Understanding and Predicting Lithium Crystal Growth on Perfect and Defective Interfaces: A Kohn-Sham Density Functional Study.

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.