Cost-Effective Single Step Cofiring Process for Manufacturing Solid Oxide Fuel Cells Using HSC™ Anode

Abstract

The anode-supported planar solid oxide fuel cell (SOFC) was fabricated by a cost-effective single step cofiring process using high shear compaction (HSC)™ anode substrate. The HSC™ process is a novel ceramic tape fabrication technique, which offers advantages in low-cost and high-volume production of the anode substrates over the conventional tape forming processes. The cell was comprised of a porous HSC™ Ni+8 mol % yttria-stabilized zirconia (YSZ) anode substrate, a porous Ni+YSZ anode barrier layer, a porous and fine-grained Ni+YSZ anode active layer, a dense YSZ electrolyte, a porous and fine-grained Ca-doped LaMnO3(LCM)+YSZ composite cathode active layer, and a porous LCM cathode current collector layer. The fabrication process involved wet powder spraying of the anode barrier layer over the HSC™ anode substrate followed by screen-printing of the remaining component layers. The cell was then cofired at 1340°C for 2 h. The microstructure and the open circuit voltage of the cell confirmed that the cell was crack-free and leak-tight. The cofired cell showed a stable and acceptable electrochemical performance at 800°C under humidified hydrogen (3–60% H2O) as fuel and air as oxidant. The anode active layer with finer and less porous microstructure increased the triple phase boundary length and improved cell performance under conditions that simulated higher fuel utilization. The material system and fabrication process presented in this work offers great advantage in low-cost and high-volume production of SOFCs, and it can be the basis for scale-up and successful commercialization of the SOFC technology.