The Membrane-Electrode Interface in PEFCs II. Impact on Fuel Cell Durability

The impact of the membrane-electrode interface on fuel cell durability was investigated in polymer electrolyte fuel cells (PEFCs). Cells using disulfonated poly(arylene ether) copolymer (BPSH) membranes exhibited greater performance loss than a cell using Nafion after 700 h of direct methanol fuel cell (DMFC) testing. Additionally, the performance loss and cell resistance within the BPSH family of copolymers increased with increasing degree of disulfonation. Membrane characterization using (1)H NMR, potentiometric titration, intrinsic viscosity, water uptake, and proton conductivity showed minimal impact from chemical/physical changes. Fuel cell performance degradation scaled well with initial membrane-electrode interfacial resistance, suggesting that the membrane-electrode interface was an important contributor to DMFC durability. These results are of particular interest for alternative proton exchange membranes where interfacial compatibility with electrodes is a critical, unresolved issue. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3481577] All rights reserved.