Lanthanum strontium cobalt ferrite (LSCF), a perovskite's family member, has gained much attention as the electrocatalyst for the oxygen reduction reaction (ORR) in intermediate temperature solid oxide fuel cells. However, it still needs a strategy to improve its catalytic activity. In this work, NiO is primarily investigated as a possible synergistic catalyst for ORR on the LSCF surface. The effect of NiO particles on the effective oxygen chemical surface exchange coefficient is revealed with the electrical conductivity relaxation (ECR) technique. At 800 degrees C, the coefficient is increased from 3.48 x 10(-5) to 6.65 x 10(-5) cm s(-1) and 6.9 x 10(-4) cm s(-1) when NiO particles are deposited using the sputter and drop coating methods, respectively. Adding 5 wt % NiO to LSCF reduces the area specific interfacial polarization resistance, for example from 0.108 to 0.082 Omega cm(2) at 700 degrees C, as demonstrated by impedance spectroscopy on symmetric cells using samaria-doped ceria as the electrolyte. Adding NiO can also improve the performance of anode supported button cells, increasing the peak power density from 0.731 to 1.031 W cm(-2) at 800 degrees C. On the whole, the increased oxygen surface exchange rate together with the reduced electrode resistance and improved power density, exhibit that NiO is a potential additive to enhance the LSCF catalytic activity. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.