Defect Detection in Fuel Cell Gas Diffusion Electrodes Using Infrared Thermography

Abstract

Polymer electrolyte membrane fuel cells are energy conversion devices that offer high power densities and high efficiencies for mobile and other applications. Successful introduction into the marketplace requires addressing cost barriers such as production volumes and platinum loading. For cost reduction, it is vital to minimize waste and maximize quality during the manufacturing of platinum-containing electrodes, including gas diffusion electrodes (GDEs). In this work, we report on developing a quality control diagnostic for GDEs, involving creating an ex situ exothermic reaction on the electrode surface and using infrared thermography to measure the resulting temperature profile. Experiments with a moving GDE containing created defects were conducted to demonstrate the applicability of the diagnostic for real-time web-line inspection.

Investigation of catalyst layer defects in catalyst-coated membrane for PEMFC application: Non-destructive method

“…Monitoring defects in the CCM within an MEA is complicated by the fact that it is contained within the GDL layers. In this case, IR thermography has been shown to be effective at characterizing defects . In this study, we use IR thermography to examine the cathode side of an MEA, as shown in the schematic side view in Figure A.…”

“…These IR results shows that these defects are also significant and should be of concern prior to MEA assembly. Although the hotspot defects do not initially appear to affect performance, they can potentially grow during cell operation and eventually cause shutdown of the PEMFC …”

“…For example, the CCM thickness can be measured manually by cutting a sample or using laser‐point measurements at specific location, but cannot be done over the entire area in real time . Novel techniques including optical reflectometry and IR imaging with DC excitation have been proposed in an attempt to meet some of these requirements . Although several studies have been performed on defects artificially introduced at specific locations, very few studies on real defects in CLs have been reported to date .…”

Reactive impinging-flow technique for polymer-electrolyte-fuel-cell electrode-defect detection

“…For RFT, a nonflammable (< 4% H 2 ) reactive mixture of H 2 /O 2 in N 2 is flowed through the GDE where the catalytic reaction on the Pt surface generates heat, creating a measurable thermal signature. A proof-of-concept of the extension of the RFT technique to an open-atmosphere environment, where the GDE is conveyed on a bench-top roller system, was previously reported and termed as reactive impinging flow (RIF) [25]. In this work, we report on the further development of the IR thermography technique coupled with RIF to detect defects in moving GDEs.…”

“…Compared to the prior modeling work of RFT [10], the model developed in this work captures the physics of impinging flow onto the porous GDE on a moving webline. Moreover, this manuscript builds upon RIF technique demonstration [25] and explores optimal parametric space for webline velocity, gas flowrate, composition, and defect geometry for defect detectability. It also provides recommendations for improved defect detection using RIF technique.…”