The Effect of the Method of Formation of Pr2CuO4-Based Cathodes on the Electrochemical Characteristics of Planar Electrolyte-Supported SOFCs.

The studies of how the method of organization of the microstructure of Pr2CuO4-based (РСО) cathodes affects the electrochemical characteristics of model electrolyte-supported solid oxide fuel cells (SOFCs) are carried out. It is shown that the higher thickness of the PCO cathode layer and the introduction of a pore-forming agent increase the power density of tested SOFCs as compared with the cathodes of the unmodified structure with the power density of 34 mW/cm2 at 850°С. The optimal thickness of the cathode layer corresponding to the maximum electrochemical performance is found to lie in the interval of 40–50 µm, which allows the power density of 116 mW/cm2 at 850°С to be reached. At the same time, with the transition from single-phase PCO cathodes to the composite PCO–Ce0.9Gd0.1O1.95 (60/40 wt %) cathodes the power density increases to 130 mW/cm2 at 850°С and the dynamics of its decrease with the decrease in temperature slows down. The analysis of impedance spectroscopy data on the total polarization resistance of model SOFCs with cathodes prepared by different methods shows that the transition from unmodified cells to cells with the thicker cathodic layer and also with composite cathodes decreases the level of polarization losses two-fold (in the former case) and three-fold (in the latter case). This is accompanied by the increase in the power density. The proposed methods of modifying the microstructure of the PCO-based cathode demonstrate the positive dynamics of growth of both the electrochemical performance of the cathode/electrolyte interface and the power density characteristics of the fuel cell as a whole. [ABSTRACT FROM AUTHOR]