Fabrication and evaluation of Ni-GDC composite anode prepared by aqueous-based tape casting method for low-temperature solid oxide fuel cell

Large-size, 8 cm × 8 cm, NiO-Gd0.1Ce0.9O1.95 (Ni-GDC) composite anodes have been successfully fabricated by aqueous-based tape casting method for anode-supported solid oxide fuel cell (SOFC). The pre-sintered anode green tape was coated with a GDC electrolyte film by spray coating method and then co-sintered together to obtain electrolyte/anode bi-layer. The cathode, which is made of La0.8Sr0.2Co0.2Fe0.8O3-GDC (LSCF-GDC) was screen printed onto the electrolyte film and sintered to form a complete anode-supported SOFC. The performance of the cell was evaluated on an in-house developed test station between 500 and 650 °C. Due to the limitation of the test station for large-cell testing, small-size samples with dimensions of 2.5 cm × 2.5 cm were cut out from the large-cell. For the single cell with humidified hydrogen as fuel and air as oxidant, the maximum power density achieved 909, 623, 335 and 168 mW cm−2 at 650, 600, 550 and 500 °C, respectively. Impedance analysis confirmed that the performance of single cells below 600 °C was retarded primarily due to the slow interfacial reaction kinetics at reduced temperatures. Development of catalytically active electrode materials, especially the cathode material and improvement of the electrode microstructure are thus crucial for achieving a high performance low-temperature SOFC.