Decreasing the polarization resistance of LaSrCoO4 cathode by Fe substitution for Ba(Zr0.1Ce0.7Y0.2)O3 based protonic ceramic fuel cells

LaSrCo1-xFexO4-delta layered perovskites with K2NiF4 structure were synthesized successfully via the Pechini method and evaluated as cathode material for Ba(Zr0.1Ce0.7Y0.2)O-3 (BCZY) electrolyte supported protonic ceramic fuel cells (PCFCs). X-ray diffraction results show that LaSrCo1-xFexO4-delta (0.0 < x < 0.5) were all single phase with K2NiF4 structure. Thermal expansion coefficient of LaSrCo0.5Fe0.5O4-delta is close to that of BCZY electrolyte. The conductivity of LaSrCo0.5Fe0.5O4-delta in air is 142 S cm(-1) at 750 degrees C. At 750 degrees C, the R-p of LaSrCo0.5Fe0.5O4-delta is measured and the value is about 0.12 Omega cm(2). The main rate-determining step in LaSrCo0.5Fe0.5O4-delta cathode is the dissociation of adsorbed oxygen molecules into atoms on the surface. Further, cathodic overpotential of 90 mV is obtained for LaSrCo0.5Fe0.5O4-delta cathode at current density of 0.2 A cm(-2) at 750 degrees C. The substitution of Co by Fe causes an enhancement of the better electrochemical properties implying that LaSrCo0.5Fe0.5O4-delta could be applied as possible cathode for PCFCs. (C) 2016 Elsevier B.V. All rights reserved.