Strong Lewis Acid Effect in the Pores of Metal–Organic Framework Host for Dendrite‐Free Lithium Deposition and Stripping

Abstract

AbstractThe homogeneous introduction of Lewis acid sites into 3D hosts of Li‐metal batteries (LMBs) is crucial for promoting Li+ dissociation and desolvation. Herein, the use of MIL‐101, a well‐known flexible metal–organic framework, loaded with uniformly distributed AlFx species with unsaturated Lewis acid sites, is proposed as a Li‐metal anode (LMA) 3D host to promote Li+ dissociation and desolvation in LMBs. A symmetrical cell using an AlFx@MIL‐101/Cu with pre‐deposited lithium (Li@AlFx@MIL‐101/Cu) exhibits stable performance for over 3600 h. In addition, a high‐loading LFP||Li@AlFx@MIL‐101/Cu full cell maintains high capacity after 4000 cycles at 1 C with an average coulombic efficiency of 99.87%. Experimental and theoretical analyses reveal that the AlFx species with strong Lewis acidity and MIL‐101 with nanospace confinement effect promote Li+ dissociation and desolvation coupled with fast and uniform Li+ transport. The MIL‐101 pores accommodate Li species, thereby inhibiting volume changes in the LMA. These results demonstrate that AlFx@MIL‐101 ensures uniform and dendrite‐free Li deposition on LMAs, making it a promising host for high‐stability LMBs.