Different concentrations of La2NiO4+δ (LNO) nanoparticles were decorated on La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) surface through one-step infiltration. Scanning electron microscope showed that LNO nanoparticles were distributed uniformly on LSCF surface, with a size range 50–250 nm. Electrochemical test revealed that compared with the bare LSCF, polarization resistance of LSCF cathode decorated with LNO particles reduced by 41%~50%, and its stability was improved, where its polarization resistance has increased by 50.42% after annealing at 750℃ for about 125 h while that of bare one increased by 76.89%. Evidenced by X-ray powder diffraction, La2SrOx phase appeared in LNO-LSCF after 100 h annealing, which was one of the possible reasons for enhanced stability. X-ray photoelectron spectroscopy showed that after annealing for 100 h, the surface Sr content decreased by 3.66% compared to that before annealing, whereas that of the bare one increased by 27.95%, indicating that LNO modification can effectively suppress Sr surface segregation of LSCF.