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La arquitectura de superficie de entropía de gradiente estabiliza el LiCoO2 a 4.7 V
Fangchang Zhang1, Xinye Mai1, Yulin Cao1
1Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
ACS nano
|February 10, 2026
Resumen
Una nueva arquitectura de superficie de entropía de gradiente (GE) estabiliza los cátodos de óxido de cobalto de litio (LiCoO2) para baterías de iones de litio, permitiendo el funcionamiento a voltajes ultra altos de hasta 4.7 V con una mayor estabilidad y retención de capacidad.
Área de la Ciencia:
- Ciencia de los materiales Ciencia de los materiales.
- La electroquímica es electroquímica.
- Almacenamiento de energía Almacenamiento de energía
Sus antecedentes:
- El óxido de cobalto de litio (LiCoO2) es un material de cátodo primario para las baterías de iones de litio tipo 3C.
- Las altas tensiones de funcionamiento por encima de 4,55 V conducen a una degradación estructural e interfacial significativa en LiCoO2.
Objetivo del estudio:
- Desarrollar una arquitectura de superficie de entropía de gradiente (GE) para mejorar la estabilidad de LiCoO2 en voltajes de corte ultra altos (4.7 V).
- Investigar los mecanismos por los cuales la arquitectura GE mejora el rendimiento electroquímico y la estabilidad.
Principales métodos:
- Se creó una capa homogénea de autoencapsulación utilizando ácido fítico e iones metálicos (Mg/Al/Ni) en la superficie de LiCoO2.
- La calcinación fue empleada para formar la arquitectura de la superficie de entropía del gradiente.
- Se evaluó el rendimiento electroquímico, incluida la retención de capacidad y la estabilidad en ciclos a 4.7 V.
Principales resultados:
- El material GE-LCO exhibió una arquitectura de superficie de gradiente con entropía decreciente desde el exterior hacia el interior.
- La superficie de alta entropía mejoró la estabilidad termodinámica, mientras que los canales de Li+ expandidos mejoraron la movilidad cinética.
- La capa de GE suprimió efectivamente la migración interfacial de cobalto y mejoró la estabilidad electroquímica-mecánica.
Conclusiones:
- La arquitectura de la superficie de entropía de gradiente estabiliza con éxito LiCoO2 a 4.7 V, superando las limitaciones de los materiales convencionales.
- Este enfoque preserva la actividad electroquímica a granel al tiempo que mejora la estabilidad de la superficie a través de mecanismos impulsados por la entropía.
- GE-LCO demostró una alta capacidad de 230,9 mAh / g y 80,6% de retención de capacidad después de 100 ciclos a 4,7 V.
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