F.A. Soto
The Penn State University-Harrisburg,
United States
Keywords: machine learning, density functional theory, AIMD simulations, lithium-ion batteries, solid-electrolyte interphase, nanoclusters, dopants
Summary:
Lithium-ion battery stability remains a critical challenge, that could be exacerbated by the detachment of reactive nanoclusters such as XLi₆ (X = N, O) during electrode cycling [1]. These clusters could interact with the solid-electrolyte interphase (SEI) and electrolyte molecules, initiating degradation pathways that compromise performance [2]. In this study, ab-initio molecular dynamics (AIMD) and density functional theory (DFT) simulations as implemented in the Quantum Espresso simulation package [3] are employed to investigate the reactivity of XLi₆ clusters with SEI components (e.g., LiF, Li₂CO₃) and electrolyte molecules (e.g., ethylene carbonate, dimethyl carbonate). Reaction pathways, energetics, and charge transfer dynamics are analyzed to elucidate the mechanisms of interfacial instability. The role of dopants (O, F, N, P, C, S) in modulating cluster reactivity is also explored, demonstrating how doped structures impact charge redistribution and degradation reactions. By integrating machine learning techniques, such as Bader charge and Hirshfeld charge analysis, reactivity trends can be predicted, and strategies can be identified to mitigate SEI degradation. This approach offers practical insights for improving SEI stability and extending battery lifespan. The findings pave the way for sustainable lithium-ion battery designs by addressing critical challenges in interfacial dynamics. REFERENCES [1] X. Lu, X. Liao, Oxidization of fluid-like Li metal with inherent LiLi2O interface from simulation insights, Journal of Materiomics, 6 (2020) 692-701. [2] M. van den Borg, D. Gaissmaier, E. Knobbe, D. Fantauzzi, T. Jacob, Theoretical studies on the initial oxidation of metallic lithium anodes, Applied Surface Science, 555 (2021) 149447. [3] P. Giannozzi, S. Baroni, N. Bonini, M. Calandra, R. Car, C. Cavazzoni, D. Ceresoli, G.L. Chiarotti, M. Cococcioni, I. Dabo, QUANTUM ESPRESSO: a modular and open-source software project for quantum simulations of materials, Journal of physics: Condensed matter, 21 (2009) 395502.