Novel layered perovskite GdBaCuFeO5+x as a potential cathode for proton-conducting solid oxide fuel cells

Abstract

A layered perovskite GdBaCuFeO5+x(GBCuF) was developed as a cathode material for intermediate-temperature solid oxide fuel cells based on a proton-conducting electrolyte of stable BaZr0.1Ce0.7Y0.2O3-δ (BZCY). The X-ray diffraction results showed that GBCuF was chemically compatible with BZCY after co-fired at 1,000 °C for 10 h. The thermal expansion coefficient of GBCuF, which showed a reasonably reduced value (15.1 × 10-6 K-1), was much closer to that of BZCY than the cobalt-containing conductor. The button cells of Ni-BZCY/BZCY/GBCuF were fabricated and tested from 500 to 700 °C with humidified H2 (~3 % H2O) as a fuel and ambient oxygen as the oxidant. A high open-circuit potential of 1.04 V, maximum power density of 414 mW cm-2, and a low electrode polarization resistance of 0.21 Ω cm2 were achieved at 700 °C, with calculated activation energy (E a) of 128 kJ mol-1 for the GBCuF cathode. The experimental results indicated that the layered perovskite GBCuF is a good candidate for cathode material. © 2013 The Author(s).