X-Ray Computed Tomography of PEM Fuel Cells

Proton exchange membrane (PEM) fuel cells were investigated by 3D x-ray computed tomography at a voxel size of 0.7 µm. It is shown that this lab-based technique is not only suitable for the investigation of gas diffusion layers (GDL) as well as the investigation of membrane electrode assemblies (MEA), but also allows the calculation of macroscopic physical properties. The resolution of computed tomography is clearly sufficient to image the carbon fiber structure of gas diffusion layers in the as received GDLs as well as GDLs integrated into membrane electrode assemblies. It is also possible to visualize the catalyst layer within the MEA, which allows the investigation of layer thickness and structural defects on a larger scale than with conventional techniques. The macroscopic effective thermal conductivities of the gas diffusion layers were computed based on the 3D GDL structure reconstructed from tomography data to produce more reliable input data for fuel cell modeling. The computation was carried out by solving the energy equation considering a pure thermal conduction problem. The computations show - in agreement with the expectation and experimental data - that the through-plane thermal conductivities are lower than the in-plane thermal conductivities.

PFRANG Andreas;  VEYRET Damien;  TSOTRIDIS Georgios;  JANSSEN Gaby; 

2010-07-21

DECHEMA e.V.

JRC58117

https://publications.jrc.ec.europa.eu/repository/handle/JRC58117,