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).

Automated summary

The OA-MOF film reinforced SEI layer shows improved performance in Li-metal batteries, with higher efficiency and lower voltage hysteresis even at ultrahigh current density.