Development of a novel type of composite cathode material for proton-conducting solid oxide fuel cells

摘要

A high-performance solid oxide fuel cell La_(1-x)Sr_xMnO_3 (LSM) cathode/metallic interconnect contact material Ni_(1-x)Co_xO, added with the mixed ionic-electronic conducting Sm_(0.2)Ce_(0.8)O_(2-δ) (SDC), was proposed as a novel composite cathode for proton-conducting solid oxide fuel cells (H-SOFCs) with BaZr_(0.1)Ce_(0.7)Y_(0.1)Yb_(0.1)O_(3-δ)s (BZCYYb) as the electrolyte. The X-ray diffraction (XRD) results indicated that the maximum doped ratio of Ni_(1-x)Co_xO was Ni_(0.7)CO_(0.3)O (NC3O), also shown that NC3O was chemically compatible with SDC at temperatures up to 1400 ℃. The TEC of NC3O was also measured to check its thermal compatibility with other components. Laboratory-sized tri-layer cells of NiO-BZCYYb/ BZCYYb/NC3O-SDC were fabricated and tested with humidified hydrogen (～3% H_2O) as fuel and static air as oxidant, respectively. A maximum power density of 204 mW cm~(-2) and a low interfacial polarization resistance Rp of 0.683 Q cm~2 were achieved at 700 ℃. The results have indicated that the NC3O-SDC composite is a simple, stable and cost-effective cathode material for H-SOFCs.