The design optimization of nanostructured hierarchical electrodes for solid oxide cells by artificial impregnation

• Published in: Materials & design Vol. 238; p. 112663
• Main Authors: Cademartori, Davide, Hubert, Maxime, Cloetens, Peter, Carpanese, M. Paola, Laurencin, Jérôme
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2024; Elsevier
• ISSN: 0264-1275; 1873-4197
• DOI: 10.1016/j.matdes.2024.112663

[Display omitted] •The morphology of freeze tape cast electrodes for solid oxide cells were characterized by X-Ray tomography.•A particle-based model was built to synthetically impregnate the electrode 3D reconstructions.•A sensitivity analysis on the nanoparticle size and catalyst loading was carried out to optimize the electrode microstructure.•Influence of nanoparticles size and scaffold morphology on the catalyst percolating properties and number of active sites was indicated. Microstructural correlations of impregnated freeze tape cast scaffolds for solid oxide cellsare studied by coupling experimental and modelling approaches. The functional and supporting layers of the hierarchical porous backbones are initially reconstructed by synchrotron X-ray micro- and nano-holotomography, respectively. A particle-based model was then builtto numerically infiltrate the scaffold walls with hemispherical nanoparticles. The electrode microstructural properties are evaluated on the artificially impregnated electrodes as function of the catalyst loading. A parametric investigation on the effect of the nanoparticle sizeisperformed to analyse the evolution of the electrode characteristics. It has been shown that the volume fraction of the infiltrated phase necessary to reach the percolating threshold is increased while increasing the nanoparticle size. The density of active sitespresents a maximum asfunction of the catalyst loading that depends on the particle size. The volume fraction of infiltrated phase required to reach the percolating threshold in the diffusion layeris one order of magnitude lower than in the functional layer (∼1 vol% compared to 3–8 vol%, respectively). The analyses contained in this paper aim at guiding the manufacturing process to the shaping of innovative electrodes microstructures combining both high activation and mass transfer properties.