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Li 6.4 La 3 Zr 1.4 Ta 0.6 O 12 (LLZTO) is a promising inorganic solid electrolyte due to its high Li + conductivity and electrochemical stability for all-solid-state batteries. Mechanical characterization of LLZTO is limited by the synthesis of the condensed phase. Here we systematically measure the elastic modules, hardness, and fracture toughness of LLZTO polycrystalline pellets of different densities using the customized environmental nanoindentation. The LLZTO samples are sintered using the hot-pressing method with different amounts of Li 2 CO 3 additives, resulting in the relative density of the pellets varying from 83% to 98% and the largest grain size of 13.21 ± 5.22 μm. The mechanical properties show a monotonic increase as the sintered sample densifies, elastic modulus and hardness reach 158.47 ± 10.10 GPa and 11.27 ± 1.38 GPa, respectively, for LLZTO of 98% density. Similarly, fracture toughness increases from 0.44 to 1.51 MPa⋅m 1/2 , showing a transition from the intergranular to transgranular fracture behavior as the pellet density increases. The ionic conductivity reaches 4.54 × 10 −4 S/cm in the condensed LLZTO which enables a stable Li plating/stripping in a symmetric solid-state cell for over 100 cycles. This study puts forward a quantitative study of the mechanical behavior of LLZTO of different microstructures that is relevant to the mechanical stability and electrochemical performance of all-solid-state batteries.
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This content will become publicly available on July 23, 2025
Thermal properties and lattice anharmonicity of Li-ion conducting garnet solid electrolyte Li 6.5 La 3 Zr 1.5 Ta 0.5 O 12
This work reports the thermal properties of garnet electrolyte LLZTO. The aged LLZTO exhibits an enhanced thermal conductivity, attributed to the formation of Li2CO3.
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- PAR ID:
- 10541585
- Publisher / Repository:
- Royal Society of Chemistry
- Date Published:
- Journal Name:
- Journal of Materials Chemistry A
- Volume:
- 12
- Issue:
- 29
- ISSN:
- 2050-7488
- Page Range / eLocation ID:
- 18248 to 18257
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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