Fast Bulky Anion Conduction Enabled by Free Shuttling Phosphonium Cations
Highly conductive anion-exchange membranes (AEMs) are desirable for applications in various energy storage and conversion technologies. However, conventional AEMs with bulky HCO 3 - or Br - as counterion generally exhibit low conductivity because the covalent bonding restrains the tethered cationic...
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Veröffentlicht in: | Research (Washington) 2021, Vol.2021, p.9762709-9762709 |
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Hauptverfasser: | , , , , , , , , , , , |
Format: | Artikel |
Sprache: | eng |
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Zusammenfassung: | Highly conductive anion-exchange membranes (AEMs) are desirable for applications in various energy storage and conversion technologies. However, conventional AEMs with bulky HCO
3
-
or Br
-
as counterion generally exhibit low conductivity because the covalent bonding restrains the tethered cationic group’s mobility and rotation. Here, we report an alternative polyrotaxane AEM with nontethered and free-shuttling phosphonium cation. As proved by temperature-dependent NMR, solid-state NMR, and molecular dynamics simulation, the phosphonium cation possesses a thermally trigged shuttling behavior, broader extension range, and greater mobility, thus accelerating the diffusion conduction of bulky anions. Owing to this striking feature, high HCO
3
-
conductivity of 105 mS cm
-1
at 90°C was obtained at a relatively lower ion-exchange capacity of 1.17 mmol g
-1
. This study provides a new concept for developing highly conductive anion-exchange membranes and will catalyze the exploration of new applications for polyrotaxanes in ion conduction processes. |
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ISSN: | 2639-5274 2639-5274 |
DOI: | 10.34133/2021/9762709 |