A Novel Co-firing Process for Multi-layers of Solid Oxide Fuel Cells

The major challenge for the commercialization of SOFCs is to reduce high manufacturing costs. By simplifying the sintering process and reducing the sintering temperature in the fabrication process, the manufacturing costs of SOFC could be lowered significantly. A low-temperature co-firing process for three layers of an SOFC including cathode (LSM/YSZ, [LSM:(La,Sr) MnO3), YSZ:Y2O3-ZrO2]), electrolyte(YSZ) and anode (YSZ/NiO) has been developed. The anode substrate of NiO/YSZ was formed and pre-sintered at 1000 degrees C for 2 hours, then the YSZ electrolyte layer and the LSM/YSZ cathode layer were deposited successively, and finally the anode-supported SOFCs were fabricated by co-firing at 1200 degrees C for 5 hours. In order to minimize the mismatch in sintering shrinkage among the components of the cell, various amounts of pore former were added to the anode and cathode layers. The mismatch in sintering shrinkage is minimized by adding 15wt% of pore former to the anode and 20wt% to the cathode. The OCV of the co-fired anode-supported trilayer cell was 1.05 V at 800 degrees C. The power density of this cell was 0.47 W/cm(2) at 800 degrees C.