Pr0.5Ba0.5Co0.7Fe0.25Nb0.05O3-delta (PBCFN) is synthesized and evaluated as air electrode for solid oxide steam electrolysis cells (SOECs). X-ray diffraction and TEM analysis show that PBCFN has a pure tetragonal perovskite structure with a lattice fringe spacing of 0.39 nm for the (110) planes. When the applied voltage is set at 1.3 V, a relatively high electrolysis current density of 470 mA cm(2) at 800 degrees C is achieved for electrolyte-supported electrolysis cells with the cell configuration of Sr2Fe1.5Mo0.5O6 (SFM)-Sm0.2Ce0.8O2 (SDC)/La0.8Sr0.2Ga0.87Mg0.13O3(LSGM)/SDC-PBCFN. In addition, there is no obvious performance degradation during the short-term stability test of the above cells at a constant electrolysis voltage of 1.3 V, indicating that PBCFN is a promising air electrode for SOECs. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.