A Y-doped BaCo0.4Fe0.4Zn0.2O3-δ perovskite air electrode with enhanced CO2 tolerance and ORR activity for protonic ceramic electrochemical cells

摘要

Protonic ceramic electrochemical cells (PCECs) are ideally suited for efficient energy storage and conversion; however, two of the hinging factors to high performance are the insufficient electrocatalytic activity for oxygen reduction/evolution and the poor stability of the air electrode. Here we report our findings in improving the electrochemical performance and structural stability of a Y doped air electrode with a composition of BaCo0.4Fe0.4Zn0.1Y0.1O3-delta (BCFZY). When applied as the air electrode of a PCEC, high performance is demonstrated, achieving a polarization resistance of 0.04 Omega cm(2) and a high peak power density of 870 mWcm-(2) at 700 degrees C. In addition, the single-cell with BCFZY electrode displays a lower degradation rate of 4.2% per 100 h when operated at 0.5Acm(-2) and 650 degrees C in fuel cell mode, much lower than that of 55% per 100 h for cells with BaCo0.4Fe0.4Zn0.2 (BCFZ) electrode under the same condition. The stable structure has been confirmed by the phase structure analyses of the electrode powder after a long-term heating treatment in air.

关键词