Role of free volumes and segmental dynamics on ion conductivity of PEO/LiTFSI solid polymer electrolytes filled with SiO2 nanoparticles: a positron annihilation and broadband dielectric spectroscopy study
| Autor: | P. Utpalla, Manjulata Sahu, Jitendra Bahadur, Debasis Sen, P. K. Pujari, Sudhanshu K. Deshpande, S.K. Sharma |
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| Rok vydání: | 2021 |
| Předmět: |
chemistry.chemical_classification
Materials science technology industry and agriculture General Physics and Astronomy 02 engineering and technology Electrolyte Polymer Conductivity 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Ion Crystallinity Chemical engineering chemistry Volume fraction Ionic conductivity Crystallite Physical and Theoretical Chemistry 0210 nano-technology |
| Zdroj: | Physical Chemistry Chemical Physics. 23:8585-8597 |
| ISSN: | 1463-9084 1463-9076 |
| DOI: | 10.1039/d1cp00194a |
| Popis: | The limited ionic conductivity of polymer electrolytes is a major issue for their industrial application. Enhancement of ionic conductivity in the poly(ethylene oxide), PEO, based electrolyte has been achieved by loading passive nanofillers such as SiO2 nanoparticles (NPs). To investigate the role of modifications in free volume characteristics and the polymer chain dynamics induced by the loading of passive fillers on the ionic conductivity of the PEO based ternary electrolyte, a systematic investigation has been carried out using positron annihilation and broadband dielectric spectroscopy. As a result of interfacial interactions, the loading of SiO2 NPs alters the semi-crystalline morphology of PEO resulting in a higher crystallinity at lower loadings due to the surface confinement of PEO chains, and the formation of smaller PEO crystallites at higher loadings due to interparticle nanoconfinement. These modifications are accompanied by a decrease in free volume fraction at the lowest loading (0.5 wt%) followed by an increase at higher loadings (≥2.0 wt%). The Almond–West formalism considering two different universalities in different temperature and frequency ranges has been used to explain the ion-conduction process at different NP loadings. The Li ion conductivity is observed to be maximum for a 5.0 wt% loading of SiO2 NPs. The enhancement in ionic conductivity is observed to be directly correlated with the free volume characteristics and segmental dynamics of the PEO matrix, confirming their role in ion transport in polymer electrolytes. |
| Databáze: | OpenAIRE |
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