کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10567751 | 973299 | 2011 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Performance of composite Nafion/PVA membranes for direct methanol fuel cells
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موضوعات مرتبط
مهندسی و علوم پایه
شیمی
الکتروشیمی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
This work has been focused on the characterization of the methanol permeability and fuel cell performance of composite Nafion/PVA membranes in function of their thickness, which ranged from 19 to 97 μm. The composite membranes were made up of Nafion® polymer deposited between polyvinyl alcohol (PVA) nanofibers. The resistance to methanol permeation of the Nafion/PVA membranes shows a linear variation with the thickness. The separation between apparent and true permeability permits to give an estimated value of 4.0 Ã 10â7 cm2 sâ1 for the intrinsic or true permeability of the bulk phase at the composite membranes. The incorporation of PVA nanofibers causes a remarkable reduction of one order of magnitude in the methanol permeability as compared with pristine Nafion® membranes. The DMFC performances of membrane-electrode assemblies prepared from Nafion/PVA and pristine Nafion® membranes were tested at 45, 70 and 95 °C under various methanol concentrations, i.e., 1, 2 and 3 M. The nanocomposite membranes with thicknesses of 19 μm and 47 μm reached power densities of 211 mW cmâ2 and 184 mW cmâ2 at 95 °C and 2 M methanol concentration. These results are comparable to those found for Nafion® membranes with similar thickness at the same conditions, which were 210 mW cmâ2 and 204 mW cmâ2 respectively. Due to the lower amount of Nafion® polymer present within the composite membranes, it is suggested a high degree of utilization of Nafion® as proton conductive material within the Nafion/PVA membranes, and therefore, significant savings in the consumed amount of Nafion® are potentially able to be achieved. In addition, the reinforcement effect caused by the PVA nanofibers offers the possibility of preparing membranes with very low thickness and good mechanical properties, while on the other hand, pristine Nafion® membranes are unpractical below a thickness of 50 μm.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Power Sources - Volume 196, Issue 5, 1 March 2011, Pages 2699-2708
Journal: Journal of Power Sources - Volume 196, Issue 5, 1 March 2011, Pages 2699-2708
نویسندگان
Sergio Mollá, Vicente Compañ,