Ceramic solid electrolytes based on LLZO (Li7La3Zr2O12) are promising candidates for all-solid-state batteries due to their high ionic conductivity and good apparent stability vs. lithium metal, however they are prone to mechanical failure. Lithium metal intrusions, alongside cell stack pressure, transition polycrystalline solid electrolyte grains into a compressed state that promotes crack propagation and fracture. Here this work examines the mechanical response of Al-substituted LLZO to compressive forces by measuring ultimate strength under pillar compression with a flat punch tip. Failure modes characterized by in situ scanning electron microscopy show diverse splitting patterns arising from internal porosity, grain boundaries, and slip planes. Large correlated variations in compressive strength (0.93–2.63 GPa) and Young's modulus (72.1–150.97 GPa) are observed across microscale regions of the solid electrolyte. Molecular dynamics simulations of LLZO with different porosities describe the variation of compressive strength and Young's modulus, and enable a microscale porosity model to be fit accounting for Young's modulus reduction across the solid electrolyte. Overall, the results indicate the importance of microscale mechanical testing of ceramic solid electrolytes to identify preferential sites for mechanical degradation and Li intrusion, and ensure the robust design of all-solid-state lithium metal batteries.
Moon, Jaron V., et al. "Microscale mechanical property variations of Al-substituted LLZO: insights from compression testing and molecular dynamics simulations." Journal of Materials Chemistry. A, vol. 12, no. 37, Aug. 2024. https://doi.org/10.1039/d4ta03596h
@article{osti_2438320,
author = {Moon, Jaron V. and Sakir, Md Takmil and Go, Wooseok and Xie, Rui and Tucker, Michael C. and Doeff, Marca and Wang, Haoran and Warren, Roseanne},
title = {Microscale mechanical property variations of Al-substituted LLZO: insights from compression testing and molecular dynamics simulations},
annote = {Ceramic solid electrolytes based on LLZO (Li7La3Zr2O12) are promising candidates for all-solid-state batteries due to their high ionic conductivity and good apparent stability vs. lithium metal, however they are prone to mechanical failure. Lithium metal intrusions, alongside cell stack pressure, transition polycrystalline solid electrolyte grains into a compressed state that promotes crack propagation and fracture. Here this work examines the mechanical response of Al-substituted LLZO to compressive forces by measuring ultimate strength under pillar compression with a flat punch tip. Failure modes characterized by in situ scanning electron microscopy show diverse splitting patterns arising from internal porosity, grain boundaries, and slip planes. Large correlated variations in compressive strength (0.93–2.63 GPa) and Young's modulus (72.1–150.97 GPa) are observed across microscale regions of the solid electrolyte. Molecular dynamics simulations of LLZO with different porosities describe the variation of compressive strength and Young's modulus, and enable a microscale porosity model to be fit accounting for Young's modulus reduction across the solid electrolyte. Overall, the results indicate the importance of microscale mechanical testing of ceramic solid electrolytes to identify preferential sites for mechanical degradation and Li intrusion, and ensure the robust design of all-solid-state lithium metal batteries.},
doi = {10.1039/d4ta03596h},
url = {https://www.osti.gov/biblio/2438320},
journal = {Journal of Materials Chemistry. A},
issn = {ISSN 2050-7488},
number = {37},
volume = {12},
place = {United States},
publisher = {Royal Society of Chemistry},
year = {2024},
month = {08}}
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
Sponsoring Organization:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Office of Sustainable Transportation. Vehicle Technologies Office (VTO); National Science Foundation (NSF)
Grant/Contract Number:
AC02-05CH11231
OSTI ID:
2438320
Alternate ID(s):
OSTI ID: 2429720
Journal Information:
Journal of Materials Chemistry. A, Journal Name: Journal of Materials Chemistry. A Journal Issue: 37 Vol. 12; ISSN 2050-7488
Ziegler, James F.; Ziegler, M. D.; Biersack, J. P.
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, Vol. 268, Issue 11-12https://doi.org/10.1016/j.nimb.2010.02.091
Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, Vol. 221, Issue 582-593https://doi.org/10.1098/rsta.1921.0006