Study on the Effect of Fabrication Method on the Polarization of Solid Oxide Fuel Cells

A promising strategy for reducing concentration polarization in solid oxide fuel cells (SOFCs) is the creation of an anode layer with aligned, channel-like pores to facilitate efficient gas transport with minimal resistance. Freeze casting is an advanced shaping technique capable of forming such a unique microstructure. In this study, three NiO-YSZ|YSZ|LSM-YSZ SOFCs were fabricated using three different methods, and their electrochemical performances were compared. The first cell featured an anode prepared via freeze casting, while the other two utilized conventional dry pressing— one with a pore former and one without. All anodes were composed of NiO-۵۰ wt.% YSZ composite powder, with YSZ electrolyte and LSM-YSZ cathode layers subsequently applied. The microstructures were analyzed using scanning electron microscopy (SEM), and electrochemical impedance spectroscopy was conducted within the ۶۵۰–۸۰۰ °C temperature range. The concentration polarization resistance of the freeze-cast anode-supported SOFC was ۰.۰۹ and ۰.۰۷ Ω.cm² at ۷۵۰ and ۸۰۰ °C, respectively. At ۸۰۰ °C, concentration polarization resistance was accounted for ۱۳% of total cell resistance in the freeze-cast anode SOFC, compared to ۲۰% and ۲۲% in the dry-pressed anodes with and without a pore former, respectively.

کلیدواژه ها:

Electrochemical impedance spectroscopy ، Freeze-casting ، Polarization Resistance ، SOFC