Design and optimization of composite electrodes in solid oxide cells
Chan, S. H.
Date of Issue2012
School of Mechanical and Aerospace Engineering
Energy Research Institute
The performance of solid oxide cells (SOCs) heavily relies on the population of three-phase boundaries (TPBs) in the composite electrodes. In this study, SOC composite electrodes are described by percolating binary particle aggregates that are constructed from random loose packing models and classical sintering theories. Summed perimeters of the sintering necks represent the total TPB lengths. A case study has been carried out on lanthanum strontium manganite (LSM)–yttria-stabilized zirconia (YSZ) composite electrodes. By employing three-dimensional data that are converted from relevant two-dimensional data, the TPB length of baseline LSM–YSZ electrodes investigated in this study is 35.4 μm μm–3. The parametric and sensitivity analyses show the changes of TPB lengths in functions of the weight fraction of powders, particle size and particle size ratio of powders, void fraction of electrodes, and density of materials. In the case of baseline LSM–YSZ electrodes, proper electrode design and optimization would result in 2–3 times of the enlargement of TPBs. Technical guidelines on the design and optimization of SOC composite electrodes are proposed.
© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.