Guidelines for the Rational Design and Engineering of 3D Manufactured Solid Oxide Fuel Cell Composite Electrodes
Guidelines for the Rational Design and Engineering of 3D Manufactured Solid Oxide Fuel Cell Composite Electrodes
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DOI：
10.1149/2.0501702jes
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发表时间：
2017
影响因子：
3.9
通讯作者：
A. Bertei;Farid Tariq;V. Yufit;E. Ruiz-Trejo;N. Brandon
中科院分区：
文献类型：
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作者：
A. Bertei;Farid Tariq;V. Yufit;E. Ruiz-Trejo;N. Brandon
The growth of 3D printing has opened the scope for designing microstructures for solid oxide fuel cells (SOFCs) with improved power density and lifetime. This technique can introduce structural modifications at a scale larger than particle size but smaller than cell size, such as by inserting electrolyte pillars of ∼ 5–100 μ m. This study sets the minimum requirements for the rational design of 3D printed electrodes based on an electrochemical model and analytical solutions for functional layers with negligible electronic resistance and no mixed conduction. Results show that this structural modification enhances the power density when the ratio k eff between effective conductivity and bulk conductivity of the ionic phase is smaller than 0.5. The maximum performance improvement is predicted as a function of k eff . A design study on a wide range of pillar shapes indicates that improvements are achieved by any structural modification which provides ionic conduction up to a characteristic thickness ∼ 10–40 μ m without removing active volume at the electrolyte interface. The best performance is reached for thin ( ∼ 80 μ m) pillars when the composite electrode is optimised for maximum three-phase boundary density, pointing toward the design of scaffolds with well-defined geometry and fractal structures. what a benchmark flat electrode can provide. In addition, an analytical approximation was proposed to predict the upper bound in performance improvement. All the results provide key insight for the rational design of electrodes through to a series of characteristic parameters, such as the characteristic active thickness of the coupled reaction/conduction process t ∗ ed , the effective conductivity factor of the ion-conducting phase in the composite elec- trode domain k eff , the ratio between pillar half-width and half-distance among pillar walls ω corresponding to the pillar volume fraction, and dimensionless factors (cid:4) W and (cid:4) h comparing pillar width and pillar thickness with the characteristic thickness.
