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Una transición de fase estructural reversible por inyección de iones impulsada electroquímicamente en un polímero
Connor G Bischak1, Lucas Q Flagg1, Kangrong Yan2
1Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States.
Journal of the American Chemical Society
|April 2, 2020
Resumen
Los polímeros conjugados exhiben transiciones de fase estructurales reversibles durante el ciclo electroquímico. Este comportamiento único en el poli[2,5-bis(tiofenilo)-1,4-bis(2-(2-metoxietoxietoxi) benceno] (PB2T-TEG) permite el transporte de iones no fickianos, crucial para el almacenamiento de energía.
Área de la Ciencia:
- Ciencias de los materiales
- Química de los polímeros
- La electroquímica
Sus antecedentes:
- Los polímeros conjugados son prometedores para el almacenamiento de energía electroquímica.
- Comprender su dinámica estructural durante el transporte de iones es fundamental para el rendimiento.
- Estudios anteriores muestran la difusión de Fickian en materiales similares.
Objetivo del estudio:
- Investigar las transiciones estructurales de fase en un polímero conjugado glicosilado (PB2T-TEG) durante el ciclo electroquímico.
- Para aclarar el impacto de estas transiciones en el transporte de pares de iones-polarón.
- Explorar aplicaciones potenciales en el almacenamiento de energía y la computación neuromórfica.
Principales métodos:
- Diseminación de rayos X de incidencia de pastoreo en ángulo amplio (GIWAXS) para analizar las fases cristalinas.
- Oxidación electroquímica y inyección de iones en un electrolito acuoso.
- Experimentos en el frente móvil utilizando microscopía óptica y microscopía de fuerza fotoinducida de súper resolución (PiFM).
Principales resultados:
- El PB2T-TEG sufre transiciones de fase estructurales reversibles tras la oxidación/reducción electroquímica.
- Estas transiciones conducen al transporte de pares de iones-polarones no fickianos con perfiles afilados.
- El comportamiento de transporte contrasta con la difusión de Fickian observada en otros polímeros como P3MEEMT.
Conclusiones:
- Las transiciones de fase estructurales observadas en PB2T-TEG son análogas a las de los materiales inorgánicos como LiFePO4.
- La ingeniería de propiedades de transición de fase similares en polímeros conjugados puede mejorar el almacenamiento de energía electroquímica y las aplicaciones de memoria neuromórfica.
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