1443
Water Management in Low Temperature Fuel Cells through in-Operando X-Ray Computed Tomography

Monday, 29 May 2017: 15:40
Grand Salon B - Section 7 (Hilton New Orleans Riverside)
S. J. Normile, O. Calzada (Tufts University), P. Mandal, D. Y. Parkinson (Lawrence Berkeley National Laboratory), X. Xiao (Argonne National Laboratory), A. Z. Weber (JCAP/ESDRD - Lawrence Berkeley National Laboratory), and I. V. Zenyuk (Tufts University)
For polymer-electrolyte fuel cells (PEFCs) and anion exchange membrane fuel cells (AEMFCs) optimal water management is essential. During start-up and at low operating temperatures, where water is present in a liquid form, it can block reactant delivery to electrocatalyst sites, resulting in significant mass-transport losses, flooding and low fuel cell power densities. Using synchrotron X-ray computed tomography (CT) we have previously shown how water transport properties depend on porous materials morphology and chemical composition, as well as cell compression.1-3 These ex- and in-situ studies isolate specific porous membrane / electrode assembly (MEA) component’s effect on water management (such as micro-porous (MPL) or gas-diffusion layer (GDL)). To understand water transport under operating conditions we use in-operandoX-ray CT studies, where water distribution is observed under various steady-state conditions.

In-operando single serpentine channel (1x1 mm) fuel cell testing hardware for synchrotron X-ray CT is used with active area of 1 cm2. Steady-state water generation and removal is observed in PEFCs and AEMFCs for temperature of 30oC with chronoamperometric holds at current densities ranges of 20 – 100 mA/cm2. Furthermore, comparison of water distribution in PGM and PGM-free catalysts for both type of fuel-cells will be presented. In all of these systems water pooling is observed at the component interfaces, indicating the importance of interfaces design.

Acknowledgment: The Advanced Light Source is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. This research used resources of the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357.

References:

1. I. V. Zenyuk, D. Y. Parkinson, L. G. Connolly and A. Z. Weber, Journal of Power Sources, 2016, 328, 364-376.

2. I. V. Zenyuk, D. Y. Parkinson, G. Hwang and A. Z. Weber, Electrochemistry Communications, 2015, 53, 24-28.

3. I. V. Zenyuk and A. Z. Weber, ECS Transactions, 2015, 69, 1253-1265.

Figure 1. In-operando cross-section tomograph of serpentine channel AEMFC operating at 30 mA/cm2, 30oC and 100 % RH.

See more of: Fuel Cell Performance 1
See more of: I02: Materials for Low Temperature Electrochemical Systems 3
See more of: Fuel Cells, Electrolyzers, and Energy Conversion
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