Probing novel triple phase conducting composite cathode for high performance protonic ceramic fuel cells

•We report triple phase conducting cathode for protonic ceramic fuel cells.•The electrochemical active sites and oxygen reduction process is improved.•The single cell exhibits superior power density and good stability.

A key obstacle to practical operation of protonic ceramic fuel cells (PCFCs) is the development of high efficient cathode materials. In this study, we report the identification of Gd0.1Ce0.9O2-δ (GDC) infiltrated PrBaCo2O5+δ (PBC) – BaZr0.1Ce0.7Y0.2O3-δ (BZCY) materials as a novel triple phase (e−/H+/O2−) conducting composite cathode of PCFCs. This triple phase conducting composite cathode is confirmed to promise the extended electrochemical active sites and the accelerated oxygen reduction process. The polarization resistance (such as 0.051 Ω cm2 at 700 °C under open circuit voltage) of GDC infiltrated PBC-BZCY electrode is lower than other reported PCFCs, indicating the advanced electrochemical performance. The encouraging result is definitely a significant progress for the PCFCs field, which demonstrates that desirable electrode performance can be realized by applying triple phase conducting composite electrode.