Multiscale Tomography-Based Analysis of Polymer Electrolyte Fuel Cells: Towards a Fully Resolved Gas Diffusion Electrode Reconstruction

The microstructure of a fuel cell electrode largely determines the performance of the whole fuel cell system. In this regard, tomographic imaging is a valuable tool for the understanding and control of the electrode morphology. The distribution of pore- and feature-sizes within fuel cell electrodes covers several orders of magnitude, ranging from millimeters in the gas diffusion layer (GDL) down to few nanometers in the catalyst layer. This obligates the application of various tomographic methods for imaging every aspect of a fuel cell. This perspective evaluates the capabilities, limits, and challenges of each of these methods. Further, it highlights and suggests efforts toward the integration of multiple tomographic methods into single multiscale datasets, a venture which aims at large-scale, and morphologically fully resolved fuel cell reconstructions.