Computational Insights into the Crystal Facet Selectivity of Cu Current Collector for the Growth of Lithium Metal

Lithium metal is considered as an ideal anode for next generation high energy density secondary batteries due to its high specific capacity (3860 mAh g–1) and low redox potential (−3.04 eV versus standard hydrogen electrode). However, the low Coulombic efficiency and severe dendrite growth of Li hinder its commercialization. As a component of the lithium anode, the current collector has a significant effect on Li nucleation and growth. In the present study, we investigate the facet selectivity of commonly used Cu current collector for Li metal electrodeposition using density functional theory (DFT) and ab initio molecular dynamics (AIMD) simulations. The adsorption energy, lattice mismatch, formation energy, and diffusion constant of lithium atoms are calculated as descriptors to evaluate the stability of nine Li–Cu interfaces composed of low-index crystal facets. The results show that Cu(100) and Cu(110) are preferential for the growth of Li(100) in Li crystal facets (100), (111), and (100), while Cu(111) surface prefers forming Li(110). For all Cu facets, we find that Cu(110) may be superior than Cu(100) and Cu(111) for Li deposition. The present study highlights the impact of the exposed facets of Cu current collector on Li deposition behavior and provides a useful guideline to improve the efficiency of Li deposition by controlling the morphology of the current collector.