Dendrite formation in Li-metal anodes: an atomistic molecular dynamics study
Summary¶
Hybrid MD of a model nanobattery examines Li dendrite growth at a Li metal anode covered by a cracked LiF SEI against 1 M LiPF₆ in ethylene carbonate electrolyte in LAMMPS. 2NN MEAM treats Li⁰ / Li⁺ (short-range) interactions; LiF uses a Born–Mayer form; EC / PF₆⁻ / ions bond-order chemistry uses an updated ReaxFF parametrization (Mahbubul et al.); nonbonded electrolyte–electrode couplings use Lennard-Jones + Coulomb (tables in the article). NPT lithiation with three charging protocols at 325 K and 410.7 K. The RSC Advances study is positioned as a mechanistic cartoon for how SEI defects focus Li deposition flux at atomistic resolution.
Methods¶
Engine and ensemble. LAMMPS; NPT for equilibration and lithiation; initial box 40.8 × 54.0 × 40.8 ų with 640 LiF formula units, 936 Li metal atoms, 424 EC molecules, 28 LiPF₆ ion pairs; pseudo-atom cathode reservoir to supply Li⁺ with prescribed charging modes.
Force fields. 2NN MEAM for Li metal and Li⁺ within 2.5 Å of metal (partitioning as in the article’s Force fields section); Born–Mayer for LiF; ReaxFF (Mahbubul et al. update) for bonded electrolyte species; LJ + Coulomb for nonbonded cross-terms between solvent/SEI/metal subsystems (Tables 2–3).
Charging protocols. (1) ~1 Li⁺ / 0.4 ps constant-current-like insertion; (2) pulse train 10 Li⁺ / 4 ps; (3) exchange protocol maintaining constant electrolyte Li⁺ count.
Parameter files, cutoffs, and neighbor skin settings for the MEAM/ReaxFF/LJ partitioning appear in papers/ReaxFF_others/Selis_Seminario_RSC_Advances_2019_dendrite.pdf alongside Movies/figure captions describing dendrite morphology metrics.
Grid / boundary / timestep / thermostat (consolidated). 3D PBC nanocell (40.8 × 54.0 × 40.8 ų as above); timestep and Nose-Hoover (or other thermostat) details in RSC Advances full text / SI; N/A to re-list here if not in the local excerpt. Lithiation NPT runs at 325 K and 410.7 K in the abstract-level summary; Hydrostatic pressure in NPT (bar) / stress as in RSC text; temperature thermostat setpoints follow these K targets. Shear, shock, applied E-field, umbrella sampling: N/A unless the SI states them.
2 — Force-field training. N/A as a new ReaxFF fit—the study uses a published ReaxFF electrolyte update ( Mahbubul et al. ) with MEAM-class Li metal and LiF SEI forms as partitioned in the article force-field section and tables (see RSC Advances PDF).
Findings¶
The SEI crack does not block lithiation but focuses and promotes dendrite growth versus a crack-free case. Dendrite formation is more favorable at 325 K than at 410.7 K under the explored conditions. Higher C-rate (2.2C vs 1.6C in the reported comparison) favors dendrites, implying lower-rate operation can be safer for energy storage in this model.
The authors relate temperature and rate trends to local Li supersaturation near the crack mouth as Li⁺ flux is channeled through the gap.
Limitations¶
Idealized nanoscale cell, fixed SEI chemistry (LiF only), and classical potentials omit electron transfer and detailed electrolyte decomposition.
Wiki prose here is a navigation aid. Definitive numbers, protocol details, and figure-level claims should be taken from the peer-reviewed article at pdf_path (and any Supporting Information cited there), not from this page alone.
Relevance to group¶
Atomistic battery-interface morphology study using LAMMPS with MEAM + ReaxFF + ionic potentials; useful hybrid FF reference for Li dendrites.
Citations and evidence anchors¶
DOI: 10.1039/C9RA05067A