Comparison of different infiltration amounts of CeO₂ inside Ni-YSZ anodes to improve stability and efficiency of Single-Chamber SOFCs operating in methane

¹ Department of Chemical Sciences, University of Padova, Via F. Marzolo 1, 35131, Padova, Italy
² ICMATE -Department of Chemical Sciences, University of Padova, Via F. Marzolo 1, 35131, Padova, Italy

^* Corresponding author: giovanni.dandrea.1@unipd.it

Abstract

Electrochemically active oxide-based anodes capable of working in Single-Chamber Solid Oxide Fuel Cells (SC-SOFCs) were developed. Their performance is related to the selectivity of the electrodes. Tests are carried out on lab-scale devices with YSZ pellets as solid electrolytes in electrolyte supported cells. Selecting methane as a fuel, a gas mixture in the ratio CH₄/O₂ = 2 was chosen. The Ni-YSZ (NiO:YSZ=60:40) anode was optimized through CeO₂ nanocatalysts infiltration to enhance the anode catalytic activity and make its reduction easier. Several infiltration amounts were compared, from null to 15% of the electrode weight. Both symmetric and complete cells (with LSCF-based cathodes) were tested in H₂ and CH4/O₂. For increasing amounts of infiltrated CeO₂, symmetric cells tests describe an area specific resistance (ASR) reduction from 40 Ω cm² to 1.7 Ω cm² in hydrogen and from 11 Ω cm² to 3.9 Ω cm² in the methane/oxygen mixture. While complete cells tests displayed an ASR drop from 30 Ω cm² to 2.9 Ω cm² in H2, and from 8.7 Ω cm² to 4.3 Ω cm² in the methane/oxygen mixture, while OCP and power grew from 478 mV and 3.7 mW cm^-2 to 766 mV and 13 mW cm^-2.