Electrochemical properties analysis of tubular NiO–YSZ anode-supported SOFCs fabricated by the phase-inversion method

A phase-inversion method was successfully developed to fabricate tubular NiO–YSZ anode-supported solid oxide fuel cells (SOFCs). The microstructure and the sintering shrinkage of the anode samples made by different pore-formers were investigated through SEM and TGA analysis. Compared with graphite pore-former, flour pore-former shows a more severe sintering shrinkage and easily introduces some bigger pores which are very detrimental to the mechanical strength of the anode supports. Experimental results show that the porosity should be less than 55%, otherwise, it will severely affect the resistance of the anode. Four single cells were fabricated at different locations on the same 15 cm long tubular NiO–YSZ anode-support; the maximum power output of the cells depended on their distance from the anode current collecting point (848, 774, 680 and 645 mW/cm2 at 800 °C, using wet hydrogen as fuel and ambient air as oxidant). Electrochemical impedance measurements reveal that change of the ohmic resistance is one of the main factors affecting power output of the presented tubular anode-supported SOFCs.