Title

Deterioration of Mechanical Properties: A Cause for Fuel Cell Membrane Failure

Document Type

Article

Publication Date

7-1-2010

Department

Polymers and High Performance Materials

Abstract

The mechanical properties of Nafion (R) membranes that were degraded after periods of open circuit voltage (OCV) conditions in a fuel cell were studied. Severe decreases in membrane modulus and ductility at 80 degrees C and 100% relative humidity were observed. Stress-at-break values for 45 and 72 h degraded membrane-electrode assemblies (MEAs) were 6 and 9 times lower, respectively, while strain-at-break was 24 and 28 times lower, respectively, than that of a control MEA. Contractile stresses developed in constrained hydrated membranes that were then dried were conducted as a function of drying time. A pre-OCV degraded MEA, when subjected to creep deformation at 10 MPa, showed surface cracks which were not present in the control MEA. The 72 h-degraded MEA exhibited wider cracks than those of the 45 h-degraded MEA sample. Spectroscopic analysis of degraded membranes showed various small molecule fragments associated with side chain degradation. (C) 2010 Elsevier B.V. All rights reserved.

Publication Title

Journal of Membrane Science

Volume

356

Issue

1-2

First Page

7

Last Page

13