Dynamical SEI reinforced by open-architecture MOF film with stereoscopic lithiophilic sites for high-performance lithium-metal batteries

A vulnerable solid–electrolyte interphase (SEI) layer cannot retard Li dendrite growth, electrolyte consumption, and anode volumetric expansion, which seriously hinders the development of high-safety Li-metal batteries (LMBs). Herein, a dynamical SEI reinforced by an open-architecture metal–organic framework (OA-MOF) film characterized by elastic expansion and contraction of the volume of stereoscopic lithiophilic sites, is designed. The self-adjustment distribution of lithiophilic sites on vertically grown Cu${}_2$(BDC)${}_2$ nanosheets enables the homogenization of Li-ion flux, smart control of Li mass transport, and compaction of Li deposition. The trapped N, N-dimethylformamide molecules in the open framework structure are favorable for the better wetting and dissolution effect of Li-ions accessing to Cu${}_2$(BDC)${}_2$. Combining these advantages, the featured OA-MOF/Cu@Li anode enables a high coulombic efficiency and low voltage hysteresis in Li||Cu cells even at an ultrahigh current density of 15 mA cm${}^{-2}$. (© 2021 Wiley-VCH GmbH)