An interesting application-oriented design of high-strength anode support for protonic ceramic fuel cells by a non-proton-conducting cermet

One key problem of protonic ceramic fuel cells (PCFCs) is insufficient mechanical strength of anode support. Herein, an interesting application-oriented design is to enhance the mechanical strength of PCFCs by using a non-proton-conducting cermet NiO-3mol%Y2O3–ZrO2 (3YSZ) based on the assumption that anode reactive thickness is relative limited. The flexural strength of NiO-3YSZ anode support can reach 210 MPa while that of NiO–BaZr0.1Ce0.7Y0.1Yb0.1O3-δ (BZCYYb) is only 58.5 MPa. Novel half-cells of NiO-3YSZ anode support, NiO-3YSZ-BZCYYb anode transition layer, NiO-BZCYYb anode functional layer and BZCYYb electrolyte layer are sequentially fabricated by tape-casting combined with the hot-pressing lamination. Fully integrated single cells can obtain a peak power density of 676 mW cm−2 at 700 °C and exhibit an acceptable long-term stability with the operation voltage of 0.75 V at 650 °C for 120 h with humid H2 as fuel and air as oxidation. Electrode polarization processes before and after the long-term stability test are further investigated by the relaxation time distribution method. The performance degradation is mainly related to the oxygen reduction reaction and oxygen ion transport processes on the cathode side, and there is little effect of the side reaction involved by Ni-3YSZ anode support.