To Hop or Not to Hop – Unveiling Different Modes of Ion Transport in Solid Polymer Electrolytes Through Molecular Dynamics Simulations
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| Název: | To Hop or Not to Hop – Unveiling Different Modes of Ion Transport in Solid Polymer Electrolytes Through Molecular Dynamics Simulations |
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| Autoři: | Gudla, Harish, Hockmann, Anne, Brandell, Daniel, 1975, Mindemark, Jonas |
| Zdroj: | ACS Applied Polymer Materials. 7(8):4716-4724 |
| Témata: | ion transport mechanisms, solid polymer electrolytes, molecular dynamics simulations, ion coordination |
| Popis: | In this work, a quantitative method is developed to estimate different ion transport mechanisms in solid polymer electrolyte (SPE) systems. The well-explored poly(ethylene oxide) (PEO) is studied along with the poly(ɛ-caprolactone) (PCL) at different molecular weights and LiTFSI salt concentrations. By tracking the cation coordination changes, three transport mechanisms are categorized, i.e., ion hopping, continuous motion (successive change of the coordination sphere), and vehicular transport. The observed dominant transport mechanism is the continuous motion, and changes from polymer-mediated to anion-mediated with increasing salt concentration. Furthermore, a higher influence of polymer-mediated vehicular transport is observed in PCL systems than in PEO systems, and a correlation is found between the anion-mediated continuous motion and the cation transference number, irrespective of polymer and salt concentrations. In both systems, ion hopping is essentially absent, as can be expected in systems with strong ion–polymer interactions. The results illustrate both how the usual description of ion transport in polymer electrolytes as coupled to segmental motions is too simplistic to catch the full essence of the ion transport phenomena, whereas the frequently used notion of “ion hopping” in the majority of cases is incorrect for SPEs. |
| Popis souboru: | electronic |
| Přístupová URL adresa: | https://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-481553 https://doi.org/10.1021/acsapm.4c03724 |
| Databáze: | SwePub |
Nájsť tento článok vo Web of Science | Abstrakt: | In this work, a quantitative method is developed to estimate different ion transport mechanisms in solid polymer electrolyte (SPE) systems. The well-explored poly(ethylene oxide) (PEO) is studied along with the poly(ɛ-caprolactone) (PCL) at different molecular weights and LiTFSI salt concentrations. By tracking the cation coordination changes, three transport mechanisms are categorized, i.e., ion hopping, continuous motion (successive change of the coordination sphere), and vehicular transport. The observed dominant transport mechanism is the continuous motion, and changes from polymer-mediated to anion-mediated with increasing salt concentration. Furthermore, a higher influence of polymer-mediated vehicular transport is observed in PCL systems than in PEO systems, and a correlation is found between the anion-mediated continuous motion and the cation transference number, irrespective of polymer and salt concentrations. In both systems, ion hopping is essentially absent, as can be expected in systems with strong ion–polymer interactions. The results illustrate both how the usual description of ion transport in polymer electrolytes as coupled to segmental motions is too simplistic to catch the full essence of the ion transport phenomena, whereas the frequently used notion of “ion hopping” in the majority of cases is incorrect for SPEs. |
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| ISSN: | 26376105 |
| DOI: | 10.1021/acsapm.4c03724 |