Electrochemical open circuit voltage (OCV) characterization of SOFC materials

In this paper, we are reporting an extensive characterization, by means of open circuit voltage measurements, of Ce0.8Gd0.2O2, La0.9Sr0.1Ga0.8Mg0.2O3, and La2Mo0.6W1.4O9 oxide-ions and BaCe0.8Y0.2O3 and BaCe0.55Zr0.3Y0.15O3 proton-conducting electrolyte materials for solid oxide fuel cell (SOFC) applications. This simple and common technique, well known for a long time in the electrochemical study of solid oxide fuel cells, has been here proposed for the electrical characterization of these ceramic materials, in order to define their ionic transport numbers, the maximum voltage performances, the thermal and chemical stability, and also to suggest the ideal temperature range for different applications, as in the electrochemical devices, sensors, and SOFC field. In the paper, controlled and reproducible working conditions have been applied in a wide range of temperature, by means of ultrapure gas (H-2 and O-2), under operational conditions found in real SOFC devices and, mainly, without the usual problems related to the chemical compatibility, the depolarization efficiency, and the high current density required to the electrode materials in the design of a more efficient SOFC device.