A single-ion-conducting lithium-based montmorillonite interfacial layer for stable lithium-metal batteries

Constructing a robust interfacial layer on lithium metal anodes (LMAs) to inhibit dendrite growth is vital in the pursuit of high-energy density lithium metal batteries (LMBs). Here, lithium-based montmorillonite (Li-MMT) is fabricated as an artificial protective layer to suppress dendritic Li deposition. The Li-MMT layer can not only act as a Li+ ion reservoir but also as a single Li+ ion conductor, enhancing Li+ ion transport kinetics and alleviating the interfacial Li+ ion concentration gradient. Theoretical calculations confirm that Li-MMT can immobilize TFSI- ions and allow fast Li+ ion shuttle with a low migration energy barrier of 0.28 eV. Finite element method (FEM) simulations further demonstrate the effective modulation of the Li-MMT layer for Li plating behavior, leading to a high Li+ transference number (t(Li)(+)) of 0.85, a favorable ionic conductivity (sigma(+)(Li)) of 5.77 x 10(-4) S cm(-1) and an extended Li plating/stripping stability over 1300 h. Consequently, excellent cycling performance (206 cycles) with remarkably improved energy density is realized for lithium-oxygen (Li-O-2) full batteries based on Li-MMT-Cu@Li electrodes.