Quasi-two-dimensional self-assembled fluorinated MOF to construct organic/inorganic hybrid double layer with burst Li+ transmission channels

Abstract The development of disordered lithium dendrite and the adverse reaction between Li and electrolyte impede the practical use of lithium metal batteries (LMB). Herein, we proposed quasi-two-dimensional fluorinated metal-organic frameworks microporous carbon (q2D-FcMOF) were utilized to construct an artificial solid electrolyte interface (ASEI) to achieve a robust and stable interfacial protective double-layer. The outer layer with quasi-two-dimensional hollow organic structure contains multistage pores, offering ample space for lithium deposition, whereas the inner layer composed of inorganic LiF, effectively conducts Li+ and prevents electron transport. Meanwhile, abundant metal ion clusters within the hybrid layer are uniformly dispersed in the matrix, and subsequent Li+ tends to be distributed, encouraging Li+ to cluster around metal active sites that are thermodynamically compatible with lithium. This guides the nucleation of lithium and ensures the growth of dendrite-free lithium during cycling. Consequently, q2D-FcZ8@Li symmetrical batteries demonstrated an ultralong cycle life of over 3600 h, outperforming bare Li and other q2D-FcMOF@Li batteries. When used with commercial cathodes (LiFePO4 or LiNi0.8Co0.1Mn0.1O2), the full cells exhibited significantly improved cyclability under conditions of high cathode loading, lean electrolyte, and exposure to air for some time. This research suggests an effective method for fabricating ASEI using 2D quasi-ordered superstructure MOF NPs, which is expected to greatly advance the development of LMB.