Combined density functional theory/kinetic Monte Carlo investigation of surface morphology during cycling of Li-Cu electrodes

We employed a combined density functional theory and kinetic Monte Carlo approach in order to investigate the nanoscale behavior of lithium stripping and plating on lithium-copper nanoalloys. Density functional theory calculations were used to develop an atom-by-atom understanding of the nucleation behavior of lithium on copper surfaces with different surface morphologies. We found that nanometric pits resulted in significantly more favorable lithium deposition when compared to pristine or lightly defective Cu surfaces, which is in agreement with previous experimental studies. We then used density functional theory and constrained ab initio molecular dynamics to develop interaction and reaction parameters for a larger-scale kinetic Monte Carlo model in order to provide insight into the stripping and plating behavior of nanostructured Li-Cu nanoalloy anodes. Substantial losses in capacity and strong indications of morphological change were observed for a wide range of Cu:Li ratios over 100 cycles. We observed a complex relationship between the nanoparticle composition and the properties of the formed solid-electrolyte interphase. (c) 2021 Elsevier Ltd. All rights reserved.

Automated summary

A combined density functional theory and kinetic Monte Carlo approach was used to investigate the nanoscale behavior of lithium stripping and plating on lithium-copper nanoalloys. The presence of nanometric pits was found to result in more favorable lithium deposition. Through the development of reaction parameters, insight was gained into the stripping and plating behavior of nanostructured Li-Cu nanoalloy anodes, revealing substantial losses in capacity and morphological changes over multiple cycles.