Elastic properties of amorphous LiTaCl6 solid-state electrolyte
Abstract
Amorphous solid-state electrolytes are attractive candidates for safe, high-energy-density all-solid-state batteries, yet their mechanical properties remain poorly understood from a computational perspective. Here, we investigate the elastic behavior of the recently discovered amorphous superionic Li-ion conductor LiTaCl6 using density-functional-theory (DFT)-based methods, including unrelaxed static, relaxed static, and strain fluctuations from molecular dynamics (MD) simulations in the isobaric--isothermal (NPT) ensemble with DFT-trained machine-learning force fields (MLFFs). While the unrelaxed static method predicts a Young's modulus an order of magnitude higher than the experiment, the relaxed static method---commonly applied to crystalline electrolytes---still overestimates the modulus by more than 170%. In contrast, the MD approach using MLFFs yields a Young's modulus of 2.84 ± 0.26 GPa, which quantitatively agrees with the experimental value of 2.91 ± 0.32 GPa. Using the MLFF-MD approach, we further predict bulk modulus (4.44 GPa), shear modulus (1.02 GPa), and Poisson's ratio (0.39) for amorphous LiTaCl6 and conclude that elastically it behaves like a soft polymer or gel. These results demonstrate that amorphous superionic materials possess some unique elastic properties and that, among the methods examined, only the MLFF-MD approach yields quantitative agreement with experiment, highlighting the necessity of a dynamical treatment to simulate their elastic response, consistent with recent findings for crystalline superionic conductors.
Versions
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BibTeX
@misc{liu2026elastic,
title = {{Elastic properties of amorphous LiTaCl$_6$ solid-state electrolyte}},
author = {Xiaolin Liu and De-en Jiang},
howpublished = {arXiv},
year = {2026},
month = aug,
doi = {10.48550/arxiv.2608.29404},
eprint = {2608.29404},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2608.29404},
}
RIS
TY - UNPB
TI - Elastic properties of amorphous LiTaCl_6 solid-state electrolyte
AU - Xiaolin Liu
AU - De-en Jiang
PY - 2026
DA - 2026/08/29
PB - arXiv
DO - 10.48550/arxiv.2608.29404
UR - https://arxiv.org/abs/2608.29404
AB - Amorphous solid-state electrolytes are attractive candidates for safe, high-energy-density all-solid-state batteries, yet their mechanical properties remain poorly understood from a computational perspective. Here, we investigate the elastic behavior of the recently discovered amorphous superionic Li-ion conductor LiTaCl_6 using density-functional-theory (DFT)-based methods, including unrelaxed static, relaxed static, and strain fluctuations from molecular dynamics (MD) simulations in the isobaric--isothermal (NPT) ensemble with DFT-trained machine-learning force fields (MLFFs). While the unrelaxed static method predicts a Young's modulus an order of magnitude higher than the experiment, the relaxed static method---commonly applied to crystalline electrolytes---still overestimates the modulus by more than 170%. In contrast, the MD approach using MLFFs yields a Young's modulus of 2.84 ± 0.26 GPa, which quantitatively agrees with the experimental value of 2.91 ± 0.32 GPa. Using the MLFF-MD approach, we further predict bulk modulus (4.44 GPa), shear modulus (1.02 GPa), and Poisson's ratio (0.39) for amorphous LiTaCl_6 and conclude that elastically it behaves like a soft polymer or gel. These results demonstrate that amorphous superionic materials possess some unique elastic properties and that, among the methods examined, only the MLFF-MD approach yields quantitative agreement with experiment, highlighting the necessity of a dynamical treatment to simulate their elastic response, consistent with recent findings for crystalline superionic conductors.
ER -