Reconstruction and Modeling of Porous Transport Layers Based on X-ray Computed Tomography Imaging
Jiang Liu, M. Takada, Felix Kerner, Yosuke Inoue, Daniel Schröder
Abstract
High Resolution Image Download MS PowerPoint Slide The porous transport layer (PTL) is one of the key components to enhancing the performance of an electrolyzer. Reconstructing the real microstructure and conducting customized modeling enable us to propose optimal design and production strategies for the PTL. This work utilizes a combination of X-ray computed tomography (XCT) imaging and image binarization for reconstructing digital representations of real PTL microstructures. Three types of commercial PTLs, i.e., sintered powder, felt, and expanded mesh, are reconstructed. The surface properties, electrical and thermal conductivities, and oxygen transport for these PTLs are computed and analyzed using pore scale modeling and lattice Boltzmann modeling. Structurally tuned sintered powder PTLs are presented to enhance the specific performance and demonstrate the advantages of the reconstruction method. The results indicate that the sintered powder with lower porosity and lower pore size provides more sufficient interfacial contact and that increasing porosity and/or pore sizes can yield improved mass transport. There is a strong correlation between the various properties of the PTL, including electrical and thermal conductivities and oxygen removal, and its structure. The methods and results bear vital practical implications for the optimal design of large-scale PTLs and can be used to manufacture optimal PTL structures for large-scale electrolyzers.