Fuel cell rejuvenation of hygrothermally aged Nafion

Floraine Collette (1) , Francette Thominette (1) , Sylvie Escribano (2, 3) , Angèle Ravachol (4, 3) , Arnaud Morin (4, 3) , Gérard Gebel (5)

1 PIMM - Laboratoire Procédés et Ingénierie en Mécanique et Matériaux
2 LITEN - Laboratoire d'Innovation pour les Technologies des Energies Nouvelles et les nanomatériaux
3 LCPEM - Laboratoire des Composants PEM
4 LITEN - Laboratoire Innovation pour les Technologies des Energies Nouvelles et les Nano matériaux [Université Hassan 1er - Settat]
5 SPRAM - UMR 5819 - Structures et propriétés d'architectures moléculaire

Nafion ® membranes stored for long periods at 80 °C under elevated relative humidity up to 95%RH exhibit large modifications of their properties attributed to the sulfonic acid end-group condensation into sulfonic anhydrides. The present study is devoted to the membrane property rejuvenation, namely the hydrolysis of the sulfonic anhydrides under different experimental conditions. Aged membranes were exposed to pure water and to acid solutions or vapors in order to check the reversibility of the condensation reaction. Indeed, the hydrolysis process is slow in pure water and limited while it is fast and complete in the presence of acid or base. The native polymer chemical structure and the main membrane properties (mechanical properties, hydrophilicity, etc.) are completely restored. No evidence of hygrothermal aging was observed after fuel cell operation and it is shown that a membrane previously aged under ex situ conditions can be completely rejuvenated when operated in fuel cell.

Mots clés: Fuel cell; Hygrothermal aging; Membrane degradation; Rejuvenation; Nafion ®

Domaines: Matériaux; Mécanique [physics.med-ph]

Floraine Collette, Francette Thominette, Sylvie Escribano, Angèle Ravachol, Arnaud Morin, et al.. Fuel cell rejuvenation of hygrothermally aged Nafion. Journal of Power Sources, 2012, 202, pp.126- 133. ⟨10.1016/j.jpowsour.2011.10.135⟩. ⟨hal-01190801⟩