Study on the Ohmic Resistance of Solid Oxide Fuel Cells Based on YSZ Membrane Fabricated by Slurry Spin Coating

Four fuel cells were prepared using anode-supported YSZ electrolyte membranes with different thicknesses using a slurry spin coating technique and tested at 700 degrees to 800 degrees C. By fitting the AC impedance spectra of the fuel cells, the ohmic and electrochemical polarization resistances were distinguished. It has been found that the directly calculated conductivity and activation energy data of ohmic resistance based on impedance spectra measurements are much lower than those from bulk electrolytes. This phenomenon is discussed by analyzing the ohmic resistance data from four fuel cells with different membrane thicknesses. According to the analysis, an approach for measuring the conductivity of electrolyte membrane was developed to improve the calculation accuracy by fitting the ohmic area specific resistance to the membrane thickness. At the same time, it also can be used to evaluate the resistance contribution of anode supporter, cathode, and current collector.