Facile preparation of patterned anode substrate for solid oxide fuel cells by direct-writing 3D printing technology

3D printing has revolutionized solid oxide fuel cell (SOFC) by introducing complicated structure and new functionalities that cannot be realized using traditional preparation process. This work provides guide and insights into the application of direct-writing 3D printing to fabricate the patterned electrolyte|electrode interface for the anode-supported SOFC using 3 mol % yttria-stabilized zirconia-nickel oxide (3YSZ-NiO) as the anode substrate material. The parameters that affected the shaping and performance of SOFC including the rheological properties of 3YSZ-NiO anode paste, the printing parameters, and the heat treatment process of the pre-sintered anode substrate were evaluated. The prepared 3YSZ-NiO paste exhibited a typical shear-thinning characteristic, "yielding" solid-like behavior, and time- and temperature-independent stability performance, which ensured the paste suitable for extrusion while allowing the shape of the printed body to be maintained after extrusion during the direct-writing printing process. The as-prepared anode paste, combined with the obtained values of 0.1 MPa, 100 mm s-1, 100 rpm, and 0.3 mm for printing parameters of the extrusion pressure, the printing speed, the screw speed, and the nozzle diameter, respectively, as well as the devised heat treatment program for the presintered 3YSZ-NiO anode substrate, successfully produced defect-free corrugated anode substrates. The cell made from the as-mentioned anode substrate showed an open circuit voltage of 1.02 V and a maximum power density of 619.44 mW cm-2 at 850 degrees C, which was comparable to the other identical cells fabricated by traditional and other 3D printing processes. Using the 3D printing process shown here, the preparation time of patterned anode substrate can be reduced and simplified.