Improvement in the Electrochemical Performance of Anode‐supported Solid Oxide Fuel Cells by Meso‐ and Nanoscale Structural Modifications

Abstract

To improve the electrochemical performance of anode-supported solid oxide fuel cells (SOFCs), microextrusion printing and wet infiltration techniques are employed for structural modification on the meso-(10-100 mm) and nanoscale order, respectively. In the mesoscale structural modification, anode ridge structures are fabricated by extruding an anode slurry on the surface of a flat anode disk to extend the electrodeelectrolyte interfacial area. In the nanoscale structural modification, gadolinium-doped ceria (GDC) nanoparticles are introduced into a porous lanthanum strontium cobalt ferrite (LSCF) cathode. To investigate the effects of mesoscale and nanoscale structural modifications, four different types of anode-supported SOFC including a conventional cell are prepared , and their performance is evaluated at several operating temperatures. It is found that both the mesoscale and nanoscale structural modifications reduce not only the polarization resistance but also the ohmic resistance in the cells, resulting in the improvement in cell performance. Moreover, it is clarified that the improvement in cell performance becomes greater with decreasing operating temperature. Specifically, the maximum power density in the cell where both mesoscale and nanoscale structural modifications are applied is increased by 66% at 600°C and 34% at 700°C, compared with that in the conventional cell.

Temperature‐controlled microextrusion printing for mesoscale interfacial designing in solid oxide fuel cells

“…This is because the effect of the interface enlargement becomes more significant at lower operating temperatures, which is because the reduction in cell overpotential becomes larger with decreasing operating temperature. This agrees with the conclusion of our previous studies [10, 14].…”

“…Thus far, various fabrication technologies, such as laserassisted machining and micro powder imprinting [11][12][13], have been proposed for electrode-electrolyte interface enlargement, and enhanced electrochemical performance has been achieved. A more detailed literature review on interfacial modification techniques can be found in our previous reports [10,14]. However, it was reported that the grooved structures fabricated by the subtractive techniques are difficult to control precisely.…”

“…Alternatively, a microextrusion-printing-based additive manufacturing technique is appreciated because of less material waste, free contact with printed objects, and the capability to fabricate precise structures [17]. We have applied this technique to the fabrication of anodesupported SOFCs to obtain enhanced cell performance [10,14]. However, the interface enlargement achieved in that study was no more than ca.…”

Prediction of electrochemical characteristics of practical-size solid oxide fuel cells based on database of unit cell performance

“…To validate the 1D unit cell model we developed, the predicted current-voltage and impedance characteristics were compared with those obtained from an experiment using an anode-supported button cell. The details of the fabrication of this cell are found elsewhere [55] and summarized as follows. First, 60 wt.% NiO powder (FUJIFILM Wako Pure Chemical Corp., Japan) and 40 wt.% YSZ powder (TZ-8Y, Tosoh Corp., Japan) were mixed by planetary ball milling in isopropanol with zirconia balls ( 4.0 mm) at 300 rpm for 3 h. After evaporating the isopropanol, the resultant NiO-YSZ mixture powder was sieved with a 53 µm mesh to remove agglomerates.…”

An Overview on the Novel Core-Shell Electrodes for Solid Oxide Fuel Cell (SOFC) Using Polymeric Methodology

“…The porous microstructure of SOFC electrodes correlates with the TPBs, gas diffusio and concentration polarization. Adding an interlayer such as an AFL between the electro lyte and anode, and impregnating electrocatalytic particles into the porous anode effec tively increased the TPBs and decreased the contact resistance between the electrolyte and the electrode [93][94][95][96]. However, the AFL and solution impregnation require additiona The porous microstructure of SOFC electrodes correlates with the TPBs, gas diffusion and concentration polarization.…”