Metal-organic framework derived gradient interfacial layer for stable lithium metal anode

The inhomogeneous deposition of lithium metal and the growth of dendrite are the key challenges for the practical application of lithium metal anode (LMA). Instead of conventional dendrite suppression strategies with mechanically strong overlayers, herein we show a bottom-up deposition and surface-regulation strategy via gradient existence of electrical-passivated, ion-conducted and anion regulated top layer (zeolitic imidazolate frame work-8, ZIF-8) and lithiophilic, electronic-conductive bottom layer (carbonized ZIF-8) to construct lithophilicity/conductivity gradient interfacial layer. The resulting LMA with a gradient interfacial layer can eliminate surface Li reduction, homogenize Li+ flux, and guide Li deposition in a bottom-up manner, which enables long-term stable Li-metal plating/stripping. This strategy is further demonstrated to provide substantially improved cycle stability and rate capability in full cells with LiCoO2 as the cathode. Moreover, this facial and effective gradient interfacial layer design not only enables a favored deposition and regulation strategy for next-generation lithium-metal batteries but can be widely applicable among varied MOF materials with a delicate tune of interaction mechanisms. © 2022