Direct epitaxial growth of MOF arrays on Cu foils to regulate Li deposition toward lean-lithium metal batteries

• The binder-free nanosheet arrays based on ZIF-67 were fabricated on the surface of Cu foil by epitaxial growth strategy. • The 3D porous array framework induces rich lithiophilic sites and inorganic-rich SEI , thus regulating Li deposition. • The lean lithium metal batteries achieve excellent long-cycling and rate performance under lean electrolyte . Anode-less Li-metal batteries (ALLMBs) are gaining prominence for improving energy density, but they suffer from nonuniform Li + flux and unstable solid-electrolyte interphase (SEI), leading to severe dendrite Li growth and poor cycle life. In this work, we designed a direct epitaxial grown zeolitic imidazolate framework-67 (ZIF-67) binder-free arrays on Cu foil as a multifunctional current collector to enable long-cycling lean lithium metal battery (LLMBs). The high surface area, abundant lithiophilic sites of MOF nanosheets significantly promote uniform Li deposition. Furthermore, MOF nanosheet arrays with abundant lithiophilic nitrogen sites also facilitate the formation of LiF/Li 3 N inorganic-rich SEI , which effectively improves interfacial stability and promotes uniform Li + flux, high ionic conductivity, as well as dense and smooth Li deposition for dendrite-free Li metal anodes. Consequently, the ZIF-67 current collector achieves superior long-term Li deposition and higher average Coulombic efficiency than the bare Cu counterpart, when coupled with sulfur and LiFePO 4 cathodes. The LLMBs show excellent rate performance and cycling stability under high cathode loading and lean electrolyte operations.