Metal-organic frameworks containing solid-state electrolytes for lithium metal batteries and beyond

For solid-state Li and other metal batteries, solid-state electrolytes (SSEs) are a bridge between electrodes, and are significant in determining the behavior of batteries. Thus, constructing stable and excellent SSEs is vital for the feasible application of metal batteries. Because of their unique and multifunctional properties, namely unsaturated metal sites, tunable structure, and high specific surface area, porous metal-organic frameworks (MOFs) have been applied to SSEs to enhance the performance of metal batteries. In this review, the mechanisms of MOFs within polymer electrolytes on improving the Li-ion movement, stabilizing the solid/solid interfacial contact, and prohibiting the Li dendrite are briefly summarized. The multiple factors of MOF-based SSEs, including MOF structures, unsaturated metal sites, incorporation with ionic liquids, different organic ligands, pore size and nano/micro hierarchical structure that affect the battery performance are comprehensively discussed. Moreover, the mechanism and advancement of MOF-based SSEs for other metal batteries, including Na, Zn, and Mg batteries, are also illustrated. Eventually, new insights and future prospects in terms of MOF-based SSEs are proposed to stimulate more innovative approaches for the commercial applications of Li and other metal batteries.