Microstructure and electrochemical characterization of solid oxide fuel cells fabricated by co-tape casting

A co-tape casting technique was applied to fabricate electrolyte/anode for solid oxide fuel cells. YSZ and NiO-YSZ powders are raw materials for electrolyte and anode, respectively. Through adjusting the Polyvinyl Butyral (PVB) amount in Slurry, the co-sintering temperature for electrolyte/anode could be dropped. After being co-sintered at 1400 C for 5 h, the half-cells with dense electrolytes and large three phase boundaries were obtained. The improved unit cell exhibited a maximum power density of 589 mWcm(-2) at 800 C. At the voltage of 0.7 V, the current densities of the cell reached 667 mAcm(-2). When the electrolyte and the anode were cast within one step and sintered together at 1250 C for 5 h and the thickness of electrolyte was controlled exactly at 20 mu m, the open-circuit voltage (OCV) of the cell could reach 1.11 V at 800 C and the maximum power densities were 739, 950 and 1222 mWcm(-2) at 750, 800 and 850 C, respectively, with H-2 as the fuel under a How rate of 50 sccm and the cathode exposed to the stationary air. Under the voltage of 0.7 V, the current densities of cell were 875, 1126 and 1501 mAcm(-2), respectively. These are attributed to the large anode three phase boundaries and uniform electrolyte obtained Under the lower sintering temperature. The electrochemical characteristics of the cells were investigated and discussed. (C) 2009 Elsevier B,V. All rights reserved.