A comparison of La_(0.8)Sr_(0.2)MnO_(3-δ), La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3-δ) and Pr2NiO_(4+δ) cathodes on the performance of anode supported microtubular cells

摘要

The performance of YSZ-Ni supported microtubular solid oxide fuel cells (mT-SOFCs) with thin YSZ electrolyte and three different cathodes: La_(0.8)Sr_(0.2)MnO_(3-δ) (LSM), La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3-δ) (LSCF) and Pr2NiO_(4+δ) (PNO) is compared. The mT-SOFC cells were fabricated using NiO-YSZ support precursors manufactured by Powder Extrusion Moulding (PEM). The YSZ layer was deposited by dip coating. The electrolyte deposition parameters and the sintering parameters were optimized to obtain a dense and thin layer. Three different cathode materials, LSM, LSCF and PNO were then deposited by dip coating. To circumvent reactivity at the sintering temperatures between LSCF and PNO with the YSZ electrolyte, barrier layers were also deposited. Electrochemical characterization under the same fuelling conditions for all the three cells was performed. The results are discussed and compared. As for example, the cell with a LSM-YSZ cathode presented a power density at 0.5V and 850 °C of 0.7 Wcm~(-2) with an ASR (area specific resistance) at OCV (open circuit voltage) of ～0.9 Ωcm~2. Similar performance was obtained when using LSCF or PNO cathodes at about 750 oC, allowing for a significant reduction of the operation temperature of these mT-SOFCs.