Improving the performance of the PrBa0.8Ca0.2Co2O5+δ cathode for proton-conducting SOFCs by microwave sintering

Protonic ceramic fuel cells (PCFCs) represent the most efficient energy conversion devices due to their high conductivity and low activation energy. The development of PCFCs, however, hinges largely on the slow kinetics of the oxygen reduction reaction (ORR) and fast degradation of the cathode. Herein, we present a high-performance PrBa0.8Ca0.2Co2O5+δ (PBCC) cathode material prepared by a one-step microwave sintering process. In comparison to the cathode formed from conventionally-fired routes, the PBCC cathode formed from the one-step microwave sintering powder (named as PBCC-M cathode) shows a relatively small grain size and an adequately porous microstructure to allow for fast mass and/or ions transport, enabling adequate activities for oxygen reduction reactions, as confirmed by the electrochemical performance and the distribution of relaxation time (DRT) analyses. The symmetrical cells with the PBCC-M cathode have low area-specific resistance (ASR) of 0.478 Ω cm2 at 650 °C, and high stability of 84 h, outperforming those with the PBCC-C cathode. The Ni-BaZr0.1Ce0.7Y0.1Yb0.1O3 anode-supported PCFCs with the PBCC-M cathode obtain a better performance (a peak power density of 1.246 W cm-2 at 650 °C) than the cells with the PBCC-C cathode (a peak power density of 0.928 W cm-2 at 650 °C). Moreover, the single cells with the PBCC-M cathode demonstrate an outstanding durability of 80 h at 650 °C.