A Comparative Study on the Performance of Proton Ceramic Electrolysis Cells under Various Gas Conditions

This study investigated the performance of proton ceramic electrolysis cells (PCECs) under various gas conditions. PCECs consisting of BaZr0.1Ce0.7Y0.1Yb0.1O3-δ (BZCYYb1711) proton-conducting electrolyte, PrBa0.5Sr0.5Co1.5Fe0.5O6 – BZCYYb1711 composite air electrode and Ni – BZCYYb1711 fuel electrode were prepared. In order to find out the performance dependence on the air gas conditions, electrochemical evaluations were conducted by changing the air flow rate and its water vapor concentration. In addition, the performance tests were carried out under hydrogen (H2) and mixed gas (H2 10% – N2 balance) conditions in order to investigate the effect of the hydrogen concentration in the fuel electrode gas on the performance. The electrochemical performance was significantly improved when the steam concentration of the air electrode gas increased from 20 to 30%, while the increase in the air flow rate decreased the performance. Additionally, the mixed gas for the fuel electrode under 20% steam condition slightly improved the performance, compared to hydrogen, but not under 30% steam conditions. These results indicate that the most influential gas condition that determines the electrochemical performance is the water vapor concentration in the air electrode gas while the air flow rate and the hydrogen concentration have a slight effect on the performance.