Novel layered perovskite GdBaCoFeO_(5+δ) as a potential cathode for proton-conducting solid oxide fuel cells

摘要

While cobalt-containing perovskite-type cathode materials facilitate the activation of oxygen reduction, they also suffer from problems like poor chemical stability in CO_2, high thermal expansion coefficients, etc. Partial B site substitution with Fe element is expected to be able to mitigate these problems while keeping high catalyst performance. In this paper, a layered perovskite GdBaCoFeO_(5+δ) (GBCF) was developed as a cathode material for protonic ceramic membrane fuel cells (PCMFCs) based on proton-conducting electrolyte of stable BaZr_(0.1)Ce_(0.7)Y_(0.2)O_(3-δ) (BZCY7). The button cells of Ni-BZCY7|BZCY7|GBCF were fabricated and tested from 600 to 700 ℃ with humidified H_2 (～3% H_2O) as a fuel and ambient oxygen as oxidant. An open-circuit potential of 1.002 V, maximum power density of 482 raW cm~(-2), and a low electrode polarization resistance of 0.11 Ωcm~2 were achieved at 700 ℃. The experimental results indicated that the layered perovskite GBCF is a good candidate for cathode material, while the developed Ni-BZCY7|BZCY7|GBCF cell is a promising functional material system for intermediate temperature solid oxide fuel cells.