Electrochemical performance and chemical stability of proton‐conducting BaZr0.8−xCexY0.2O3−δ electrolytes.

Protonic ceramic fuel cells (PCFCs) using BaZr0.8−xCexY0.2O3−δ (BZCY) as electrolyte materials have attracted widespread attention because of their high performance at reduced temperature. However, there are few systematic studies on both the performance and stability of BZCY materials. In this paper, we report our work on the electrochemical performance and chemical stability of BaZr0.8−xCexY0.2O3−δ (x = 0, 0.1, 0.3, 0.5, and 0.7) series. The results show that electronic hole conductivity decreases with increasing Ce4+ content, especially at high temperature. In addition, H2 atmosphere reduces the conductive activation energy of BZCY. On the contrary, air atmosphere causes serious electronic leakage. These effects are also reflected in the operation of PCFCs, that is, the higher the Ce4+ content, the higher the open‐circuit voltage and output power density. However, low Ce4+ content may stabilize the materials in CO2 atmosphere. At 700°C, an anode‐supported PCFC based on BaZr0.1Ce0.7Y0.2O3−δ electrolyte, using humid H2 fuel, gives a peak power density of 1.0 W cm−2. At 600°C, BaZr0.8Y0.2O3−δ and BaZr0.7Ce0.1Y0.2O3−δ show a good stability in CO2‐containing atmosphere. [ABSTRACT FROM AUTHOR]