Metal–Organic Frameworks

The global transition from fossil fuels to green energy necessitates the development of high-capacity energy storage solutions. Metal–organic frameworks (MOFs), with their unique 3D porous structures and tunable chemical functionalities, have emerged as promising materials for energy storage due to their ability to accommodate and transport electrochemically active ions. This focuses on the current status and prospects of anionic MOF-based quasi-solid-state electrolytes (anionic MOF-QSSEs) for lithium metal batteries (LMBs). Anionic MOF-QSSEs leverage the negatively charged frameworks of MOFs to stabilize and facilitate the movement of lithium ions (Li⁺), resulting in high ionic conductivity, thermal and chemical stability, and enhanced safety. Recent advances in understanding the ion transport mechanisms within these materials are discussed, highlighting selective transport channels and pore size optimization. A comparative analysis with other electrolyte systems — liquid electrolytes, solid-state electrolytes (SSEs), and gel polymer electrolytes (GPEs) — demonstrates the superior balance of conductivity, stability, and safety offered by anionic MOF-QSSEs. Additionally, strategies for further enhancing Li⁺ conductivity, including chemical functionalization, topological modulation, solvent optimization, and interface engineering, are explored. The continuous advancements in material design and fabrication techniques underscore the potential of anionic MOF-QSSEs to revolutionize LMBs and contribute significantly to the global shift towards sustainable energy storage systems.