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Protocol of Electrochemical Test and Characterization of Aprotic Li-O2 Battery
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Reacciones en la batería recargable de litio-O2 con electrolitos de alquilo carbonato
Stefan A Freunberger1, Yuhui Chen, Zhangquan Peng
1School of Chemistry, University of St. Andrews, North Haugh, St. Andrews, Fife KY16 9ST, UK.
Journal of the American Chemical Society
|April 29, 2011
Resumen
Las baterías de litio-O2 no acuosas descomponen los electrolitos de carbonato de alquilo durante la descarga y la carga, formando productos sólidos que causan el desvanecimiento de la capacidad. Esta descomposición de electrolitos limita la vida útil de estos avanzados sistemas de almacenamiento de energía.
Área de la Ciencia:
- La electroquímica es electroquímica.
- Ciencia de los materiales Ciencia de los materiales.
- Almacenamiento de energía Almacenamiento de energía
Sus antecedentes:
- Las baterías recargables de litio-O2 no acuosas ofrecen una alta densidad de energía teórica.
- La descomposición de electrolitos es un gran desafío que limita su aplicación práctica y la vida útil del ciclo.
Objetivo del estudio:
- Para dilucidar los mecanismos específicos de descomposición de electrolitos durante los ciclos de carga y descarga en las células Li-O(2).
- Para identificar las especies químicas formadas y su impacto en el rendimiento de la batería.
Principales métodos:
- Análisis de los productos del cátodo formados durante la descarga.
- Investigación de los cambios en la superficie del ánodo durante el ciclo.
- Proponer mecanismos de reacción para los procesos de carga y descarga.
Principales resultados:
- Las formas de descarga son C(3)H(6)(OCO(2)Li)(2), Li(2)CO(3), HCO(2)Li, CH(3)CO(2)Li, CO(2) y H(2)O en el cátodo.
- La carga implica la oxidación de estas especies con CO2 y H2O evolucionando.
- La descomposición del electrolito conduce a la acumulación de productos sólidos, la formación de gel en el ánodo, el desvanecimiento de la capacidad y la falla de la célula.
Conclusiones:
- Los mecanismos de reacción propuestos explican la brecha de voltaje observada en las células Li-O(2).
- El consumo continuo de electrolitos y la acumulación de productos son las principales causas de la disminución de la capacidad y la vida útil limitada del ciclo.
- Abordar la estabilidad del electrolito es crucial para el desarrollo de baterías prácticas de Li-O.
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