Fabrication of alloy foam-supported solid oxide electrolysis cell (SOEC) for hydrogen production

¹ Centre of Excellence on Catalysis and Catalytic Reaction Engineering, Department of Chemical Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok, 10330, Thailand
² PTT Innovation Institute, PTT Public Company Limited, 13170, Thailand

^* Corresponding author: pattaraporn.k@chula.ac.th

Abstract

Alloy foam-supported SOEC is fabricated. Nickel-iron (Ni-Fe) alloy foam (Porosity: 5-130 ppi) is used for cell support. Single thin-cell composed of Ni- Sc_0.1Ce_0.05Gd_0.05Zr_0.89O₂ (SCGZ) cathode, SCGZ electrolyte and Ba_0.5Sr_0.5Co_0.8Fe_0.2O₃- δ (BSCF) anode is fabricated. Electrode powders are mixed with additives forming as slurry for wet chemical coating. 70%weight content of cermet provides smooth surface and sufficient viscosity to prevent slurry sweep through the porous foam. However, severe cracking is clearly seen on the surface of the cell because of mismatching of thermal expansion coefficient (TEC) during sintering. Therefore, the cell with three cathode layers having TEC gradient (13.83, 13.62 and 13.40 ppmK^-1) and %weight content of cermet gradient (70%, 60% and 50%weight) is fabricated. Heating rate and steps are controlled at 0.5˚C/min (600 ˚C), 3˚C/min (800 ˚C) and 1˚C/min (1,300˚C, 4 h) to burn off additives before sintering.