A high-performance solid oxide fuel cell La1-xSrxMnO3 (LSM) cathode/metallic interconnect contact material Ni1-xCoxO, added with the mixed ionic-electronic conducting Sm0.2Ce0.8O2-delta (SDC), was proposed as a novel composite cathode for proton-conducting solid oxide fuel cells (H-SOFCs) with BaZr0.1Ce0.7Y0.1Yb0.1O3-delta (BZCYYb) as the electrolyte. The X-ray diffraction (XRD) results indicated that the maximum doped ratio of Ni1-xCoxO was Ni0.7Co0.3O (NC3O), also shown that NC3O was chemically compatible with SDC at temperatures up to 1400 degrees C. 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 (similar to 3% H2O) 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 Omega cm(2) were achieved at 700 degrees C. The results have indicated that the NC3O-SDC composite is a simple, stable and cost-effective cathode material for H-SOFCs. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.