Efficient Lithium Dendrite Control and Intimate Li/Garnet Interface Built through a Carbonized Metal–Organic Framework Layer

Solid garnet-electrolyte-based lithium metal batteries with electrochemical stability and high ionic conductivity are ideal electrolyte materials for the next generation of high-energy devices. However, the limited interfacial contact between garnet electrolyte and Li anode, as well as the huge volume change of the Li anode during successive lithium-ion plating/stripping processes, limit their application. Here, we demonstrate an exceedingly simple and effective strategy for simultaneously restricting volume change and ensuring intimate contact at the lithium/garnet interface through a carbonized metal–organic framework (CMOF) layer. The abundant Zn clusters in the CMOF layer interact with the molten Li metal (Li-CMOF) to form a tight interfacial contact between the Li metal and the Li_6.75La₃Zr_1.75Ta_0.25O₁₂ (LLZTO) pellet, which acts as a nucleation site to guide the lithium deposition, thus ensuring the homogeneous distribution of the electric field and lithium-ion fluxes and preventing the formation of lithium dendrites. As a result, the Li-CMOF/LLZTO/Li-CMOF symmetric cell can be steadily cycled for more than 1000 h without short-circuiting at 0.1 mA cm^–2/0.1 mAh cm^–2, and the Li-CMOF/LLZTO/NCM811 cell exhibits superior cycling stability at 0.5C for 100 cycles. This work provides a strategy to simultaneously improve the interface wettability at the interface with Li and endure the Li metal volume change via the CMOF layer coated on the surface of the garnet electrolyte.