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

A temperature-controlled microextrusion printing technique is proposed to realize the increased aspect ratio of mesoscale convex structures at the anode-electrolyte interface in solid oxide fuel cells (SOFCs). The rheological properties of the anode ink for microextrusion printing are experimentally measured at various temperatures, and it is found that the viscosity of the ink and the wettability of the ink to the anode substrate decrease at lower temperatures, which is desirable for the ink to retain its shape on the substrate. The anode-supported SOFC button cells are fabricated by microextrusion printing with and without temperature control and compared in terms of their interfacial structures and electrochemical performance. The aspect ratio of the interfacial structure is increased from 0.16 to 0.28 by lowering the ink temperature, resulting in a higher interface enlargement of 25%. Owing to the enlarged interfacial area, enhanced cell performance is also achieved.