Electrochemomechanical failure in layered oxide cathodes caused by rotational stacking faults.
Nat Mater
; 23(8): 1093-1099, 2024 Aug.
Article
em En
| MEDLINE
| ID: mdl-38702413
ABSTRACT
Electrochemomechanical degradation is one of the most common causes of capacity deterioration in high-energy-density cathodes, particularly intercalation-based layered oxides. Here we reveal the presence of rotational stacking faults (RSFs) in layered lithium transition-metal oxides, arising from specific stacking sequences at different angles, and demonstrate their critical role in determining structural/electrochemical stability. Our combined experiments and calculations show that RSFs facilitate oxygen dimerization and transition-metal migration in layered oxides, fostering microcrack nucleation/propagation concurrently with cumulative electrochemomechanical degradation on cycling. We further show that thermal defect annihilation as a potential solution can suppress RSFs, reducing microcracks and enhancing cyclability in lithium-rich layered cathodes. The common but previously overlooked occurrence of RSFs suggests a new synthesis guideline of high-energy-density layered oxide cathodes.
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01-internacional
Base de dados:
MEDLINE
Idioma:
En
Ano de publicação:
2024
Tipo de documento:
Article