Effects of tape thickness on the fabrication and performance of microtubular solid oxide fuel cells manufactured by tape casting

The role of tape thickness in the fabrication of microtubular anode supports for solid oxide fuel cells (SOFCs) by tape casting and isostatic pressing is investigated in this study. The anode support slurry of the same formulation is tape cast by varying the doctor blade gap (DBG) from 100 mu m to 700 mu m and the obtained tapes are wrapped at different lengths on a metal pin of 5 mm in diameter, while the appropriate tape length for each DBG is decided by considering anode support microtubes with a similar geometry for a reasonable comparison. The analyses reveal that the microstructure of the anode support microtube varies depending on DBG and in general delamination and crack formations occur in the supports at high DBGs. The resultant porosity and pore/grain sizes are also found to be different depending on DBG. Therefore, the supports and the cells with these supports show different mechanical and electrochemical performances. In this regard, DBG of 300 mu m provides microtubular anode supports without any microstructural problems. The microtubular cell built on this support also exhibits the highest peak performance of 0.313 Wcm(-2) at an operating temperature of 800 degrees C under 300 sccm hydrogen flow and open cathode condition.