Lithiophilic Reduced Graphene Oxide/Carbonized Zeolite Imidazolate Framework-8 Composite Host for Stable Li Metal...

Lithium (Li) metal is regarded as a next-generation anode material owing to its high energy density. However, issues such as dendritic growth and volume changes during charging and discharging pose significant challenges for commercialization. We propose using lithiophilic reduced graphene oxide (rGO) and carbonized zeolite imidazolate framework-8 (C-ZIF-8) composites as host materials for Li to address these problems. The rGO/C-ZIF-8 composites are synthesized through a simple redox reaction followed by carbonization and are characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The roles of chemical composition, characteristics, and morphology are demonstrated. As a result of these favorable structural and functional properties, the Li symmetric cell with rGO/C-ZIF-8 exhibits a stable voltage profile for more than 100 h at 1 mA cm^-2 without short-circuiting. A relatively low Li plating/stripping overpotential of ~101.5 mV at a high current density of 10 mA cm^-2 is confirmed. Moreover, a rGO/C-ZIF-8-Li full cell paired with a LiFePO₄ cathode demonstrates good cyclability and rate capability.