Single Step Production of Cathode Supported SOFC

Cathode-supported solid oxide fuel cells (SOFCs) offer several advantages over anode-supported ones. In terms of structural stability, for example, they do not suffer from the volume contraction and expansion typical of the redox cycle of Ni-based supported cells. For the production of the half-cell a thin film electrolyte is screen printed on the green tape substrate and co-sintered to form the electrolyte/cathode bilayer. The anode is commonly deposited on the as-sintered half-cell. An additional thermal treatment at lower temperatures is necessary to obtain a complete cell. In this study the possibility to obtain a SOFC constituted by a porous LSM-GDC supporting cathode with GDC dense electrolyte and a NiO-GDC anode in a single thermal step that includes also the formation of the perovskitic cathodic phase was investigated. The so-called reactive sintering was in fact considered to exploit the porosity induced by the precursor decomposition during the thermal treatment for the formation of the La0.8Sr0.2MnO3 (LSM) phase. To obtain dense electrolyte and porous electrode a sintering aid and a pore former were added respectively to the GDC and NiO-GDC starting powders. The effect of the reactive sintering approach on the single step production of the entire cell was investigated. Cathode supported cell with dimension 5x5cm2 has been successful fabricated by cost-effective technologies in a single-step.