Lithium-metal solid-state batteries (LMSSBs) are regarded as highly promising Post-Lithium-Ion Technology due to their high energy density and exceptional safety. However, their practical application remains challenging because of the interfacial issues at the metallic lithium|solid-state electrolyte interface (e.g., contact resistance and dendrite formation). In this regard, interlayer engineering based on carbon materials with different dimensions and fluorination degrees has been proposed to effectively address interfacial issues. Specifically, carbon quantum dots (0D), nanostripes (1D), and nanosheets (2D) will be used to clarify the influence of the geometric structure of carbon on the plating/stripping performance of lithium ions. Also, the fluorination degrees of carbon nanostructures will be precisely regulated to quantitively understand the fluorine chemistry-electrochemical performance relationships. Ultimately, this project will fill the knowledge gap in geometric design and chemical modification of carbon-based interlayer materials for developing safety LMSSBs with energy density > 500 Wh kg-1 and cycling life > 2000 times.