(Invited) Insights from the inside: Imaging Water in the Porous Structures of Fuel Cells

Abstract

Imaging is a powerful tool to understand and optimize the water management in acidic and alkaline fuel cells. A topic that has also been a subject of collaboration between the authors and Shimshon Gottesfeld. Neutron radiography is a truly non-destructive method with the advantage of large fields of view, easy penetration of structural materials and negligible radiation damage. This allows for exposure over long periods of operation and therefore dedicated parameter studies. In alkaline fuel cells the water management is of high importance and a crucial point to optimize performance. Insight will be presented fon different scales, from the differential cell to the stack level using neutron radiography (Figure 1). X-ray tomographic microscopy is a complementary imaging method when information on the pore scale in a small field of view and fast dynamics are required. Recent developments and insights from sub-second synchrotron based tomographic imaging on the dynamics of water in the gas diffusion layer will be discussed. Figure 2 shows a series of 0.1s tomographic scans after a current jump from OCV to 0.5 A/cm2, showing the dynamic development of liquid saturation in the GDL. Figure 1