Exploring Li-ion Transport Properties of Li$_3$TiCl$_6$: A Machine Learning Molecular Dynamics Study

التفاصيل البيبلوغرافية
العنوان: Exploring Li-ion Transport Properties of Li$_3$TiCl$_6$: A Machine Learning Molecular Dynamics Study
المؤلفون: Selvaraj, Selva Chandrasekaran, Koverga, Volodymyr, Ngo, Anh T.
المصدر: Journal of the Electrochemical Society 171 (2024) 050544
سنة النشر: 2024
المجموعة: Condensed Matter
Physics (Other)
مصطلحات موضوعية: Condensed Matter - Materials Science, Physics - Chemical Physics, Physics - Computational Physics, 81-XX Quantum theory 81-XX Quantum theory 81-xx, J.2
الوصف: We performed large-scale molecular dynamics simulations based on a machine-learning force field (MLFF) to investigate the Li-ion transport mechanism in cation-disordered Li$_3$TiCl$_6$ cathode at six different temperatures, ranging from 25$^\mathrm{o}$C to 100$^\mathrm{o}$C. In this work, deep neural network method and data generated by $ab-initio$ molecular dynamics (AIMD) simulations were deployed to build a high-fidelity MLFF. Radial distribution functions, Li-ion mean square displacements (MSD), diffusion coefficients, ionic conductivity, activation energy, and crystallographic direction-dependent migration barriers were calculated and compared with corresponding AIMD and experimental data to benchmark the accuracy of the MLFF. From MSD analysis, we captured both the self and distinct parts of Li-ion dynamics. The latter reveals that the Li-ions are involved in anti-correlation motion that was rarely reported for solid-state materials. Similarly, the self and distinct parts of Li-ion dynamics were used to determine Haven's ratio to describe the Li-ion transport mechanism in Li$_3$TiCl$_6$. Obtained trajectory from molecular dynamics infers that the Li-ion transportation is mainly through interstitial hopping which was confirmed by intra- and inter-layer Li-ion displacement with respect to simulation time. Ionic conductivity (1.06 mS/cm) and activation energy (0.29eV) calculated by our simulation are highly comparable with that of experimental values. Overall, the combination of machine-learning methods and AIMD simulations explains the intricate electrochemical properties of the Li$_3$TiCl$_6$ cathode with remarkably reduced computational time. Thus, our work strongly suggests that the deep neural network-based MLFF could be a promising method for large-scale complex materials.
Comment: 8 pages with 6 figures
نوع الوثيقة: Working Paper
DOI: 10.1149/1945-7111/ad4ac9
URL الوصول: http://arxiv.org/abs/2403.01077
رقم الأكسشن: edsarx.2403.01077
قاعدة البيانات: arXiv
الوصف
DOI:10.1149/1945-7111/ad4ac9