MOF-derived 3D host nanostructures combining the advantages of microporous MOFs and carbon for stable Li deposition

초록

Preventing Li dendritic growth and top-accumulation is crucial for the commercialization of Li metal anodes (LMAs). Researchers have extensively explored the use of gradient layers composed of insulating and lithiophilic materials to prevent surface Li reduction and promote bottom-up Li deposition. In this study, a nanostructure, ZIF-C500, derived from metal-organic frameworks (MOFs), is synthesized as a single-material structure capable of replacing gradient layers through a facile aqueous liquid-phase synthesis and optimized heat-treatment process. ZIF-C500 combines the well-developed micro- and mesoporous characteristics of MOFs with insulating properties that prevent Li accumulation while also exhibiting lithiophilic properties derived from the N-doped carbon of the carbonized MOF. The LMA utilizing ZIF-C500 as the host material effectively suppresses dendritic growth and dead Li formation during repeated Li deposition/stripping cycles, demonstrating high coulombic efficiencies in asymmetric cell tests. In symmetric cell tests, it exhibits stable cycle performance for 1050 h at a current density of 1.0 mA cm-2. Furthermore, full-cell tests with a commercial LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode and LiFePO4 (LFP) show significantly better cycle stability and rate capability than the bare Li foil, demonstrating its excellent electrochemical properties in full cells.

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