Lithium (Li) deposition behavior plays an important role in dendrite formation and the subsequent performance of lithium metal batteries. This work reveals the impact of the lithiophilic sites of lithium-alloy on the Li plating process via the first-principles calculations. We find that the Li deposition mechanisms on the Li metal and Li22Sn5 surface are different due to the lithiophilic sites. We first propose that Li plating on the Li metal surface goes through the "adsorption-reduction-desorption-heterogeneous nucleation-cluster drop "process, while it undergoes the "adsorption-reduction-growth "process on the Li22Sn5 surface. The lower adsorption energy contributes to the easy adsorption of Li on the lithiophilic sites of the Li22Sn5 surface. The lower Li reduction energy on the Li metal surface indicates that it is easy for Li to be reduced on the Li metal surface, attributed to its higher Fermi energy level. Furthermore, the faster Li diffusion on the Li22Sn5 surface results in smooth Li deposition, which is based on a "two-Li synergy diffusion "mechanism. However, Li diffuses more slowly on the Li metal surface than on the Li22Sn5 surface due to the "single Li diffusion" mechanism. This work provides a fundamental understanding on the impact of lithiophilic sites of Li alloy on the Li plating process and points out that the future design of 3D Li-alloy substrates decorated with multilithiophilic sites can prevent dendrite formation on the lithium-alloy substrate by guiding uniform Li deposition.
Y. He and M. Zhang and A. Wang and B. Zhang and H. Pham and Q. Hu and L. Sheng and H. Xu and L. Wang and J. Park and X. He, "Regulation of Dendrite-Free Li Plating Via Lithiophilic Sites on Lithium-Alloy Surface," ACS Applied Materials and Interfaces, American Chemical Society, Jan 2022.
The definitive version is available at https://doi.org/10.1021/acsami.2c05801
Mechanical and Aerospace Engineering
Keywords and Phrases
adsorption energy; Li diffusion; lithiophilic sites; reduction energy; the first-principles
International Standard Serial Number (ISSN)
Article - Journal
© 2023 American Chemical Society, All rights reserved.
01 Jan 2022
National Natural Science Foundation of China, Grant U21A20170