels for ion transport in solid-state or pseudo-solid-state electrolytes; 2) MOFs act as sub-nano molecular sieves for regulating solvation structures of lithium ions at interfaces. First, the structural characteristics of MOFs and their advantages in LMB electrolytes are comprehensively elucidated. Then, the advances and challenges pertaining to MOF-guided ion transport in LMB electrolytes are discussed in detail. Finally, future research directions and design principles for LMB electrolytes based on MOFs are proposed.