Water management is critical for polymer-electrolyte fuel cells (PEFCs), anion exchange membrane fuel cells (AEMFCs) and polymer electrolyte membrane (PEM) electrolyzers, as depending on a device, water is used as either a reactant or byproduct of electrochemical reaction and its location, as well as transport is critical for these devices operation. In PEFCs during start-up and operation liquid water formed as a byproduct of electrochemical reaction can block gas (reactant) delivery to a catalyst, resulting in flooding, mass-transport losses, and low cell power densities. For AEMFCs water is a reactant in the cathode and its transport from the anode is critical for the cell operation. Addressing and understanding water transport issues, is made possible by introducing the capabilities for in-operando X-ray CT. In this presentation a single serpentine channel, 1 cm2 active area fuel cell and electrolyzer operating at 30 and 60oC will be presented. Cells with Platinum-group medals (PGM) and PGM-free electrodes on either cathode or anode will be presented with examples of water distributions. It was observed that for PGM-free electrodes water accumulates at components interfaces, where large voids are present. For electrolyzers water distribution in the anode under 50 and 200 mA/cm2will be shown. Furthermore, application of nano- X-ray CT for in-operando PEFCs will be demonstrated, as well as micro-CT for in-situ batteries characterization.
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