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Abstract Solid state lithium metal batteries using garnet solid electrolytes such as LLZTO (Li6.4La3Zr1.5Ta0.5O12) 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 cm−2. 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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A Highly Efficient All‐Solid‐State Lithium/Electrolyte Interface Induced by an Energetic Reaction
Abstract The energetic chemical reaction between Zn(NO3)2and Li is used to create a solid‐state interface between Li metal and Li6.4La3Zr1.4Ta0.6O12(LLZTO) electrolyte. This interlayer, composed of Zn, ZnLixalloy, Li3N, Li2O, and other species, possesses strong affinities with both Li metal and LLZTO and affords highly efficient conductive pathways for Li+transport through the interface. The unique structure and properties of the interlayer lead to Li metal anodes with longer cycle life, higher efficiency, and better safety compared to the current best Li metal electrodes operating in liquid electrolytes while retaining comparable capacity, rate, and overpotential. All‐solid‐state Li||Li cells can operate at very demanding current–capacity conditions of 4 mA cm−2–8 mAh cm−2. Thousands of hours of continuous cycling are achieved at Coulombic efficiency >99.5 % without dendrite formation or side reactions with the electrolyte.
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- PAR ID:
- 10159774
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Angewandte Chemie International Edition
- Volume:
- 59
- Issue:
- 33
- ISSN:
- 1433-7851
- Page Range / eLocation ID:
- p. 14003-14008
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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