Electrochemical performance of BaZr0.1Ce0.7Y0.1Yb0.1O3−δ electrolyte based proton-conducting SOFC solid oxide fuel cell with layered perovskite PrBaCo2O5+δ cathode

Abstract

BaZr0.1Ce0.7Y0.1Yb0.1O3−δ (BZCYYb) exhibits adequate protonic conductivity as well as sufficient chemical and thermal stability over a wide range of SOFC operating conditions, while layered perovskite PrBaCo2O5+δ (PBCO) has advanced electrochemical properties. This research fully takes advantage of these advanced properties and develops a novel protonic ceramic membrane fuel cell (PCMFC) of Ni–BZCYYb|BZCYYb|PBCO. The performance of the button cell was tested under intermediate-temperature range from 600 to 700°C with humified H2 (∼3% H2O) as fuel and ambient air as oxidant. The results show that the open circuit potential of 0.983V and the maximal power density of 490mWcm−2 were achieved at 700°C. By co-doping barium zirconate–cerate with Y and Yb, the conductivity of electrolyte was significantly improved. The polarization processes of the button cell were characterized using the complicated electrochemical impedance spectroscopy technique. The results indicate that the polarization resistances contributed from both charge migration processes and mass transfer processes increase with decreasing cell voltage loads. However the polarization resistance induced by mass transfer processes is negligible in the studied button cell.