3D reconstruction of a gas diffusion layer and a microporous layer

The focus of the current study is on a state-of-the-art twin-layer gas diffusion layer (GDL) which consists of carbon tissues with a fibre diameter of 5–20 μm, and contains a microporous layer (MPL) coating which has sub-micron porous features. In the current study, real-world digital three-dimensional images of the GDL-MPL assembly are created through X-ray nano-tomography with a 680 nm pixel resolution for the GDL and focused ion beam/scanning electron microscopy (FIB/SEM) nano-tomography with a 14 nm pixel resolution for the MPL. The critical nano-structural features including porosity, characteristic lengths and 3D pore size distribution are determined directly from the 3D digital representation. In addition to morphological parameters, the FIB/SEM nano-tomography technique has been combined with lattice Boltzmann (LB) numerical modelling in order to calculate the tortuosity and permeability of the MPL.