A composite cathode with undoped LaFeO3 for protonic ceramic fuel cells

A composite cathode for protonic ceramic fuel cells was developed using undoped, electronically conductive LaFeO3 (LF) and proton conductive Ba(Ce0.51Zr0.3Y0.15Zn0.04)O3−δ (BCZY). A comparison of the cathodic performance of Sr-doped LaFeO3 (LSF), a material with both electronic and oxygen-ion conductivity, with that of the undoped LF revealed the effect of oxygen-ion conductivity on the cathodic performance in protonic ceramic fuel cells (PCFCs). The cathodic performances of the LF/BCZY and LSF/BCZY composites were similar; this implied that the oxygen-ion conductivity had a minimal contribution toward the cathodic performance in PCFCs, unlike the case with oxygen-ion conducting fuel cells. Based on these results, an alternative electrochemical reaction mechanism was proposed for producing water at the cathode using protons and oxygen.