Impedance Spectroscopy Study of Electrode-Electrolyte System in Solid Oxide Fuel Cells

摘要

Planar electrolyte-supported solid oxide fuel cells were studied. Dense membranes of the dimensions: 100 x 100 mm and a thickness of 130 μm, made from yttria-stabilized zirconia (both tetragonal and cubic) were used as solid electrolytes. Ni-zirconia cermet and La_(0.8)Sr_(0.2)MnO3 layers were deposited on the surfaces of the electrolyte as the anode and the cathode, respectively. Electrochemical impedance spectroscopy was used in order to characterize the electrical properties of the solid electrolyte membranes and the electrolyte-anode and electrolyte-cathode systems. It was found that an equivalent circuit is composed of two series of resistor- constant phase element connected in parallel. No additional elements in the equivalent circuit originated from either the anode or the cathode layers have been observed with respect to the single electrolyte sample.