Key Laboratory for Advanced Materials, School of Chemistry & Molecular Engineering , East China University of Science and Technology , Shanghai 200237 , China.
School of Chemical Engineering and Technology , Sun Yat-sen University , Zhuhai , Guangdong 519000 , China.
ACS Appl Mater Interfaces. 2019 Oct 9;11(40):37239-37246. doi: 10.1021/acsami.9b10893. Epub 2019 Sep 24.
Uncontrolled lithium dendrite growth in lithium metal batteries (LMBs) can result in a series of security problems, and designing dendrite-free LMBs is an important issue in real world application. However, current synthesis methods for dendrite-free LMBs are lacking theoretical guidance. In this work, we use Kohn-Sham density functional theory to study lithium crystal growth on different interfaces, including perfect crystal surfaces, surfaces with dislocation defects, and surfaces with heteroatom defects. The theoretical results show that nucleation is the key to lithium crystal growth on perfect interfaces, and the dislocation defects decrease the binding energy for the first lithium atom and have a long-range effect on the crystal growth. S and C are favorable heteroatoms for lithium crystal growth in the (110) and (200) directions, respectively; Cl may be a favorable heteroatom for dendrite-free LMBs, as Cl atoms tend to float upon the lithium crystals and may protect the dendrites from uncontrolled growth. The O and F heteroatoms are favorable for lithium nucleation on Cu foil, which is in contrast to Zn heteroatoms.
锂金属电池（LMBs）中不受控制的锂枝晶生长会导致一系列安全问题，因此设计无枝晶 LMBs 是实际应用中的一个重要问题。然而，目前无枝晶 LMBs 的合成方法缺乏理论指导。在这项工作中，我们使用 Kohn-Sham 密度泛函理论研究了锂在不同界面上的晶体生长，包括完美晶体表面、位错缺陷表面和杂原子缺陷表面。理论结果表明，成核是锂在完美界面上晶体生长的关键，位错缺陷降低了第一个锂原子的结合能，并对晶体生长具有远程效应。S 和 C 分别是锂在（110）和（200）方向上晶体生长的有利杂原子；Cl 原子可能是无枝晶 LMBs 的有利杂原子，因为 Cl 原子倾向于在锂晶体上漂浮，从而可能防止枝晶不受控制地生长。O 和 F 杂原子有利于锂在 Cu 箔上成核，这与 Zn 杂原子相反。
