Accelerated Degradation of Polymer Electrolyte Membrane Fuel Cell Gas Diffusion Layers: II. Steady State Liquid Water Distributions with in Operando Synchrotron X-ray Radiography. Issue 7 (2nd May 2017)

• Record Type: Journal Article
• Authors: Liu, Hang; George, Michael G.; Banerjee, Rupak; Ge, Nan; Lee, Jongmin; Muirhead, Daniel; Shrestha, Pranay; Chevalier, Stéphane; Hinebaugh, James; Zeis, Roswitha; Messerschmidt, Matthias; Scholta, Joachim; Bazylak, Aimy
• Is Part Of: Journal of the Electrochemical Society. Volume 164:Issue 7(2017)
• Page Start: F704
• Page End: F713
• Publication Date: 2017-05-02
• Subjects: accelerated ageing -- ageing effects -- gas diffusion layer -- liquid water management -- polymer electrolyte membrane fuel cell -- synchrotron X-ray radiographic imaging; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/2.0081707jes
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : In this work, as-received pristine GDLs were degraded (aged) through an accelerated ageing process by immersion into a 35% wt. solution of H2 O2 at 90°C for 12 hours. Pristine and degraded GDLs were assembled in custom-built fuel cells for in operando synchrotron X-ray visualization. Electrochemical impedance spectroscopy (EIS) measurements were obtained, while synchrotron X-ray radiography was performed to investigate the effect of ageing on liquid water transport behavior. In both pristine and aged GDLs, the liquid water profile converged to an upper (terminal) threshold in the saturation pattern as the current density increased. The terminal steady state liquid water profile was established at a lower current density for the aged GDLs compared to that of the pristine GDLs. Higher water quantities of liquid water accumulated at the GDL/flow field channel and MPL/carbon fiber substrate interfaces of the fuel cell with an aged GDL compared to the fuel cell with a pristine GDL. The aged GDLs exhibited more liquid water accumulation at lower current densities. Increases in liquid water accumulation and reduced performance were attributed to the reduction in hydrophobicity of the GDL.