Role of protic ionic liquid concentration in proton conducting polymer electrolytes for improved electrical and thermal properties
Protic ionic liquids (PILs) in the acidic medium are known to show higher ionic conductivity than neat PIL or PIL in alkaline media. Hence, polymer electrolyte membranes (PEM) containing both PIL and acids are considered ideal for non-humidified intermediate temperature PEM fuel cells. Herein, we re...
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| Format: | Article |
| Language: | English |
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IOP Publishing
2020-01-01
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| Series: | Materials Research Express |
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| Online Access: | https://doi.org/10.1088/2053-1591/ab9665 |
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| author | Manjula G Nair Saumya R Mohapatra Marie-Rose Garda Bindu Patanair Allisson Saiter-Fourcin Sabu Thomas |
| author_facet | Manjula G Nair Saumya R Mohapatra Marie-Rose Garda Bindu Patanair Allisson Saiter-Fourcin Sabu Thomas |
| author_sort | Manjula G Nair |
| collection | DOAJ |
| description | Protic ionic liquids (PILs) in the acidic medium are known to show higher ionic conductivity than neat PIL or PIL in alkaline media. Hence, polymer electrolyte membranes (PEM) containing both PIL and acids are considered ideal for non-humidified intermediate temperature PEM fuel cells. Herein, we report non-aqueous proton conducting PEM made up of diethylmethylammonium trifluoromethanesulfonate; [dema][TfO] and neat phosphoric acid (H _3 PO _4 ) with poly (vinylidene fluoride-co-hexafluoropropylene); PVDF-HFP as the host matrix. The presence of PIL significantly modified the structure and microstructure of the electrolyte films with the emergence of micropores in the PIL containing membranes. SEM images suggest leaching of PIL and phosphoric acid above 80 wt% of PIL in the electrolyte membranes. Thermogravimetric studies show that the dehydration in the PEM films due to phosphoric acid condensation at 100 °C–200 °C region is arrested by the presence of PIL. The maximum ionic conductivity at room temperature is ∼6.3 × 10 ^−4 S cm ^−1 at 40 wt% of [dema][TfO] addition, which is two orders higher than that of the primary electrolyte (PE) containing only phosphoric acid in PVDF-HFP. This high conductivity in PEM films can be correlated to the increase in polar β and γ phases as well as a drop in the total crystallinity fraction in the film. The study using dielectric spectroscopy reveals a strong coupling of ionic conductivity with the structural or segmental relaxation of the PVDF-HFP due to the presence of [dema][TfO] in the PEMs. |
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| language | English |
| last_indexed | 2024-03-12T15:35:54Z |
| publishDate | 2020-01-01 |
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| spelling | doaj.art-f55f407459f941db9189cf4ce376989e2023-08-09T16:14:29ZengIOP PublishingMaterials Research Express2053-15912020-01-017606400510.1088/2053-1591/ab9665Role of protic ionic liquid concentration in proton conducting polymer electrolytes for improved electrical and thermal propertiesManjula G Nair0Saumya R Mohapatra1https://orcid.org/0000-0002-6753-5312Marie-Rose Garda2Bindu Patanair3Allisson Saiter-Fourcin4https://orcid.org/0000-0001-9275-6865Sabu Thomas5Department of Physics, National Institute of Technology Silchar, Silchar—788010, Assam, IndiaDepartment of Physics, National Institute of Technology Silchar, Silchar—788010, Assam, IndiaNormandie Univ , UNIROUEN, INSA Rouen, CNRS, GPM, 76000 Rouen, FranceNormandie Univ , UNIROUEN, INSA Rouen, CNRS, GPM, 76000 Rouen, FranceNormandie Univ , UNIROUEN, INSA Rouen, CNRS, GPM, 76000 Rouen, FranceInternational and Inter-University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University , Kottayam 686560, Kerala, IndiaProtic ionic liquids (PILs) in the acidic medium are known to show higher ionic conductivity than neat PIL or PIL in alkaline media. Hence, polymer electrolyte membranes (PEM) containing both PIL and acids are considered ideal for non-humidified intermediate temperature PEM fuel cells. Herein, we report non-aqueous proton conducting PEM made up of diethylmethylammonium trifluoromethanesulfonate; [dema][TfO] and neat phosphoric acid (H _3 PO _4 ) with poly (vinylidene fluoride-co-hexafluoropropylene); PVDF-HFP as the host matrix. The presence of PIL significantly modified the structure and microstructure of the electrolyte films with the emergence of micropores in the PIL containing membranes. SEM images suggest leaching of PIL and phosphoric acid above 80 wt% of PIL in the electrolyte membranes. Thermogravimetric studies show that the dehydration in the PEM films due to phosphoric acid condensation at 100 °C–200 °C region is arrested by the presence of PIL. The maximum ionic conductivity at room temperature is ∼6.3 × 10 ^−4 S cm ^−1 at 40 wt% of [dema][TfO] addition, which is two orders higher than that of the primary electrolyte (PE) containing only phosphoric acid in PVDF-HFP. This high conductivity in PEM films can be correlated to the increase in polar β and γ phases as well as a drop in the total crystallinity fraction in the film. The study using dielectric spectroscopy reveals a strong coupling of ionic conductivity with the structural or segmental relaxation of the PVDF-HFP due to the presence of [dema][TfO] in the PEMs.https://doi.org/10.1088/2053-1591/ab9665[dema][TfO]polymer electrolyte membranesH3PO4protic ionic liquid (PIL) |
| spellingShingle | Manjula G Nair Saumya R Mohapatra Marie-Rose Garda Bindu Patanair Allisson Saiter-Fourcin Sabu Thomas Role of protic ionic liquid concentration in proton conducting polymer electrolytes for improved electrical and thermal properties Materials Research Express [dema][TfO] polymer electrolyte membranes H3PO4 protic ionic liquid (PIL) |
| title | Role of protic ionic liquid concentration in proton conducting polymer electrolytes for improved electrical and thermal properties |
| title_full | Role of protic ionic liquid concentration in proton conducting polymer electrolytes for improved electrical and thermal properties |
| title_fullStr | Role of protic ionic liquid concentration in proton conducting polymer electrolytes for improved electrical and thermal properties |
| title_full_unstemmed | Role of protic ionic liquid concentration in proton conducting polymer electrolytes for improved electrical and thermal properties |
| title_short | Role of protic ionic liquid concentration in proton conducting polymer electrolytes for improved electrical and thermal properties |
| title_sort | role of protic ionic liquid concentration in proton conducting polymer electrolytes for improved electrical and thermal properties |
| topic | [dema][TfO] polymer electrolyte membranes H3PO4 protic ionic liquid (PIL) |
| url | https://doi.org/10.1088/2053-1591/ab9665 |
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