Deciphering Lithium Deposition Behavior in Elemental Alloy Anodes for Lithium Metal Batteries

Nano Lett. 2024 Nov 22. doi: 10.1021/acs.nanolett.4c03387. Online ahead of print.

Abstract

Lithium (Li) dendrite is one of the most fatal obstacles for developing practical high energy Li metal batteries, while Li alloy substrates, with strong lithiophilicity, have attracted increasing interest for directing uniform Li deposition. However, most of the previous research studies associated Li dendrite inhibition closely with high adsorption energy. Yet, the Li deposition process is not solely about the adsorption of an isolated Li atom, where a comprehensive understanding of the interfacial lattice mismatch and the Li atom diffusion should also be taken into account. Here, we explore the Li deposition behavior from adhesion work, representing interfacial stability and bonding strength, and both Li adsorption and diffusion. It is found that the overpotential of Li deposition is inversely related to adhesion work, while uniform Li deposition requires a high adsorption energy and low Li atom diffusion barrier. These detailed relationships may offer guidance for subsequent substrate development.

Keywords: Li dendrite; Li deposition barrier; adhesion work; deposition thermodynamics; diffusion kinetics.