Effect of Sintering Temperature and Applied Load on Anode-Supported Electrodes for SOFC Application

Anode-supported cells are prepared by a sequence of hot pressing and co-sintering processes for solid oxide fuel cell (SOFC) applications. Commercially available porous anode tape (NiO/YSZ = 50 wt %/50 wt %), anode tape (NiO/YSZ = 30 wt %/70 wt %), and YSZ are used as the anode substrate, anode functional layer, and electrolyte layer, respectively. After hot pressing, the stacked layers are then sintered at different temperatures (1250 degree C, 1350 degree C, 1400 degree C and 1450 degree C) for 5 h in air. Different compressive loads are applied during the sintering process. An (La,Sr)MnO3 (LSM) paste is coated on the post-sintered anode-supported electrolyte surface as the cathode, and sintered at different temperatures (1100 degree C, 1150 degree C, 1200 degree C and 1250 degree C) for 2 h in air to generate anode-supported cells with dimensions of 60 60 mm2 (active reaction area of 50 50 mm2). SEM is used to investigate the anode structure of the anode-supported cells. In addition, confocal laser scanning microscopy is used to investigate the roughness of the cathode surfaces. At sintering temperatures of 1400 degree C and 1450 degree C, there is significant grain growth in the anode. Furthermore, the surface of the cathode is smoother at a firing temperature of 1200 degree C. It is also found that the optimal compressive load of 1742 Pa led to a flatness of 168 mu m/6 cm and a deformation of 0.72%. The open circuit voltage and power density of the anode-supported cell at 750 degree C were 1.0 V and 178 mW times cm-2, respectively.