Cobalt-free perovskite oxides, BaFeO3-delta and BaM0.05Fe0.95O3-delta (M = Ti, Zr and Ce), were prepared as the cathode of intermediate-temperature solid oxide fuel cells (IT-SOFCs). High temperature X-ray diffraction (HT-XRD) results show that BaFeO3-delta and BaM0.05Fe0.95O3-delta (BTF) have a complex phase composition, and the phase composition changes with temperature. BaM0.05Fe0.95O3-delta (BZF) has a cubic perovskite structure above 400 degrees C, while BaM0.05Fe0.95O3-delta (BCF) has a cubic perovskite structure from room temperature (25 degrees C) to 1000 degrees C. Thermogravimetric analysis (TG) and oxygen temperature-programmed desorption (O-2-TPD) analysis reveal that the phase transition affects the oxygen-release properties of these materials. In contrast to BaFeO3-delta and BTF showing phase-transition-dependent electrical conductivity, BZF and BCF show typical curves similar to other mixed ionic-electronic perovskite oxides. On an electrolyte of Sm0.2Ce0.8O1.9 (SDC), a single cell with a BCF cathode exhibits polarization resistances of 0.027, 0.046, 0.087 and 0.186 Omega cm(2) at 750, 700, 650 and 600 degrees C, respectively. The peak power densities of the single cell are 482, 415 and 315mWcm(-2) at 750, 700 and 650 degrees C, respectively. This indicates that the Co-free BCF has a good electrocatalytic activity toward the oxygen reduction reaction and is a promising cathode for IT-SOFCs. (C) 2018 Elsevier Ltd. All rights reserved.