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Garnet type LLZTO ceramic oxide is a promising solid-state electrolyte for use in Li-ion batteries because it has good chemical stability, adequate mechanical strength. However, lithium dendrite growth still needs to be addressed. The opacity of the solid electrolyte hinders in-situ investigation of dendrite growth. Therefore, semi-transparent LLZTO with high-density is needed. The traditional fabrication process for the garnet type LLZTO is cumbersome, and dense LLZTO disks with high transparency are difficult to fabricate. In this work, Al-LLZTO powder was made by solid-state reaction. A wet ceramic processing method, pressure filtration followed by sintering, was developed to make dense LLZTO with high ionic conductivity (1.47×10-4 S/cm) and adequate transmittance (17–23%) to visible light from 500 to 800 nm to observe and monitor dendrite growth.
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Lithium Dendrite Deflection at Mixed Ionic–Electronic Conducting Interlayers in Solid Electrolytes
Solid state lithium metal batteries using garnet solid electrolytes such as LLZTO promise substantial improvements in energy density and safety. However, practical implementation is hindered by lithium dendrite penetration at high current densities. Recent work shows that internal electrochemically induced mechanical stresses are large enough to propagate lithium dendrites and subsequently fracture solid electrolytes. This study builds on this understanding and demonstrates that stress‐driven dendrite propagation can be controlled via deflection at weakly bonded internal interfaces. This approach, based on a fracture‐mechanics analysis of multilayered composites, is investigated with a variety of interlayer materials that are embedded into LLZTO. The viability and effectiveness of dendrite deflection are most clearly evident with reduced graphene oxide where the critical current density increased from 0.6 to 3.8 mA / cm2. In this material, both the weak interface with LLZTO and the mixed ionic–electronic conducting nature of the interlayer appear to contribute to the improved performance. Additional insight into the mechanics of multilayered electrolytes is also obtained with finite element modeling. The overall results present a promising proof‐of‐concept demonstration along with important generalized design guidelines for creating multilayered solid electrolyte architectures that can enable high‐performance solid‐state batteries.
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- Award ID(s):
- 2124775
- PAR ID:
- 10612369
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- Advanced Energy Materials
- Volume:
- 15
- Issue:
- 13
- ISSN:
- 1614-6832
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.1002/aenm.202403179
