Development of electrochemically active electrodes for BaCe0.89Gd0.1Cu0.01O3 − δ proton conducting electrolyte

Abstract

A row of Co-free and Co-containing electrode materials were synthesized and characterized and the electrode polarization resistance in contact with a proton-conducting BaCe0.89Gd0.1Cu0.01O3−δ electrolyte was studied by means of electrochemical impedance spectroscopy in a temperature range of 600–800°C, an oxygen partial pressure range of 10−3–0.21atm and a water partial pressure range of 4×10−4–0.1atm. The electrodes with Pr1.9Ca0.1NiO4+δ–BaCe0.89Gd0.1Cu0.01O3−δ and Y0.8Ca0.2BaCo4O7+δ functional layers was found to exhibit the lowest polarization resistance equal to 0.49 and 0.46Ωcm2 at 700°C, respectively, with less pronounced deterioration of their characteristics in wet conditions than for all the other investigated electrodes. The shunt effect of the electronic conductivity in the electrolyte on the electrode response was shown to be an important factor for consideration when comparing behavior of the electrodes in contact with different proton-conducting electrolytes.