The effect of ferric ions on the conductivity of various types of polymer cation exchange membranes

Autor: Vassili Glibin, Victor Pupkevich, Dimitre Karamanev
Rok vydání: 2007
Předmět:
Zdroj: Journal of Solid State Electrochemistry. 11:1429-1434
ISSN: 1433-0768
1432-8488
DOI: 10.1007/s10008-007-0306-4
Popis: Recently, rejuvenated interest to fuel cells has posed a number of problems regarding the polymer electrolyte membrane properties and their behaviour in different electrolyte solutions. This work was dedicated to study the conductivity of H+-, Fe3+- and mixed H+/Fe3+-forms of cation exchange membranes Neosepta CMS, Nafion 112, 115 and 117 and Selemion HSF under conditions similar to these in the Fe3+/Fe2+–H2/H+ fuel cell in the range of current densities 0–90 mA/cm2. It was found that the conductivities of these membranes in 1.09 M H2SO4 solution decrease in the following order: Selemion HSF › Nafion 117 ≈ Nafion 115 ≈ Neosepta CMS › Nafion 112. Conductivities of perfluorinated membranes were discussed in terms of Hsu and Gierke percolation theory [20]. The Fe3+-forms of Nafion membranes studied displayed a monotonous decline in the resistance when current increased, which is a manifestation of gradual conversion of the Fe3+-form into H+-form of these membranes. Unlike the Nafion membranes, the Fe3+-forms of Neosepta CMS and Selemion HSF membranes exhibited a sharp jump of resistance at relatively high current densities (more than 70 mA/cm2) that is most probably a result of concentration polarization.
Databáze: OpenAIRE
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