Performance of metal-supported SOFCs with infiltrated electrodes

Metal-supported solid oxide fuel cells (SOFCs) with thin YSZ electrolyte films and infiltrated Ni and LSM catalysts are operated in the temperature range 650–750 °C. A five-layer structure consisting of porous metal-support/porous YSZ interlayer/dense YSZ electrolyte film/porous YSZ interlayer/porous metal current collector is prepared at 1300 °C in reducing atmosphere. This cell structure is then sealed and joined to a cell housing/gas manifold using a commercially available braze. Finally, the porous YSZ interlayers are infiltrated with Ni and LSM catalyst precursor solutions at low temperature prior to cell testing. Infiltrating the catalysts after the high temperature sintering and brazing steps avoids undesirable decomposition of LSM, Ni coarsening, and interdiffusion between Ni catalyst and FeCr in the support. Maximum power densities of 233 and 332 mW cm⁻² were achieved at 650 and 700 °C, respectively, with air as oxidant. With pure oxygen as oxidant, power densities of 726, 993, and >1300 mW cm⁻² were achieved at 0.7 V at 650, 700, and 750 °C, respectively.